System requirements (1)
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Transcript of System requirements (1)
Components & Subsystems
New generations of RF Amplifiers:from system requirements to technologies
Michel Caplot, Christian Robert, Michel Grezaud, Bernard Darges and Pascal Ponard
cw RF Workshop – CERN – March 2008
Components & Subsystems2
System requirements (1)
From System requirements to Technologies….and not the opposite way
System requirements do include technical performance but are not limited to these performance
Systems requirements should cover system life time
Cost of a system is not limited to purchasing cost: it clearly include Life Cycle Costs (LCC)
• Purchasing cost• Maintenance cost• System evolution cost• Supplier support cost• Spare part cost• ……
Components & Subsystems3
System requirements (2)
Systems Requirements
Technical performance
LCC including availability of spare parts over 2 or 3 decades
System architecture
System reliability
System availability (fault tolerance, graceful degradation, maintainability, testability, …)
Components & Subsystems4
Architectures (1)
Large klystron based RF amplifiers
Multi-IOT based RF amplifiers
High powerFew items to maintainCentralized architecture
Lower power at each stageEasy replacementDecentralized architecture with local control
Components & Subsystems5
Multi-coupled IOT based RF amplifiers
Architectures (2)
Multi-coupled Solid State based RF amplifiers
Coupling lossesGraceful degradationEasy replacement
Coupling lossesLow voltageObsolescence management
Components & Subsystems6
Architectures (3)
Architecture should not take into account technologies
Architecture is strongly dependent on requirements
Solid State vs. Electron Device architectures : really a debate ?
Solid State Electron Devices
Low voltage High voltage
Graceful degradation but coupling losses Some possible graceful degradation
Obsolescence management Few suppliers but existing (!!!)
Components not driven by science marketAbility to produce components some decades after system start
LCC (design evolution due to new components) LCC
In both cases, experienced high power RF designers are mandatory !!!
Components & Subsystems7
Electron device evolution - Klystrons & IOTs (1)
KlystronsKlystrons
1 GHz 10 GHz 100 GHz
10 MW
1 MW
100 kW
10 kW
IOT
CWKlystrons
PulsedKlystrons
MBK
EIK
µs Klystrons
1 kW
Radiotherapy SecurityIndustry
Radiotherapy SecurityIndustry
ScientificAccelerators& Fusion
ScientificAccelerators& Fusion
BroadcastBroadcast
DefenseDefense
<P>
f
Ppeak
IOTsIOTs
Components & Subsystems8
Electron device evolution – Triodes & Tetrodes (2)
DiacrodesDiacrodes1 MW
100 kW
10 kW
10 MHz 100 MHz 1 GHz1 MHz
TVTV
DiacrodesInductionInduction
LaserLaser
RadioRadio
Triodes & tetrodes
ScientificAccelerators& Fusion
ScientificAccelerators& Fusion
ScientificAcceleratorsScientificAccelerators
Triodes & TetrodesTriodes & Tetrodes
Components & Subsystems9
Electron device evolution – Solid State Device (3)
Solid State amplifiersSolid State amplifiers
1 W
1 kW
1 MW
Si/GaAs
PWM (S-class)
E classAB
classF class
PWM (S class)
C (D) class
AB class
C classA class
Si/SiC/GaN
1 MHz 1 GHz
Components & Subsystems10
Diacrode - A major evolution for tetrode technology (1)
Cathode
ControlGrid
ScreenGrid
Anode
The end capacitance is mainly done in this area
K
G1
G2A
K
G1
G2A
K
G1
G2A
K
G1
G2A
K
G1
G2AK
G1
G2AK
G1
G2A
K
G1
G2AK
G1
G2AK
G1
G2A
Two tetrodes
K
G1
G2A
K
G1
G2A
K
G1
G2A
K
G1
G2A
K
G1
G2AK
G1
G2A
K
G1
G2AK
G1
G2A
One Diacrode
Components & Subsystems11
Diacrode - A major evolution for tetrode technology (2)
0
0,2
0,4
0,6
0,8
1
1,2
1,4
1,6
1,8
20 30 40 50 60 70 80 90
Tetrode DiacrodeFrequency - MHz
cw Power - MW VSWR = 2.0:1
Both tubes with the same cathode
Components & Subsystems12
Solid State – Amplifier Class of Operation Impact (1)
100%
A
AB
B
C
D98%
0.1
Frequency, MHz
75%
65%
55%
25%
1 10 2713
80%
Thales new design
Si MOSFET Technology
500100
Am
pli
fie
r C
las
s o
f o
pe
rati
on
Eff
icie
nc
y,
%
Components & Subsystems13
Solid State – Amplifier structure Impact (2)
Si LDMOS Technology (low frequency)
No required tuning or adjustment90 % SMT technologyLast MOSFET technologyRoHS compliance
In case of component technology evolution, Pallets arechanging but not Case Interface and not Racks
Pallet
Case
Racks
10 kWComplete rack
600 WComplete rack
Components & Subsystems14
Solid State – GaN device for high frequency (3)
KORRIGAN : a GaN foundry for Europe
GaN TECHNOLOGY
RF power density x 10 Output power x 10 Power added efficiency x 2 Junction temperature > 250°C Voltage supply > 28V
Components & Subsystems15
Solid State – GaN device for high frequency (4)
Substrates
Epitaxy
Process
DieBank
AssemblyTest
FinalProduct
Delivery
CTH, ISOM, CIDA, PTOU.Roma TV, CNR IFN
GaN HEMT FoundriesSELEX, UMS (<-Tiger), QinetiQ
TNO, IRCOM, CTH
System HousesELT, SELEX, Thales,
Indra, EMW, SAAB, BAE ISOM
TNO
GaN epi-wafersPicogiga, QinetiQ
LiU, Tiger, ULE
U.Padova, ISOM, CIDA
NORSTEL
KORRIGAN : a GaN foundry for Europe
Components & Subsystems16
IOTs – Modularity based design (1)
DiamondTH793 IOTs450-850 MHz80 kW cw
TH713 IOTsL band16 kW cw
Components & Subsystems17
IOTs – Modularity based design (2)
Combined RF Output
Couplingcavity
Modularity allows for Fault tolerance through graceful degradation, due to the operation of each RF source at a lower power: in case of one source failure, two remaining can supply full power
Components & Subsystems18
Conclusion
New generations of RF amplifiers should be defined by System Requirements that include technical performance but also system operation requirements and Life Cycle Costs (and not only Purchasing Cost)
There is not a debate between Solid State and Electron devices: based on system requirements, technological answers may be based on a unique type or on a combination of technologies
Both Solid State and Electron devices have evolutions. SSD design based amplifier must incorporate an architecture that allows to mix different solid state technologies in order to take into account that science is not the market driver