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1st Annual Report

SKADS

Square Kilometre Array

Design Study

implemented as

Specific Support Action Contract number: 011938 Project Co-ordinator: Prof. ir. A. van Ardenne Project website: www.skads-eu.org Reporting period: from 01 July 2005 to 30 June 2006 Project funded by the European Community under the “Structuring the European Research Area” Specific Programme Research Infrastructures action

2 Contract 011398 Annual Report

A. Activity Report

1 PROGRESS REPORT.............................................................................................................................. 10 1.1 SUMMARY OF THE ACTIVITIES AND MAJOR ACHIEVEMENTS ................................................................ 10 1.2 CONSORTIUM MANAGEMENT ACTIVITIES ............................................................................................ 11 1.3 DS2 SCIENCE & ASTRONOMICAL DATA SIMULATIONS....................................................................... 15

1.3.1 DS2-T1 Science Simulations ......................................................................................................... 15 1.3.2 DS2-T2 Astronomical Data Simulations....................................................................................... 18

1.4 DS3 THE NETWORK AND ITS OUTPUT DATA ...................................................................................... 21 1.4.1 DS3-T1 Network Infrastructure and Data Transmission.............................................................. 21 1.4.2 DS3-T2 Data Handling, Control and Distributed Computing...................................................... 27 1.4.3 DS3-T3 Overall Architecture and the Network Simulator ............................................................ 28 1.4.4 DS3-T4 Siting and Related Issues ................................................................................................. 30 1.4.5 DS3-T5 SKA for the User.............................................................................................................. 34 1.4.6 DS3-T6: Scalable Design and Implementation............................................................................. 35

1.5 DS4: TECHNICAL FOUNDATIONS AND ENABLING TECHNOLOGIES...................................................... 37 1.5.1 DS4-T1: InP LNA and ADCs ........................................................................................................ 41 1.5.2 DS4-T2 Signal Control and digitisiation. ..................................................................................... 60 1.5.3 DS4-T3 RFI mitigation strategies Study Task............................................................................... 62 1.5.4 DS4-T4 Wide band Integrated antennas ....................................................................................... 65 1.5.5 DS4-T5 Beam Forming ................................................................................................................. 74 1.5.6 DS4-T6 2-PAD Construction and Tests ........................................................................................ 77

1.6 DS 5 EMBRACE ............................................................................................................................... 82 1.6.1 DS5-T1 EMBRACE Design........................................................................................................... 82 1.6.2 DS5-T2 EMBRACE Development ............................................................................................... 107 1.6.3 DS5-T3 EMBRACE Test and Evaluation .................................................................................... 120

1.7 DS-6: CLINDRICAL CONCEPT DEMONSTRATOR................................................................................. 130 1.7.1 DS6-T1 Design of subsystem....................................................................................................... 130 1.7.2 DS6-T2 Development and Demonstration ................................................................................. 134

1.8 DESIGN STUDY 7 - ASSESSMENT OF PREPARATORY WORK AND STUDIES......................................... 137 1.8.1 DS7-T1: Continuous assessment and Critical Design Reviews .................................................. 138

1.9 UPDATE OF THE NON-CONFIDENTIAL PROJECT INFORMATION........................................................... 140 2 LIST OF DELIVERABLES ................................................................................................................... 141

3 USE AND DISSEMINATION OF KNOWLEDGE ............................................................................. 142

ANNEXES ......................................................................................................................................................... 146

B. MANAGEMENT REPORT (FINANCIAL INFORMATION) ............................................................... 149

1 JUSTIFICATION OF THE RESOURCES DEPLOYED ................................................................... 150 1.1 JUSTIFICATION OF RESOURCES ASTRON (1) ................................................................................... 151 1.2 JUSTIFICATION OF RESOURCES UMAN (2) ....................................................................................... 154 1.3 JUSTIFICATION OF RESOURCES JIVE (3) ............................................................................................ 157 1.4 JUSTIFICATION OF RESOURCES OPAR (4)......................................................................................... 158 1.5 JUSTIFICATION OF RESOURCES INAF (5) .......................................................................................... 161 1.6 JUSTIFICATION OF RESOURCES FG-IGN (6)...................................................................................... 166 1.7 JUSTIFICATION OF RESOURCES MPIFR (7) ........................................................................................ 167 1.8 JUSTIFICATION OF RESOURCES UOXF (8) ........................................................................................ 168 1.9 JUSTIFICATION OF RESOURCES CSIRO-ATNF (9)............................................................................ 169 1.10 JUSTIFICATION OF RESOURCES PRAO LPI (10) ................................................................................ 172 1.11 JUSTIFICATION OF RESOURCES NRC (11) ......................................................................................... 173 1.12 JUSTIFICATION OF RESOURCES NRF (12) ......................................................................................... 174 1.13 JUSTIFICATION OF RESOURCES UMK (13) ........................................................................................ 174 1.14 JUSTIFICATION OF RESOURCES CHALMERS (14)................................................................................ 176


1.15 JUSTIFICATION OF RESOURCES UCAM DPHYS (15)........................................................................ 177 1.16 JUSTIFICATION OF RESOURCES RUG (16) ......................................................................................... 178 1.17 JUSTIFICATION OF RESOURCES LEIDEN OBSERVATORY (17)............................................................. 179 1.18 JUSTIFICATION OF RESOURCES CU (18)............................................................................................ 179 1.19 JUSTIFICATION OF RESOURCES U. GLASGOW (19) ............................................................................ 180 1.20 JUSTIFICATION OF RESOURCES SWINBURNE (20) .............................................................................. 182 1.21 JUSTIFICATION OF RESOURCES U. ADELAIDE (21) ............................................................................ 183 1.22 JUSTIFICATION OF RESOURCES UMEL (22) ....................................................................................... 184 1.23 JUSTIFICATION OF RESOURCES U. SYDNEY (23) ............................................................................... 185 1.24 JUSTIFICATION OF RESOURCES UORL (25) ...................................................................................... 186 1.25 JUSTIFICATION OF RESOURCES CNRS (26) ....................................................................................... 187 1.26 JUSTIFICATION OF RESOURCES UKZN (27) ...................................................................................... 188 1.27 JUSTIFICATION OF RESOURCES UNIVLEEDS (28) ........................................................................... 189 1.28 JUSTIFICATION OF RESOURCES UVEG (29) ...................................................................................... 190 1.29 JUSTIFICATION OF RESOURCESOMMIC (30) .................................................................................... 191

2 FORMS C - FINANCIAL STATEMENTS........................................................................................... 192 2.1 FORM C OF ASTRON (1) ................................................................................................................. 193 2.2 FORM C OF UMAN (2) ..................................................................................................................... 200 2.3 FORM C OF JIVE (3) ......................................................................................................................... 205 2.4 FORM C OF OPAR (4)....................................................................................................................... 209 2.5 FORM C OF FG-IGN (5).................................................................................................................... 213 2.6 FORM C OF IGN (6) .......................................................................................................................... 217 2.7 FORM C OF MPIFR (7) ...................................................................................................................... 222 2.8 FORM C OF UOXF (8)....................................................................................................................... 227 2.9 FORM C OF CSIRO-ATNF (9) .......................................................................................................... 232 2.10 FORM C OF PRAO-LPI (10) ............................................................................................................. 238 2.11 FORM C OF NRC (11) MISSING ...................................................................................................... 243 2.12 FORM C OF NRF (12) MISSING ...................................................................................................... 248 2.13 FORM C OF UMK (13) ...................................................................................................................... 253 2.14 FORM C OF CHALMERS (14).............................................................................................................. 258 2.15 FORM C UCAM DPHYS (15) .......................................................................................................... 261 2.16 FORM C OF RUG (16)........................................................................................................................ 266 2.17 FORM C OF LEIDEN OBSERVATORY (17)........................................................................................... 271 2.18 FORM C OF CU (18).......................................................................................................................... 276 2.19 FORM C OF U. GLASGOW (19) .......................................................................................................... 281 2.20 FORM C OF SWINBURNE (20) ............................................................................................................ 286 2.21 FORM C OF U. ADELAIDE (21) .......................................................................................................... 290 2.22 FORM C OF UMEL (22) ..................................................................................................................... 295 2.23 FORM C OF U. SYDNEY (23) ............................................................................................................. 300 2.24 FORM C OF U.ORL (24).................................................................................................................... 304 2.25 FORM C OF CNRS(26) ..................................................................................................................... 308 2.26 FORM C UKZN (27) ......................................................................................................................... 314 2.27 FORM C OF UNIVLEEDS (28) ......................................................................................................... 319 2.28 FORM C OF UVEG (29) .................................................................................................................... 323 2.29 FORM C OF OMMIC (30) ................................................................................................................. 327

3 SUMMARY FINANCIAL REPORT .................................................................................................... 331

C. REPORT ON THE DISTRIBUTION OF THE COMMUNITY FINANCIAL CONTRIBUTION..... 339


List of figures

Figure 1-1 an idealised SKA array configuration based on a symmetric 5-arm logarithmic spiral array

for the LNSD concept (125 stations). The four panels show the configuration on four different spatial scales: bottom right, 1 km (core); bottom left, 5 km (central area); top right, 300 km (near remote sites [with 10% tolerance on position]); and top left, 6000 km (remote sites). This configuration follows the constraints on collecting area distribution contained in the RFP and the CSTF guidelines.......................................................................................... 20

Figure 1-2 the current roadmap towards the completion of the SKA of the International SKA Project; note the 2006Q3 determination of the SKA sites short list and the provisional 2008Q3 date of the SKA site selection........................................................................................................ 31

Figure 1-3 Comparison of Gate-Source diode IV (1x200µm device) for conventional (VMBE 1855) and newly developed structure (VMBE1831) ....................................................................... 42

Figure 1-4 Comparison of optimum noise figures of the improved (VMBE1831) and conventional (VMBE1855) pHEMTs ......................................................................................................... 43

Figure 1-5 Simulated and Measured High- Frequency performance of a 5×5µm2 emitter area microwave device FT=71GHz @ IC=14.8mA ...................................................................... 43

Figure 1-6 .............................................................................................................................................. 44 Figure 1-7 Microphotograph and transmission of the Tchebytchev band-pass filter............................ 45 Figure 1-8 Microphotograph and transmission of the low-pass/high-pass filter................................... 46 Figure 1-9 Comparison of the transmission for both manufactured filters ........................................... 46 Figure 1-10 Layout and noise figure of the differential 300 MHz – 2 GHz QuBiC4G LNA ............... 47 Figure 1-11 Gain and matching of the differential 300 MHz – 2 GHz QuBiC4G LNA....................... 47 Figure 1-12 LNA complete electrical scheme....................................................................................... 48 Figure 1-13 PHILIPS QUBIC4G Bi CMOS SiGe Library. LNA layout .............................................. 49 Figure 1-14 LNA Differential mode gain.............................................................................................. 49 Figure 1-15 LNA differential mode noise figure .................................................................................. 50 Figure 1-16 Schematic of the dual feedback LNA................................................................................ 51 Figure 1-17 Simulated performance of the dual feedback LNA ........................................................... 51 Figure 1-18 Microphotograph of the realized LNA .............................................................................. 51 Figure 1-19 Photograph of the InP 0.1µm differential LNA................................................................. 52 Figure 1-20 Radio interferences in Medicina........................................................................................ 53 Figure 1-21 Undersampling block diagram........................................................................................... 54 Figure 1-22 Measures............................................................................................................................ 54 Figure 1-23 Test with monochromatic signals: clock from medium-quality signal generator.............. 54 Figure 1-24 Test with monochromatic signals: clock from PLL........................................................... 55 Figure 1-25 Test with a radioastronomical signal ................................................................................. 55 Figure 1-26 Test with a radioastronomical signal with strong undersampling ..................................... 56 Figure 1-27 Sync board ......................................................................................................................... 56 Figure 1-28 LVDS output clock............................................................................................................ 57 Figure 1-29 VIIP board ......................................................................................................................... 58 Figure 1-30 Polyphase spectrum with 8k integrations .......................................................................... 58 Figure 1-31 Polyphase spectrum with 16k integrations ........................................................................ 59 Figure 1-32 Polyphase spectrum with a 8k on–off acquisition ............................................................. 59 Figure 1-33 Vivaldi Array simulation ................................................................................................... 66 Figure 1-34 Test load and differential LNA.......................................................................................... 66 Figure 1-35 Prototype array comprised of 112 Aluminium Vivaldi Elements ..................................... 67 Figure 1-36 Balun.................................................................................................................................. 71 Figure 1-37 Vivaldi Coplanar antenna .................................................................................................. 71 Figure 1-38 Simulations of Vivaldi coplanar antenna........................................................................... 72 Figure 1-39: Dipole antenna.................................................................................................................. 72 Figure 1-40 Simulated and measured results of the CMOS LNA......................................................... 73 Figure 1-41 Layout of the 4 channels – 2 beams first prototype beamformer chip .............................. 74


Figure 1-42 Simulated phase and gain 8 states ..................................................................................... 75 Figure 1-43 Outline block diagram of 2-PAD „Tile Processor“, including beam-forming. ................. 76 Figure 1-44: Station Aperture Array - Side view .................................................................................. 79 Figure 1-45: Station Aperture Array - Plan view .................................................................................. 79 Figure 1-46: Screened twisted pair performance................................................................................... 80 Figure 1-47: The work packages for DS5-T1 ....................................................................................... 83 Figure 1-48: EMBRACE system architecture....................................................................................... 84 Figure 1-49: The element design of the first iteration (actually four elements are shown)................... 86 Figure 1-50: Possible element setup for the 10 tile proto...................................................................... 87 Figure 1-51: Several building blocks used for the tile. ......................................................................... 87 Figure 1-52: Base boards of a single tile mounted on a carrier frame................................................... 88 Figure 1-53: Close-up of an assembled channel (the white blocks are vector modulators). ................. 88 Figure 1-54: Initial test, with an antenna mounted on the Base-board.................................................. 88 Figure 1-55: Artist impression of the CDC-unit prototype. .................................................................. 89 Figure 1-56: Astron single channel beamformer chip. .......................................................................... 89 Figure 1-57: OPAR beamformer chip. .................................................................................................. 90 Figure 1-58: Picture of the LOFAR Receiver ....................................................................................... 90 Figure 1-59: Signal Multiplexer. ........................................................................................................... 91 Figure 1-60: Prototype high pass and low pass filters........................................................................... 92 Figure 1-61: active receive/transmit multiplexer................................................................................... 92 Figure 1-62: Signal conditioning for 500 MHz bandwidth digital link. ............................................... 93 Figure 1-63: SCW simulation of the receiver........................................................................................ 94 Figure 1-64: Receiver Schematic .......................................................................................................... 95 Figure 1-65: LOs Corporate feed distribution ....................................................................................... 96 Figure 1-66: LOFAR digital back end: one sub-rack with two data processing ................................... 98 Figure 1-67: 1-tile prototype design and real thing............................................................................. 100 Figure 1-68: Antenna concepts............................................................................................................ 101 Figure 1-69: Selected Antenna concepts for EMBRACE ................................................................... 101 Figure 1-70: Tile concepts................................................................................................................... 102 Figure 1-71: Contacts between antenna elements ............................................................................... 103 Figure 1-72: The work packages for DS5-T2 ..................................................................................... 108 Figure 1-73: Coordination process for the Tile development ............................................................. 109 Figure 1-74: location of EMBRACE test station at Westerbork ......................................................... 111 Figure 1-75: Dimensions of the test platform on the test site.............................................................. 112 Figure 1-76: Elevated EMBRACE...................................................................................................... 112 Figure 1-77: EMBRACE with crane ................................................................................................... 113 Figure 1-78: EMBRACE on wheels.................................................................................................... 113 Figure 1-79: Nançay Site layout.......................................................................................................... 116 Figure 1-80: The work packages for DS5-T3 ..................................................................................... 121 Figure 1-81: Engineering measurement blocks................................................................................... 122 Figure 1-82: 1 to 16 Passive splitter 400-1600 MHz enabling testing the RF performance of the

antennas and frontend .......................................................................................................... 124 Figure 1-83: 1 to 16 Passive splitter 400-1600 MHz with active control enabling performance testing

of the antennas. .................................................................................................................... 124 Figure 1-84: Beam former chip carrier enabling functional testing the beam former chip performance

............................................................................................................................................. 125 Figure 1-85: Beam former chip control enabling functional testing the beam former chip performance

............................................................................................................................................. 125 Figure 1-86: Beamformer bonded in leadframe for testing DC, Logic and basic RF properties ........ 125 Figure 1-87: Testboard for beamformer chip in leadframe ................................................................. 126 Figure 1-88: Measurement control software for testing beam former chip......................................... 126 Figure 1-89: Measurement setup for testing beamformer chip ........................................................... 126 Figure 1-90 The Northern Cross at Medicina, Italy. ........................................................................... 130 Figure 1-91 The balanced LNA prototype. ......................................................................................... 131 Figure 1-92 BEST-1 Front End with single ended LNA..................................................................... 132 Figure 1-93 BEST-1 overall chain with single ended LNA. ............................................................... 132


Figure 1-94 BEST-1 Front End with balanced LNA........................................................................... 132 Figure 1-95 BEST-1 overall chain with balanced LNA...................................................................... 133 Figure 1-96 Comparison between two receivers total power outputs of BEST-1 on the Cass A transit

............................................................................................................................................. 133 Figure 1-97 Optical link gain fluctuations Vs temperature variation (test performed in our labs). .... 134 Figure 1-98 First transit of Cassiopea A with the BEST-1 prototype. ................................................ 135 Figure 1-99 Old version of the N/S cylindrical concentrator (left) and a N/S cylinder modified (right).

............................................................................................................................................. 135 Figure 1-100 Tsys obtained following the German Cortes Paper. ...................................................... 136 Figure 1-101 Tsys measured with a radio source observation. ........................................................... 136


List of tables

Table 1: List of contractors leading tasks in Design Study DS4........................................................... 40 Table 2: Participants in DS4.................................................................................................................. 40 Table 3: DS4 milestones........................................................................................................................ 41 Table 4: DS4-T1 Deliverables............................................................................................................... 60 Table 5: DS4-T2 Participants efforts..................................................................................................... 60 Table 6: Meetings attended ................................................................................................................... 62 Table 7: DS4-T2 delliverables .............................................................................................................. 62 Table 8: DS4-T3 Participants efforts..................................................................................................... 62 Table 9: DS4-T3 Summary of meetings attended, DS4-T3 .................................................................. 64 Table 10 DS4-T3 Milestones and deliverables defined in the contract that have been achieved during

the reporting period................................................................................................................ 64 Table 11 DS4-T4 person man-months .................................................................................................. 65 Table 12: DS4-T4 milestones................................................................................................................ 65 Table 13: DS4-T4 meetings .................................................................................................................. 65 Table 14: DS4-T5 Deliverables............................................................................................................. 77 Table 15: Meetings attended ................................................................................................................. 77 Table 16: List of participant, their short name and the man - month spent during this reporting period.

............................................................................................................................................... 82 Table 17 List of milestones and deliverables defined in the contract that has been achieved during this

reporting period.................................................................................................................... 105 Table 18 List of the major meetings and workshops organised under this activity during this reporting

period. .................................................................................................................................. 106 Table 19: List of participant, their short name and the man - month spent during this reporting period.

............................................................................................................................................. 107 Table 20: List of milestones and deliverables defined in the contract that has been achieved during this

reporting period.................................................................................................................... 118 Table 21: List of the major meetings and workshops organised under this activity during this reporting

period. .................................................................................................................................. 119 Table 22: List of participant, their short name and the man - month spent during this reporting period.

............................................................................................................................................. 120 Table 23: List of milestones and deliverables defined in the contract that has been achieved during this

reporting period.................................................................................................................... 128 Table 24: List of the major meetings and workshops organised under this activity during this

reporting period.................................................................................................................... 129 Table 25: List of participant, their short name and the man - month spent during this reporting period.

............................................................................................................................................. 130 Table 26 Main measured balanced LNA parameters. ......................................................................... 131 Table 27: List of participant, their short name and the man - month spent during this reporting period.

............................................................................................................................................. 134


1 Progress report

1.1 Summary of the activities and major achievements This first annual report already represents an impressive embodiment of active involvement of all 29 participants. Technical and scientific activities address solving important unknowns to increase the astronomical and engineering feasibility as important development steps toward the SKA. Close interactions took place between the participants and between the SKA and other communities, in Europe and elsewhere. Globally, the activities lead to an increased awareness of the usefulness of array technologies for larger fields of view in particular for so called focal plane arrays applications. The activities in SKADS focussed on so called aperture arrays addressing technologies that are of interest to other implementations as well i.e. focal plane arrays. Below is a summary overview of SKADS in its first year. In the first year of SKADS the emphasis was on (i) finishing and agreeing the DOW with all participants, (ii) successfully finishing the contract negations to the EC, (iii) setting up the project management and control organization including the appointment of the project manager, scientist and engineer, (iv) to start the project and line-up/synchronize the activities in all tasks according to the DOW and (v) to get agreement on the Consortium Agreement and the associated agreement on the Pre-Existing Know How. Other activities aim to formalize closer connections from SKADS to the International SKA project recognizing that SKADS is the major endeavour on the SKA context, to increase the inflow of (new) scientific insights into SKADS, to absorb developments in the SKA context in as far as relevant to SKADS and to optimize the representation of other European countries and SKA (related) activities in the US and elsewhere and to properly set up the internal and external communication representation and documented reporting. Of some concern over this reporting period was the potential impact of the late start of activities (as compared to the formal SKADS starting date of 1 July 2005) of most partners as a result of late national funding and the receipt of the advanced payment in January 2006. This included the manning of the SKADS Project management Team of which the Project Engineer and Project Scientist took office in January 2006 and which only was completed end of March when the Project Manager took office. The slower ramp up then planned obviously required adequate management attention. The rapid start up of activities in the second half of the first year i.e. from 1 January 2006) together with the evolution of the ones that were already started, largely compensated the delay. At the end of this first year the value of the work spend, is estimated to be over 5MEuro as compared to the approximate 7MEuro planned. In view of the responses and gradual filling of vacancies published for some time now and the expected release of national funds, we expect to largely recover in the first half of the second year. The project management and control system is fully operational and a scheme of regular meetings and reporting is implemented. The management activities and general progress is available through the Webpage (www.SKADS-eu.org) and internal progress is communicated through password protected access to minutes and the WIKI pages as the platform in which the project intricacies are communicated and exchanged. For the occasion of the EC gathering in July 2005, a SKADS logo and subsequently, a brochure was produced of which over 1500 have been handed out so far at this and other SKADS occasions and because of requests to the SKADS project office ([email protected]). The SKADS letter identity was subsequently added for all communication on paper. General agreement on the Consortium Agreement (containing a paragraph on IPR issues) was obtained at the last Board Meeting in June and the last signatures are being collected. Several visits have taken place by members of the SKADS MT to participants and to the US to coordinate and communicate the general state of affairs.


Representatives from SKADS have been present at workshops related to SKA science and have started to recruit young scientists and PhD’s to work in the context of SKADS (DS2). This DS2 also made good progress in the area of technical simulations (see the detailed reports). Excellent progress was achieved with EMBRACE (DS5) mainly executed by partners from the Netherlands (ASTRON), France (OPAR, OMMIC), Italy (INAF) and Germany (MPIfR). In this context progress was made also for closer cooperation with industry. Good progress was also achieved in BEST (DS6) which contributions mostly originate from Italy. As a result of delayed national funding in the UK the progress in DS3 and DS4 was less then anticipated but overall the nominal tasks all started some at nominal speed. Connection to the ISPO was greatly enhanced by a substantial representation of SKADS workers on the different subcommittees while the SKADS-Project Engineer is represented as the vice-chair of the SKA Engineering Working group. Also, the SKA is represented as the SKA Director and Project Engineer are observers at the SKADS Board and the SKADS coordinator is member of the SKA Steering committee on behalf of Europe, is. As the International project has evolved in parallel to (setting up) SKADS, emphasis was put on siting issues and on defining a so-called SKA Reference Design among other purposes for engineering and costing reference reasons. In this, Aperture Arrays (the core of the SKADS activities) are supported for their innovative wide-field “Mid Frequency” potential emphasizing the importance of SKADS. For SKADS the so-called Benchmark Design was adopted again with Aperture Arrays as the mid-frequency but with a different high frequency concept (i.e. a small dish concept) for frequencies beyond about 1-1.2GHz. The SKADS activities on siting of course will benefit on this progress on the SKA siting. A one-day SKADS Workshop has been prepared which will be held in September 2006. Although intended to be held before July, the SKADS management decided to postpone as in that case in would coincide/preemp with the SKA Engineering Working group meeting thus favouring close interactions.

1.2 Consortium management activities The Table below represents the effort of the SKADS Management close to the estimated planned effort up to this phase. Participant number 1 2 4

Participant short name

ASTRON UMAN1 OPAR2 Total

Person-months 22.8 1.5 1.5 25.8

The first opportunity after the signing of the DOW for the SKADS community to assemble, exchange views and establish concrete working relations, was at the occasion of a two-day SKADS Kick Off meeting mid November 2005. Organized by the Project Office, it was held at an inspiring location near Brussels. This proved a solid ground for the over 50 scientists, engineers and funding agencies to get fully acquainted with the SKADS goals and objectives through presentations of the key project parts (DS1-8) and their DS-Tasks (see the DOW). Program and presentations can be found on the SKADS webpage. Considerable delay was experienced in recruiting the Project Management team but in January both the Project Engineer and Project Scientists came onboard. Both enjoy having extensive experience at positions in industry and scientific institutes respectively. The Project Manager boarded SKADS essentially full time from 1 April after supporting SKADS part-time already since November. Regular SKADS MT meetings started from February with face to face meeting at least once per quarter. These are minuted meetings and are part of the SKADS Management info. First task was the establishment of a (web-based) project management and control system, to make the web/WIKI pages 1 Work is charged under DS7 in the Justification of Resources 2 Work is charged under DS7 in the Justification of Resources


into an information and progress tool for DS- and DS-T leaders and all participants, to start all activities and to prepare for the Annual report. Apart from that considerable progress was made on establishing firm working relations with most participants and other groups (e.g. the ATA/SETI group and the USSKAC). The Management team was involved in discussion with the International SKA Project Office on the SKA Reference Design and on the organization of the yearly SKADS workshop, this year in co-operation with ISPO which had decided to have their workshop in September. For arguments of optimizing cross fertilization of SKADS to the global SKA community and vice versa as for practical reasons, it was decided to have a combined event in Paris organized by the Observatoire de Paris. The Coordinator visited the UK (Manchester 2x), France (Paris, Nancay) and Italy (Bologna) when finalizing the DOW to reach agreement on the funding distribution, and subsequently to OdP (Paris, Nancay), Bonn, Onsala and SETI in the US for operational reasons and to assess and discuss in detail the SETI and Univ. of Berkeley experience with the Allen Telescope Array (“ATA”). This low cost high frequency small dish represents an approach which is relevant as the high frequency “neighbour” for SKADS in the context of the SKADS Benchmark Design (LOFAR-like technologies being the low frequency neighbour). The visit to France jointly with the Project manager was for general discussions on coordination and of operational issues. Discussion took place with representatives of the USSKAC in particular about a closer level of cooperation. It was concluded that representatives through the USKAC-Chair would be invited to all SKADS general meetings and workshops. Trip reports from visits of the Project Engineer to the US (SETI) and Canada (NRC), South Africa (NRF), Australia (CSIRO), France (Nancay/OdP) and Italy (Bologna/INAF-IRA) Visit of US and Canada (trip report) are summarized in Annex 1. Other visits relate to the development of EMBRACE (DS5) and Workshops in the UK (DS2/DS3 in Manchester and a Cosmology workshop in Oxford) In May, the ELT Project Manager visited ASTRON as the coordinating Institute of SKADS and attended a Project Management Meeting. Transfer of experiences with ELT Design Study was considered useful for both parties. At three occasions in the second half this year, following a preparatory MT-meeting, a telecom meeting with the Coordinating Committee took place. As this involves both the DS-leaders as the SKADS Chair and vice –Chair, this constitutes an essential meeting from the perspective of operations, outreach, content and monitoring, change and organization control and legal issues. It was e.g. decided to have a Scientific Advisory Group for which a proposal was put to the Board, issues regarding the Consortium Agreement, the one- day SKADS Workshop, the Benchmark Design, the Annual report and general progress. The meetings are minuted and are part of the SKADS Management info residing on the Web. Two Board meetings were held, one in January and one in June. While it was clear that the first was essential to understand and cohere on the SKADS objectives, general working methods and reporting and the Consortium agreement, the second not surprisingly was more operational e.g. with regard to progress toward the Mid term review while at the same time considering larger issues e.g. SKADS and the SKA Reference Design and SKADS and FP7. Also at the last meeting a letter from interested institutes in Portugal was discussed and it was decided to allow the interested parties the status of observer (to the Board meetings) (note that in DS2 cooperation with a Portuguese institute already takes place). A summary of conclusions of the Board meetings is found in Annex 1. At the Board meeting in June progress with respect to the Consortium Agreement, led to the collection of the signatures from the partners. As a result of the summer period, the SKADS Office still awaits a number of these but it can be expected that these will be complete early September.


The Table below show all formal management meetings in time order.

Date Title/subject of meeting Location Number of

attendees

Website address

17/18-11-2005

SKADS Kick Off meeting Limelette, Be 53 http://www.skads-eu.org/p/past_meetings.htm

26-01-2006 SKADS Board Meeting Zaandam,Nl 23 www.skads-eu.org/boardminutes

28-2-2006 SKADS MT-1 Phone 3 www.skads-eu.org/minutes/

28-3-2006 SKADS MT-2 Phone 3 www.skads-eu.org/minutes

29-03-2006 SKADS Coordination Committee Phone 13 www.skads-eu.org/boardminutes

6-4-2006 SKADS MT-3 Dwingeloo, Nl

4 www.skads-eu.org/minutes










29-06-2006 SKADS Board Meeting Zaandam,Nl 30 www.skads-eu.org/boardminutes

No deviations from the planned work as set out in the DOW were encountered although the possible impact of the SKA Reference Design on SKADS warranted attention (mostly in DS2 and DS3). To ease the administrative load on some smaller AC-participants, the SKADS Office proposed to administer their funds instead. This essentially concerns the bookkeeping and payment of travel funds only. The Table below depict the milestones due and their expected finishing date. Not planned as milestone is the Consortium Agreement containing the SKADS IPR-Policy. This arranges IPR issues between partners and third parties for the purpose of SKADS. The SKADS Office aims to coordinate the SKADS IPR policy with the broader issue of SKA so as not to restrain the SKA developments unneccessary.


Deliverable/ Milestone No

Deliverable/Milestone Name Workpackage /Subtask No

Lead Contractor(s)

Planned (in months)

Achieved (in months)

1. Organize kick-off ASTRON 3 5 2. Implement adequate management

tools ASTRON 3 6

3. Continuous coordination and management

ASTRON - ongoing

4 Continuous assessment and control

ASTRON - ongoing

5 Document on outreach policy ASTRON 4 12 6 Establish web-page ASTRON -3 3 7 Document on IPR Policy ASTRON 4 7 8 SKADS international symposia ASTRON 9 14

In general the timescales have been shifted forward as a result of the delayed start of the project at large. It is felt that while the results of the first year have been already impressive, that progress reporting and objective management of the second year leading to the Mid-term review becomes more important. As many new approaches and technologies are explored in SKADS, leading toward a next generation of scientific users and engineers, it is generally felt that the goals of the Project could benefit from a separate supporting program. Therefore, some efforts were directed toward an EC supporting program in the context of Marie Curie.


1.3 DS2 Science & Astronomical Data Simulations Overall Management Structure DS2 comprises two inter-related tasks. Task 1 focuses on the topic of SKA Science Simulations (DS2-T1). Task 2 focuses on SKA Astronomical Data Simulations (DS2-T2). DS2-T1 and DS2-T2 are run on a daily basis by Dr. Matthew Jarvis (Oxford) & Dr. Cormac Reynolds. Overall responsibility for DS2 lies with Dr. Michael A. Garrett (JIVE). Prof. Steve Rawlings (Oxford; formerly chairman of the International SKA Science Working Group) also plays an important role in providing a close link between international science simulation efforts and SKADS DS2 activtities. Garrett, Jarvis & Rawlings are all members of the SKA Science Working Group. Jarvis and Reynolds interact with other members of DS2-T1 and DS2-T2 on a daily basis, mostly via e-mail. Summary of Activities While some other SKADS Design Studies formally started in July 2005, DS2-T1 and T2 have only recently become active. In particular, it was not possible to appoint new Post-doctoral researchers until the first EC (and national) funding began to flow (1 April 2006). As a result, almost all the results detailed in the following reports arise from matching effort. It is expected that the total effort will expand greatly once the new Post-doctoral appointments are in place. As reported here, good progress has been made in filling these positions and a comprehensive work programme has also emerged as part of the matching (national) contribution. It is expected that rapid progress will be made with this programme in year 2 of the SKADS project. Both DS2-T1 and T2 recently organised kick-off meetings with significant overlap in participation. It is crucial to ensure that the excellent communication established between the task leaders continues to be maintained through the course of the project.

1.3.1 DS2-T1 Science Simulations Participant number 8 2 4 7 15 17 Participant shortname

Oxford

UMAN

OPAR

MPlfR

UCAM

Leiden

Person-months 17 0.0 5.6 4.2 1.25 0 Participant number 20 21 22 27 Total Participant shortname

Swinburne

U. Adelaide

UMel Natal Univ.

Person-months 6 11 12 0 57.05 Many aspects of DS2-T1 have been slow in getting underway due to the delay in employing people to work on the science simulations full time. Many positions are now filled or will be filled by the end of summer 2006. Thus, the majority of the work undertaken in DS2-T1 has been of a preparatory nature. Nonetheless, as highlighted below, the science simulation effort should accelerate over the coming year. This has been aided by the successful conference `Cosmology, Galaxy Formation and Astroparticle Physics on the Pathway to the SKA’, held in Oxford in April 2006 and directly relevant to WP1 and WP2. The new DS2-T1 task leader also organized the DS2-T1 kick-off meeting in Oxford in June 2006, where many of the people working on the various aspects of the science simulations attended and delivered their reports on how the simulations across the work packages will be carried out.

1.3.1.1 Continuum Surveys

Leiden has employed a person to work on the continuum simulations. This person, Ilse van Bommel, will begin work on SKA science simulations in October 2006. Swinburne’s contribution to the DS2-


T1 effort will be to provide support for the supercomputer facility at Swinburne, it is envisaged that this facility will be used extensively over the remainder of SKADS for both continuum surveys and the other work packages within DS2-T1. Oxford has been working on generating a continuum sky simulation based on observed luminosity functions and correlations between other wavebands and the radio waveband. The first continuum sky simulation, incorporating both AGN and starburst populations, will therefore be provided by Oxford to the leaders of the other DS2-T1 work packages where required by mid-August 2006, this will also be published as a refereed journal article by Jarvis et al (see SKADS wiki:) Oxford will continue with this effort by including galaxy clustering within the simulation and will work with Leiden in further enhancing the simulation and also undertake the various analyses to maximize scientific optimization using the Swinburne supercomputer. Miller (Oxford) has also started to collaborate with Castro (CENTRA-Lisbon, non-skads member) to assess the SKA’s ability to carry out weak-lensing surveys.

1.3.1.2 Line Surveys

Jarvis, Kay, Kloeckner and Obreschkow (Oxford) are currently using numerical simulations to estimate the HI mass function in the local Universe and its evolution with cosmic epoch (see SKADS wiki page for a report on the simulation method). A paper led by PhD student Obreschkow should be submitted by December 2006. Rawlings (Oxford) has been working with Filipe Abdalla (UCL, non-SKADS member) and Chris Blake (shortly to be at Swinburne) on simulating how HI redshift surveys with the SKA will constrain cosmological parameters. Quantitative constraints on the dark-energy parameter `w’ and the absolute mass scale of neutrinos have been produced, all as functions of field-of-view, frequency range and spatial resolution. Angel Torres Rodriguez and Catherine Cress (Natal) have been investigating the potential for constraining the sound speed of dark energy using a combination of CMB data and an SKA HI-survey.

1.3.1.3 Polarization Surveys

For the Galaxy, Reich (MPIfR) currently has an all-sky polarization map at 1.4GHz with a resolution of 36’. They will simulate high-resolution maps with 1arcsec resolution for various U, Q distributions of small scale emission and contributions from resolved sources. Results for this part of the simulation effort are expected by December 2006. For extra-galactic starbursts the MPIfR group under Beck, require a simulated continuum sky provided initially by Oxford under WP1. Further work will be needed to understand how the continuum emission arises from various galaxy types, star-formation rate, interaction rate and redshift. This will benefit from the continuum surveys WP groups working close with the WP3 groups. The MPIfR group has also formed collaborations with non-SKADS members in Russia (Perm) and the UK (Newcastle), in addition to the group at Manchester to model the magnetic field evolution and cosmic-ray production in star-forming galaxies. UCAM are concentrating on assessing the polarization of the radio-loud active galactic nuclei in the Universe. Alexander (Cambridge) has been working on developing realistic radio sources evolution models with the inclusion of magnetic fields. The initial statistical 3-D rotation measure grid will be derived from the first continuum simulation made available by Oxford as part of WP1. This initial 3-D rotation measure grid is expected to be in place by October 2006. The second part of this work will couple the radio source evolution models with the luminosity functions and continuum sky simulations from the work to be completed by October 2006. The expected completion time for this part of the simulation is December 2006. Further along radio sources in cluster environments will be included to produce the most realistic 3-D rotation measure grid across the sky.

1.3.1.4 Pulsar Surveys

The work in the reporting period has been slower than was planned in the contract. This slower pace is due to a delay in hiring the Post-doctoral researcher who will be carrying out most of the simulation


work. A person has been identified who accepted the offer made and will start the SKADS work at November, 1st, 2006, after his current post finishes in October. Despite this considerable delay, some progress has been made. Based on work from JBO colleague Duncan Lorimer (now University of West Virigina) new population studies are now available (to be published as Lorimer et al.). These are based on results of the Parkes Multibeam Survey for Pulsars (PKSMB). This most successful pulsar survey in history was led by JBO pulsar astronomers (SKADS Pulsar work package leader Kramer is also leader of the JBO pulsar group) and provides an excellent base for the simulations of the pulsar sky as seen by the SKA. Combined with some initial groundwork by the task leader, studying the requirements to time 20,000 pulsars efficiently and adequately, the appointed post-doctoral researcher will be in an excellent position to proceed and to deliver the sky-simulations to DS2-T2 without further delay. Fortunately, the DS2-T1 WP4 output is mostly relevant for DS2-T2-WP4, carried out by the same team, so that problems for other work packages are not expected. In addition to the DS2-T1 kick-off meeting, Kramer (UMAN) organised an international workshop, Testing Gravity in the next decade, at Birmingham in March 2006. This meeting was a joint workshop with colleagues working on the astrometry mission GAIA and the Laser Interferometer Space Antenna (LISA) in order to discuss the pulsar SKA Key Science aspects with respect to possible synergies between the different experiments. While this dialogue with other scientists working on complementary experiments continues, it is anticipated that the possible outcome of such a discussion will have impact on later parts of this work package when the timing requirements for the SKA gravity experiments are studied.

1.3.1.5 Epoch of Reionisation Surveys

Wyithe (Umel) continues to work on the physical processes which may be important for studying the epoch of reionisation. He recently submitted a paper on the neutral hydrogen profile of cosmological HII regions (astro-ph/0607246) and the effect that galaxy clustering has on the profile. Ferreira, Jarvis and Kay (Oxford) have recently formed a collaboration with Santos (CENTRA-Lisbon) to address the science simulations of the Epoch of reionisation further. Santos has been working on developing a detailed statistical description of the 21cm signal from reionisation and, in particular, the power spectrum. This means not only developing a semi-analytical model for reionisation, but also taking into account all the important contributions to the full 21cm signal (see Santos et al 2003, 2005 and 2006 for details). We believe that being able to describe the 21cm signal at high redshifts through a semi-analytical model that is reasonably quick to generate and depends on a small set of parameters (in much the same spirit as what is currently done for the CMB), will have several advantages: it will allow to quickly run the signal through the "observation pipeline" to check for things such as design optimization, power spectrum estimators, foreground removal methods, etc and it will also be important at a later time, when doing the data analysis, so that we can constrain the parameters and quantify in a proper way what is the preferred reionisation model. In terms of this line of work, we plan to improve our reionisation model by comparing it with detailed numerical simulations. This will allow us to check for issues such as the ionisation fraction spatial correlations, the size of the ionised bubbles as a function of redshift and the importance of the non-Gaussian signatures in the signal. Deliverables: No deliverables were scheduled during the first year of this report and no deliverables were achieved


Date Title/subject of meeting /workshop Location Number of

attendees Website address

30-31/03/2006

Joint SKA/GAIA/LISA workshop Birmingham 48 http://www.jb.man.ac.uk/ska/gravmeeting06

10-12/04/2006

Cosmology, Galaxy Formation and Astroparticle Physics on the Pathway to the SKA

Oxford 105 http://www-astro.physics.ox.ac.uk/LOSKA/CONFERENCE

07/06/2006 DS2-T1 Kick-off meeting Oxford 30 http://webmail.jb.man.ac.uk/skadswiki/Ds2T1Kickoff

1.3.2 DS2-T2 Astronomical Data Simulations

Participant number 3 1 5 7 8 9 10 14 Participant short name

JIVE ASTRON

INAF/IRA

MPlfR

Oxford

CSIRO

PRAO

Chalmers

Person-months 5.5(0) 0.9 4.8(0) 2(0) 1(0) 6(0) 1 0 Participant number 16 17 19 20 29 Participant short name

RUG Leiden

U. Glasgow

Swinburne

Valencia

Total

Person-months 0(0) 0 0 12 2 35.2 (0)

DS2-T2, Astronomical Data Simulations, kicked off on 10 February 2006 with a meeting of the participants in Bonn. At this meeting the details of the work packages that comprise DS2-T2 were discussed and agreed upon. Minutes of the meeting and slides from the presentations made there are available on the SKADS wiki. Since the kick off meeting, efforts have concentrated on recruitment of staff to fill the newly available positions. Most of the available positions have now been filled with the successful candidates having either taken up the positions already or expected to do so early in the second year of the project. There has also been progress in putting in place the communication channels necessary to exchange information effectively between DS2-T2 and the other SKADS tasks on which it depends (principally DS2-T1, DS3-T5, DS5-T3). To this end DS2-T2 has been represented at the kick off meetings of DS2-T1, DS3-T5 and at the SKADS technical meeting held in Jodrell Bank on 15-16 March 2006.

1.3.2.1 Aperture Array and FPA Simulations

JIVE and ASTRON have begun investigating the options for implementing a model of Aperture Arrays in the available software packages. This will lead to the “Critical Review of Simulations Software” deliverable which is due in the 22nd month of SKADS. The MeqTree package, being developed at ASTRON, has considerable potential for this as it provides a simple means of describing and solving for arbitrary instrumental and atmospheric effects. The package has been designed with parallel processing in mind which will make it straightforward to port it to the large supercomputing environments that will be required for large scale simulations. JIVE has employed Shanmugha Sundaram to work as a postdoctoral researcher on array simulations. He is expected to take up the position in August/September 2006. Tim Cornwell of the xNTD project at ATNF (CSIRO) conducted side-by-side simulations of the continuum imaging performance of a SD+FPA (single dish with focal plane array) and ATA (Allen Telescope Array)- type telescope (T.J. Cornwell, “LNSD reconsidered the Big Gulp option”, SKA memo 61), and also simulations of a SD+FPA telescope with alt-azimuth and equatorial mounts (T.J.


Cornwell, “Computing costs of imaging for the xNTD”, ATNF SKA memo 1). The ATA-type telescope (also known as Big Gulp) has the best imaging performance but requires large resources for correlation and data processing. Ignoring calibration concerns, the two SD+FPA systems have similar imaging performance but the equatorial mounts reduce the computing costs by a large factor, probably an order of magnitude. Tim Cornwell and Enno Middelberg also investigated the role of asymmetries in the ATCA voltage beam in limiting the dynamic range of deep continuum mosaics. Simulations and measurements show that the blockage and diffraction due to the quadrupod is responsible for limiting the dynamic range. Modeling this behavior is in concept straightforward if the voltage beam can be measured sufficiently accurately. Work on this latter step is still proceeding. Similar effects are certain to limit the imaging performance of the SKA reference design unless countermeasures are taken.

1.3.2.2 .Configuration Studies

Members of DS2-T2, led by Steve Tingay (Swinburne), have been exploring different types of configurations that conform to criteria set out in the Request for Proposals (RFP) issued by the International SKA Steering Committee (ISSC) and the International SKA Project Office (ISPO) Configuration Simulations Task Force (CSTF) guidelines for site proposers. These documents set out the basic criteria constraining the number of stations in the SKA array and the distribution of collecting area with radial distance form the array core. While these criteria have been generated for the purposes of the international site short listing process and do not constitute a final configuration design goal, they are founded in the scientific requirements for the SKA, as determined by the ISPO Science Working Group (SWG). As such, these configuration studies represent a useful starting point, to determine the basic properties of the imaging capabilities of the SKA, and also allow real-world constraints on antenna placement to be explored. The DS2-T2 team started their work by generating idealised configurations based on either a Large-N Small-D (LNSD) concept (as shown in Figure 1-2 for example) or a Small-N Large-D (SNLD) concept. These idealised arrays were then optimised for use at each of the candidate SKA sites, by the site proposers. The results of this optimisation process were reported to the CSTF and evaluated in terms of a number of uniform figures of merit, in order to asses a particular site’s suitability to host the SKA. The work of the CSTF and the DS2-T2 teams has therefore had a strong overlap and in this sense the DS2T2 team has been a major contributor to the ISPO efforts over the last 18 months. The DS2T2/CSTF work has been reported to the International Site Advisory Committee (ISAC) as a contribution to the site short listing process. Currently the ISAC is deliberating and until the results of the site short listing process has been announced, the DS2-T2/CSTF work is embargoed. Once the ISAC decision has been made public, sections of the DS2-T2/CSTF report will be re-packaged to fulfill the first milestone of the DS2-T2 work package, the preliminary report on SKA array configurations. This is expected to occur in the second half of 2006. Continuing work following from this report will fulfill milestone number 3, the final report on SKA array configurations. This final report will additionally take into account the results of the ISAC site short listing process and also the recent convergence to an SKA reference design. MPIfR/Valencia and Swinburne staff (led by Lobanov and Tingay) have also been investigating numerical methods to obtain estimates for the additional configuration figures-of-merit proposed in SKA memo 38 (Lobanov). Swinburne is providing the supercomputing resources required for the configuration studies. Once the ISAC decision on the site short list has been made, the geographical constraints of the short listed sites will be incorporated into the configuration study. MPIfR have hired Viram Dir Lal to work on this next stage of the configuration studies. He is expected to take up the position in the summer of 2006.


Figure 1-1 an idealised SKA array configuration based on a symmetric 5-arm logarithmic spiral array for the LNSD concept (125 stations). The four panels show the configuration on four different spatial scales: bottom right, 1 km (core); bottom left, 5 km (central area); top right, 300 km (near remote sites [with 10% tolerance on position]); and top left, 6000 km (remote sites). This configuration follows the constraints on collecting area distribution contained in the RFP and the CSTF guidelines

1.3.2.3 Calibration and Imaging Techniques

Calibration and imaging is due to be investigated later in the project after significant progress has been made in the other simulations areas and no deliverables are due before the 4th year of SKADS. However, some progress has been made in assessing the calibration requirements of Focal Plane Arrays (see description in section 1.3.2.1). Leiden, who will carry out a study of the requirements for ionospheric calibration, has employed Ilse van Bommel who will begin working on aspects of DS2 in October 2006. Deliverables: No deliverables were scheduled during the first year of this report and no deliverables were achieved. Date Title/subject of meeting /workshop Location Number of


1-feb-2006

DS2-T2 kick off meeting Bonn, Germany

19 http://webmail.jb.man.ac.uk/skadswiki/KickOff


1.4 DS3 The Network and Its Output Data Introduction DS3 considers and analyses the issues associated with producing the most cost-effective overall architectural design for the SKA “network” which satisfy the specifications established in DS2 and deliver the scientific objectives to the end-user. The work within this DS is focussed on the specific requirements and costs associated with a aperture-array telescope and considers the telescope on scales larger than that of an individual tile (taken to be the smallest correlatable element). Where there are common aspects close collaboration with USSKADS will be put in place. The original specified objectives of this Design Study were:

• Assess and cost possible technologies for the distribution of electrical power, phase-coherent signals and data transfer over distances required for the SKA design.

• Assess and cost possible technologies for the provision of processing power to the SKA both for a central processor and distributed processing elements – a key aspect will be to determine the fixed and upgradeable elements of the “network”.

• Produce an overall functional simulator for the network – including models for the data flow, power consumption, processing requirements – which will integrate with the astronomical simulations of DS2; the simulator will enable suggested architectures for the telescope to be assessed and costed.

• The production of a full plan for siting and related issues for the SKA, encompassing environmental issues (including conditioning, impact and adopting the advanced technology to arid lands), radio frequency monitoring/protection over a long term and potential maintenance regimes.

• Analyse the effectiveness of the emerging design from the point of view of the end user astronomer with the specific objective of optimising the scientific output and flexibility of the instrument and to cost the long term observatory support required for a given design.

Progress towards milestones and deliverables Details of each design study task are given in the next section. Here issues relating to the design study as a whole are considered. There is overall a slow start to the tasks considered here due to the late start of SKADS relative to the nominal start date. This has resulted in a delay in appointing new personal in AC institutes in particular. Furthermore delays in the availability of National Funding in the UK (although fully secured) have further delayed the appointment of new staff within the UK (a major contributor to DS3). As a result some re-scheduling of activities within the tasks has been required, however this is not a problem with the overall delivery of the project “deliverables” and “objectives”. Two issues must be noted:

1. The DS milestone (DS3.1) and deliverable (DS3.T1.1) Delivery of a prototype phase transfer link have been re-scheduled from T0+24 months to T0+42 months

2. There have been significant changes to Task 4, Siting and Related Issues. These have been required owing to the progress external to SKADS in the site selection process for the SKA. Although this process has been driven external to the SKADS project, SKADS participation has been central to the work which has been completed. Significant re-phasing and re-focussing of the work of this task has therefore been made. Details are given under the task report below.

1.4.1 DS3-T1 Network Infrastructure and Data Transmission Participants in the task


Participant number 2 1 5 8 9 Participant short name UMAN ASTRON INAF-

IRA OXF DP CSIRO Total

Person-months 0 0.2 0.9 0 0 1.1 Introduction DS3-T1 is a feasibility study of the optical fibre network required to support the various network architectures considered by SKADS. This network must carry the huge volumes of data produced from each station, distribute control and monitoring information and provide the picosecond timing signal which allows the whole array to act as a coherent telescope. Minor parts of DS3-T1 will look at power distribution and network deployment. European partners in DS3-T1 are Astron, JBO and IRA-INAF. Astron are primarily studying commercial equipment both for the data links and the monitor and control network; JBO is working on component based implementation of the data network and phase/timing transfer; IRA-INAF is working on short range analogue links. All three groups have now deployed staff although decisions on staffing at JBO due to funding availability have delayed some of the work. Some tasks will now be scheduled to run in parallel rather than sequentially, with no effect on the overall project schedule. Meetings Date Title/subject

of meeting /workshop

Location Number of attendees

Website address

26/6/06

DS3-T1 kickoff meeting

JBO 10 http://webmail.jb.man.ac.uk/skadswiki/Ds3T1

Discussion of work packages WP-01 Low bandwidth network The monitor and control (M&C) network is fundamentally responsible for sending telescope control/configuration messages from a central operations hub to each individually steerable station or small dish. In addition, this network will carry ancilliary data products from the stations/telescopes back to the data processing nodes for calibration purposes and station monitoring data back to the control hub for status displays and logs. Additional channels on this network may be used for telephony/video links between station sites. Typical data rates will be of order 1 Gb/s per station and this network will likely use commercial Gigabit Ethernet technology or similar. For the most distant stations, the M&C network is likely to use production/research internet connections. Unlike the data transfer system, where under many circumstances, a small degree of data loss is tolerable, the M&C network needs to have commercial levels of reliability (>99.9%) in order for the whole array to be operated efficiently and safely. The operational requirements for the M&C network will be refined in consultation with other DS tasks in order to clarify data rates, latency issues and reliability. The overall network hierarchy in terms of distributed processing and control will be studied by other tasks in DS3 and fed through via DS3 coordination meetings. Technology options will be investigated by ASTRON later in the course of the project (currently scheduled for year 4). In the meantime, ASTRON’s experience with the implementation of the LOFAR M&C network will provide useful lessons and comparisons.


In order for the SKA to function as a coherent telescope, the time and/or frequency standards at each station must be synchronized. To keep decorrelation loss below 1%, the phase jitter must be less than 8 degrees rms, which at a top observing frequency of 20 GHz, is equivalent to time synchronization of 1 ps. Achieving such synchronization across distances of 100s to 1000s km is a challenge. The MERLIN array solved this problem over 25 years ago with a novel method of time division multiplexed pulses on two way radio links at 1486.3 MHz, achieving few ps synchronization across 200km. The send/receive pulses can be separated and pulse length discrimination allows multiple telescopes to be serviced with a single frequency. Smaller arrays have used RF signals on cable/waveguide, whereas larger arrays (VLBI) use independent H-masers. ALMA is developing a sophisticated LO distribution technique using an optical beat note on fibre. This would be expensive for SKA. EVLA has developed two-way phase measurements using two fibres in the same cable but this system has required careful thermal control of the fibre, keeping it quite deeply buried or thermally lagged. This may be restrictive for SKA. Options for SKA include independent time/frequency standards, distributed time/frequency standards using the optical fibre network, two-way satellite time transfer and GPS carrier phase techniques. DS3-T1 will primarily investigate phase transfer using optical fibre but we shall also make cost/performance comparisons with the other techniques. So far satellite techniques typically achieve syncronisation of 0.1-1 ns over long distances. However, if GPS/GNSS signals are within the aperture array observing band it may also be possible to perform much higher precision extraction of the carrier phase by tracking/beamforming on the individual satellites. This approach can provide much higher signal-to-noise and immunity from multipath signals, which are the main limitation of current GPS carrier phase techniques. Initial experiments with phase transfer on optical fibre are being done in two ways at JBO. The basic principle of these phase transfer links is to measure the go-and-return delay and assume that the one-way delay is half of this. However, various effects in optical fibre are non-reciprocal and so initial tests are aimed at quantifying these effects. Firstly, we will use a test test-up in the lab with a 1 GHz laser modulation to test one-way and two-way delay measurements over 1-100 km of spooled fibre. Analysis of initial results over 20km indicate that the performance is limited by leakage in the optical circulators, but after modeling these effects, the residual phase error is about 1 dg, corresponding to 2 ps, which is promising for such a simple setup. The second technique is a direct implementation of the MERLIN L-band link over fibre, modulating a laser at 1486.3 MH and using the MERLIN L-band link hardware for the phase extraction and measurement. A conceptual design of this implementation has been developed and discussed. This option allows rapid demonstration of the feasibility of phase transfer over long distances. Once tested in the lab, it can be deployed on the optical fibres installed as part of e-MERLIN and tested over links from JBO to e-MERLIN telescopes with distances ranging from 13km to 400km. This work is being done at JBO. Since some of the tests require familiarity of the MERLIN L-band link and the e-MERLIN optical network, it has been decided to redeploy MERLIN/JBO staff rather than take on a new engineer. The phase transfer prototyping, will now be rescheduled to run in parallel with the work on component-based data transfer links. WP-02 Data Transmission Based on the international reference design presented in Memo 69, and assuming that the number of bits per sample declines from 12 at the lowest frequencies (as used by LOFAR) to 4 at the higher frequencies (ALMA, EVLA, e-MERLIN use 3 bits) the expected data rates are in the range 14 – 72 Gb/s per station per beam. For 10 – 100 beams per station, this implies 0.1 – 10 Tb/s per station. Handling such large data rates will require a large amount of transmission equipment and initial cost predictions (eg Spencer 2005, SKA memo 75) show that this is a challenge over short distances


because of the number of connections, while the costs of the long distance links may be dominated by the civil engineering required. DS3-T1 will investigate commercial (COTS) equipment (led by ASTRON and informed by LOFAR experience); component based approaches with digital transmission (led by JBO and informed by e-MERLIN/ALMA experience); and short range analogue links (led by INAF, based on BEST experience). ASTRON are developing a detailed costing model for a generic wide area network, using commercial transmission equipment (10 GigEthernet, perhaps 100 GigEthernet in future, or Infiniband). The model covers everything from the transmission equipment, routers, fibre cable and installation to the service contracts required for long term operation. A provisional version is ready now and is being documented. A technology survey has been carried out and has been written up. JBO are investigating the available technologies for low cost transmission equipment over various distances. ALMA & e-MERLIN experience has found that home-made designs using off the shelf building blocks can meet specialist needs more efficiently and cheaply than a system solution. Components developed for OEM applications provide scope to cut down on development eg. Transponders, Gain Blocks etc. One particularly promising area is the current push for ‘fibre to the home’. To be commercially viable, this requires very cheap connections over short distances - similar requirements to SKA. Hence there is now much research and development activity in industry into technologies such as VCELs, plastic optical fibre, mechanical splices, and cheap connectors. A technology survey of this area has been started now, ahead of the original schedule, and industrial links will be sought later this year. IRA/INAF are investigating low cost short-range analogue links which may be used to bring signals from individual array elements to digitizer/beamformer units. A major effort in IRA has been made to evaluate the best solution for antenna remoting in the BEST project (the SKA testbed based on the Northern Cross antenna at Medicina). In order to be able to place the digital processing equipment in a central lab, BEST now uses a solution involving analogue optical links directly between the receivers on the antenna to the receiving rooms. In collaboration with the University of Florence, a reliability analysis has been performed, which shows that this approach reduces the failure rate by a factor of 4. This is clearly an important consideration given the large volume deployment envisaged for SKA. Alternative low cost technologies, such as VCSELs will also be investigated by the IRA/INAF group. Both commercially developed (Tekmar) and custom-made analogue links have been evaluated. Detailed tests of the transmitter performance over a range of temperatures were also carried out. The custom-made link, has so far only been developed for a low bandwidth (16 MHz), but performs well. Field tests on the BEST antenna have revealed some performance issues. Diurnal temperature variations of up to 30 degrees in Spring caused an undefined, low level ripple in the output of receivers connected via the commercial analogue transmission system. WP-03 Network Deployment This work package has not yet begun and was not scheduled to do so within the reporting period. The nature of this work package has been modified slightly due to the expected availability of site specific costing models arising from the international site selection process. We will no consider common technical issues in relation to this site specific data. The cost model will be coordinated with the new cost model coordination work. WP-04 Power Requirements/Distribution This work package has not yet begun and was not scheduled to do so within the reporting period.


The nature of this work package has been modified due to the expected availability of site specific costing models for power distribution. These will be incorporated into the network costing model by the new cost model coordination work. Task deliverables There were no task deliverables or milestones planned within the reporting period. Corrective actions and updated implementation plan The late start to the SKADS as discussed above has required a change to the timescales of this task. These changes have no impact on the interaction of this task with the rest of the design study. The most significant change is that the delivery of the prototype phase transfer prototype is delayed until Q4 2008 from end Q2 2007.


1.4.2 DS3-T2 Data Handling, Control and Distributed Computing Participants in the task Participant number 1 5 15 Participant short name ASTRON INAF-

IRA UCAM DP

Total

Person-months 2.9 0 0 2.9 Study the optimal signal handling and data processing issues arising from with the enormous aggregate of data produced in the SKA instrument. Processing tasks exist at the “central processor” (correlator), at station-level processing and tile signal processing. Considering the broad spectrum of available and yet to be developed technologies, the required processing power can re-distributed throughout the system. Therefore this study will address the optimal distribution of processing tasks and the most cost-effective technology for delivering it. Input to the task, in the form of requirements for the software will come from the studies of DS2-T2. The study will bring in the LOFAR system design knowledge and experience. As the concepts and models are formulated within this task they will be input to the functional simulator (DS3-T3). Meetings Date Title/subject of

meeting /workshop Location Number

of attendees

Website address

29-06-06 Next generation correlators

Groningen >50 http://www.radionet-eu.org/rnwiki/NextGenerationCorrelator

Discussion of work packages The initial progress of the task has been delayed due to the general late start of SKADS. Initial work has concentrated on analysis of processor technologies. Reflecting on the LOFAR correlator development project we identified some distinctive aspects of this process: the total development from initial design sessions to the working initial release took only two years and the manpower used was less than 5 man-year. These characteristics are the result of reuse of the large knowledge base in cluster computing technology. This work suggests that future correlator systems, and typical station signal processing systems, may benefit from software-based technology. We will have performed an analysis of both the “hard” resource requirements for processing and data transport, as well as the “soft” requirements for advanced controllability, fault tolerance and other quality attributes. Based on this analysis an ideal future chip design will be compared with some existing chip developments. We will present architectures for the SKA correlator and station processing system based on this software-centric approach. Task deliverables There were no task deliverables or milestones planned within the reporting period. Corrective action and updated implementation plan


The late start to the SKADS as discussed above has required a change to the timescales of this task. These changes have no impact on the interaction of this task with the rest of the design study.

1.4.3 DS3-T3 Overall Architecture and the Network Simulator Participants in the task Participant number 15 1 2 8 9 18 Participant short name UCAM

DPHYS ASTRON UMAN OXF

DB CSIRO CU Total

Person-months 2 0 0 0 5.2 0 7.2 Introduction The objective of this design study is to consider the issues associated with producing the most cost-effective overall architectural design for the SKA “network” which satisfy the specifications established in DS2 and deliver the scientific objectives to the end-user. The work within this design study is closely focused on the specific requirements and costs associated with a fully phased-array telescope. Within the context of DS3 the telescope is considered on scales larger than that of an individual tile (in this case taken to be the smallest correlatable element). The main objective is to develop a functional simulator for the telescope and employ this functional simulator to model the behaviour and performance of the phased-array SKA concept. The starting point for the simulator will be the work already developed for the LOFAR project. The simulator will act as a component of the phased-array module for the international end-to-end simulator and will complement and make full use of the international effort input to the and-to-end simulator. Complementary work will be undertaken within the proposed US design study; for the US study the specific considerations associated with the “LargeN(umber of stations)SmallD(iameter)”- design study will be considered. Where there are common aspects close collaboration between the two studies will be put in place. Meetings Date Title/subject of

meeting /workshop Location Number of


6/6/06 DS3-T3 kickoff/Simulation meeting

Oxford 10 http://webmail.jb.man.ac.uk/skadswiki/Ds3T3/WorkPackages

Discussion of the work packages The start of this task has been delayed principally due to the late availability of funds from the EU and availability of the secured National Funding within the UK where the majority of the work associated with this task will be undertaken. These issues have delayed the effective start of most sub packages by approximately 9 months from the official start of the project. However these delays are not serious to the long term completion and the design study deliverables and milestones are expected to be reached on time – none are due in the current reporting period. One sub-task deliverable is delayed. The kickoff meeting for the task was held in Oxford on 6 June 2006. This meeting also included representatives of DS2-T2 (astronomical technical simulations) and was attended by the project engineer and project scientist. A report of the outcome of the meeting can be found at http://webmail.jb.man.ac.uk/skadswiki/Ds3T3. A main outcome of the meeting was to identify the interface and simulation responsibilities between DS2-T2 and DS3-T3. Alexander attended the technical meeting in Jodrell and presented an analysis of the network infrastructure and its impact on the system design of the SKA.


DS3-T3-01 Network simulator The network or functional simulator will be a series of software packages and analytical modeling tools designed to simulate key areas of the network and processing aspects of the SKA designs considered in this study. This work package has been delayed as discussed above. Alexander has contributed to the initial analysis of tile- and station-level processing and data flow. A similar analysis of out-of-station data flow will be the next action to be undertaken. Together these will form the basis for the preliminary analysis of the network which is the delayed task deliverable. Application of simulator to model SKA design This work package has not yet begun and there were no planned deliverables or milestones in the reporting period. Network architecture and processing methodology Tim Cornwell of the xNTD project at ATNF conducted side-by-side simulations of the continuum imaging performance of a SD+FPA and ATA-type telescope (T.J. Cornwell, "LNSD reconsidered – the Big Gulp option", SKA memo 61), and also simulations of a SD+FPA telescope with alt-azimuth and equatorial mounts (T.J. Cornwell, "Computing costs of imaging for the xNTD", ATNF SKA memo 1). The ATA-type telescope (also known as Big Gulp) has the best imaging performance but requires large resources for correlation and data processing. Ignoring calibration concerns, the two SD+FPA systems have similar imaging performance but the equatorial mounts reduce the computing costs by a large factor, probably an order of magnitude. Tim Cornwell and Enno Middelberg also investigated the role of asymmetries in the ATCA voltage beam in limiting the dynamic range of deep continuum mosaics. Simulations and measurements show that the blockage and diffraction due to the quadrupod is responsible for limiting the dynamic range. Modeling this behavior is in concept straightforward if the voltage beam can be measured sufficiently accurately. Work on this latter step is still proceeding. Similar effects are certain to limit the imaging performance of the SKA reference design unless countermeasures are taken. Tim has worked to define the computing model for the xNTD (ATNF SKA memo 2) and to discuss it with the various xNTD stakeholders. He has worked with Jasper Horrell of the Karoo Array Telescope to set up a collaboration, called Convergent Radio Astronomy Demonstrator (CONRAD), aimed at producing operational software for SD+FPA type telescopes. Tim and Max have worked to refine the xNTD/KAT simulation capabilities to allow answering of many questions about the design of SD+FPA type telescopes. Initial results have shed light on the computing costs for both alt-azimuth and equatorially mounted antennas (ATNF SKA memo 1). Management of the data flow This work package has not yet begun and there were no planned deliverables or milestones in the reporting period.


Task deliverables Task number

Deliverable No

Deliverable Name Workpackage /SubTask No

Delivered by Contractor(s)

Planned (in months)


DS3-T3 1 Initial report on conceptual issues

DS3-T3-01 UCAM DPHYS. OXF DP, CU

7 N/A

Corrective action and updated implementation plan The late start to the SKADS as discussed above has required a change to the timescales of this task. These changes have no impact on the interaction of this task with the rest of the design study. One task deliverable has been delayed and the new date for this deliverable is December 06. Again this will not alter the schedule for the rest of the design study.

1.4.4 DS3-T4 Siting and Related Issues Participants in the task Participant number1 4 1 9 Participant short name2 OPAR ASTRON CSIRO Total Person-months3 1(0) 10.5 14.4 25.9 Introduction – significant changes in the SKA siting process At the time of the definition of the SKADS Description of Work, two-and-a-half year ago as of date, the objectives of DS3-T4 were summarized as follows: “The production of a full plan for siting and related issues for the SKA, encompassing environmental issues (including signal conditioning, impact and adopting the advanced technology to arid lands), radio frequency monitoring/protection over a long term and potential maintenance regimes.” Meanwhile significant changes have occurred in the SKA site selection procedure that were not foreseeable at the time of the submission of the SKADS proposal, and which have a significant impact on the work to be carried out within DS3-T4. At the time of the submission of the SKADS proposal it was expected that the SKA site would be chosen in the third quarter of 2006; this date has now effectively been postponed to the third quarter of 2008 in the current version of the International SKA Project’s roadmap (see Figure 1-2 below). In August 2006 the International SKA Steering Committee (ISSC) will draw up a short list from among the 4 sites that were proposed for the SKA in December 2005 (by Australia, Argentina/Brasil, China, and South Africa) and present its findings to the Funding Agencies Working Group for the Future of Centimetre Wavelength Astronomy that was established in February 2006 in a meeting between national and international government and funding agency officials and ISSC representatives. It has become clear that some of the work that was originally foreseen within DS3-T4 will in fact be carried out within the framework of the activities of the International SKA Project (specifically the Site Evaluation Working Group and its Task Group on Regulatory Issues, and the ISSC) and as part of the studies made by the aforementioned five countries that have submitted proposals for siting the SKA to the International SKA Project Office in December 2005.


In this report the impact of these developments on DS3-T4 will be analysed in as far as this is possible, given all information that is presently available both from within and from outside SKADS. Overview of activities carried out within the Task WP2: RFQ meetings/CRAF/IUCAF/etc consultations From the DoW: “Working with national, regional and international communications authorities to ensure maximum practical radio frequency environmental protection for the chosen site.”

Figure 1-2 the current roadmap towards the completion of the SKA of the International SKA Project; note the 2006Q3 determination of the SKA sites short list and the provisional 2008Q3 date of the SKA site selection.

Regulatory issues concerning the requirements of a Radio Quiet Zone for the SKA: The DS3-T4 activities under WP2 have been in support of the International SKA Project Office (ISPO) and subject tot the specific timeline of the SKA project. The SKA Task Force on Regulatory Issues of the Site Evaluation Working Group of the SKA International Project has undertaken to establish requirements and standards for Radio Quiet Zones and resulted in the writing of “Spectrum Protection Criteria for the SKA”, ISPO Memo No. 73. This activity has been carried by ASTRON (chair), OPAR, CSIRO, and representative from Republic of South Africa and the USA. During the evaluation period of the four Siting Proposals, the Task Group on Regulatory Issues provided support in specifically evaluating the proposed regulatory framework and procedures leading towards Radio Quiet Zones for all four proposed SKA sites. This activity was done by ASTRON (chair), OPAR and with consultation by staff of the Arecibo Observatory in the USA. CSIRO participated in the definition of the Radio Quiet Zone requirements for the proposed site of the SKA core site in Western Australia, including dealing with the Western Australia Government on the establishment of a large radio astronomy site and the regulatory requirements for the proper protection of SKA observations from man-made radio interference. This process resulted in the publication of a Spectrum Planning Discussion Paper on a proposed Radio Quiet Zone (RQZ) for Western Australia by the Australian Communications and Media Authority in March 2006.


ASTRON and OPAR participated in the submission, through the ISPO, of public comments on the abovementioned ACMA Discussion Paper that were prepared by the Task Group on Regulatory Issues (April 2006). CSIRO, OPAR and ASTRON supported the work towards a global Recommendation by the International Telecommunication Union (ITU) on the requirements for an SKA Radio Quiet Zone, within the international community of astronomers involved in spectrum management, through the activities of IUCAF (the ICSU Scientific Committee on Frequency Allocations for Radio Astronomy and Space Science) in consultation with CRAF (the Expert Committee on Radio Astronomy Frequencies of the European Science Foundation), and at Working Party 7D (radio astronomy) of the ITU. WP3: Downselection of viable Sites based on Technical and Scientific Merits From the DoW: “Liaising with the International SKA Site Evaluation Working Group (SEWG) throughout this study to identify issues between the potential SKA technology solutions and the technical and scientific characteristics of the 5 candidate sites”. Establishing the technical characteristics of proposed SKA sites: EU funding was used for 10 months’ salary of the ASTRON engineers that carried out the extensive and homogeneous Radio Frequency Interference (RFI) monitoring campaign of all four proposed SKA sites. The final report of the SSSM will be (partially) publicly available at the end of the current evaluation period of the proposed sites. National security issues will be considered before public dissemination. Extensive and comprehensive testing of the long-term RFI conditions at the proposed site of the SKA core in the Western Australian desert near Mileura by the CSIRO team. This report and those of the other proposed sites will be (partially) publicly available at the end of the current site evaluation period and after consultation on national security issues. Progress towards milestones and deliverables Deliverables: The four main DS3-T4 Deliverables are:

1. First Overview Report and Final Report on Site Selection Procedures and Criteria 2. Report on Site Selection and Final report with long-range plan for selected site 3. Final report containing discussion of (adapting to the) site environment, environmental impact

analyses, facility maintenance options, other land (access, purchase/lease) issues 4. Summer RF workshop on spectrum and other site related issues

Objectives for the first year of SKADS: Deliverable 1 - WP1: “First overview report due [ June 2006]” General site selection procedures and criteria have been partially established and implemented for the SKA, and during 2006 candidates sites are being evaluated on the basis of scientific and technical criteria and infrastructure cost. However, the implications of the site selection criteria and short-listed sites for the EMBRACE system have not yet been fully explored. It now appears to be more efficient to produce the “First overview report” part of Deliverable 1 once the short-list of acceptable sites for the SKA has been determined by the ISSC in August 2006. Deliverable 2 - WP2: “Report at site selection time due [September 2005]”


The SKA site selection time, originally expected to occur during the third quarter of 2006, has effectively been postponed till the third quarter of 2008. As described in Sect. 1.2.1 the DS3-T4 teams participated actively in various processes related to defining the regulatory protection requirements for a SKA Radio Quiet Zone and in valuating the four site proposals. ISPO Memo 73 on “Spectrum Protection Criteria for the SKA” takes the place of the DS3-T4 Report that was intended for September 2005. Deliverable 3 - WP3: “Engagement with other site monitoring campaigns executed in collaboration with ASTRON Team [March 2006]”. As shown in Sect. 1.2.1 the RFI monitoring campaigns by ASTRON and CSIRO of proposed SKA sites were successfully completed and reports produced. These reports will be made (partially) public at the end of the current site evaluation procedure after consideration of national security issues. Deliverable 4 - “Summer RF workshop on spectrum and other site related issues”: Preparations have started on organizing the “RFI2007 Workshop on Mitigation of Radio Frequency Interference for the SKA” will be held at the University of Manchester in September 2007, preceding the international scientific symposium “From Planets to Dark Energy: the Modern Radio Universe” and a meeting of the ISSC. Identification of the problems encountered and corrective action taken The following modification was made with respect to the Description of Work:

• Change the lead participant from ASTRON (1) to OPAR (4) This change was decided by the SKADS Board in its 29-30 June 2006 meeting Work Packages: WP2: RFQ meetings/CRAF/IUCAF/etc consultations The DoW states that “As the site decision will be third-quarter 2006, these discussions will start on a more general basis during SKADS then focus in on the chosen site in the latter part of the study.” As explained above, the SKA site selection has been postponed until the third quarter of 2008, and in the third quarter of 2006 only the short list of proposed SKA sites will be established. As a result the restriction on “the chosen site” in the DoW should be changed to “the short-listed sites”. WP3: Downselection of viable Sites based on Technical and Scientific Merits The DoW states that “Liaising with the International SKA Site Evaluation Working Group (SEWG) throughout this study to identify issues between the potential SKA technology solutions and the technical and scientific characteristics of the 5 candidate sites” For the same reason as given under WP2 above, in the DoW “the 5 candidate sites” should be changed to “the short-listed sites”.


Financial overview of the Task During the first year of SKADS, EU funding was used for 10 months’ salary of the ASTRON engineers who carried out the RFI monitoring campaign of all proposed SKA sites. It is not foreseen that any EU budget will be used for DS3-T4 during the next 18 months. or: During the next 18 months it is foreseen that EU funding will be used for 2 person-months at ASTRON only.

1.4.5 DS3-T5 SKA for the User Participants in the task Participant number

15 1 2 8 3 9 16 18


UCAM DPHYS

ASTRON UMAN OXF DP

JIVE CSIRO KAPT CU Total

Person-months 0 0 0 0 0 0 0 0 0 Introduction The objective of this design study is to consider the impact on the design of the requirements of the end-user astronomer. A key aspect common to all the design studies is the necessary trade off between flexibility and performance on the one hand and cost and practical implementation on the other. This study examines these same issues from the point of view of the end-user astronomer and ensures that flexibility and data throughput is matched by the end-user ability to optimise the use of the instrument and analyse the data to produce astronomy. The cost of providing user support type services during the operational phase of the SKA is considered. Finally, the study considers what tools will be required to monitor the data from the telescope from the point of view of the end user astronomer and telescope operators. Meetings There have been no meetings within the reporting period and none were planned Discussion of work packages


This task has not yet begun and was not planned to have started during this reporting period. There is therefore no activity to report and there were no planned milestones or deliverables due during this reporting period. Task deliverables None during this reporting period

1.4.6 DS3-T6: Scalable Design and Implementation Participants in the task Participant number 1 Participant short name ASTRON Total Person-months 0.5 0.5 Introduction The objective of this work package is to prepare for a scalable design and implementation for SKA. This approach will optimize the integration of key (sub)system elements addressed in DS4 and DS5, and at the same time anticipate the very large scale SKA requirements. The focus is on the interfaces and the platforms (hardware and software) for the control and digital data processing. Meetings Date Title/subject of

meeting /workshop


Website address

29-06-06 Failing scaling and roadmapping to new architectures.

Groningen >50 http://www.radionet-eu.org/rnwiki/NextGenerationCorrelator

Discussion of work packages Survey of methodology and technology We have finished a first memo which analyses the required methodology for the design of SKA’s embedded signal processing and computing systems. There is quite an extensive vocabulary to familiarise ourselves with in the discipline., This first memo provides a good start for just that. Despite Moore’s Law there is a productivity gap, i.e. the complexity of system design increases with Moore’s Law but the design methods do not keep pace. There are two distinct approaches: a programming/software approach and synthesis approach originating from hardware design. The latter has elements for model driven design. We have identified two key aspects to be investigated (in the next memo): complexity of architectural design and seamless scalable integration. We propose a roadmap along three lines: systematic design space exploration (including traceability of architectural evolution), analysis and methods to design for life-cycle aspects such as power consumption and finally raising the level of abstraction in design to improve technology adaptiveness and multi-aspect optimization. In the next memo we will discuss of models-of-computation, models-of-architecture, state-of-the-art and engineering practice. Analysis of the scalability needs We have analyzed the scalability of correlator architectures, our results have been presented at the radionet correlator workshop organized by JIVE on June 26-29th 2006 in Groningen: “Failing Scaling and roadmapping to new Architectures”. We intend to write a short memo to summarize our considerations. Here are the main conclusions. Given the emerging optimization criteria related to


Total-Cost-of_ownership (TCO), a one-to-one scaling of existing architectures will fail. The technology advances with Moore’s Law are not sufficient to provide a suitable architecture for SKA’s central processor. We can benefit from platform-specific R&D invested by industrial machine manufacturers, if we pursue short time-to-market (TTM) strategy. Demonstration and discussion of key techniques We have started work on a demonstration of methodology to arrive at a distributed parallel implementation of data-flow with a hierarchical and scalable control network from models and scalable and portable building blocks. Research on the required modeling and a specification of the mapping transformations has also started. Assessment of Model-driven design approaches A study is being conducted on this topic. Our focus is now on the analysis of requirements on methodologies in our specific domain. Recommendations concerning model-driven design approaches This subtask has not started yet. Task deliverables Task number

Deliverable No



Planned (in months)


DS3T6 1 Orientation Report

DS3T6 Astron 1 1

DS3T6 2 Survey Report including an analysis of scalability needs

DS3T6 Astron 3 N/A

DS3T6 3 Recommendations and evaluation of key techniques

DS3T6 6 N/A

Corrective action and updated implementation plan Two task deliverables which were due within this reporting period have not been delivered. This has no impact on the rest of the design study and the task can be re-phased to achieve all deliverables to an acceptable schedule.


1.5 DS4: Technical Foundations and Enabling Technologies Introduction DS4 is concerned with developing new technologies for the sub-systems within a phased array system, together with determination of the digitization requirements and mitigation techniques for radio frequency interference (RFI). DS4 provides a small demonstrator system, 2-PAD, built using the best sub-systems available at the beginning of 2008. DS4-T6 has been extended following the submission of the description of Work to consider the system design of an overall aperture array station which could be used in the SKA. This is to ensure that the developments within the rest of DS4 and that the design of 2-PAD can be regarded as a part of full implementation and does not overlook system integration. DS4 has many institutions across multiple countries involved, this first year of start-up has been rather patchy, with some countries/institutions starting in anticipation of funding e.g. ASTRON and FG-IGN, others starting relatively promptly e.g. OPAR and INAF-IRA and the UK in particular being quite slow due to delays in national funding from PPARC. Despite these variances this design study, in keeping with the rest of SKADS is being re-scheduled in order to be completed in June 2009. In general terms the schedule for DS4 is:

• 2006 – review and investigate all potential approaches; • 2007 Q1 – select 2 or 3 most promising techniques; • 2007 – build prototypes and models for the selected techniques; • 2008 Q1 – select the technologies for 2-PAD; • 2008 – Build 2-PAD; • 2009 until June – Test and report on 2-PAD performance;

Note that the individual sub-system development will continue through 2008 and 2009, 2-PAD will use the most appropriate system available at the start of 2008. Detailed Task activities, including meetings attended, are provided in the individual Task reports. It has become clear that the design of an advanced phased array for astronomical use as being designed in DS4 needs tight interaction with the specification and network studies in DS2 and DS3, this is being done. It is also apparent that work will also be required in the calibration requirements (SKADS does not cover the implementation) to bring the absolute performance of the phased array up to the standards required by the SKA. Benchmark Design In reviewing the requirements of a mid-frequency range aperture array collector for the SKA, it has become clear that the frequency range and performance requirements needed to be specified. This provides a specification for the scientists to use in their simulations and targets for the engineers to meet. SKADS is charged with providing the SKA specification requirements for at least the mid-frequencies, which can only be finalized after completing detailed simulations, however, the requirement for an initial specification is apparent. Consequently, a ‘SKADS Benchmark’ design is being prepared and will be put on the SKADS Wiki site for use and comment. The Benchmark design necessarily covers anticipated collector technologies for the full SKA and thus places the technical developments within SKADS in context and provides the scientists with full view of the instrument for their simulations. This was agreed in the 2nd SKADS board meeting. No technical development will take place on the collectors outside of the nominal SKADS frequency range, however, advice and specifications for both high and low frequencies will be taken from other groups who are working on them.


The frequency coverage from the benchmark design is 0.3 - 1.0GHz. The reasons for this are:

1. Low frequency reduced to 300MHz to match with the high frequency limit of the projected sparse aperture array being designed – LOFAR and the MWA. The coverage from 300-500MHz is particularly difficult to stretch up from the low frequencies and for dishes, which would have to be too large for SKA field-of-view requirements to have good aperture efficiency. Close packed aperture arrays are particularly well suited to this frequency range;

2. High frequency is reduced primarily to reduce projected cost of the aperture array. Due to element spacing scaling with λ, the cost increases with the top frequency as a square law simply from geometrical considerations, further, due to more expensive components being required and likely increased processing requirements at higher frequencies, the cost may scale as much as f3. Hence reducing the top frequency to 1.0GHz reduces the cost by a factor of 2-3. The scientific requirement is for the very large fields of view provided by aperture arrays below 1.0GHz, while beneficial the extremely large fields of view are not so critical above 1.0GHz.

System Design The system design work undertaken in DS4-T6 has highlighted the requirements for performance and cost profile of each of the sub-system design; it has also identified the need for work on a very low cost, short range analogue link – work which will also be done as part of DS4-T6. The system design has focused the requirements for the sub-systems and provides the necessary context for this work. Expectations While the specifications and cost targets are very stringent, the initial work conducted in DS4 indicates that the systems projected for building 2011 onwards should be able to meet these requirements. It is incumbent upon SKADS to demonstrate that this is the case. Other specific activities (Design Study/Construction activities) The detailed reports for each Task are contained in a separate report, below here is a brief overview of each Task. DS4-T1: Front-end Technologies The key component defining the noise performance of the aperture array, the LNA, has a number of different approaches being developed. There has been very encouraging progress indicating that either ambient temperature or only slightly cooled devices will meet the required specification. Indeed we may have more than one option available. These devices need to be developed in close collaboration with the antenna element in order to optimize the match between the two. Since we are developing specific designs we can control some normally fixed parameters e.g. input impedance. Selection will be made on the grounds of system performance and to a lesser extent cost – since improved performance reduces the need for building as much collecting area for the SKA, which would make a dramatic cost reduction for a slight improvement in system noise. This trade-off will be determined in the SKA costing model, which is part of SKADS. The other major development is for a very low cost, high performance and low power analogue to digital converter (ADC). This development is still at an early stage, but due to the critical nature of the device in an all-digital aperture array such as 2-PAD, development will be closely monitored over the next 18 months. DS4-T2: Signal Conditioning and Digitisation Work on analogue to digital conversion has been ongoing as discussed in the DS4-T2 report. The crucial question that needs to be answered in the short term is ‘how many bits of digitisation are


required at the front end antenna’. It is important to remember where the SKA will be sited (currently the precise site is subject to considerable international discussion); whichever site will be chosen it will have a very low RFI profile – radically different from the RFI environment in Europe. The implications for the digitisation bit count and the consequent affordability of an all-digital aperture array are very substantial. The known number of bits required for Europe is 12-14 c.f. LOFAR and studies at Medicina, whereas the first calculations for a low RFI environment using fast sampling >500MS/s shows that 1-2 bits may be sufficient to prevent saturation of the ADC. We are presently planning on using 4-bits to provide headroom and good sensitivity. This is an important result at this stage of the project. Over the next 18 months firmer results will be obtained for the necessary and projected number of digitisation bits, further the required number of bits being processed and the length of the coefficients necessary at the various processing stages will be determined. RFI mitigation strategies The research of the various possible techniques for RFI mitigation has been started, it is currently running behind schedule for the resourcing reasons discussed above. There is strong international collaboration on the various techniques. Over the next 18 months the inventory will be competed and implementation schemes will start to be explored. Wideband Integrated Antennas This is a very major task with a lot of participants. Success in the design of a wide bandwidth, low cost, well matched, excellent polarisation performance and easy to assemble antenna array is a major technical goal in SKADS. The performance of the antenna, coupled with the LNA determines the viability of an aperture array in the SKA. However, for prototyping purposes in developing the rest of the system, there are existing designs. The start up of the various groups has been varied, with a lot of work at ASTRON and FG-IGN, and only initial work in the UK. The obvious choice of antenna uses the Vivaldi design, however, there are significant issues with Vivaldis in terms of construction, matching and polarisation properties. Other designs have not been studied in as much detail – hence the number of groups involved. There is a goal that to find an effective circularly polarised antenna could have significant calibration benefits over a linearly polarised array. The next 18 months should bring substantial progress in construction, cost and performance of the antenna elements. Beamforming and Station Signal processing There are three approaches to beamforming being considered in this task: analogue, digital and photonic. The analogue techniques, presently being exploited in EMBRACE, are integrating phase shifters for multiple elements within a single chip. There are two systems being made which are both roughly on schedule and making good progress. These will be integrated in EMBRACE over the coming 18 months. The photonic approach gives true time delay using optical ring resonators. The has been little progress so far, however over the next 18 months the first samples will be available and integrated.


The digital processing approach has been designed as part of an overall system developed in DS4-T6 outlined above. Inherently, this is expensive at the present time due to available processor limitations, however, work is focussed on selecting processor technologies which will maximise the benefits of ongoing device developments. The key advantage of digital processing is the ability to correct for the inherent defects in the rest of the system – relatively poor polarisation, variations in gain and time delays – further the ability to correct online for atmospheric issues and RFI mitigation is important to reach the performance requirements of the SKA. The ability to make arbitrarily many beams makes digital processing a strong contender for the final solution. So far, the overall system design has been put in place, which can now evolve in terms of performance and flexibility. Over the next 18 months there will be selection of the most promising processing technologies, also, prototype systems will be built in readiness for the selection as part of the 2-PAD design. PAD Construction and Tests The activities in the Description of Work have yet to commence for this task, since it is the construction of 2-PAD which will not commence until 2008. However, as is reported above, this Task is the vehicle for an all-digital station system design. Over the next 18 months we would expect the station design to be refined in the light of SKA requirements e.g. additional collecting area at lower (3-500MHz) bands in order to preserve sensitivity at these crucial frequencies. Participants Table 1: List of contractors leading tasks in Design Study DS4

Participating Institution Short name DS Tasks Task titles The University of Manchester, UK

UMan DS4-T1 and T6 Front-end technologies, 2-pad demonstrator

Stichting Astronomish Onderzoek in Nederland

ASTRON DS4-T4 Wideband Integrated antennas

Istituto Nazionale di AstroFisica, Italy

INAF-IRA DS4-T2 Signal control and Digitisation

Observatoire de Paris, France

OPAR DS4-T3 RFI Mitigation Strategies

The Chancellor, Masters and Scholars of the University of Oxford, UK

Oxford DS4-T5 Beam forming at Patch Level

Table 2: Participants in DS4

No. Short name T1 T2 T3 T4 T5 T6 1 ASTRON 1 2 3 4 5 6 2 UMAN 1 4 5 6 4 OPAR 1 3 4 5 5 INAF-IRA 1 2 3 4 5 6 6 FG-IGN 4 8 OXF-DB 4 5 6 9 CSIRO 1 2 3 4 11 NRC 4 15 UCAM DPHYS 4 6 25 UORL 3 26 CNRS 2 5 30 OMMIC 1 4 5 Shading indicates task leadership. No deliverables are expected in this first reporting period.


Table 3: DS4 milestones

Target date Task Milestone T0+12mo T3 Inventory of RFI mitigation techniques and applicability to SKA

(T3) T0+18mo T1 SiGe band pass filter using PIC technology prototype T0+18mo T5 Prototype low cost SiGe analogue beamformer T0+24mo T1 Hybrid LNA first devices T0+24mo T3 Evaluation of impact of moving interference sources on SKA T0+24mo T5 Simulated digital beamformer for 2-PAD T0+28mo T4 Characterised antenna element T0+30mo T1 ADC performance evaluation T0+32mo T4 Antenna element with integrated MMIC prototype T0+42mo T6 Prototype complete 2-PAD all digital tile T0+48mo T1-T6 Final reports on: semiconductor technologies,RFI mitigation

strategies, antenna element design, digital beamformer design, 2-PAD performance

Although the EC project formally started in July 2005, funding has only been available since early 2006. Realistically, T0 is about 1st April 2006, and no milestones have yet been reached on this basis.

1.5.1 DS4-T1: InP LNA and ADCs The Manchester-specific Ds4-T1 concerns the design and fabrication, using a first generation 1µm optical lithography process, of low noise InGaAs-InAlAs pseudomorphic High Electron Mobility Transistors (pHEMTs) with improved breakdown voltages and with adequate noise figure (< 35K @ 1.4GHz). It also involves the design and fabrication of high speed InGaAs-InP Heterojunction Bipolar Transistors (HBTs) with cut-off frequencies > 70 GHz but still based on the same optical lithography process. These are the basic building blocks upon which the MMICs and Analogue to Digital Converter (ADCs) integrated circuits will be developed for the next phase of the SKADS programme. Concomitantly a detailed study of passive components is being pursued (SiN-based capacitors, NiCr high precision resistors and Ti/Au inductors) Participants in the task Participant number

2 1 4 5 9 26 30


UMAN ASTRON OPAR INAF-IRA

CSIRO CNRS OMMIC Total

Person-months 18.4 19.4 18 0.34 15 2 5 78.09 High Breakdown Voltage/Low noise pHEMT The key objective was the realisation of rugged, low-noise room temperature operating devices. For the upcoming SKA telescope, rugged (high voltage breakdown), high performance (low noise and high gain) room temperature operation is paramount as is the need for low cost since in the aperture design concept, hundreds of millions of amplifiers would be needed. While existing commercial devices (mainly 0.1µm gate InP–based pHEMT) are able to fulfil the noise requirements of SKA, their cost and breakdown fragility (~ 2V) precludes their use in this particular application. Our approach for SKA thus relies on materials and RF performance improvement predominantly through materials and band-gap engineering and not through aggressive scaling. From a manufacturability viewpoint, materials designed and processed using “relaxed” optical lithography for the low frequency band of SKA (0.5 to 2GHz) are likely to be more cost effective than nanoscale lithography in either Si or InP technology. Furthermore for this frequency range, plastic packaging will significantly contribute to component cost reduction.


The first stage of the project was the epitaxial growth, using Molecular Beam Epitaxy, of a series of InGaAs-InAlAs 2DEG systems to study the effect of charge transfer from the doped supply layer on the 2DEG concentration and mobility and ultimately on the breakdown properties of pHEMTs and DC-FETs. This led to the discovery of a novel band structure giving rise to extremely high breakdown voltages and low leakage currents, which are notoriously high in conventional InGaAs-InAlAs pHEMTs (and hence their low inherent breakdown). The second stage was concerned with developing fabrication and measurement techniques for the 1µm gate pHEMT devices. Very little work had previously been done on these fairly large gate geometries for two reasons: the first is that most applications of InP-based devices have been in millimetre-waves systems for which gate lengths of 0.1 um or less are required. Second, the material is notoriously leaky at room temperature (leakage currents > few µA) and thus a 1 µm gate device will exacerbate the leakage even further, since the effective gate area will be at least 20 times larger. The measurement strategy consisted of studying the effect of impact ionisation on the leakage and deducing methods of reducing it. We were able to achieve leakage currents of around 10 nA in 1 x 200 um2. This is the lowest ever reported in InGaAs-InAlAs pHEMTs and has been a key component in the fabricated low noise devices

Figure 1-3 Comparison of Gate-Source diode IV (1x200µm device) for conventional (VMBE 1855) and newly developed structure (VMBE1831)

Noise Performance Room-temperature, optimum noise figures are shown in Comparison of optimum noise figures of the improved (VMBE1831) and conventional (VMBE1855) pHEMTs Figure 1-4. 2, up to 5 GHz, for the two structures. It is clear that the noise characteristics are better for the new device, reflecting the effect of the reduced leakage current. This effect is more pronounced at higher frequencies. At 1.4GHz [ The 21 cm Neutral Hydrogen line] the noise figure is less than 0.5 dB (35K noise temperature), in these geometrically un-optimised (in terms of gate resistance and gate width) devices. We estimate that up to 0.2dB is added to the noise because of the rather thin gate metallisation we used (~ 150 nm). Our calculation of gate resistance predicts that Fmin of ~ 0.3 dB (~21K) would be achieved by thickening the gate metal to 450 nm. These values are comparable to those of 0.1 m e-beam (rather than optically) defined gates – which would be much more expensive to manufacture in large quantities for the SKA.


0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 1 2 3 4 5 6

N.F_1831 (dB)

N.F_1855 (dB)

Figure 1-4 Comparison of optimum noise figures of the improved (VMBE1831) and conventional (VMBE1855) pHEMTs

In summary, we have designed, fabricated and characterised a family of InP based pHEMTs combining 1 µm gate geometry with state-of-the-art performance compared with the best 1µm devices reported in the literature but with VBDG > 14 V and noise Figures of < 0.5 dB (~ 35K) at 1.4 GHz. These are amongst the lowest Fmin ever reported for such large gate geometry and are only 0.2dB worse than state-of-the art e-beam defined 0.1 µm devices. By further optimisation of the gate metallisation we are confident of achieving Fmin values of 0.3dB (~21K) even at 1 µm gate length. GHz class ADC Design and Fabrication The High speed ADC design and fabrication started with the fabrication of optically defined Heterojunction Bipolar Transistors (HBTs) which have shown cut off frequencies in excess of 70 GHz. This is considered adequate for the development of 4Gs/s high speed blocks. We have secured SILVACO licences for the design aspect of the work and this has been used to simulate DC and RF behaviour of InGaAs-InP HBT (see Figure 1-5).

Figure 1-5 Simulated and Measured High- Frequency performance of a 5×5µm2 emitter area microwave device FT=71GHz @ IC=14.8mA

Successful implementation allows for epilayer and mask layout optimisation with the ability to simulate actual processes with virtual wafer fabrication. A great deal of work has gone into optimising the passive component and especially the SiN capacitor structures.


Figure 1-6

In the high speed ADC work, the accomplished tasks to date have been:

• Silvaco implemented

• Capacitors for track and hold and LNA completed

• NiCr Resistor mask designed

• Quick test HBT mask designed

• Thinned Epilayer structures grown to improve high-frequency

• New high frequency mask currently being designed with the aid of Silvaco and ADS In conclusion, the high speed ADC Design and fabrication Task is on track. A great deal of work has been spent on optimising and fabricating the passives and the basic HBT building Block.

• Reflectivity Results uniformity ~ 5% • Capacitor values better than 2% (σ=0.36) • Quality factor > 300 • Target power dissipation << 1W


LNA and filters in Silicon technology The OPAR contribution in DS4-T1 is centered on the use of low cost silicon-based technologies for the design of some of the basic building blocks of SKA such as filters and wide band LNAs. Filter design in PICS technology PICS is a low cost 1µm silicon technology available from Philips Semiconductors that offers high quality passives and the ability to achieve a highly integrated System in Package by using the substrate itself for interconnecting individual dies that may be made from different materials for building a super-die. This low cost technology coupled with the capability of achieving high integration can be very valuable for decreasing the cost of SKA. The high quality of the passives is used to build a band pass filter which constitutes the DS4-T1.3 deliverable. Results are described in the report "Design and Realization of 2 Band-pass Filters in PICS Technology – Marie-Line Grima – June 2006". Realization of a super-die by taking advantage of the interconnect ability will be the object of deliverable DS4-T1.9 later on in the project. Filter design Two band pass filters have been designed according to the following requirements:

• dB bandwidth: 350 MHz-2 GHz • ripple < 0.1 dB in the passband • rejection > 60 dB above 4 GHz

The first one is a 5th order Tchebytchev band-pass filter and the second one is a high pass filter cascaded with 1 (or 2) low pass filter. Then these filters have been manufactured and tested. Filter measurements Both filters were manufactured simultaneously and measured on wafer. The Tchebytchev filter is slightly larger (2.8 x 1.6 mm²) than the low-pass/high-pass combination (2.13 x 1.15 mm²).

Figure 1-7 Microphotograph and transmission of the Tchebytchev band-pass filter


Figure 1-8 Microphotograph and transmission of the low-pass/high-pass filter

BP S21 LP2&HP

-70

-60

-50

-40

-30

-20

-10

0

0 1 2 3 4 5 6 7 8 9 10

GHz

dB

Figure 1-9 Comparison of the transmission for both manufactured filters

Both filters are in good agreement with the simulations with the low-pass/high-pass structure exhibiting a better rejection than the band-pass one. Results from this first iteration are good enough to allow us to go ahead with the second step that is to use this substrate and a next iteration of this filter as an interconnect substrate to realize a LNA/filter combination on a super-die. Silicon technologies for LNA Despite the fact that silicon and SiGe technologies are potentially less low noise than GaAs and InP, their low cost makes them very interesting for the design of wide band amplifiers. We chose the QuBiC4G SiGe technology from Philips Semiconductors. This technology exhibits a minimum noise figure NFmin of 0.6 dB at the frequency of 2 GHz. Another technology, QuBiC4X that is a SiGe:C technology even achieves a NFmin of 0.4 dB. Its use will be assessed later on. A lot of development work has been done on narrow-band ultra low noise amplifiers but few wide band ultra low noise amplifiers have been designed so far. In order to assess the potentiality of silicon-based technologies for wide band LNAs, we designed a 300 MHz – 2 GHz amplifier both in single ended and in differential configuration. As both configurations lead to similar results, only the differential configuration is presented here.


0,70

0,80

0,90

1,00

1,10

1,20

0,3 0,5 0,7 0,9 1,1 1,3 1,5 1,7 1,9frequency (GHz)

dB

NF NFmin

Figure 1-10 Layout and noise figure of the differential 300 MHz – 2 GHz QuBiC4G LNA

The minimum noise figure (0.9 dB @ 2 GHz) is close to the minimum noise figure of the technology (0.6 dB@ 2 GHz). The noise figure is as low as 0.93 dB around 700 MHz and is below 1.2 dB from 300 MHz to 2 GHz.

2424,5

2525,5

2626,5

0,3 0,5 0,7 0,9 1,1 1,3 1,5 1,7 1,9frequency (GHz)

dB

Sdd21

-22

-17

-12

0,3 0,8 1,3 1,8frequency (GHz)

dB

Sdd11 Sdd22

Figure 1-11 Gain and matching of the differential 300 MHz – 2 GHz QuBiC4G LNA

The chip has been taped out and measurements will follow soon. We have demonstrated that it is possible to design a wide band LNA in the 1 dB NF range with a flat gain and good input and output matching using a low-cost commercially available 0.25 µm Silicon technology. We hope to decrease still further this value as technologies with lower NFmin become available. LNA and filters in Silicon technology


This CNRS report describes the design of a low noise wide band differential amplifier using PHILIPS QUBIC4G BiCMOS SiGe Technology working in the band 0,1-1,8GHz. This circuit has been designed with specific mode conversion optimization. The LNA design and results are presented in the report " An integrated low noise wide band amplifier, in the band 0,1-1,8GHz using Philips technology QUBIC4G BiCMOS SiGe “ Vincent ARMENGAUD, Julien LINTIGNAT Bruno BARELAUD, Laurent BILLONNET, Bernard JARRY – XLIM – CNRS – “06 July 2006DS4_T1_July_2006_CNRS_Report pdf file” Cascode silicon LNA design principle The proposed amplifier is based on a differential cascode topology, combined with thermal noise canceling principle on the first stage in common emitter configuration. The LNA has been optimized in the band 100MHz-1,8GHz. It has been developed thanks to PHILIPS QUBIC4G Bi CMOS SiGe Library. Its complete electrical scheme is presented in Figure 1-12.

Figure 1-12 LNA complete electrical scheme

The layout proposed in Figure 1-13 is 930 µm wide by 880 µm high, for a total area of 0,8mm2.


Figure 1-13 PHILIPS QUBIC4G Bi CMOS SiGe Library. LNA layout

LNA simulation results The circuit has been simulated and optimized with four port simulation test bench using the mixed mode formalism. With the help of baluns, the linearity and the noise figure have been simulated. The power supply voltage source is set to 2.7 V. Differential mode : The input matching is greater than -7 dB all over the working frequency bandwidth, and the output matching is better than -10dB for any working frequency. Differential mode gain is about 18.5 dB for a frequency bandwidth of 400MHz and the “Gmax-3dB” cut of frequency is 1,8GHz (Figure 1-5)

Figure 1-14 LNA Differential mode gain


Mode conversion terms : The circuit has been designed so that the conversion terms are minimized for both common to differential and differential to common mode. Common mode : Common mode gain is at worse about -7dB, this means that the CMRR is about 25dB. Two port simulation with balun : Noise figure and linearity As seen in the previous section, mode conversions are highly rejected. It means that the differential mode noise figure and linearity can be directly evaluated by simulation with balun. The simulated noise figure is lower than 1.35dB all over the working frequency bandwidth. It is even better than 1.2dB up to 1.3GHz. Indeed the equivalent noise temperature is about 84K at 300MHz and about 107K at 1,7GHz (Figure 1-6).

Figure 1-15 LNA differential mode noise figure

The simulated -1dB compression point is reached for -21dBm input power at 0.5GHz and -17dBm at 1.8GHz. Moreover, the output referred IP3 is reached at 22,2dBm. With 2.7V DC voltage and 11,5mA current value the power consumption is 31,5mW. Conclusion In this report an original low noise wide band differential amplifier has been presented, it works in the band 0.1-1.8GHz with a gain of 18dB and a noise figure that is lower than 1.3dB up to 1.7GHz. Another design is actually analyzed, using a new BiCMOS PHILIPS technology and is expected to allow improvements on both linearity and noise figure. Low Noise Amplifiers ASTRON concentrated on the use of existing Integrated Circuit processes with a strong focus on III/V technologies for the implementation of Low Noise Amplifiers. Dual Feedback Low Noise Amplifier


Dual-loop negative feedback amplifiers have been studied since they are suitable for both wideband and low noise applications. Compared to the conventional inductive-degenerated low noise amplifiers, the dual-loop feedback amplifier offers well-defined input impedance and signal transfer function and potentially good noise performance simultaneously. The dual-loop power-to-power configuration is mostly used for applications that have a well-defined source and load impedance, since its input impedance depends on the load and the output impedance depends on the source. The dual-loop power-to-voltage and power-to-current configurations do not have these limitations and are therefore very suitable for active antenna applications. An effort has been made to implement the power-to-current topology in a low cost SiGe technology (0.35µm) with disappointing results partly due to the technology and partly due to limitations of the concept not dominant in the power-to-power approach. Therefore the power-to-power principle has been implemented in 0.2µm GaAs technology from OMMIC, partner in SKADS. A very good input impedance match combined with a good noise match has been achieved. Measurements of the realized device are in progress.

Figure 1-16 Schematic of the dual feedback LNA

Figure 1-17 Simulated performance of the dual feedback LNA

Figure 1-18 Microphotograph of the realized LNA


Differential Low Noise Amplifier Design In order to avoid the need for a balun (balanced-unbalanced) circuit between the antenna and the LNA, a differential LNA concept has been implemented in InP (NGC) and GaAs (OMMIC). The differential LNA can be connected directly to the differential antenna concepts like the Vivaldi antenna. For the intermitted impedance levels non-50 Ohm impedance can be selected in order to avoid further ‘matching’ circuitry losses. Characterization of these circuits is however very complicated. This will be described in more detail in the report of DS4T4, wide band integrated antennas.

Figure 1-19 Photograph of the InP 0.1µm differential LNA

CMOS LNA With the miniaturization of the ‘standard’ CMOS, higher cut-off frequencies and lower noise figures can be realized. A more or less standard LNA concept has been implemented in 0.18µm CMOS technology from UMC. The impedance and noise matching on the input requires an off-chip transmission line, limiting the frequency band width somewhat. The measured noise figure reaches the 0.5dB as can be seen from the plot below. Analog-Digital Converter Bit Number and Input Power Evaluation (GB – INAF) During the first year of activity, we found a methodology to calculate the ADC bit number for radio-astronomical applications and the ADC input power. To evaluate the number of necessary bits in an ADC system, the dynamic range of the input signal has to be analysed. Because of the RFI (Radio Frequency Interference), the radio astronomic signal raises in power: this increment has to be taken into account to avoid the converter saturation. Thus, the 2-3 bits that could be sufficient for the radio astronomic signal are not enough because of this problem. A measurement campaign has to be performed to evaluate the maximum dynamic range of the ADC input signal. To obtain a worst-case estimation of the RFI situation in Medicina, a spectrum analyser in max-hold configuration was connected to 2 log-periodic antennas, while they were moving to cover 360 deg at a height of 22 m.


Figure 1-20 Radio interferences in Medicina

Considering the radio interferences scenarios in Medicina, we need a 10-bits ADC (7 bits for the dynamic range and 3 bits to describe the radio astronomic signal). Considering AD9445 from Analog Devices, the calculated input power is – 53 dBm. Focus of ASTRON is on the objective (ASTRON) To define the A/D dynamic range requested to handle the RFIs environment and selection of the most suitable digitization position in the chain. This will be input to deliverable: “Sizing of the digital word at the different levels of the system chain (T0+18)”, with main focus on the required nr. of bits for digitization. A study on satellites present in the 500Mhz-2000Mhz was performed. In this frequency range GPS is present at 1176Mhz, 1220Mhz and 1575Mhz. The power level of the GPS satellites at earth surface is relatively low (-100dBm - -120dBm). Iridium at 1620Mhz is more powerful (-80dBm- -100dBm). Depending on the required instantaneous bandwidth and the required nr. of bits in the noise level, 4-6 bits are required to convert the Iridium signal without causing distortion. Two other satellite systems in the frequency range 500-2000Mhz are Glonass (Russian GPS) and Gallileo (European GPS, should become operational in 2008). RFI spectra of potential SKA sites are required to complete the study on the required nr. of bits. According to the RFI measurement protocol, in these measurements special attention is paid to Distance Measuring Equipment of aircrafts in the 1000-1400Mhz range. DME signals are pulsed signals, with a relatively high peak power level. If it will be required to handle these signals without distortion, the nr. of bits has to increase. Inventory of different receiver architectures, applicable for an environment with a low level of RFI was made. Inventory of advantages and disadvantages of different receiver architectures was made. A selection of a receiver architecture can only be made when the RFI environment of the SKA site is known, as well as the frequency range targeted. Undersampling techniques in radio astronomical applications (INAF) In the Medicina station laboratories we have performed some tests about undersampling techniques, to understand if these represent a useful approach for radioastronomical applications. The first results seem to be very promising, but it is highly important to carefully set the clock source and clock distribution to ADC: a low jitter clock is needed to obtain a high SNR. We planned some tests with different input signals: at first we used a monochromatic signal, then we used a radioastronomical signal acquired by BEST-1.


Figure 1-21 Undersampling block diagram

Figure 1-22 Measures

Test with monochromatic signals Two different input signals at 20 MHz and at 100 MHz were taken. They were sampled with two different clock sources at 80 MSPS:

1. Clock from medium-quality signal generator 2. Clock from PLL

In the first case, moving the input frequency from 20 MHz to 100 MHz, we have observed an increase of the system noise level of 10 dB.

Figure 1-23 Test with monochromatic signals: clock from medium-quality signal generator


In the second case (PLL source), when we moved the input frequency from 20 MHz to 100 MHz, we have observed the same level of system noise, but we also noticed an increase of phase noise around the carrier due to the PLL.

Figure 1-24 Test with monochromatic signals: clock from PLL

Test with a radioastronomical signal from the Northern Cross antenna (BEST-1) We have sampled a 8 MHz bandwidth cantered at 408 MHz from BEST-1 with a 80 MHz clock frequency. The result is given in the picture below. The noise level is –105dBm and a radio interference is evident, as in the spectrum analyser.

Figure 1-25 Test with a radioastronomical signal

If we decrease even more the clock sample (from 80 MSPS to 50 MSPS), we see a large growth of the noise level.


Figure 1-26 Test with a radioastronomical signal with strong undersampling

For obvious reasons, the clock has to be very stable (very low jitter): increase of the clock jitter increase of the power floor. This problem is very crucial for a high undersampling factor (fNYQUIST/fSAMPLE). In conclusion, undersampling in radioastronomical applications seems to be possible, but it is very important to take particular care of the clock source and the clock distribution to ADC: a low jitter clock is fundamental to achieve a high SNR. Synchronization distribution (INAF) We have realised and tested a prototype board to distribute the clock and sync signals. The board receives two input signals:

• PPS (Pulse Per Second) • Signal from H-Maser

PPS is a sync signal. This is buffered and distributed to the digital receiver board in LVDS or PECL format (it is possible to commute the output format using an on-board switch). With an H-Maser - a very stable signal - we generate a clock: the H-Maser frequency is multiplied by PLL and then it is transformed in LVDS or PECL output signal (commutations is possible using an on-board switch, as above).

Figure 1-27 Sync board


The LVDS output clock is shown in the picture below.

Figure 1-28 LVDS output clock

It is possible to raise the frequency up to 100 MHz. The clock jitter has a few pico-seconds rms. Now we are improving the jitter performances thanks to a new very low-jitter clock distributor. This new board is under test and we will provide results in two months. VIIP: a low-cost re-configurable Polyphase filter bank based on FPGA in a PCI board (INAF) In the Medicina laboratories we developed a Pci board named VIIP (Very Inexpensive Industrial Prototype) that allowed us to implement a Polyphase filter bank. The board carries high-speed, high-resolution analog to digital converters (105MSPS and 14 bit) and a 3 million gate Fpga with 600 I/O pins fully configurable. It contains a Pci interface to connect the board to a Pc with 32/64 bits, up to 66 MHz bus Pci. This board allows to acquire up to a 100 MHz real bandwidth or up to a 50 MHz + 50 MHz complex bandwidth and to decompose it in channels, depending on the datapath width. If the datapath is 8+8 bits wide (I+Q), the number of channels is 8k, if the datapath is 4+4 bits wide (I+Q), the number of channels is 16k, therefore a very high resolution is reached. The VIIP board has two inputs for analog signals and one input for the clock. It is composed by: two ADCs - which digitise the signals coming from analog inputs -, one FPGA - which implements a polyphase filter bank - and a bridge for VIIP bus Pci connection. The VIIP board can work in two different modes, depending on how the FPGA is programmed. It can receive two analog input signals from two different IF lines or it can receive I and Q components of a quadrature demodulated analog input signal. In this case a direct conversion is necessary before the VIIP board, while in the first case a DDC (Digital Down Converter) performing a digital quadrature demodulation (I and Q) is implemented on FPGA, before PFB. The polyphase filter bank has an out of band rejection ratio of 60 dB: in this case a strong interference can be easily isolated, nulling those channels which contain the interference. The costs are low and they are essentially relative to the Field Programmable Gate Array (FPGA), the core of the card, and also to the PCB. The VIIP board uses a Xilinx FPGA, from the Virtex-II family. In particular, the component used is the XC2V3000, composed by 3.000.000 gates, working up to 420MHz.


Figure 1-29 VIIP board

We have performed some tests and the resulting spectra are given in the pictures below. The first picture shows a 22GHz maser line – source: molecular cloud W3 OH – with 8k spectrum integrations. In this case we have programmed a DDC inside the FPGA. The poly-phase spectrum consists of 8K channels and the integrations are performed in the Pc. We can notice a border effect due to a DC modulation operated by the DDC.

Figure 1-30 Polyphase spectrum with 8k integrations

In the picture below we have the same plot as above, but the integrated spectra are 16k.


Figure 1-31 Polyphase spectrum with 16k integrations

The picture below illustrates the spectrum obtained with an on source–off source acquisition. The border effects are clearly attenuated. Near the W3 OH maser line a small signal seems to be present; it is to be ascertained with further investigations whether it is a sky source or a saturation effect of the ADCs.

Figure 1-32 Polyphase spectrum with a 8k on–off acquisition

List of deliverables


Table 4: DS4-T1 Deliverables

Task number

Deliverable No

Deliverable Name

Workpackage /SubTask No


Planned (in months)


Ds4-T1 DS4-T1.1 Establish benchmark LNA simulations to provide performance feedback for device process development for various semiconductor technologies.

UMAN, ASTRON

T0+12 12

Ds4-T1 DS4-T1.2 RF on wafer (RFOW) measurements on device wafers fabricated, extract scaleable equivalent circuit model.

UMAN T0+9 to T0+15

12

DS4-T1 DS4-T1.5 ADC Design rule established and recommended ADC architectures selected.

UMAN T0+1 to T0+12

DS4-T1 DS4-T1.3 Design, fabrication and testing of SiGe band pass filter using PIC Technology

OPAR T0+6 to T0+18

12

1.5.2 DS4-T2 Signal Control and digitisiation.

Table 5: DS4-T2 Participants efforts.

Participant number 5 1 9 Participant short name INAF ASTRON CSIRO Total Person-months 2.7 3.7 4.2 10.6 The SKAMP1 correlator is now operational and it will test operation of an 8-bit A/D converter, together with 4-bit coarse quantisation into the cross multiply-accumulators of the correlators. The RFI in the band that this is operating is quite benign. In the next stage of development the same scheme will be used in a high RFI environment. We are still awaiting data analysis of the SKAMP1 data. Work is well underway in the design of the SKAMP 2 correlator architecture. This correlator will use two stages of polyphase filters to analyse the data. Nominal specification for these filters is -60db stop band attenuation.


At Marsfield (Sydney), a 24MHz 24-input beamformer/ correlator has been installed on the two element interferometer with 10-bit A/D converters. The system includes a 24 channel down conversion system. The down converter first upconverts to 2.4 GHz. Shifting the LO for this mixer allows the 24 MHz receive band to be moved anywhere within a 1.7 to 0.7 GHz band. In the first instance this beamformer will be used with a modified THEA tile purchased from ASTRON. This system is used in a suburban environment and the intermodulation distortion on the THEA tile (from high level interference from out-of-band analogue television signal at 526 MHz) has proved excessive. This has necessitated the installation of bandpass filters after the first LNA on each element of the tile to eliminate the most severe interferers. Some residual intermodulation still exists and we will investigate the performance of the system when the THEA tile is mounted on the East antenna during August.


Table 6: Meetings attended

Date Title/subject of meeting /workshop

Location Number of Attendees

Website address

19 April 2006 DS4 T2 Kick-off Meeting Medicina 15 See wiki page 2. List of deliverables Table 7: DS4-T2 delliverables

Task number

Deliverable No

Deliverable Name



Planned (in months)


DS4-T2 1 Wide band high, dynamic range A/D blocks

9 9

DS4-T2 2 Digital Down Converters

9 9

DS4-T2 4 Low cost Poly-Phase filter banks

9 9

DS4-T2 5 Data distribution and synchronization

6 12

1.5.3 DS4-T3 RFI mitigation strategies Study Task

Table 8: DS4-T3 Participants efforts.

Participant number 25 4 1 5 6 9 Participant short name

UORL OPAR ASTRON INAF FG-IGN CSIRO

Total

Person-months3 12.5 5 5.7 0 20.5 3.8 48.4 AC contractors must include both the total estimated human effort (including permanent staff) and, in brackets, additional staff only. Activity summary of the first year 1) The first year of the Task was partly devoted to establishing an inventory of existing methods of RFI mitigation (first deliverable), including references to previous experiments that have proven their efficiency in this field. Since new methods which are presently still in the design or simulation phase will become available as SKADS progresses in time, this inventory should be considered a working document that will constantly be updated. This inventory is under ASTRON supervision, in coordination with the task leader. 2) ASTRON started work on the first deliverable (RFI methods inventory), a.o. overview, excision and spatial filtering. Due to the late start this deliverable was rescheduled to December this year. ASTRON also worked on the second deliverable (evaluation and influence of RFI mitigation on the data quality). In this context, a linearity-intermodulation study was conducted and verified experimentally with a LOFAR antenna (in progress). Also, a preliminary analysis was made on the number of required ADC bits for a typical SKA site environment. ASTRON also started work on the fourth deliverable (cost effectiveness and requirements) by conducting a study on signal processing


requirements for SKA (memo). In the context of investigating the impact of moving interferers on SKA (third deliverable) a study was conducted (conference paper) in which the use of NOAA weather satellites for aperture array calibration was investigated. The RFI mitigation part of this deliverable has not yet been started. 3) Other activities are related to demonstrations of RFI mitigation techniques (fifth deliverable). Although work on this should start at the beginning of year 3 according to the DoW, we considered this deliverable important enough to start working on it in the first year. OPAR (4) participant: - Implementation of real-time RFI detection methods involving blanking in the time and frequency domains with the RDH digital receiver on the decimetre wave Radio Telescope and the decametre wave array at the Nançay Radio Station. Observations of galaxies in frequency bands with radar emissions. ASTRON (1) participant: - elaboration of a test plan for EMBRACE, under discussion. See also point 2 above. INAF (5) participant: - Design of beam nulling techniques, and studies of the possibility to implement them in the BEST (DS6) demonstrator. Deterministic and adaptive beam nulling simulations have been performed in the context of BEST-1. - RFI cancellation has been obtained with the use of a reference antenna, at frequencies around 408 MHz. CSIRO (9) participant: - a prototype FPGA implementation of a real-time adaptive filter for RFI mitigation (designed to be used for pulsar observations) has been built. This unit has a 50 MHz bandwidth and a 2048 channel polyphase filter. - a second team has been investigating the cancellation of digital TV signals in the 50cm wavelength band at Parkes Observatory using dual "reference antenna" methods. The aim is RFI cancellation down to sensitivity levels that are radiometer noise limited. UORL (25) participant: - research on radio interferences detection, cancellation and estimation techniques using cyclostationary (hidden periodicity) properties of interference sources. Results were obtained on simulated and real data. - design of real-time detection and blanking in both time and frequency domains. 4) In the course of the DS4-T3 activities, participants have attended the following meetings: - SKADS kick-off meeting at the Château de Limelette (close to Bruxelles) on 17-18 November 2005 - Technical Meeting at Jodrell Bank Observatory, UK, on 15 - 16 March 2006, organized by the SKADS Project Engineer. From the signal conditioning and RFI mitigation points of view, we have had some useful discussion on the necessary number of bits in the ADC (Analogue to Digital Converters). The focus was on the minimum necessary number of bits to cope with radio frequency interferences, as those could dominate the choice of the necessary dynamic range and could have a large impact on costing issues. - Joint DS4-T2 and DS4-T3 kick-off meeting near the Medicina radio astronomy station, Italy, on 18-19 April 2006. Presentation of participant activities. The minutes of the meeting and the presentations are on the wiki page http://webmail.jb.man.ac.uk/skadswiki/Ds4T2kickoff


Continuation of the "required number of bits" discussion. A proposition on this issue is posted in the minutes. Participation of several persons (from OPAR, ASTRON, and INAF) involved in the DS4-T3 task in a number of EMBRACE meetings (DS5), at the international level or national level. It is important to keep contact with the DS5 team, in view of the RFI mitigation demonstrations that are planned with EMBRACE. Table 9: DS4-T3 Summary of meetings attended, DS4-T3

Date Title/subject of meeting /workshop Location Number of Attendees

Website address

17-18 Nov 2005

SKADS kick-off meeting at the Château de Limelette (close to Bruxelles)

15 - 16 March 2006

Technical Meeting Jodrell Bank Observatory, UK

18-19 April 06

DS4-T2 and T3 Kick off meeting Medicina, Italy 12 http://webmail.jb.man.ac.uk/skadswiki/Ds4T2kickoff

Identification of the problems encountered and corrective action taken The first deliverable was planned to be achieved at T0+12 months. Due to the late start of the related work, we think T0+18 months is reasonable as an achievement date. Table 10 DS4-T3 Milestones and deliverables defined in the contract that have been achieved during the reporting period

Task number

Deliverable No



Planned (in months)


DS4-T3 1 RFI mitigation Inventory

12 18(Dec06)

2 Influence on data quality

0 Y3Q4

3 Impact of moving interference sources

12 Y2Q4

4 Cost effectiveness and technical requirements for the selected SKA site

12 Y3Q4

5 Report on demonstration of RFI mitigation techniques

0 Y4Q4

6 Report on RFI mitigation strategies for the SKA concepts

12 Y4Q4

For the complete deliverable names, please consult http://webmail.jb.man.ac.uk/skadswiki/Ds4T3


1.5.4 DS4-T4 Wide band Integrated antennas

Table 11 DS4-T4 person man-months

Participant number 1 5 8 9 11 15 Participant short name

ASTRON INAF-IRA

UOXF CSIRO NRC UCAM Total

Person-months 12.6 6 15 6 0.25 33.85 Table 12: DS4-T4 milestones


Deliverable/Milestone Name

Workpackage/Subtask No

Lead Contractor(s)

Planned (in months)


1 Kick-off All ASTRON 1 7 Table 13: DS4-T4 meetings



Website address

19-1-2006 and 20-1-2006

Kick-off meeting ASTRON, Dwingeloo

14 ~/skadswiki/IntegratedAntennasKickoffMeeting

25-1-2006

Work session OMMIC, Paris

5 ~/skadswiki/OmmicMeeting1

3-3-2006

UK Kick-off Manchester 6 ~/skadswiki/AntennasKickoffMeeting

16-5-2006

Antenna design Yebes 6 ~/skadswiki/YebesMeeting


Progress Report ASTRON The work on all the objectives of this task has been initiated and first results will be reported in following sections. Antenna Modeling The work on antenna modeling concentrated on the writing of a computing time efficient code that will be able to simulate finite by finite antenna arrays with sizes up to a couple of tiles (several hundreds of antenna elements). The method adopted to realize this is “Characteristic Basis Functions”, making use of symmetry and repetition of sub blocks. A 144 dual polarized Vivaldi array has been analyzed using solely translation symmetry. A significant reduction of the number of unknowns has been achieved and the complete structure could be analyzed accurately in 7 minutes computing time per frequency.

Figure 1-33 Vivaldi Array simulation

Active Antenna design A small 3-element Vivaldi antenna array has been build with Low Noise Amplifier integrated on them, avoiding inter stage matching, connector losses and even the balanced-unbalanced by using a differential LNA. For the differential LNA a custom Integrated Circuit design has been used as well as an off-the-shelf IC, both processed with OMMIC technology. Results are promising however more work is required to fully understand in particular the issues with characterization. Also a larger active antenna will be build with more elements. Characterization

Figure 1-34 Test load and differential LNA

Characterization of active wide band antennas requires a new approach for the Low Noise Amplifier, the antenna and the complete structure. Figure 1-5 shows the specially developed load for hot-cold noise tests for a differential LNA. For the complete active antenna, the sky is used as cold source and


RF absorbing material is used as hot source, both when installed in the ‘retired’ Dwingeloo radio telescope. The telescope serves as a shield for RF interference. Good results have been achieved. RF-Photonic Interface No significant progress in Y1 due to personnel hiring issues, which are resolved recently. Low Cost solutions for the Radiator Various low cost antenna materials have been investigated replacing the expensive printed circuit boards used for the antenna. This includes full metal antennas (avoiding dielectric), antennas on polyester sheets, Silver painted antennas (avoiding etch processing) and antennas on paper. Two proto-types have been built. A full tile, 112 antennas, made out of Aluminum sheets, has been produced and tested. And antennas on polyester foils have been produced.

Figure 1-35 Prototype array comprised of 112 Aluminium Vivaldi Elements

Progress Report on University of Manchester The UoM DS4-T4 activities relate to array geometry, element design and integration of the LNA. In the UK, these link with the tasks being carried out at Universities of Cambridge and Oxford on antenna elements , and with the EU particularly with work at ASTRON and by the Spanish team. The dedicated funded staff at UoM is to comprise two Research Assistants , one concentrating in the first instance on array geometry studies , mutual coupling and related aspects, the other on detailed element design and matching to the LNA. Clearly these two need to work closely together. Academic leadership is provided by Prof A.K.Brown with detailed modelling expertise from Dr F Costen. Unfortunately the slow release of funds has delayed recruitment of these two RA posts. However the posts have now been offered and accepted by good candidates and, subject to necessary UK work permits, both posts should be full time from August 2006. This has necessarily slowed our progress in the technical development work. Nonetheless a start has been made.


Initial Activities Activities undertaken in this period include:

1. Development of outline for detailed specification for 2-PAD hardware 2. Contribution to 2-PAD system design concept (DS4-T6) 3. Initial array geometry studies 4. Element study review and initial simulations

Key to the successful development of these tasks has been the liaison within the SKADS team . The initial specification activity (task 1 above) was initiated followed the DS4-T4 kickoff meeting in Dwingloo. The idea was to produce a specification for 2-PAD to be frozen before hardware build but which would highlight the detailed performance parameters required for a phased array solution. This is, at least in part, to stimulate discussion with the SKA science community whereby the identified science goals can be met whilst exploiting the unique advantages of a phased array solution. Significant discussion and collaboration has taken place in the development of the specification template. This includes key meetings of the DS4 team leader kick-off (held in Manchester) the UK antenna team frst technical meeting (also held in Manchester) and visits to partners in Spain and France. The result has been the completion of a specification template as a “living” document posted on the UK-SKADS Wiki site. This includes a clear text description of each performance parameter for the non-phased array specialist. The intention is to provoke discussion and resolution of issues not just by the SKA engineering community but by those involved in the science objectives, resulting in a clear specification for 2-PAD. Technical Development The technical development tasks at Manchester on DS4-T4 commence with detailed array geometry and element studies. Turning first to the array geometry studies. It is recognised that the most efficient geometry from a simple array model is not normally a square grid. Often either hexagonal grid or concentric ring arrays offer benefit in the number of elements needed for a given scan angle performance. Statistical thinning is a further possibility where peak sidelobe level in a sparse array is controlled at the expense of mean sidelobes. When RF beamforming is used benefits of non-rectangular grid geometries tend to be outweighed by complexity of the beamformer. However one of the benefits of receive only digital beamforming is the ability to locate elements anywhere in the aperture plane with apparently no real cost in complexity. This of course needs detailed performance trade-offs to have any certainty. Options have been identified and a start has been made in these trade off studies. One area of known difficulty is the control of the element pattern particularly in the presence of mutual coupling. This relates to basic element size, separation and type, with typical “dipole-like” elements generally having radiation patterns which limit the scan angle to about 45 degree (for of the order 2 dB maximum loss in scan angle array gain due to element pattern fall-off). Regarding the coupling, this has the effect of introducing a non linear variation (with respect to frequency) in the voltages received from a source at a given angle. One method to reduce the coupling variation is to maximise the element separation; unfortunately this is limited at the top frequencies by the need to limit grating lobe production, so that at the bottom end of the frequency band the elements are extremely close electrically and hence have high coupling . Two techniques have been identified to help deal with the limitations to performance caused by mutual coupling,


In the first, the array geometry is used such that not all the elements has a full bandwidth available to it. The rationale for this is to note that if , say , a element separation criterion is set to avoid grateing lobes at the top frequency,then to retain the same sampling criteria across the frequency range means only one in three elements need be active at the low frequency. A similar argument can be used at mid-range frequencies. Hence all elements are active at the highest frequency , but a reduced set is used at lower frequencies. This helps in a number of ways, but in particular the mutual coupling effect is reduced at lower frequencies. Obviously, the allowable size of any element design is driven by the array geometry required, as well as the element radiation pattern (scan angle requirements). These studies are just commencing, but early results indicate that the “band interleaving” approach to the antenna design could well prove a useful approach and may give us useful benefits in both complexity of the digital beam former and in controlling the mutual coupling without loss of efficiency With respect to the elements themselves, progress has been limited due to resource issues noted above. An initial design of a multi-choke exponential slot antenna is being developed. This is a derivative of the standard Vivaldi design which it is hoped will give improved VSWR performance particularly at the higher frequencies. In parallel with this there is some work underway on the anti-podal slot element (so called “rabbit ears”). Currently there are difficulties in making this antenna compact enough for the array environment. Nonetheless this is a promising approach in input VSWR terms . We intend to progress the design of this and other candidates as soon as the RAs are actually in post. The framework for FG-IGN During the first 4 years scheduled for SKADS, engineers and astronomers from FG-IGN will focus their efforts on DS4-T4 (Technical foundations and enabling technologies). This work package is related to the development of wide-band integrated antennas for phased arrays. The development of the planar array and the low noise amplifier to be integrated with each antenna element belonging to the array will be the main tasks of this package. Most of the studies in relation to DS4-T4 will take place at Centro Astronómico de Yebes (CAY), a facility of Observatorio Astronómico Nacional (OAN) operated by FG-IGN. During the first year, developments in radiating elements have been the main task of the project and first results have been obtained. LNAs development is starting and will be soon an important part of the researching activities. Finally, test ranges for the measurement of antenna radiation patterns have been searched and selected. Works and developments during the first year During the first 12 months of works, engineers at CAY have been afforded the following tasks:

• Preliminary studies on radiating elements including the exploration of the potential antenna elements for SKA.

• Preliminary studies on wide band LNAs. • First simulations and measurements of the most suitable antenna element candidates. • Search for test ranges to measure the radiation pattern at the lower end of the SKA frequency

band (<0.3 GHz). 2005-2006 July-Sep Oct-Dec Jan-Mar Apr-June Preliminary studies on antenna X X Preliminary studies on LNA X X First simulations on antenna X X Search for test range X X X


The First year Schedule Preliminary studies on radiating elements This task was scheduled for the first six months of the project. The study was focused to the search of a radiating element with the following specifications:

• ultrawide-band (UWB) antenna (0.2-1.4 GHz). • easy LNA integration capabilities. • array integration capabilities. • low cost, low weight and compactness.

The works were focused to planar printed antenna, starting with a survey on current technologies on this field. Antennas based on Vivaldi, Spiral, Bow Tie or dipole were simulated using commercial state of the art software such as HFSS from ANSOFT and CST. Prototypes have been built and the reflection coefficient and the radiation patterns were measured.

The main conclusions of this study are:

• Dipole and Vivaldi like antennas can achieve SKA specifications. • 0.3 to 1.0 GHz is a realistic frequency band to be achieved with this type of antennas.

Preliminary LNA studies Our work in this task has been focused to discrete type LNA to be integrated with hybrid technology to the radiating element. As a first step, a survey of the state of the art has been achieved and the best low noise devices have been selected. The experience of CAY with low noise cooled amplifiers has been applied to this task. Commercial and home made software is available for the development of the amplifier and matching networks and also the measurement instrumentation. One important part of the work has been the adaptation of these tools to the frequency band and technology that we are using in SKADS. First antenna simulations Three guidelines have been covered within this task:

• Vivaldi like antennas. • Wide band dipole antennas. • Printed circuits for a balanced feed.

Vivaldi antennas have been broadly studied and developed in this band. Many different kinds: antipodal, planar, with different transitions, with and without baluns, and with a very huge bench of modifications and optimizations being applied to its arms. An interesting improvement in Vivaldi apertures was done concerning to the radiation pattern stability. By means of introducing some extra-edges on the arms, an improvement of 6 to 8 dB in the cross-polar component of classical Vivaldi’s was found, and the radiation pattern was kept stable for a longer portion of the impedance band, so as more flat in comparison to a classical Vivaldi antenna. A model was built and tested successfully in a 7:1 band starting in 1.5 GHz. Wide Band dipoles are the other line of study for this first simulations. They are not able to show the same UWB performance than the previous one (at least initially), but they assure good scalability, so allowing us to simulate models on upper frequencies and keeping the same good capabilities at lower frequencies for realizable models, also in radiation pattern. These Wide Band dipoles are mainly thick


dipoles, which helped by corrugations, parasitic elements and smooth shapes in some cases, are capable of increasing the inherent narrow band of a classical dipole. Several models are being developed and already one has been built, with a band of 2.6:1, which in principle will be already enough to fully cover the working band we have assigned to. Finally, later simulations are pointing to fractal solutions composed of 2 or 3 Wide Band Dipoles. The feeding point of all these antennas is a key feature for a right performance, especially in the UWB case. The design of transmission line technology transitions and impedance transformers and also the right location of the lines have been carefully considered. Different balance mechanisms, often called baluns, were also developed, in order to be used for feeding some of the models. Furthermore, these baluns will allow us to use non-differential amplifiers at the beginning of the front-end. For instance, a model based on a CPW to CPS transition was built, working from 0.1 up to 3 GHz with a transmission coefficient better than 1.5 dB. This balun was used in some of the radiating elements simulated and tested.

Figure 1-36 Balun

Figure 1-37 Vivaldi Coplanar antenna


Figure 1-38 Simulations of Vivaldi coplanar antenna

Figure 1-39: Dipole antenna Antenna test range One of the key features on the development of the radiating element and array is the antenna test range. The frequency band, well below 1 GHz, is a serious drawback that can be solved with scale models. However this is not suitable for active antennas were the active element is integrated and plays an important role. We have made an effort in searching current facilities for the radiation pattern measurement in this frequency band, and have found a nearby outdoor ground reflection test range which will be available for our measurements. The antenna test range covers the frequency band from 80 MHz to 6 GHz. The distance between antenna transmitter and receiver can be chosen among 61, 117.5 and 347 meters allowing the test of antenna elements and arrays 2 x 2 square meters in the whole band.


Figure 1-40 Simulated and measured results of the CMOS LNA


1.5.5 DS4-T5 Beam Forming Participants in DS4-T5 Participant number

8 1 2 4 5 26 30


OXF-DB

ASTRON UMAN OPAR INAF-IRA

CNRS OMMIC Total

Person-months 0 1.4 8 9.4 Analog beamformer in Silicon The OPAR contribution in DS4-T5 concerns mainly the design of a low cost analogue beamformer in Silicon. Beamforming can require an analogue first stage that is done by a RF integrated circuit that can be either in GaAs or in a Silicon based technology. The advantages of Silicon technologies are that they are low cost, allow a high degree of integration and ease the design of the digital part necessary for control of the analogue functionalities. To design the prototype of a beamformer chip we chose the QuBiC4G 0.25 µm SiGe technology from Philips Semiconductors. This technology is a good trade-off between price and performance. The first prototype chip combines the signals from 4 antennas to form 2 independent beams at the output. A single ended configuration is used both at the input and output. The phase and gain of each input signal coming from a single antenna can be controlled independently for each beam. 3 bits phase shifters are used to achieve a 360° phase variation with 45° step and gain can be changed with 0.6 dB step on a 3 dB range with a 3 bits control as well. A full digital serial interface is built on the chip. Different parts of the circuit can be put ON or OFF and the different phase and gain states are controlled using this interface.

Figure 1-41 Layout of the 4 channels – 2 beams first prototype beamformer chip


Figure 1-42 Simulated phase and gain 8 states

Digital beamformer for the all-digital aperture array Progress this period The digital beamforming task is primarily intended to feed in to the design of the all-digital aperture array demonstrator, 2-PAD, the construction of which is in DS4-T6. Activity in this period has concentrated on producing an overall system architecture for 2-PAD, of which the beam forming is an integral part. The intention of 2-PAD is to demonstrate an aperture array concept in which the signals from each antenna element are digitised directly, and all subsequent processing, including frequency-space filtering and spatial processing (ie beam forming) is done in digital hardware. During this period, academic staff from Oxford and Manchester have been investigating concept designs for 2-PAD which will allow detailed design to progress in year 2. After detailed discussions with suppliers and users of various kinds of digital signal processing hardware (including processors, FPGAs and DSP chips), we have concluded that multi-core processors provide the most likely route to providing the density of processing and inter-element connectivity required. The IBM/Sony/Toshiba Cell processor is an example of such a device, and although no currently available devicemeets the specification required for SKA, the roadmaps of the device developers show that the required performance should be available on the timescale of the SKA construction. We are therefore proceeding with an architectural design for 2-PAD that will be able to be upgraded to the full SKA performance as the hardware improves over the next decade. Figure 1-43 shows an outline block diagram of the processing scheme that is currently proposed. The architechture has been design to allow the maximum flexibility in applying corrections to the individual antenna element signals in order to improve the dynamic range of the synthesised beams. It is very likely that the antenna elements will exhibit significant changes in polarization, amplitude and phase response over the large angular and frequency range which they have to cover. It is therefore important to be able to apply corrections to the signals at various levels in the beam-froming process.


For example, at the top of Figure 1-43 the nominally orthogonal polarizations from one antenna element are divided into narrow frequency channels in the same processing device. Here they can be combined to form truly orthogonal polarizations, calibrating out even rapidly varying cross-polarization as a function of frequency. Similarly, adjacent antenna elements can be corrected for varying mutual cross-coupling, improving the spatial dynamic range of the beams. These kind of corrections will be essential to achieve the required dynamic range for the system performance.

Figure 1-43 Outline block diagram of 2-PAD „Tile Processor“, including beam-forming.

Since one of the aims of 2-PAD is to provide the most flexible possible beam-forming system, with multiple fields of view across the whole sky, and also with upgradeable performance as processing capabilities increase, we have been considering beam-forming by Fast Fourier Transform (FFT) rather than direct beam forming. The advantage is that while direct beamforming on N elements requires order N operations per beam, FFT beamforming forms all N possible beams for only order NlogN operations. This is advantageous if you wish to form most of the possible beams. Our outline design takes 16 x 16 ‚tiles’ of elements and forms all 256 beams, covering all of the accessible sky. Subsequent processing takes these tile beams and forms ‚station’ beams from them. In the 2-PAD outline design all the digital processing for a station is in the same physical enclosure (see DS4T6 report), so in principle all interconnects between different tile in a station are possible. The system also allow for flexibility of data decimation. Even if it were possible to generate all the station beams simultaneously, the problem of transporting all the beams back to the central correlator is many orders of magnitude too difficult with current or foreseen technology. A choice must therefore be made at the station as to what data to keep and what to discard. With the proposed architecture a trade-off can be made between number of beams and bandwidth, keeping the total output bit-rate constant. It is also possible to trade word-width against other parameters, eg some observations requiring high dynamic range could use 8 or 12 bits per word, wheras observations could cut down to as low as 1 bit, sacrificing some sensitivity and accuracy for maximum number of beams. Photonic Beamforming

210

Polyphase

XX 210 8-bit

Prese

210

Polyphase

XX 210 8-bit

Prese210 spectral channels 0

Horiz. Vert. Polarisation

… …102 0 102

Linear Matrix Mult. to ‘correct’ El t

Inter-element scaling (matrix mults)

0 ….. 4-bit 25

16 x 16 element, 2-D FFT (1 of 210) Horiz. pol

0 ….. Inter-element scaling (matrix mults)

0 ….. 255

16 x 16 element, 2-D FFT (1 of 210) Vert. pol

0 …..

256 8 FOV selector (1 of 210)

FOV…..

255 25

1 pair of 256

256 8 FOV selector (1 of 210)

255 …..

Linear Matrix Mult. to ‘correct’ Fi ld f Vi

210/m 1 Data multiplexer (1 of 8)

8-bit 7 0 7

….. 255 ….. 210/m 1 Data multiplexer (1 of 8)

Freq. Split. n

2-D FFT, m


Within the DS4-T5 task ASTRON works on the study and development of photonic beamforming technology. In this work ASTRON will employ a photonic integrated circuit (PIC) based beamformer that provides a broadband, ns range, true time delay with the use of (integrated) optical ring resonators [1]. These ring resonators offer a continuously tunable effective delay that is determined by the group delay of the optical delay element (ring resonator). The delay can be controlled by tuning the coupling coefficients between the waveguide and the ring resonator, and the round-trip phase shifts of the ring resonator. Two main goals can be distinguished in this ASTRON task. The first goal is to develop and study a tile beamformer system based with the PIC beamformer component. Next, the photonic beamfomer will be applied in a tile demonstrator, which is the second goal. In the reporting period the work was started up with the specification of the requirements for the photonic beamformer. Since the photonic beamformer is to be demonstrated in an EMBRACE tile, the specification is for a large part based on the EMBRACE specification. The signal transport through the beamformer chip is done with the use of optical analogue links. For the development of these links a low cost, high performance optical analogue link study has been started, which provided an initial link design. In the coming time this design will be further elaborated. The first photonic beamformer chip samples will become available in the autumn of 2006. These chips will be tested and investigated in a photonic phased array lab set-up whose development has started in the reporting period. In the coming period this lab set-up work will be continued. [1] L. Zhuang, C. G. H. Roeloffzen, W. van Etten, “Continuously tunable optical delay line,” Proc. of the 12th IEEE/CVT Symp. in the Benelux, Enschede, The Netherlands, November 2005. DS4-T5 List of deliverables Table 14: DS4-T5 Deliverables

No deliverables are due in Y1. Table 15: Meetings attended

Date Title/subject of meeting /workshop Location Number of attendees

Website address

None in this period

1.5.6 DS4-T6 2-PAD Construction and Tests Participants in this task: Participant number 2 8 15 5 1 Participant short name UMAN OXF UCAM IRA ASTRON Total Person-months 0 The workpackages and deliverables described in the Description of Work for this Task are not planned to be completed until 2-4 years into the SKADS programme. The work was anticipated to be the bringing together of the developments within DS-T1 to T5 and manufacturing a working all-digital tile. This is a strict ‘bottom up’ approach. As has been reported in many of the Tasks within SKADS there has been significant delays due to the late start of work due to funding availability, both EC and National, and the consequent late starting of recruitment programmes. This period the delay has been taken as opportunity to consider in some detail the overall system design necessary for an all digital Aperture Array suitable for the SKA. This is to some extent an extension of this Task – however, this is the most appropriate place to report on this work. The work has been carried out by academic staff at the universities of Manchester, Oxford and Cambridge and the Project Engineer. The Technical Meeting reported on below was a key meeting in assisting the thinking behind the system design work.


The system design has taken a top down methodology, by first considering the overall design of the SKA. Hence, how an affordable and scientifically valuable aperture array would relate to the other collector technologies at frequencies above and below the target frequencies of the aperture array. This results in the frequency range and specification for the mid-range aperture array being designed in SKADS. Clearly, the aperture array will need to built as ‘stations’ in an SKA system. These stations are anticipated (but will need to be shown in DS3) to have a collecting area equivalent to a 50-100m diameter dish. By considering how an aperture array of this size could be constructed, the technical requirements of the demonstration 2-PAD all digital tile can be determined; knowing that it can be scaled up to a full SKA station. By taking these considerations into account guidance for the array components: antenna element, semiconductors, beamforming etc can be determined, plus unexpected requirements such as the need for very low cost, short range analogue links. SKA overall design It has been shown that an SKA using mid-frequency aperture arrays could be built using at least three different collector technologies:

• Sparse aperture arrays at low frequencies up to ~300MHz. This work is being done in LOFAR and MWA.

• The mid range frequencies from ~300MHz to ~1.0GHz are best served with close packed aperture arrays – the technical development in SKADS.

• The higher frequencies >1.0 GHz need to be realized using ~6m dish technologies. This concept has been embodied in the SKADS ‘Benchmark’ design and approved by the SKADS Board on 30 June 2006. The concept requires that the aperture array development will satisfy the SKA performance and cost requirements for an imaging radio telescope. This has become the challenge for SKADS technical deliverables. Frequency Range of 2-PAD The cost of an aperture array is critically dependant on the top frequency planned for the array. This is due to the size of the receiving elements scaling linearly with wavelength, hence since this as two dimensional structure, the cost is at least a function ftop2. The top frequency is still being actively considered, and is major deliverable from the scientific simulations in DS2. However, the engineering teams in DS4 are presently working with 1.0 GHz as the highest frequency, thus halving the system cost over using 1.4 GHz. Implementing a Station sized Aperture Array For the SKA to be effective it must have superb performance in terms of dynamic range and polarization purity; as well as many other parameters which will be specified as part of DS3. To achieve this quality it is important that the array of elements does not have any discontinuities over the whole station. This in turn means that it is not straightforward to consider building the array out of individual, identifiable tiles. Further, the digital processing must be as isolated as possible from the antenna array in order to minimize self induced RFI. Also, for maintainability, reliability and upgradeability the digital signal processing is ideally housed in screened, air conditioned rooms in conventional 42U high 19” racks. Consequently, the connection between the elements and the analogue to digital converters will need to use analogue signal transport, a development which will undertaken as part of this Task. A possible overall system design for the station level aperture array is shown below. It is constructed under one overall cover, with the antenna elements elevated for maintenance purposes. The digital processing is divided into four areas to keep the analogue links short enough (~20m) such that screened twisted pair can be used as the low cost signal connection. The digital processing is in screened rooms and cooled; intermediate links between the rooms use digital fibre optic links for data capacity and essentially no RFI. It should be stressed that this is the first of what is expected to be an evolving concept over the next 12-18 months.


Desert

Station Proc. Local P.

FOV processing+ ¼ tile processing10m x 5m

FOV processing+ ¼ tile processing10m x 5m x 2.5m

Cooling systemUsing heat transfer ground

Optical fibredigital links

Tile processingfor ¼ of array5m x 5m x 2.5m

Array supportsproviding ~1.6m headroom

Inflation pumpEntrance

Element array50m x 50m

Short range analogue links from elements to local processing

Array physical support grid

Inflatable Raydome

Desert

Station Proc. Local P.


FOV processing+ ¼ tile processing10m x 5m x 2.5m

Cooling systemUsing heat transfer ground


Tile processingfor ¼ of array5m x 5m x 2.5m

Array supportsproviding ~1.6m headroom

Inflation pumpEntrance


Short range analogue links from elements to local processing

Array physical support grid

Inflatable Raydome

Figure 1-44: Station Aperture Array - Side view

LocalProc.

LocalProc.

StationProcessing

LocalProc.

Matrix of supports~2m spacing (625)

Inflatable Ray dome

Entrance

Inflationpump


Tile processingfor ¼ of array5m x 5m


Wide area fibre link to

Correlator


Short range analogue linksfrom elementsto local proc(only ¼ shown)

StationStationLayoutLayout(looking up)(looking up)

LocalProc.

LocalProc.

StationProcessing

LocalProc.

Matrix of supports~2m spacing (625)

Inflatable Ray dome

Entrance

Inflationpump


Tile processingfor ¼ of array5m x 5m


Wide area fibre link to

Correlator


Short range analogue linksfrom elementsto local proc(only ¼ shown)

StationStationLayoutLayout(looking up)(looking up)

Figure 1-45: Station Aperture Array - Plan view

Analogue Links The cost of the analogue links is critical to the success of this digital tile station design. Consequently, initial work has been undertaken to determine the most cost effective approach. Currently, the most likely contender is screened twisted pair cable. This is expected to be the next de-facto standard for high speed local area networks and hence will be very cheap. Also, twisted pair copper has the benefit of being able to line-power the LNA and line driver components at the element, thus avoiding


additional cabling. The key is to ensure that the attenuation at the highest frequency and coupling between the cables is not excessive. Initial tests are very promising as is illustrated in the frequency-attenuation characteristics of a CAT-7 specified cable shows below:

Figure 1-46: Screened twisted pair performance

Conclusion While there has been a significantly different approach taken to that described in the Description of Work, the teams working on 2-PAD have greater confidence in achieving deliverables that can be directly translated into a viable SKA design. The period waiting for funding has therefore been used effectively and given the direction to guide the engineers throughout the rest of DS4, as they become available.


Date Title/subject

of meeting /workshop


Website address

15-16 March 2006

Technical Meeting

Jodrell Bank

16 http://webmail.jb.man.ac.uk/skadswiki/TechnicalMeeting

List of deliverables None due in Y1 reporting period

Abbreviations CDC: Control and Downconverter COTS: Commercial Of The Shelf DS: Design Study EMBRACE: Electronic Multi - Beam Radio Astronomy Concept LCU: Local Control Unit LOFAR: LOw Frequency ARray MAC: Monitoring And Control SKADS: Square Kilometer Array Design Study VLBI Very Large Baseline Interferometry WP: Work Package


1.6 DS 5 EMBRACE DS5 – EMBRACE represents the main focus the SKADS proposal, with a major deliverable due at the end of the studies, in four years time. It represents the major European concept put forward to the SKA, for further considerations by the International SKA Steering Committee (ISSC). As expected, it has significant European dimension to it, where the major partners include, ASTRON, OPAR, INAF and MPiFR, involved in the design and development of this demonstrator. Other European partners are also involved in the engineering and scientific testing of this demonstrator. Within the first reporting period we have made significant progress both in the design of this demonstrator. The entire project is identified, first in terms of Tasks. These tasks are as follows, together with the Institute leading it. Task 1: Design of Embrace (ASTRON) Task 2: Development of Embrace (ASTRON) Task 3 : Test and Evaluation (OPAR) Each of the Tasks is then further sub-divided in terms of the Work Packages (WP) and a WP Leader is assigned to it from the four major participants identified above. Each of these WPs is then further divided into smaller project as required. The reporting for this Design Study is very detailed, which includes the WP Leader reporting on each of the smaller projects, within the Work Package. These are then collated by the Design Study Task Leader. This report contains detailed work carried out at the DS 5 - Task level.

1.6.1 DS5-T1 EMBRACE Design

Participant number

1 4 5 7 9 12 30


Astron OPAR INAF-IRA

MPiFR CSIRO NRF OMMIC Total

Person-months 104.6 16 3.6 8.0 (2.0)

7.0 0.5 139.7

Table 16: List of participant, their short name and the man - month spent during this reporting period.

During this reporting period, within EMBRACE we have made significant progress, between our European partners and have identified the sub systems within the Embrace design Task (DS5-T1). The Embrace Design Task consists of seven (7) sub – systems work packages. They are:

1. Systems

2. Front End

3. Signal Transport

4. Receiver

5. Digital processing

6. Control

7. Mechanical


As the work package (WP 6) on Control relates predominantly to Digital Processing (WP 5), they are reported together. Each of the sub – system work packages are further divided into smaller tasks as shown in Figure 1-47. The reporting division has been made at this level.

Figure 1-47: The work packages for DS5-T1

EMBRACE sub-system tasks are divided between the European partners, so the international flavour of the project is inherent. The main partners in this task are the OPAR, INAF and MPiFR, as well as ASTRON. The reporting is presented at each sub-system level so that the individual contribution of each of the institution is easily assessed.


Systems : The systems work package (WP1) with participation of ASTRON and OPAR keeps an overview of the technical content of the DS5 project. Architecture/design: An architecture document has been written with a requirements breakdown for the 1-tile prototype. This document will be updated along with the testing program for the single tile prototype to get a product specification of the tile. The overall EMBRACE system architecture is shown in Figure 1-48. Note that the 1-tile prototype has been designed to specifically test the Front End/Antenna as part of the design process and besides a Tile Mechanics optimized for testing the Front End/Antenna, none of the other system parts are used in the 1-tile prototype.

Figure 1-48: EMBRACE system architecture

In parallel, work is ongoing on an architecture document for the 10-tile prototype. During the coming 18 months, the product specification describing the one tile prototype will be finalized and the architecture document and product specifications of the 10-tile prototype will be written. Interface control: Most interfaces in the EMBRACE system are the same as in the LOFAR system with minor adaptations. The adaptations have been identified and documented. As the concept of an antenna tile is new in EMBRACE, the interface between the control system MAC/LCU and the antenna tile has been investigated and documented. Small updates are expected as the design of the 10-tile prototype is ongoing. Also the interface towards the Westerbork and Nançay correlators is new for EMBRACE and under investigation. One solution is an analogue interface in both Westerbork and Nançay. Another option is the use of the VLBI Mark 5B interface. In parallel there are activities in DS5-T3 on the definition of scientific experiments and in close cooperation with these activities, the interfaces required will be defined and specified during the next 18 months. QA Several activities have been performed from a Quality Assurance point of view.


To ease the communication between different partners a secure document server has been setup locally at Astron and access has been granted to all partners in the development activities. The document server is used to exchange working documents and source code for the different software/firmware development activities. By using a CVS based document server, revisions are tracked automatically and the latest version of each document is always available for the other designers. A risk analysis has been performed for the DS5 project. The main development risk at the beginning of the project was the beamformer chip which is being designed by Astron in DS5-T1 WP2. As a result, there is a close cooperation with OPAR where a similar beamformer chip is under development in an alternative process as part of DS4. OMMIC is also developing a beamformer chip with a lower level of integration but with significantly lower power consumption. The risks in the project are tracked continuously and if changes occur, these are reported in the regular project progress meetings. The Quality plan that will be used in EMBRACE will be based on the Quality plan on SKADS’ level, however, this document is not yet available at the time of writing of this progress report.


Front End (ASTRON): Within the front-end work package a working antenna tile should be delivered. The antenna tile consists of the antenna, low-noise amplifiers, phase shifters and combining networks. All the components are appraised for good performance and acceptable cost. Especially the latter topic will often be mentioned in this section. This section will mainly deal with the first prototype, which was not built to be compliant with all specifications yet. Instead it was built to verify the design tools, design strategies and our understanding of phased array systems. In other words the main goal of the first prototype is verifying predictability of our design tools and methodologies. Array: Several array simulations have been performed to determine element pitch, sidelobe levels, etc. This all leads to the current constraints for the antenna and tile dimensions. One specific topic which was addressed is the instantaneous bandwidth. Since the beam steering of the phased array is mainly performed using phase-shifters, the squint will limit the instantaneous bandwidth. To overcome this problem, true time delay (TTD) has been used. TTD however, tends to be bulky, lossy, costly and very difficult to integrate. The solution used for the first prototype of EMBRACE is to have a hybrid solution between phase-shift and TTD. This compromise means having several phase shifters and a few TTD-lines. To verify the compromise, the first prototype is deliberately over designed so it should have almost four times the instantaneous bandwidth needed for EMBRACE. Antennas: A linearly polarized bilateral Vivaldi element was chosen for the first iteration, as shown in Figure 1-49. Vivaldi elements are easily implemented in both linear and dual polarized arrays and can exhibit broad bandwidths on the order of 5:1. The performance of bilateral configuration is well known and presents low technical risk for the first iteration tile. The antenna is analysed in an infinite array environment. It was designed using PB-FDTD which is periodic boundary finite time domain simulator. The PB-FDTD is well suited for detecting high Q resonances which are characteristic of scanned infinite bilateral Vivaldi arrays. The final design results were verified using a U-Mass MoM code and CST. This verification showed good tracking between the results of the different codes.

Figure 1-49: The element design of the first iteration (actually four elements are shown).


As mentioned before, the element, selected for the first iteration had low technical risk. The design for the following iterations will incorporate more risk, at the benefit of possible substantial cost reductions. The present idea for the next iteration, is to separate the feed and the radiator functions, as shown in Figure 1-50. This way the radiator can be produced either as a metal foil, or a metal plate, while the feed network can be located on a small PCB. This separation of functions thus allows us to choose separate materials for each function, instead of having to make a compromise.

Figure 1-50: Possible element setup for the 10 tile proto.

Prototype Tile An incremental design procedure is used for the first EMBRACE prototype. Several building blocks have been designed, produced and characterized separately, as shown in Figure 1-51. Simulated performance in Agilent ADS, showed good correlation with measured performance.

Figure 1-51: Several building blocks used for the tile.

Using these building blocks the design of the first tile started. As already mentioned, this first prototype is all about verifying predictability of the design. So the design is not the final design. All functions were built using readily available COTS components. The final design will include custom ICs.


Physically the tile is constructed using four Base board PCBs, shown in Figure 1-52, which have multiple functions as shown in Figure 1-53. The PCB will contain all electronics and it takes care of the signal distribution over the tile. And last but not least, it will act as a ground plane for the Vivaldi antennas, Figure 1-54.

Figure 1-52: Base boards of a single tile mounted on a carrier frame.

Figure 1-53: Close-up of an assembled channel (the white blocks are vector modulators).

Figure 1-54: Initial test, with an antenna mounted on the Base-board.

CDC-unit: During systems design, the need for an additional hardware unit, apart from the LOFAR Station hardware became clear. It was christened CDC-unit, which is an abbreviation for Control and Down


Converter unit, as shown in Figure 1-55. As the name implies, it will take care of the digital interface between antenna tile and LCU, as well as performing the frequency band selection and the frequency translation from the RF frequencies, to the A/D-converter input range. By physically separating this functionality from the receiver, this allows us to improve synergy between LOFAR and EMBRACE. The separation also gives improvement with respect to the EMC/EMI issues.

Figure 1-55: Artist impression of the CDC-unit prototype.

Beamformer Chip: A fully integrated beam former Monolithic Microwave Integrated Circuit (MMIC) has been designed by both Astron, shown in Figure 1-56 and OPAR, shown in Figure 1-57, for EMBRACE. The chip will take care of the beam control by means of phase-shift as well as amplitude control, if required by the system design. The design includes an input Low Noise Amplifier, output buffer amplifiers and digital control around a core of the actual beam circuits. Two independent beams are generated. A new beam forming technique, for which a patent has been filled, has been used. This techniques has been successfully tested on a Gallium Arsenide MMIC (Monolithic Microwave Integrated Circuit), designed, processed and tested, however in order to achieve the EMBRACE cost targets a higher integration density and a lower cost technology are required. Therefore the new chip has been designed in a Silicon Germanium process, a more or less standard Silicon process with Germanium added for high frequency performance while maintaining all the benefits of mainstream Silicon technology.

Figure 1-56: Astron single channel beamformer chip.


Figure 1-57: OPAR beamformer chip.

Receiver The Receiver in EMBRACE is a copy of the Receiver from LOFAR as shown in Figure 1-58

Figure 1-58: Picture of the LOFAR Receiver

The Receiver is designed for low cost large scale production and can be used with minor changes. Not all connectors and filter sections as implemented for LOFAR are used in EMBRACE and these can be removed to further cut cost. The performance of the receiver is well documented and by limiting the number of changes on the receiver, the test and integration time for the receiver can be minimized.


Signal Transport (MPiFR): The work package called ”Signal Transportation” is dealing with the transmission of the huge amount of information from the antenna tiles to the receiver station. The distances to be bridged are up to some 100 meters maximum. In principle there are two suitable possibilities: sending the analogue signal to ether a coaxial line or modulate it onto an optical emitter and transmit it via optical fibre. The coaxial line transmission is the simplest system, as it does not need any signal conversion for frequencies up to 1 GHz. For short distances this leads to a simple and cheep solution. For longer transmission lines the price of the copper cable is increasing dramatically and cable attenuation is degrading. In that case the effort of converting the signal onto an optical carrier pays as the price of the pure fibre is low and considerable losses occur only after thousands of meters length. Therefore a tradeoff has to be considered which system to be used for the case of EMBRACE and what is suitable for a future SKA telescope. Analogue link: Coaxial cable link For signal transportation between the antenna tiles and the receivers of the EMBRACE demonstrator it was decided to use analogue coaxial cables as the maximum distance is considered to be 30 m. This turned out to be the cheapest and fastest solution for the needs of EMBRACE. On this link three signals have to be transmitted:

• IF frequencies 400 MHz to 1600 MHz from the antenna tiles to the CDC Unit, • Digital control signals (Ethernet) in both directions, • DC for power supply of 48V and 3 Amps to the antenna tiles.

The coaxial cable that was chosen is a COTS low cost TV-cable with 75 Ohms impedance. This turned out to be sufficient for the needs. Furthermore this cable was tested and proven in the LOFAR project. To multiplex the three signals a planar circuit is under development. Following major boundary conditions have to be considered:

• send (Tx) and receive (Rx) on a single line (full duplex mode), • reducing bandwidth of the digital signal with no loss of information, • matching the signal specification of the control and down converter unit (impedance, power

level), • multiplexing RF, control signal and DC, • avoiding distortion and signal interferences, • keeping the design cheap and mass producible, • PCB layout on simple and cheap material like FR4.

Figure 1-59: Signal Multiplexer.

Figure 1-59 shows the Block diagram of the circuit. The core of the circuit is a diplexer to separate the frequencies of the 100BaseT Ethernet and the IF. DC is supplied via coil, thus the 100BaseT and IF have to be DC free. The diplexer is designed as a classical lumped element circuit with the

lowpass

31,25MHz

lowpass

31,25MHz

Tx

Rx

RF (400 - 1600 MHz)

DC (48V/3A)

RF (400 - 1600 MHz)

DC (48V/3A)

Tx

Rx

coaxial cable

diplexer diplexer


inductances realized by high impedance lines on the PCB. The high pass part is designed with a high stop band rejection to avoid distortion from the digital signal part. The diplexer low pass section has moderate frequency response, as there will be additional filtering on the active receive/transmit multiplexer. Figure 1-60 shows the prototype design of the high pass and low pass filters.

Figure 1-60: Prototype high pass and low pass filters.

In Figure 1-61, the simulation of the active receive/transmit multiplexer is shown. In principle the function of the unit can be described as follows. The coaxial cable carries the sum of the two signals Tx1 and Tx2. Taking a look at the inputs of the operational amplifier U2 for example Tx1 is subtracted from this composite signal. The resulting signal Rx1 correlates to Tx2. Similar to this Rx2 correlates to Tx1 in the other part of the circuit so that the unit works as an active circulator.

U1

OPAMP_3T_VIRTUAL

U2

OPAMP_3T_VIRTUAL

R3

51Ω

R4

51ΩR5

51Ω

R6

51Ω

R1

51ΩR2

51Ω

U4

OPAMP_3T_VIRTUAL

U5

OPAMP_3T_VIRTUAL

R10

51Ω

R11

51ΩR12

51Ω

R13

51Ω

R17

51ΩR18

51Ω

Tx1

Tx2

Rx1

Rx2

coaxial cable

Figure 1-61: active receive/transmit multiplexer

Optical fibre link For investigations on analogue signal transmission on optical fibers a fiber link has been established at the Effelsberg telescope. The length of the fiber is about 300 m with a usable bandwidth of 2 GHz. Standard COTS equipment has been used for the first investigations. During these first measurements, strong gain variations during telescope movements have been observed. This has to be investigated further. The timeline of this topic is not critical for the project, as it is not needed for EMBRACE. Digital link: A digitiser unit for an L-band receiver at frequencies from 1200 to 1800 MHz is currently under development. The signal will be sampled in two bands 1200 to 1500 MHz and 1500 to 1800 MHz with


a maximum bandwidth of 500 MHz. An analogue signal conditioning unit is under design, where the two bands are carefully filtered. Figure 1-62 shows the layout of the unit.

Figure 1-62: Signal conditioning for 500 MHz bandwidth digital link.

The A/D converter samples with 8 bit and a sampling rate of 1 GHz, using the 3rd and 4th Nyquist band. The converter unit is already available, control PCBs are designed but have to be assembled. For the data transmission a 10 Gbit link has to be used. First literature studies have been made on this. Network: The works on this sub task have not been started yet.


Receiver (INAF): In the first year of working, we have investigated different designs and architectures for the up and down conversion block in order to satisfy both cost target and technical specifications. This up/down conversion block is implemented on the CDC, after the optional tile combiner. Particular care has been taken in the design phase to ensure the proper gain, Tsys, bandwidth (0.4 -1.6 GHz@3dB) and dynamic range. The target specifications and the simulation results, shown in Figure 1-63, enable us to reach these goals.

GOAL SIMULATION NF <10dB 8.37dB IIP3 >0dBm 3.91dBm GAIN >20dB 21.5dB

Figure 1-63: SCW simulation of the receiver

In order to understand the right filter IF1 selectivity and to avoid inter-modulation products (RF-LO1 and LO1-LO2), an ad hoc written software has been used to choose and to verify the best local oscillators frequencies. Results show that the LOs have been chosen properly.


Prodotti Armoniche Multiple (fol1 e fol2) sulla IF2

1600 1800 2000 2200 2400100

120

140

160

180

200

o1 y( )

o2 y( )

o3 y( )

o4 y( )

o5 y( )

o6 y( )

o7 y( )

o8 y( )

o9 y( )

o10 y( )

o11 y( )

o12 y( )

o13 y( )

o14 y( )

y

Funz (m*Fol1+n*Fol2)1 (1,-1)2 (-1,1)3 (1,-2)4 (1,2)5 (1,-3)6 (-1,3)7 (2,-1)8 (-2,1)9 (3,-1)10 (-3,1)11 (-3,1)12 (-3,2)13 (2,-3)14 (-2,3)

Calcolo Spurie 4 ordine sulla IF1

600 800 1000 1200 1400

2960

2980

3000

3020

3040f1 x( )

f2 x( )

f3 x( )

f4 x( )

f5 x( )

f6 x( )

f7 x( )

f8 x( )

f9 x( )

f10 x( )

f11 x( )

f12 x( )

f13 x( )

f14 x( )

f15 x( )

x

Funz (m*Frf+n*k*Fol1)1 (1,1)2 (-1,1)3 (1,-1)4 (1,2)5 (-1,2)6 (1,-2)7 (1,3)8 (-1,3)9 (1,-3)10 (2,1)11 (-2,1)12 (2,-1)13 (3,1)14 (-3,1)15 (3,-1)

Here the following values of the LOs and filters specifications are reported Flo1_min=1550MHz Flo1_max=2450MHz Flo2=2850MHz IF1c=3000MHz IF1BW=100MHz@3dB ATT@IF1c±80MHz=15dB(min) IF2c=150MHz IF2BW=100MHz@3dB ATT@IF2c±80MHz=15dB(min) RF1c=1000MHz RF1BW=1200MHz@3dB ATT@RF1c±750MHz=20dB(min) RF2c=1300MHz RF2BW=600MHz@3dB ATT@RF2c±400MHz=20dB(min) RF3c=700MHz RF3BW=600MHz@3dB ATT@RF3c±400MHz=20dB(min) RF4c=1000MHz RF4BW=600MHz@3dB ATT@RF4c±400MHz=20dB(min) Filters specifications: IF1, IF2 and Filter bank switch A programmable filter bank has been inserted after the first amplification to better match the receiver bandwidth to the RFI environment. The overall schematic design is shown in Figure 1-64.

Figure 1-64: Receiver Schematic


In the receiver architecture, shown in Figure 1-64, cost and performances are directly linked with the correct choice of the mixers, filters and high stability amplifiers. A wide commercial survey has been done for these crucial components in order to minimize cost without reducing the final performance. The partlist will allow us to compute an approximate cost. Clock/LO: The architecture selected for the LO distribution is a standard corporate feed configuration to ensure the same (and stable) phase to all receiver conversion stages. A significant amount of experience has been gained for this type of LO distribution as it is used in the large Northern Cross radio telescope array based on cylindrical concentrators

Figure 1-65: LOs Corporate feed distribution

We have 8 levels of splitting giving 24 dB + 2 dB insertion loss, as shown in Figure 1-65. Taking in consideration the coax cables and connectors, the total attenuation of this distribution scheme is about 30 dB.


Digital Processing and Control (OPAR): Digital processing (WP5): This task concerns the dataflow processing after the signal digitisation in EMBRACE. The subsystems required for data interfacing and high throughput digital processing and data distribution are designed and tested to operate in an integrated system. The dataflow processing includes digital filtering, sub band select, beam forming, correlator interface and calibration. Control (WP6): This task concerns the monitoring and control function on the EMBRACE system. This function monitors and controls both the infrastructure and the data flow processing. The development of the infrastructure required specifically for the system monitoring and control is also part of this work package. The control application can be split into a real time layer (i.e. the space and time monitoring processes, the beamformer weight estimation, health monitoring, online settings) for the subsystems and a non-time critical layer (i.e. calibration, off-line configuration, maintenance) for the system. The real time control layers are strongly coupled to the digital processing platforms. With Monitoring and Control, users can configure EMBRACE system in operating modes allowing:

• engineering tests operation • astronomical tests operation • maintenance tasks

Hardware platform: The hardware platform has to deliver the required digital processing power in order to operate EMBRACE as a phased array system consisting of up to 100 tiles (Nançay Test Array) or 75 patches of each 4 combined tiles (Westerbork Test Array), each tile and patch outputs 2 Radio Frequency beams (each beam 200Ms/s 12bits wide). Data flow input to the hardware platform is up to 100 * 2 * 200 = 40000 Ms/s ~500 Gb/s input data rate. Digital processing is mainly based on MAC (Multiply and Accumulate Computation), processing of the input data flow requires about 2000 G MAC/s. No affordable commercial system exists for such a data rate and signal processing power. In the radio astronomy community, the LOFAR (Low Frequency Array) project is building dedicated digital processing back ends delivering suitable signal processing power for very high input data rate. We decided to use LOFAR digital back end with the required firmware change to fulfill EMBRACE digital processing requirements, with an external correlator interface hardware platform to format LOFAR back end data output to the specific data format of external data analyzers such as Westerbork and Nançay correlators Work done toward subsystem work package objectives:

• Learning of LOFAR digital back-end architecture and functionality • Learning of LOFAR digital back-end firmware implementation • Embrace digital processing requirements and architecture • Embrace Antenna Tile and “Control and Down Converter” unit control link (hardware) • Embrace External Correlator Interface requirements and architecture • Minimal test bench definition: requirements and architecture

Work planned the coming year:

• Set up a test bench in Nançay


• Validation of Embrace digital processing for the Nançay test bench • Data processing algorithms for External Correlator Interface: definition, simulation, firmware

implementation • External Correlator Interface hardware platform: input data flow validation

Figure 1-66: LOFAR digital back end: one sub-rack with two data processing

Algorithm &software: Use of LOFAR digital back-end, as shown in Figure 1-66, for EMBRACE hardware platform leads to reuse LOFAR software implementation as much as possible wherever the EMBRACE requirements may be fulfilled by LOFAR software. This is the case at the lower software level where software is deeply related to hardware implementation. For higher level, LOFAR software must be adapted or discarded and EMBRACE dedicated software must be done. Software main tasks needed to operate EMBRACE:

• Data processing boards setup and control • Embrace Antenna Tiles setup and control • Control and Down Converter units setup and control • External Correlator Interface setup and control • Parameter computation for the above subsystems setups • Operator interface

Work done toward subsystem work package objectives:

• Learning of LOFAR software architecture and functionality • Learning of LOFAR software implementation and build mechanism • Embrace control software requirements and architecture • Embrace Antenna Tile and “Control and Down Converter” unit control link (protocol) • Nançay Local Control Unit setup with low level LOFAR software for minimal test bench

setup


Work planned the coming year:

• Software development for a minimal test bench platform (10 tiles): • Data processing boards setup and control • Embrace Antenna Tiles (Control and Down Converter) setup and control • Local oscillators setup and control for Embrace specific bandwidth • External Correlator Interface setup and control • Parameter computation for the above subsystems setups • Supervisory software (for engineering and astronomical tests)

Power supply Power supply system will be divided in two subsystems:

1. Digital back-end (LOFAR type) sub racks power supply: LOFAR defined modules used inside each sub rack.

2. Embrace Antenna Tiles, Control and Down Converter units, auxiliary subsystems power supply.

The latter one is strongly infrastructure dependant (on tiles number and down converters number) and will be designed under the infrastructure task leadership.


Mechanical: (ASTRON): This WP started with identifying the goals for the mechanical EMBRACE. The two primary goals are: prove performance and cost feasibility of SKA. Then a project plan was made based upon the three planned prototypes all with their own specific purpose.

• 1-tile prototype test bench for the antenna and electronics development • 10-tile prototype real mechanical prototype of the final EMBRACE • 100-tile prototype is seen as a 0-series

The 1-tile prototype, shown in Figure 1-67, is realised at this moment, as can be seen on the middle photo. The tile is made such that it is easy to interchange the baseline antenna for some other antenna concepts. The whole tile can be lifted in to the antenna measurement room and the tile electronics are accessible for test and debugging purposes by turning over the top part of the tile frame.

Figure 1-67: 1-tile prototype design and real thing

Manufacturability: In parallel to the 1-tile prototype design a series of brainstorm/concept meetings where held towards the final EMBRACE design.

• Antenna concept inventory meeting • Infrastructure brainstorm • Mechanical tile concept meeting • Industrial meetings

Still to come is the transmission line and interconnection concept meeting

1. Antenna concept inventory meeting Starting point for this meeting where the PACMAN antenna concepts, as shown in Figure 1-68. All concepts shown below are judged on antenna functionality, Cost and development time. Most of the concepts were rejected because development time would not fit the EMBRACE timeframe.


Figure 1-68: Antenna concepts

The following two antenna concepts came on top, as shown in Figure 1-69. Both antenna concepts shown below are in principal the same. It is build-up by a single radiator and a feed board. The radiator part could be fabricated as a sheet of metal, foil or a sandwich of low cost carrier and a copper or aluminum radiator. In all situations the feed is fabricated by standard PCB laminating processes with a metal layer at the back side of the feed board so that it becomes a strip line

Figure 1-69: Selected Antenna concepts for EMBRACE

2. Infrastructure concept meeting

The infrastructure concept meeting results are not shown in this part of the document but in the infrastructure WP section. Housing:

• Mechanical tile concept meeting This meeting started with identifying the main requirements for the EMBRACE tile housing and radome. Again the PACMAN housing and radome studies gave a good starting point for this meeting, as shown in Figure 1-70.


Figure 1-70: Tile concepts

Outcome of this concept meeting was that the mechanical modularity (tile size) may differ from the electric modularity and that the antenna pattern continuity is an important driver for the tile size. In parallel the same concept are discussed with the industry during the industrial meetings described in the industrial section. One of the things learned from these meetings is that the tile cost could be lowered by choosing a small module size which matches for instance one antenna element. There for a tile size study is started that searches for the optimum trade off between the following design drivers:

1. Radome loss/Noise contribution • RF material properties: εr, tan δ • Thickness, amount of material in the signal path • Mechanical material properties: E-modulus, σ0.2

2. Antenna pattern continuity 3. Environmental influences: Snow load 200kg/m3 equivalent for 40cm heavy snow, water

transport, thermal loading: solar and internal dissipation 4. Cost: material, production, transport, assembly 5. Accessibility for installation, testing, maintenance

The antenna pattern continuity is an important driver which pushes towards the largest module size possible, which might not be the best solution looking at the other design drivers. Solution might be found in the following antenna contact elements that are based upon aluminium extrusion or stamped profiles that make the connection between the antenna elements, as shown in Figure 1-71.


Figure 1-71: Contacts between antenna elements

When this or one of the other contact element concepts gives a good RF-connection, then the antenna pattern continuity becomes independent of the module size because same technique can be used to make interconnections between for instance 1x1 meter tiles or any other mechanical module size Further studies in this direction are needed for the coming period to prove that this is a reliable RF-connection. Material: Radome, antenna substrate and RF-transmission line design depend on reliable RF-material properties. Many of the low cost plastics are measured over a wide frequency band and under different environmental condition within the PACMAN project. These material properties are an integral part of the above described design path


Additional Contributions from other partners: Australian contribution A 24 element narrow band beamformer has been built for the NTD. This will demonstrate the implementation and flexibility of digital beam forming systems for comparison with RF beam formers. In the first instance this beamformer will be used with the THEA tile acquired from ASTRON. Work is now underway on a full beamformer, with 192 inputs and 300 MHz of bandwidth per input. The design for this beamformer is now on its fourth revision. Both beamformers include polyphase filter banks using 12-bit filter coefficient.


Table 17 List of milestones and deliverables defined in the contract that has been achieved during this reporting period.




Lead Contractor(s)

Planned (in months)


1 Design the first tile finished

DS5-T1 ASTRON (T0+8 months) T0+8 Months)

2 Design ten tile system finished

DS5-T1 ASTRON (T0+19 months)

3 System Requirements frozen (T0+27months)

DS5-T1 ASTRON (T0+27months)

4 Design final station finished

DS5-T1 ASTRON (T0+30 months)


Table 18 List of the major meetings and workshops organised under this activity during this reporting period.



Website address

26/7/05 SKA management meeting #9 Astron 7 ?? 30/8/05 SKA management meeting #10 Astron 4 20/9/05 SKA management meeting #11 Astron 6 20/10/05 SKA management meeting #12 Astron 6 07/12/05 EMBRACE project meeting #1 Astron 12 05/01/06 EMBRACE project meeting #2 Astron 8 27/01/06 EMBRACE project meeting #3 Astron 9 23/02/06 EMBRACE project meeting #4 Astron 9 09/03/06 EMBRACE project meeting #5 Astron 9 23/03/06 EMBRACE project meeting #6 Astron 8 07/04/06 EMBRACE project meeting #7

face to face Astron 14

20/04/06 EMBRACE project meeting #8 Astron 8 04/05/06 EMBRACE technical meeting

#1 INAF/MPiFR/ASTRON

Bologna 9

11/05/06 EMBRACE project meeting #9 Astron 9 23/05/06 EMBRACE project meeting #10 OPAR 9 02/06/06 EMBRACE project meeting #11 Astron 5 13/06/06 EMBRACE technical meeting #

2 (OMMIC/ASTRON/OPAR by phone)

Astron 7

22/06/06 EMBRACE project meeting #12 Astron 8 06/07/06 EMBRACE project meeting #13 Astron 6


1.6.2 DS5-T2 EMBRACE Development

Abbreviations EMBRACE: Electronic Multi - Beam Radio Astronomy Concept WP: Work Package EMBRACE Development Table 19: List of participant, their short name and the man - month spent during this reporting period.

Participant number

1 4 5 30 12


Astron OPAR INAF-IRA OMMIC NRF Total

Person-months 0.45 1.0 (0.0) 1.2 2.65 During this period we have made some progress as the progress very much depends on the progress made in DS5-T1. Again we have divided this task up for several sub-system level tasks and have allocated one of our partners from for each of the sub-system. The Embrace Development Task consists of three (3) sub – systems work packages. They are:

1. Industrialisation:

2. Infrastructures:

3. System Integration:

Each of the sub – systems work packages are further divided into smaller tasks as shown in Figure 1-72. The reporting division has been made at this level.



EMBRACE Development task is identified above however the Work Package 3 in this task has not been allocated yet as it is somewhat premature.


Industrialisation (ASTRON) The industrialisation work package started with the question if EMBRACE should follow the European Procurement Directives. This is not the case because EMBRACE is a SKA demonstrator and therefore a prototype which does not fall within the scope of the European Procurement Directives. Still good procurement practice will be followed with in the EMBRACE project. Goals of the industrialisation WP are:

• Organise the industrialisation of all Embrace hardware/parts such that engineers can do their work without the burden of outsourcing aspects.

• Find industrial partners or suppliers so that a low cost EMBRACE or phased array SKA becomes feasible

• Collaborate with suppliers/industrial partners which are located in the EFRO subsidy areas • Select suppliers and/or industrial partners through a transparent selection procedure which

follows “good procurement practice”. Co-ordination: First an industrial process was set up which is based upon the project plan and contains 3 prototypes and the final EMBRACE deliverable. Each prototype and design phase contains different ways of collaboration with the industry, as shown in Figure 1-73.

Figure 1-73: Coordination process for the Tile development

During the concept phase, we have started a search for possible industrial partners with whom the concept design could be made. In practice this is organised by inviting groups or clusters of companies. With these companies the EMBRACE concepts and design challenges will be discussed.


Two meetings have already taken place with the Aadvise cluster and with Coredeveloper. Future meetings will be held with Brecon Ridge in September as well as with a group of companies from the EFRO subsidy areas. The meeting with Aadvise resulted in some new ideas on how to realise a low cost antenna. Also the presented €125 tile housing cost seemed realistic according to the Aadvise representatives. Outcome of the meeting with Coredeveloper was a bit thin which is not surprising due to the fact that they are an engineering group who sells knowledge on how to design for low cost production and the associated production equipment. Coredeveloper could therefore act as a design reviewer. After these discussions it will be clear which concept is the most promising for final EMBRACE. The 10-tile prototype will be realised in close collaboration with the industry. The production of the 100-tile and final EMBRACE will then be tendered by a call for proposal on which the already involved companies and others can bid. The call for proposal and contracts will be written by the WP manager and ASTRON purchase department. Production and Assembly: After contract signing the production and assembly phase of EMBRACE will commence. This phase contains the following control tasks:

• Hardware production and assembly cost control • Coordinate production phase

o production planning o quality control o storage of parts o logistics/transport o assembly


Infrastructures Two test sites for the Embrace demonstrator are identified; Westerbork Antenna Tests Site (WATS) and Nancay Antenna Test Site (NATS). The EMBRACE demonstrators at Westerbork and Nancay will be identical to large extent. A difference between the two demonstrators is the size of the array. WATS will cover a surface of 300m2, while NATS covers a surface of 100m2. Both use an aperture array configuration built with modular tiles. The demonstrators will be connected to the local correlator at Westerbork and Nancay. The work descriptions for both test stations are reviewed and available at the EMBRACE document server. They are also aligned with the other work descriptions in the EMBRACE (DS5) project. Looking at the project Gantt chart the first infrastructure work will start in Q4 2006. Both test stations will be ready for the demonstrator before Q1 2008. Assembly and system integration of 100 tiles will begin in Q1 2008 at Westerbork, closely followed with the Assembly and integration of 100 tiles at Nancay. Westerbork Antenna Test Site (WATS): Description WATS is the test platform for the 300 m2 EMBRACE demonstrator. The EMBRACE demonstrator will be assembled and tested at WATS. The objective of WATS will be the construction of the test platform and infrastructure to fully enable the potential of the EMBRACE demonstrator. WATS is located at the Westerbork location of ASTRON, where it also hosts the well known Westerbork Syntheses Radio Telescope (WSRT), see Figure 1-74. Also different demonstrators are being tested at Westerbork (LOFAR / SKA). WATS test platform is located in the middle of the forest. Approximate distance between the WSRT telescope 8 and the EMBRACE demonstrator is ~1400m. The dimension of the test platform at the test site is shown in Figure 1-75.

Figure 1-74: location of EMBRACE test station at Westerbork


Figure 1-75: Dimensions of the test platform on the test site

Work done in the work package

• The requirements for WATS have been investigated and written down in the WATS requirement document. Issues such as AC power lines, groundwork and communications link with WSRT, Vandalism, Backend housing, roads to the test site and legal issues are addressed.

• A theoretical / practical study has been performed on the maximum allowable RFI levels

generated by EMBRACE. This is necessary due to the very sensitive WSRT telescope in near vicinity. All parts (RF front end, cabling, backend, digital links and clocks) of EMBRACE have been investigated regarding their minimum required shielding effectiveness. The output of this study will be used in the design of the test platform. For the digital backend an EMC shelter is proposed. This shelter will attenuate a great portion of the generated RFI.

An initial concept study on the test platform has been performed. The study presents the following options below.

Figure 1-76: Elevated EMBRACE

The tiles of Embrace are elevated by a mechanical rail construction to 1.9m, as shown in Figure 1-76. This creates an easy accessible tile on the bottom side. Assembling of Embrace is done using the rails


on top side. It should be possible to remove one tile from the bottom side with a small lift device that shifts the tile from its place. The tiles are from the ground, so no problems with excessive water. Large rodents have no easy access to the tile when using traps on the side edges. An additional benefit is the easy access to cables on bottom side.

Figure 1-77: EMBRACE with crane

The EMBRACE with crane concept has been investigated in more detail, as shown in Figure 1-77. A large rail crane construction in the figure above shows the ability to remove one tile and have easy access to all the tiles. The construction is strong enough to carry two persons and one tile. When not used it is moved to one side of the test platform.

Figure 1-78: EMBRACE on wheels

Two by nine tiles are placed on large carriers with wheels, as shown in Figure 1-78. The carriers also include local (shielded) cabling, which makes it easy to disconnect a carrier and move it outside the configuration. The tiles are then accessible from the side of the carrier. The tiles are app. 30cm above the ground, which makes it easier to get rid of rain water (water management). It is still possible to change configuration


Work to be done for the coming year

• Final test platform concept will be chosen in close collaboration with NATS work-package • based on final requirements. • Procedures obtaining legal permits required for building on the test site will be set in motion. • The first groundwork will be defined, planned and started on the test site. • An EMC-shelter for the digital backend will be selected. • Lightning protection of the RF hardware will be investigated.


Nançay Antenna Test Site (Nats) : Description NATS is the test site for the one hundred square meters part of the EMBRACE demonstrator in Nançay. The main objective of this DS5-T2 work package is to provide a suitable site for the demonstrator integration and operation. Issues to be addressed:

• electrical power supply • connection to LAN-WAN • tiles platform • backend shelter • RFI compatibility with on-site telescopes

Identified activities:

• site choice within the Nançay Observatory boundaries • infrastructures: groundwork, connections to site networks, array integration

Working done toward subsystem work package objective

1) Management of this subsystem work package: Participation to the Embrace Project Meetings Local management of the subsystem's tasks

2) Site choice within the Nançay Observatory boundaries (activity one)

The Nançay Observatory houses (on about 1.50 million m²) three large radio telescopes, a high energetic particles radio detection instrument under construction and some other antennas. This leads to the following constraints:

• RFI compatibility with all site instruments • suitable EMBRACE location regarding groundwork, roads availability, access to the various

networks, etc. Work already done:

• Site instruments RFI susceptibility evaluation using a locally transmitted signal and associated computations

• Measurements of received RFI levels with the site RFI monitoring antenna and associated computations

• Selection of the best location meeting all above issues • selected site measurements taking


A location has been selected for the EMBRACE site, shown in Figure 1-79. The decision will be finalized before the end of 2006.

3) Infrastructure (activity two): The EMBRACE demonstrator (a hundred square meters in Nançay) is a compact array made of one hundred identical tiles (one square meter each). A tough maintenance issue is to easily disconnect and remove a tile from inside the array.

A study of a specific lifting and handling tool has started.

Figure 1-79: Nançay Site layout

Work planned for the coming year

• Site location final decision • Detailed groundwork definition • Final networks requirements

o power supply: electrical power, length, etc. o LAN: data rate, physical link media, length, etc. o WAN

• Shelter requirements and availability • Detailed study of the tile handling tool

Main power

100 m

LAN ≈ 240 mPower line ≈ 290 m

Radioheliograph

Shelter Main power

Computer Engineering Lab

100 m

LAN ≈ 240 mPower line ≈ 290 m

Radioheliograph

Tiles

Shelter

Embrace


System Integration (Not assigned yet) The system integration activity has not been started yet as there is no work planned on this activity in the first year.


Table 20: List of milestones and deliverables defined in the contract that has been achieved during this reporting period.




Lead Contractor(s)

Planned (in months)


1 Manufacture and integration of the first Tile & Report

DS5-T2 Astron (T0+12 months)

As planned

2 Manufacture and integrate a 10 Tiles system


3 Manufacture and integrate first 100 tiles of the final test station

DS5-T2 Astron (T0+35 Months)

4 Finalize production and integration of the final stations at Westerbork and Nancay



Table 21: List of the major meetings and workshops organised under this activity during this reporting period.

Date Title/subject of meeting /workshop Location Number of attendees

Website address

Please see the meeting for DS5-T1


1.6.3 DS5-T3 EMBRACE Test and Evaluation Abbreviations EMBRACE: Electronic Multi - Beam Radio Astronomy Concept EMBRACE Test and Evaluation Table 22: List of participant, their short name and the man - month spent during this reporting period.

Design Task: DS5 – T3 Assessment of EMBRACE Performance

Participant Name & Number

OPAR (4)

ASTRON (1)

JIVE (3)

UMAN/UCAMDPHYS (2+15)

INAF-IRA (5)

UMK (13)

OXF-DB(8)

NRF (12)

TOTAL

Man months 1.25(0) 0 0 0 0 0 ?

The Embrace Test and Evaluation Task consists of three (2) sub – systems work packages. They are:

• Test, Evaluation and Validation:

• Operations: Each of the sub – systems work packages are further divided into smaller tasks as shown in Figure 1-80. The reporting division has been made at this level.



Test, Evaluation and Validation (ST – OPAR): The goal of this task is the evaluation of the EMBRACE demonstrator as an astronomical instrument. This task includes the engineering performance and characterisation of the system, as well as the use of the system in astronomical experiments related to the SKA Key Science Projects. Ds5T3 currently has 18 participants from five SKADS partner institutes: OPAR (task leader), ASTRON, JIVE, UORL, OXF-DB. There have been four meetings of the Ds5T3 group during this reporting period, including the kickoff on April 6th, 2006, followed by three teleconferences on May 12th, June 1st, and June 22nd. Participants communicate via the skads-wiki email distribution list, and also by refering to documents on the Ds5T3 skads wiki page which is found at http://webmail.jb.man.ac.uk/skadswiki/Ds5T3 During the next 18 month period the engineering and scientific testplans will undergo continued revision. The test plans are deliverables required at T0+28 months and T0+32 months respectively, so they will be submitted with the 3rd annual report. There will be 16 meetings of the DS5T3 team during the next 18 months, corresponding to approximately once per month. Most of these will be teleconferences, however several will be face-to-face meetings organised in conjunction with the bi-monthly EMBRACE international meetings.


Also within the next 18 month period engineering tests on all the parts of the one tile prototype will be in full progress and reported in the 1-tile test report. The main focus lies on the RF part of the signal path, but engineering system tests on one tile prototype will also be carried out. Calibration (MR – ASTRON): Initial discussions with the LOFAR calibration group are in progress. Engineering Testing (MR – ASTRON): Description Main goal of these engineering tests are: -Validation of the required blocks against specification -Verification of the simulation results -Increasing confidence level of the design The engineering tests are defined from detailed level following a bottom up structure to system level tests. Main focus lies on the signal path starting at the antenna until the output of the correlator. The main test blocks are shown below. Blocks that do not fit the signal path are shown below the signal path. The test approach is kept general for all blocks. This means that testing is performed starting with small blocks, integrating them to larger complex test blocks while keeping control of the design verification.

Figure 1-81: Engineering measurement blocks


Work done in work package

• The first draft EMBRACE engineering test plan for the demonstrator was written and reviewed at ASTRON. The document is under continued revision in collaboration with the DS5T3 team. The excel sheet is available on the EMBRACE document server and on the SKADS wiki.

• General verification is performed on RF circuits which will be used on the quadrant board. Detailed measurements will be performed in the coming quarter

• First functionality of one passive channel of quadrant board has been tested. • Test hardware and software has been designed, simulated and build to enable verification of

the antenna performance of one tile, and the performance of one quadrant board. • Test hardware and software has been designed, simulated and build to enable verification of

the beamformer chip. • The mechanical testframe for one tile has been designed and built (see mechanical design

DS5-T1 ) • A number of RFI measurements and simulations have been performed to fully understand the

RFI levels of different back end systems of the EMBRACE demonstrator. This work will be continued in the coming year.

Work that will be done in the coming year

• Engineering tests on all the parts of the one tile prototype will be in full progress and reported in the 1 tile test report. Main focus lies on the RF part of the signal path.

• Engineering system tests on one tile prototype.


Pictures

Figure 1-82: 1 to 16 Passive splitter 400-1600 MHz enabling testing the RF performance of the antennas and frontend

Figure 1-83: 1 to 16 Passive splitter 400-1600 MHz with active control enabling performance testing of the antennas.


Figure 1-84: Beam former chip carrier enabling functional testing the beam former chip performance

Figure 1-85: Beam former chip control enabling functional testing the beam former chip performance

Figure 1-86: Beamformer bonded in leadframe for testing DC, Logic and basic RF properties


Figure 1-87: Testboard for beamformer chip in leadframe

Figure 1-88: Measurement control software for testing beam former chip

Figure 1-89: Measurement setup for testing beamformer chip


Scientific Testing (ST – OPAR): Several scientific measurements of astronomical objects are envisaged in order to demonstrate the success of the EMBRACE aperature plane phased-array system. While limited in collecting area, there is still sufficient sensitivity in the EMBRACE system to carry out interesting astronomical measurements. The proposed observations are listed in the engineering test plan. These currently include:

• pulsar timing timing of multiple pulsars at different directions in the sky o (testing multibeaming, and source tracking)

• HI mapping o (testing spectroscopic capability, and beam scanning)

• Continuum mapping o (testing system stability and mapping)

• Long baseline interferometry o (testing clock stability, and long baseline capability of the phased array)

Operations (ASTRON): (not yet assigned)


Table 23: List of milestones and deliverables defined in the contract that has been achieved during this reporting period.




Lead Contractor(s)

Planned (in months)


DS5T3.1 Engineering Testplan WP1 ASTRON T0+28 Not due DS5T3.2 Astronomical Testplan WP1 OPAR T0+32 Not due DS5T3.3 Initial Engineering

Test Report WP1 ASTRON T0+42 Not due

DS5T3.4 Final Engineering and Astronomical Test Report

WP1 OPAR T0+48 Not due


Table 24: List of the major meetings and workshops organised under this activity during this reporting period.



Website address

6 April, 2006

DS5T3 Kickoff Dwingeloo

8

http://webmail.jb.man.ac.uk/skadswiki/Ds5T3?action=AttachFile&do=get&target=ds5t3_minutes20060406.txt

12 May, 2006

Test plan teleconference

8

http://webmail.jb.man.ac.uk/skadswiki/Ds5T3?action=AttachFile&do=get&target=ds5t3_minutes20060512.txt

1 June, 2006

Test plan teleconference 8

http://webmail.jb.man.ac.uk/skadswiki/Ds5t3Actions

22 June, 2006

Test plan teleconference 9

http://webmail.jb.man.ac.uk/skadswiki/Ds5t3Actions


1.7 DS-6: Clindrical concept demonstrator SKADS is planning to use a second demonstrator based on a large platform equipped with shaped cylindrical reflectors (DS6) in order to assess some results at (sub)system level early-on in the project (some results will be available for the mid term review). In particular the digital beam forming on a wide angle, multi beam and the use of phased arrays along their line-foci, potentially offers a cost-effective way to obtain the large sky coverage for the low-frequency survey science as well as a (sub) system testbed on a large collecting area. DS6 is linked with other ongoing projects through the world, to compare and/or contrast possible new technology solutions and to disseminate results. The aim of this DS is to prove the viability and scalability of the (sub) systems using existing cylindrical concentrator. To achieve it, the BEST programme (Basic Element for SKA Training) will re-engineer (in three steps: BEST-1, BEST-2 and BEST3 different in sizes) a fraction (~25% about 8000 m2) of the “Northern Cross”; a T-shaped cylindrical concentrator array located in Medicina, Italy (Figure 1-90). Particular issues are the accuracy of the calibration achievable in the face of RFI and RFI mitigation strategies. The final step of BEST (BEST-3) is an order-of-magnitude larger in area than EMBRACE and hence is susceptible to a different range of calibration problems. SKAMP is another SKA-related initiative in Australia that involves the Molonglo Cross telescope of the University of Sydney. Since both BEST and SKAMP are projects relating to cylinder-array concepts, in this DS a full collaboration between INAF-IRA and the Australian group (U.Sydney) is planned. The skills and activities of the two groups are complementary.

Figure 1-90 The Northern Cross at Medicina, Italy.

The ongoing activities for the DS6, composed by 4 tasks, are on track with what is reported in the Gantt chart of DoW. (But DS6-T1 reports a 6 month delay!!, this does not result in a shift of end-date)

1.7.1 DS6-T1 Design of subsystem The activities in this Task have been concentrated on the design and preliminary tests of the more crucial blocks for the different steps of BEST programme. In the whole, we are on the track of the Gantt chart for this Task. Table 25: List of participant, their short name and the man - month spent during this reporting period.

Participant number

5 9 23


INAF-IRA

CSIRO Sydney Total

Person-months 25.6 1.0 5.4 32.0


FRONT END: Electronic part. A prototype of a new release of the LNA (see Figure 1-90) for the BEST demonstrator has been designed, tested and characterised. Basically it is a balanced configuration. This offers a better performances in terms of matching (input and output return loss) and dynamic (IP3 and one dB gain compression point) with a little worsening in terms of noise figure (0.45dB=26.5K instead of 0.38dB=31.7K) respect to the actual single ended one. In table 1 are summarized the main measured parameters of interest. The 380-450MHz bandwidth is fixed by the condition NF<0.5dB. From table 1 we can see that such a LNA can operate on a broader bandwidth than the 16MHz @ 408MHz expected for the BEST-1 prototype. Concerning the front end, at present we are planning the replacement of the single ended LNA with a balanced one. Right now, the Department of Electronic and Telecommunications (DET) of the Florence’s University is performing a comparison between the two version of the front ends, the former with the single ended LNA, see Figure 1-91, and the latter with the balanced one, see Figure 1-94, within a reliability prediction exercise. Figure 1-92 and Figure 1-94 overall BEST-1 chain, from the antenna to the input of the A/D converter, respectively, with the standard front end (with single ended LNA) and the new one (with BAlanced LNA).

Figure 1-91 The balanced LNA prototype.

Table 26 Main measured balanced LNA parameters.

Frequency 380 MHz 408 MHz 450 MHz11S (dB) -30.85 -37.46 -23.09

22S (dB) -27.26 -27.04 -25.36

21S (dB) 25.11 24.45 23.51 NF (dB) 0.5 0.45 0.5 OIP3 (dBm) +34.08 +34.5 +34.46

outdBP1 (dBm) +21.32 +21.24 +21.48


Figure 1-92 BEST-1 Front End with single ended LNA.

Figure 1-93 BEST-1 overall chain with single ended LNA.

Figure 1-94 BEST-1 Front End with balanced LNA.


Figure 1-95 BEST-1 overall chain with balanced LNA.

FRONT END: Opto-electronic stage . One of the most critical blocks, in term of performances and costs optimisation, is the analog optical link. A commercial link and a home made link have been tested and compared. Particular care have been taken in testing the performances Vs the temperature variations. Comparisons (see Figure 1-96) performed, on the Cass A radiosource transit, between a receiver equipped with commercial optical link (blue) and another one with coax cable (green), underlined a small gain oscillation (in the commercial optical link) superimposed to the normal gain variation Vs temperature changes. In practice it is very small in amplitude, about +/-0.02dB, in a 10-15 minutes interval of time. The discovery of this efffect has to be considered as one of the preliminary output from the demonstrator. This underlines the importance to have a demonstrator for test on the field. What causes the gain ripple is still under investigation, this will delay this task. Efforts are also devoted to reduce costs of the optical link. (can you be more specific, what type of efforts?)

Figure 1-96 Comparison between two receivers total power outputs of BEST-1 on the Cass A transit


Figure 1-97 Optical link gain fluctuations Vs temperature variation (test performed in our labs).

A test bench to measure the gain and some other parameters (as the laser biasing current) of DUT under slow temperature gradients is already set. At the same time we will perform, in collaboration with DET (Florence University, Italy), a reliability prevision test on the home made optical transmitter designed and realised expressly for the BEST project.

1.7.2 DS6-T2 Development and Demonstration

Table 27: List of participant, their short name and the man - month spent during this reporting period.

Participant number

5 23


INAF-IRA

Sydney Total

Person-months 12.1 12.1 In the first step of the BEST programme (BEST-1 170 m2), 4 receivers (see Figure 1-98) have been installed on the focal line of a single cylindrical concentrator (North-South arm). This way some tests on the field of the blocks developed in T1 have been performed. The RF (408 MHz- 16 MHz BW) is directly transported in the control room via an analogue optical link. This configuration dramatically increases the MTBF (Mean Time Between Failures) of the system. Using a summing correlators, calibration of such a mini array has been exercized with good results

-30.10

-30.05

-30.00

-29.95

-29.90

-29.85

-29.80

-29.75

-29.70

-29.65

-29.60

-29.55

-29.50O

ptic

al G

ain

[dB

]

33

34

35

36

37

38

39

40

41

42

43

44

45

Tem

pera

ture

[°C

]

Optical Link Temp


Figure 1-98 First transit of Cassiopea A with the BEST-1 prototype.

Mechanical Modification: many modification have been investigated and introduced in order to be able to start the BEST-2 preparation just after the summer 2006. All these modification of the mechanical part of the cylindrical concentrators will fit the requirements of the preparation of the SKADS prototype. The original cylinder and the modified version are visible in Figure 1-99. All the implemented modifications will allow to install the front-end/optical link Tx on the focal line and the proper handling of the optical fibers and cables installation.

Figure 1-99 Old version of the N/S cylindrical concentrator (left) and a N/S cylinder modified (right).

First results from the demonstrator: In addition to the just mentioned radio source observation, BEST-1 was also used to compare the Tsys compute following the German Cortes paper [1] and the Tsys measured using the BEST-1 demonstrator (reported in Figure 1-100). Here the Tsys has been obtained using an ad hoc Fortran/Matlab code in combination with antenna pattern simulations made with the commercial software GRASP, following the German Cortes Paper, while in Figure 1-101 is visible the Tsys measured exploiting the transit of a strong radiosource.

5.6o x 70

1 Rx=¼ of NS cylinder

4 RX =1 NS cylinder


Figure 1-100 Tsys obtained following the German Cortes Paper.

Figure 1-101 Tsys measured with a radio source observation.


2. List of deliverables Task number

Deliverable No



Planned (in months)


DS6-T1 1 Analogue and dig. opt. .link

17 Planned in 23

DS6-T1 2 Architecture and tecnology

7 7

DS6-T2 2 Replicable electronics

12 12

DS6-T2 3 LO and sync distrib 38 DS6-T2 4 Wide band and

high dynamic range AD

39

DS6-T2 5 Software Beamforming

39

DS6-T2 6 Tested adaptive beamforming and RFI mitigation

39

DS6-T3 1 Simulation Software for sensor array

DS6-T3 2 Methodology to compare expected results with the simulated ones

DS6-T3 3 Comparison of performances with SKAMP

DS6-T4 1 Report T0+12 12

1.8 Design Study 7 - Assessment of Preparatory Work and Studies DS7 comprises one task, DS7-T1, entitled “Continuous assessment and Critical Design Reviews.” As described in the DoW, the primary goals of DS7 are twofold: 1) to provide a semi-continuous monitoring of progress within SKADS, which entails the critical examination of the results of the SKADS, ensuring the flow of information within SKADS, and engaging in discussions on the goals and objectives of SKADS in relation to the requirements for the SKA. 2) to organize two full-scale reviews of all the work carried out within SKADS: a Mid-Term Design Review and a Final Design Review The DS7 core team consists of the SKADS Project Scientist, who is based at OPAR (4), and the SKADS Project Engineer, who is based at UMAN (5). They are assisted in their work by the DS7 Manager, who is based at OPAR (4). Although it is sometimes difficult to make a clear-cut division between the activities of the DS7 team members for SKADS Consortium Management (DS1) and DS7, as the two are inherently linked, the activities described here are all aimed at achieving the DS7 goals.


1.8.1 DS7-T1: Continuous assessment and Critical Design Reviews

1.8.1.1 Overview of activities carried out within the Task

Participant number1 4 2 Participant short name2

OPAR UMAN Total

Person-months3 4 0.5 4.5 1.5 mmonth for DS7 from both participants was charged on DS7 but performed for DS1 In the course of their activities on monitoring of progress within SKADS the Project Scientist, Project Engineer, and DS7 Manager individually or collectively attended the following international meetings:

• SKADS, Kick-off meeting, Limelette, Belgium, 18-19/11/2005, http://www.skads-eu.org/past_meetings.htm

• DS and Task leaders, Technical Meeting, Jodrell Bank, UK, 15-16/03/2006, http://webmail.jb.man.ac.uk/skadswiki/TechnicalMeeting

• DS2-T1, Kick-off meeting, Oxford, UK, 7/06/2006, http://webmail.jb.man.ac.uk/skadswiki/Ds2T1Kickoff

• D2 + DS3-T3, Simulations meeting, Oxford, UK, 6/06/2006, http://webmail.jb.man.ac.uk/skadswiki/Ds3T3/WorkPackages

• DS3-T1, Initial meeting, Jodrell Bank, UK, 26/06/2006 • DS4-T1, Front-end Technologies, Manchester, UK, 16-17/02/2006,

http://webmail.jb.man.ac.uk/skadswiki/FrontEndKickoffMeeting • DS4-T2 + DS4-T3, Kick-off meeting, Medicina, Italy, 18-19/04/2006,

http://webmail.jb.man.ac.uk/skadswiki/Ds4T2Kickoff • DS4-T4, Integrated Antenna Kick-off meeting, Dwingeloo, Netherlands, 19-20/01/2006,

http://webmail.jb.man.ac.uk/skadswiki/IntegratedAntennasKickoffMeeting • DS4-T6, Antennas kick-off meeting, Manchester, UK, 3/03/2006,

http://webmail.jb.man.ac.uk/skadswiki/AntennasKickoffMeeting • DS5, Project meeting, Dwingeloo, Netherlands, 7/04/2006,

http://webmail.jb.man.ac.uk/skadswiki/AprilMeeting

• Cosmology, Galaxy Formation, and Astroparticle Physics on the Pathway to SKA, Oxford, UK, 10-12/4/2006, http://www-astro.physics.ox.ac.uk/LOSKA/CONFERENCE/

• SKA 2005, Pune, India, 31/10-03/11/2005, http://www.ncra.tifr.res/in/~ska_pune/ • International SKA Project Steering Committee, Pune, India, 4-5/11/2005,

http://www.skatelescope.org/pages/page_astronom.htm (access to documents restricted to ISSC members)

• International SKA Project Steering Committee, Socorro, NM, USA, 16-17/3/2006, http://www.skatelescope.org/pages/page_astronom.htm (access to documents restricted to ISSC members)

Besides attending these international meetings the DS7 team members also participated in national and institutional meetings aimed at coordinating local work on SKADS, and in yearly national astronomical society meetings where they reported on progress made throughout SKADS. The team participated in meetings that were aimed at stimulating the participation of scientists and engineers from other scientific communities (notably astro-particles research) in SKA science and, potentially, in SKADS activities. The SKADS Project Engineer made working visits to the SKADS participants OPAR, France (13-14/2/2006), INAF-IRA, Italy (22-23/2/2006), FG-IGN, Spain (30-31/2/2006).


The DS7 team is also responsible for the contents of the SKADS website www.skads-eu.org, and it has reported twice during the past year on progress within SKADS the to the Newsletter of the International SKA Project, which is made available through the website www.skatelescope.org, Progress towards milestones and deliverables Deliverable 2, the “2006 Annual report to the International SKA Project Office”, which was scheduled for delivery on 1 July 2006, was completed on time and is appended to the present annual report. As explained in Sect. 1.3.1.3 the first four issues of Deliverable 1, the “Quarterly reports for distribution within SKADS” could not be completed since the DS7 core team could only be put into place much later than was foreseen at the time of the submission of the SKADS proposal. • Identification of the problems encountered and corrective action taken Although SKADS officially started on 1 July 2005 the EU funding for the design studies became available in early 2006 only. Due to this delay the personnel required for the DS7 core team could only effectively be put in place in April 2006. As a result, the first four issues of Deliverable 1, the “Quarterly reports for distribution within SKADS” which were due in, respectively, September 2005, December 2005, March 2006 and June 2006, could not be completed. The decision was made to work on Deliverable 2, the “2006 Annual report to the International SKA Project Office” instead, as the purpose of this document is to inform the International SKA Project community of progress made in SKADS – see Sect. 1.3.2. • Financial overview of the Task During the next 18-month period (01/07/2006-30/06/2007) it is foreseen that the Project Scientist position will be financed during 5 months on national funds and on EU funds for the remaining 13 months, whereas it is expected that the Project Engineer position will be funded uniquely on EU funds. It is foreseen that the expenses for travel and subsistence will continue at the same level as before. List of deliverables Task number

Deliverable No

Deliverable Name



Planned (in months)


DS7-T1 2 2006 Annual report to International SKA Project Office

OPAR 0.5 0.5


1.9 Update of the non-confidential Project information Project Summary European Radio Astronomers are developing the most versatile, flexible and technologically most advanced concept toward the Square Kilometre Array ("SKA"). Using phased arrays, it allows multiple fields of view in a stand-alone observing instrument or, in its technology scope, is the enabling technology for all other realisations. During this four-year Square Kilometre Array Design Study ("SKADS") the partners will develop a full understanding of all aspects of the array concept relevant to the implementation of the SKA and demonstrate the array’s candidacy as a SKA pathfinder within the international SKA planning and budgetary process. Preparing for SKA´s next phase, SKADS strengthens the technology basis and the organizational framework of the European SKA Community, involving industry in several key areas and establishes a key role for European radio-astronomy and technology on a global scale. Feasibility Studies within SKADS involve science, technological and architectural aspects on system level through a number of Tasks and Technical Preparatory Work as Tasks for key technology R&D on "tile level" and for performance Demonstrators. The Feasibility Studies map astronomical objectives and requirements onto the system implementation e.g. through simulations, the network design and its infrastructure. The Preparatory Work concerns the technological maturity, technology selection, cost and other relevant considerations as well as proof-of-concept demonstrators and the development of superior subsystems. Together, these tasks constitute a coherent framework allowing critical assessments as input to the final Tasks of SKADS, the Overall Design and the Preliminary SKA Plan. In concluding SKADS, the R&D readiness is addressed, the feasibility of aperture arrays as enabling instrumental approach for future astronomy in the radio band and the feasibility within the planning, siting and costing framework of the international SKA project. Reporting Period: AR1, AR2,… according to the actual reporting period: 1st, 2nd, … Project Objectives: 1. Arrive at a full understanding of all aspects of the phased array concept relevant to the implementation of the SKA and to demonstrate its viability within the International SKA scientific, planning and costing goals; 2. Prove the feasibility of phased arrays as enabling instrumental approach for SKA in the lower frequency range and evaluate the trade-offs of instrument specifications and science output to derive the detailed instrument specifications, involving industries in some key areas; 3. Perform technology R&D in critical areas, assessments, and demonstrators to select the cost-effective technologies and solutions for the phased array approach supporting all specifications allowing considered choices in these; 4. Cohere the international activities within the European framework of radio astronomy, involving industries in some key areas to establish the relevant R&D platform and relate to technology developments in recent projects in South Africa (NRF) and Australia (CSIRO) both of which aim at using Focal Plane Arrays in reflector systems; 5. Identify all steps for the advancement into the Engineering Phase within the planning and engagement model of the International SKA project.


2 List of deliverables

Task number

Deliverable No



Planned (in months)


DS1-T1 DS 1.1 Report on IPR Policy ASTRON 4 12 DS1-T1 DS 1.2 Report on Outreach ASTRON 4 12 DS1-T1 DS 1.3 Progress Report and

Yearplans ASTRON 12 13

DS1-T1 DS 1.4 SKADS YeaRLy Symposium

ASTRON 9 15

DS2-T2 1 Preliminary Report on SKA Configurations

10 N/A

DS3-T3 1 Initial Report on conceptual issues

UCAM-DPHYS, OXF, DP, CU

7 N/A

DS3-T4 1 First Overview Report OPAR/ASTRON/CSIRO

11 N/A

DS3-T43 2 Report at site selection OPAR/ASTRON/CSIRO

2 Not Public

DS3-T6 1 Specification of a prototype control and data processing system

ASTRON 6 12

DS4-T1 1 Establish benchmarkLNA simulations

WP4 UMAN 12 12

DS5-T1 1 Design of the first tile ASTRON 8 8 DS7-T1 1 Annual Report to

ISPO OPAR 0.5 0.5

3 The process agreed for site selection does not allow these reports to become partly public prior to the announcement of the site selection shortlist


3 Use and dissemination of knowledge

DS1: - Coordinator visits in 2005 to the UK (Manchester 2x), France (Paris, Nancay) and Italy

(Bologna) when finalizing the DOW to reach agreement on the funding distribution, and subsequently in 2006 to OdP (Paris, Nancay), Bonn, Onsala and SETI in the US for operational reasons and to assess and discuss in detail the SETI and Univ. of Berkeley experience with the Allen Telescope Array (“ATA”).

- PM visit combined with Coordinator visit to France (Paris, Nancay) in 2006 for general discussions on coordination and of operational issues.

- Coordinator discussion took place with representatives of the USSKAC in particular about a closer level of cooperation.

- Coordinator discussions with representatives of funding agencies and several large companies e.g. IBM

- Visits of the Project Engineer to the US (SETI) and Canada (NRC), South Africa (NRF), Australia (CSIRO), France (Nancay/OdP) and Italy (Bologna/INAF-IRA). Other visits relate to the development of EMBRACE (DS5) and Workshops in the UK (DS2/DS3 in Manchester and a Cosmology workshop in Oxford)

- Visits of the Project Scientist to Workshops in the UK, Netherlands and several national activities

- Visit of the ELT Project Manager to ASTRON in May 2006. - Representation of the Coordinator in the ISSC and the ESKAC, and of the Project Engineer on

the ISSC EWG - Presentation of SKADS at the URSI-General Assembly in New Delhi in October 2005and in

general to ensure an appropriate level of presentations of SKADS activities at this General Assembly as with other conferences and presence at the upcoming IAU e.g. through the SKA booth.

- Actively managed webpage for internal (management, information, progress) and external purposes (information)

- For the occasion of the EC gathering in July 2005, SKADS was presented. A SKADS logo and subsequently, a brochure was produced for the event of which over 1500 have so far been handed out at this and other SKADS occasions and because of requests to the SKADS project office ([email protected]). The SKADS letter identity was added in September 2005 for all communication on paper.

DS2: Participants of DS2 are actively promoting the SKA both within the “local” European (SKADS) context and more widely as part of the overall SKA international project. Various conference presentations, memos, outreach activities (including brochures) and other results are made available via the following project web pages: www.skads-eu.org & www.skatelescope.org. Michael Kramer (leader of Pulsar Simulation Studies in DS2-T1) is also chairman of the International SKA Outreach Committee. Michael has been responsible for the creation of various movies (e.g. www.skatelescope.org/pages/page_genpub.htm) including a nice example of the advantages offered by a multi-field Aperture Array concept (such as EMBRACE) DS3:


DS3: Papers and presentations not at SKADS meetings Ralph Spencer, Signal Transport for the SKA, SKA memo 75: http://www.skatelescope.org/PDF/memos/75_Spencer.pdf Kjeld van de Schaaf et al., Software technology and microprocessor cores in future correlators, Next generation correlator meeting: http://www.radionet-eu.org/rnwiki/NextGenerationCorrelatorWorkshopProgramme Martijn van Veelen, Failing Scaling and Roadmapping to New Architectures, Next generation correlator meeting: http://www.radionet-eu.org/rnwiki/NextGenerationCorrelatorWorkshopProgramme SKA Task Group on Regulatory Issue, Spectrum Protection Criteria for the Square Kilometre Array , SKA Memo 73: www.skatelescope.org/PDF/memos/73_RITaskForce.pdf Final reports of SSSM RFI monitoring (ASTRON) campaign of all proposed SKA sites, to be made public. Top-level Project summary report SSSM_Project_Report_SiteX_v1.0.pdf for each sites Data Summary Report SSSM_Summary_SiteX_v1.0.pdf for each site Detailed Report SSSM_Detailed_SiteX_v1.0.pdf for each site Compact Report SSSM_Compact_SiteX_v1.0.pdf for each site Extended report SSSM_Extended_SiteX_v1.0.pdf for each site Technical memos with descriptions of SSSM equipment and procedures Final reports on CSIRO RFI monitoring of the proposed SKA site in Mileura, Western Australia, to be made public Spectrum Planning Discussion Paper on a proposed Radio Quiet Zone (RQZ) for Western Australia, Australian Communications and Media Authority, March 2006. ISPO comments on ACMA Public Consultation, Part of ACMA Public Consultation procedure. Authors include ACMA personnel, Tasso Tzioumis and Michelle Storey Poster on Radio-quiet Zone for the SKA. Workshop on the Applications of Radio-science, February 2006, NSW, Australia. DS3: Other activities Contacts with potential users outside the consortium: • Government of Western Australia • International SKA Steering Committee • Australian Communications and Media Authority SKADS technical meetings 26/6/06 DS3-T1 kickoff meeting JBO http://webmail.jb.man.ac.uk/skadswiki/Ds3T1 6/6/06 DS3-T3 kickoff/Simulation meeting Oxford http://webmail.jb.man.ac.uk/skadswiki/Ds3T3/WorkPackages


DS3: Planned activities The dissemination of information during the next 18 months will proceed in the following way A. Dissemination within the design study 1. All activity within DS3 will be recorded on the SKADS WIKI which will also be used for discussion of intra- and inter-task matters. 2. Active participation on SKADS-wide issues on the WIKI 3. Regular six-monthly meetings of all contributors to DS3 4. Participation of members of DS3-T3 and DS3-T6 in regular simulations workshops B. Dissemination outside of the design study 1. All reports will be published to the SKADS WIKI and where appropriate the SKADS www site 2. Participants will attend SKA related conferences and technical meetings relating to the technology considered within the design study 3. Key results from the design study will be communicated to the SKA project via SKA memos.

Describe all the actions undertaken during the reporting period to disseminate, promote and exploit the knowledge derived from the project. For each action indicate the Web-link, if any. Areas to be covered may include: • publications resulting from the project; • patentable results, including a list of patents applied for; • conference presentations resulting from the project; • Web-based activities; • actions undertaken in implementation of the plan to raise public participation and awareness

i.e. the activities engaging with actors beyond the research community and with the public as a whole, to help spreading awareness and exploring the wider societal implications of the proposed work;

• contacts with potential users outside the consortium. • [Give an updated version of the plan for the use and dissemination of knowledge covering the

above areas.] DS7: Publications: • van Driel, W. 2005, SKA Breakthrough Science, in SF2A/Scientific Highlights 2005, ed. F.

Casoli, T. Contini, J.M. Hameury & L. Pagani, EdP-Sciences Conf. Series, pp. 53-56 • van Driel, W. 2005, Cosmology with the SKA, in SF2A/Scientific Highlights 2005, ed. F. Casoli,

T. Contini, J.M. Hameury & L. Pagani, EdP-Sciences Conf. Series, pp. 701-704 Conference presentations:

1. Pulsars with ALFA and Embrace, presentation at the French Pulsar Workshop, Paris, France, 16-17 January 2006 (S. Torchinsky, SKADS Project Scientist), http://lpce.cnrs-orleans.fr/~pulsars/PSRworkshop/AtelierPulsar.pdf

2. French participation in SKA, presentation at the LOFAR Workshop, Meudon, France, 28-29 March 2006 (S. Torchinsky, SKADS Project Scientist), http://www.lesia.obspm.fr/plasma/LOFAR2006/CR_Atelier_francais.pdf

3. SKA: a billion galaxies in HI (in French), presentation at the prospective workshop of the French Programme National Galaxies, Paris, France, 01/3/2006 (W. van Driel, DS7 Manager), http://aramis.obspm.fr/PNG06/index.php

DS7: Web-based activities:


In addition to the DS7 Deliverables, the DS7 team also provides a short article on progress within SKADS to the Newsletter of the International SKA Project, which is made available twice a year through the website www.skatelescope.org, and it will be responsible for the SKADS Newsletter, which will be made available twice yearly through the SKADS website. The DS7 team is responsible for the contents of the SKADS website http://www.skads-eu.org The DS7 team actively uses the SKADS wiki pages http://webmail.jb.man.ac.uk/skadswiki (access restricted to SKADS participants) as a tool for achieving its goals. DS7: Contacts with potential users outside the consortium: The DS7 team actively participated in meetings that were aimed at stimulating the participation of scientists and engineers from other scientific communities (notably astro-particles research) in SKA science and, potentially, in SKADS activities. • Meeting at the Observatoire de Paris, Meudon, France, 17/01/2006 • Meeting at the Laboratoire de l’Accelerateur Lineaire, Orsay, France, 13/06/2006 • Meeting at the College de France, Paris, France, 7/07/2006 General outreach The SKA project – towards a giant international radio telescope (in French), presentation at the BEATEP (Brevet d’Etat d’Animateur Technicien d’Education Populaire) astronomy training course, Marly-le-Roi, France, 07/2/2006 (W. van Driel, DS7 Manager) http://www.obspm.fr/~webufe/beatep/


Annexes

Annex 1 – Summaries and main conclusions of the General Meetings (section 1.2) Summary of 1

st meeting of the full SKADS Board January 26, 2006

This one day meeting took place in Zaandam. After some deliberation the meeting appointed Professor Dr. Peter Wilkinson from the University of Manchester, Jodrell Bank Observatory as Chair and Dr. Franco Mantovani from Istituto di Radio Astronomia – INAF as Vice Chair (in his absence), which was happily accepted. The meeting went through considerable deliberations regarding the contents of the Consortium Agreement and the collected information was taken back as advice to the next version. The meeting was assisted by a legal advisor in particular regarding IPR issues. The Project Coordinator took it on him to get the final version ready before the next meeting of the Board. In this discussion it was agreed to change the name of the Executive Committee, as mentioned in the Description of Work, into Coordination Committee with additional representatives from Spain and Germany. The constitution of the SKADS Project Management was discussed and Dr. Steve Torchinsky from l’Observatoire de Paris was confirmed as Project Scientist and Dr. Andrew Faulkner from the University of Manchester as Project Engineer. At this point in time the function of Project Manager to be filled in by ASTRON was not yet completed. Some discussion took place on the representations from the US and China as observers to the Board and the meeting generally agreed that they would be invited by the Chair for the next meeting. The Director of the International SKA Project Office expressed his satisfaction with the large number of SKADS persons appointed recently in SKA Working Groups. This was agreed at the SKADS kick off meeting in November, 2005.


Summary of 2nd

meeting of the full SKADS Board June 29-30, 2006 This was a 1½ day meeting in Zaandam. Good general progress, both technical and scientific, was reported by the Project Engineer & Scientist. The Coordinator expressed the general concern that the late start in November 2005 and the receipt of the advance payment only in January 2006 has caused a slower ramp up on the project than planned and felt desirable. This was also confirmed by spenditure profiles shown by the Project Manager, André van Es from ASTRON, who took up office in March, 2006. The Board expresses the wish to implement measures to get a faster speed up so as to minimize the danger of delaying the Mid Term Review. Essentially all Design Studies and Tasks are formally started through kick off meetings since the last Board meeting. Project Engineer Andrew Faulkner presented the SKADS Benchmark Design (SBD). This strategy was motivated by the potential of low cost small dishes for high frequencies after the visit of the Coordinator and the Project Engineer to the SETI Institute in California. The SBD consists of an aperture array up to about 1 Ghz. and ATA-like dishes for higher frequencies. The Consortium Agreement was generally approved and sent around. Signatures are being collected. To maximise the benefit of new scientific flow of insight to SKADS the Board approved the SAG (Scientific Advisory Group). This SAG will be coordinated by the Project Scientist and will consist of a small group of outstanding active scientists. The recommendation to draw membership from among the European members of the Scientific Worksing Group of ISPO was approved. An overview was given by the connections between SKADS and ISPO, which could be summarized as follows: SKADS Board: standing invitation to ISPO Director and Project Engineer SKADS Board: standing invitation to USSKA Consortium and NAOC SKADS Project Scientist: proposed to ISPO Director to be a member of international SWG A strong costing link with ISPO was agreed and the SKADS costing will be coordinated by DS3 (Network and Output Data). A major agenda item was the discussion of the response of SKADS to the SKA Reference Design and it was agreed that DS2 (Science and Technical Simulations) and DS3 (Network and Output Data) will explore both the Reference Design and the SKADS Benchmark Design. A discussion was held about the smooth transition from SKADS R & D into FP7 to maximize the synergy, possibly with a role of the European SKA Consortium. Phil Diamond (RadioNet Coordinator) gave an update of the FP7 Call for Preparatory Actions and its Terms of Reference. SKADS Board received a request from a representative from Portugal to investigate the possibilities of closer connections to SKADS and the Board agreed on an observer status of the Portuguese representative at the Board meeting. Also visits will be paid by SKADS Management to detail links at SKADS activities. Annex 2 – Updated non-confidential Project information (section 1.4)


Annex 3 – CD-ROM with the deliverables produced during the reporting period (section 2)


B. Management Report (financial information)


1 Justification of the resources deployed

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