Atacama Large Millimeter/submillimeter Array Karl G. Jansky Very Large Array Robert C. Byrd Green...

Atacama Large Millimeter/submillimeter Array

Karl G. Jansky Very Large ArrayRobert C. Byrd Green Bank Telescope

Very Long Baseline Array

Band 2 Workshop IntroductionBand 2 Design Study Summary

E. Bryerton, M. Morgan, M. Pospieszalski, S. Srikanth, K. Saini, D. Vaselaar

ALMA

2

Band 2 Workshop Schedule

09:00-09:30 Design Study Overview (Bryerton)09:30-09:50 GBT 4mm Receiver (Frayer)09:50-10:10 UAz 4mm Receiver - Part 1 Technical (Lauria)10:10-10:30 UAz 4mm Receiver - Part 2 Observations (Ziurys)10:30-10:45 Break [WebEx & audio inactive]10:45-11:10 Star Formation (Oberg)11:10-11:35 Deuterium-Bearing Molecules in Dense Cores (Schnee) 11:35-12:00 The Evolution of N2H+ and N2D+ in the Protostellar Phase (Tobin)12:00-12:30 NH2D and CH2D+ (Wootten)12:30-13:30 Lunch (supplied by workshop) [WebEx & audio inactive]13:30-14:00 Studies of Star Formation in the Nearby Universe (Mangum)14:00-14:20 Redshifted Molecular Gas (Frayer)14:20-14:45 Discussion of science drivers 14:45-15:15 Panel Discussion15:15-15:30 Break [WebEx & audio inactive]15:30- Workshop summary and adjourn

Band 2 Workshop Charlottesville, VA 29-May-2013

ALMA

Band 2 Frequency Range

Band 2 Workshop Charlottesville, VA 29-May-2013 3

• Band 3 is 84-116 GHz• Current Band 2 Spec is 67-90 GHz

ALMA

4

Where Would Band 2 Go?


ALMA

Band 2 Workshop Goals

• Focus on uniqueness of science case• Some technical overviews at beginning for context• Open discussion encouraged• Questions now:

– How much overlap with band 3 is desirable?– Is extending band 3 below 84 GHz (to ???) an option?

Only if performance in current band 3 range is unaffected?

• Question to answer in ~2 years time– Is full installation of band 2 receivers on ALMA worth the

approximate $12M price tag?


ALMA

6

ALMA Development Program

• Funding lines in NA, EU, and EA• Two types: Design Studies & Development Projects• Development Projects

– Funding ramps up to $13.6M per year total from all partners in 2015

– ~$5M per year from NA– Required ASAC approval and JAO coordination

• $500K per year per partner in design studies (strictly regional)– One-year, <$200K– Current NA and EU band 2 efforts are design studies


ALMA

Current Development Projects

• Band 5 Construction– European led effort for full installation of band 5 on all

antennas– ESO spending ~$16M from 2013-2017 (all their project

funding)– NA-NRAO supplying LO (~$3M)

• Fiber Connection OSF-Santiago– 25x increase in data rate

• ALMA Phasing Project (VLBI)– $0.52M from ALMA-NA, remaining funds from NSF MRI

• Band 1 (EA)– Nov. 2012: ALMA Board approved development of prototype

band 1 receiver


ALMA

8

NA FY14 ALMA Development Call for Proposals

• Development Projects– $4.3M total available in FY14 and FY15– $1.5M maximum award (over two-year period)

• Design Studies– $1M available in FY14– Will be another call for FY15 ($500K available)


ALMA

9

European Band 2 (+3) Design Study• 18-month study begun in June 2012 (STFC / IRAM / INAF)• Deliverables: Science case, study of key technologies to

develop a band 2 or a band 2+3 cartridge design• Science Workshop held earlier this week


ALMA

10

NA Band 2 Design Study Overview• Joint NRAO-ARO Study• Oct. 2012 – Sep. 2013, $100K• Concentrate on demonstrating technology readiness of key

components– Low-noise amplifiers– OMT– Optics– Downconverter

• Science Motivation– Unexplored bandwidth, especially with interferometry– Deuterated species in cold cores– Galaxies at intermediate redshift– Complex organics


ALMA

Band 2 Gain/Noise Budget


Component/Stage Gain (dB) Noise Temperature (K) TEQ (K) referenced to the input

Lens/Window (297K) -0.16 11.1 11.1IR Filters (15K, 110K) -0.1 2.5 2.6Feedhorn (15K) -0.1 0.35 0.4OMT (15K) -0.1 0.35 0.4Cryogenic LNA (15K) 30 30 33.4Cryogenic Isolator (15K) -1 3.9 insignificantCryogenic Postamp (15K) 25 80 0.1Waveguide Feedthru (297K) -1 77 insignificantDonwnconverter (297K) -15 5000 insignificantWarm IF Amplifier (297K) 20 175 insignificantTotal 57.5 48.0

Table 2: Preliminary gain and noise budget for the ALMA band 2 receiver.

• Current ALMA Band 2 Noise Specification: 30 K SSB over 80% of the RF band and 47 K SSB at any RF frequency in the band, where the RF band is defined as 67-90 GHz. • Given baseline optics design (warm refractive optics), this is extremely difficult and

perhaps impossible (requires LNA with <15K noise temperature)• Slightly more realistic would be cold lens and a LNA with 20K noise temperature• Really need reflective optics, but may not fit (currently under study)

ALMA

12

Band 2 Turnstile-Junction OMT


• X-band (8-12 GHz), Ku-band (11-18 GHz), and Q-band (35-52 GHz) versions already demonstrated

• Band 2 version (currently in fabrication) will be ~32 grams (not including #0-80 screws)

ALMABand 1 OMT Measurements

13Band 2 Workshop Charlottesville, VA 29-May-2013

• Three Band 1 OMTs fabricated and measured

ALMAInsertion Loss In Al, Au Band 1OMTs


Gold PlatingNominal zincateAlkali copper : 25μ “

Pur-a-gold 125: 50μ “

S21 0.3 to 0.35 dB

Theory 0.34 dB at 40 GHz for AuPredicted S21 of 0.12 dB at 15K

ALMAProposed Band 1 OMT and Amplifier Layout


• Band 2 Cartridge layout will be similar

ALMA

60 65 70 75 80 85 90 95 1000

20

40

60

80

100

120

140

160

180

200MMIC-A1

MMIC-A2

MMIC-A3

MMIC-B1

WM022C

WM024C

WM025C

WM026C

WM027C

WM060C

Frequency (GHz)

No

ise

Tem

p [

K]

Low Noise Amplifiers for Band 2


3-stage MMIC LNA (MMIC-A and MMIC-B two different designs)

6-stage hybrid LNA (WM###)

ALMA

Low Noise Amplifiers for Band 2


• Two 35nm MMIC designs have been tested, both 3-stage with ~30dB gain• 2 of 3 35nm wafer runs so far have given good cold results (4th run preliminary results encouraging)• Samples from APRA3 35nm wafer recently delivered, will be tested this summer• Broadband Cryo3 MIC LNA to be tested this summer• Current generation of 35nm MMIC design are 3-stage, 30 dB gain. Would really like 4-stage, 40 dB gain (eliminates need for 2nd cold LNA)

ALMA

Proposed Band 2 Block Diagram


11

0 K

& 1

5 K

IR

Filt

ers

Ort

ho

Mo

de

T

ran

sdu

cer

Win

do

w (

Le

ns?

)

Bia

s F

ilte

r C

ard

Cold Cartridge Assembly 40.02.02 Warm Cartridge Assembly 40.10.02

110 K Stage15 K Stage

HFET Amplifiers

HFET Amplifiers

WR-12 Waveguide

RF: 67 – 94 GHz

LO: 76 – 85 GHz

Amplifier Bias

IF Outputs4 – 12 GHz

DC

Pow

er

Op

tical

Re

fere

nce

S

ign

al

Fir

st L

O

Off

set

Re

fere

nce

M&

C

Lin

es

Pol-0

Pol-1

ICD1

ICD2

ICD3

ICD4

ALMA Band-2 Receiver67 – 94 GHz

Top Level Block DiagramKSS / 2012-01-30

ICD1

ICD2

ICD3

ICD4

ICD5

INTERFACESCold Cartridge Assembly to ALMA Cryostat

Cold Cartridge Assembly to Warm Cartridge Assembly

Cold Cartridge to Bias Module

FE LO to BE Photonics LO

Cold Cartridge Assembly to IF Switch Subsystem

ICD5ICD6

ICD6Warm Cartridge Assembly to Harness Plate

I/O Signals to/from the Receiver(Harness Plate)

FrequencyTripler

AMC

PA

X3

Photo Mixer

Phase Locked Loop

12.6 – 14.2 GHzC

art

rid

ge

Bia

s M

od

ule

4

0.0

4.0

2

LO M&CPower

Amplifier Drain BiasPA

2SB Processor2 Repeats (for Pol-0 & Pol-1)

Pol-0

LO for Pol-1

90o

90o

MC

DP

LL

Warm IF Amplifiers

Pol-1

Pol-0 Pol-1

YTO

USB IF

LSB IF (?)Horn

+Lens?

X2

FrequencyDoubler

ALMA

Band 2 Multi-Chip I/Q-Mixer

LO=75 GHz

LO=80 GHz• Commercial MMIC mixers• Machined RF quadrature

hybrid and LO splitter• Tested with external Band

6 IF hybrid (coaxial, not shown)


ALMA

Band 2 MMIC I/Q-Mixer

Chip PhotoSimulated Performance


(fixed IF)


The National Radio Astronomy Observatory is a facility of the National Science Foundation

operated under cooperative agreement by Associated Universities, Inc.

www.nrao.edu • science.nrao.edu

Atacama Large Millimeter/submillimeter Array Karl G. Jansky Very Large Array Robert C. Byrd Green...

Documents

Transcript of Atacama Large Millimeter/submillimeter Array Karl G. Jansky Very Large Array Robert C. Byrd Green...