Transcript Slide 1

LNA progress
4th SKADS Workshop, Lisbon, 2-3 October 2008
LNA progress
Dr Danielle Kettle
1
Current work overview
• LNA designs to perform system tests of 2 PAD and
validate 2PAD front-end concept
• Concentrating on differential designs but have 1 singleended design in fabrication
• Characterising devices at various possible operating
temperatures (including commercial devices)
• Testing and test plan issues
• Array cross-coupling
4th SKADS Workshop, Lisbon, 2-3 October 2008
LNA progress
Dr Danielle Kettle
2
Device characterization
• Measuring and characterizing devices in terms of small
signal and noise parameters
• Range of temperatures: 350K – 77K
• On-wafer and packaged tests
• Current devices under test:
– 70nm GaAs mHEMT
– 100nm InP pHEMT
– 0.5um GaAs pHEMT E-mode
– 0.5um GaAs HEMT D-mode
4th SKADS Workshop, Lisbon, 2-3 October 2008
LNA progress
Dr Danielle Kettle
3
LNA Design I
• Single-ended MMIC LNA using 70nm mHEMT process
at OMMIC
– Bandwidth 300 MHz – 3 GHz
– Simulated noise temperature ~ 22K
– Simulated gain ~ 35 dB
– Delivery due October 2008
4th SKADS Workshop, Lisbon, 2-3 October 2008
LNA progress
Dr Danielle Kettle
4
LNA Design II / III
•
Differential LNA – 2 designs
– Using COTS components
– FHC40LG and ATF35143 (lower noise resistance) (commercial
GaAs HEMTs / pHEMT)
– Input impedance designed for antennas developed by UoM and
ASTRON
– Prototype I measured at room temperature
– Construction of prototype II underway – measurements
scheduled for end of October 2008
Personnel responsible for LNA design MUST consider
integration with antenna AND packaging issues
4th SKADS Workshop, Lisbon, 2-3 October 2008
LNA progress
Dr Danielle Kettle
5
Array cross-coupling
• Noise implications of antenna array cross-coupling
– Investigating fundamental principles
– Developing ADS model
– Performing measurements on commercial packages LNAs
4th SKADS Workshop, Lisbon, 2-3 October 2008
LNA progress
Dr Danielle Kettle
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Conclusion
• Transistor modeling and optimization (still) crucial!
• Noise budget leaves not much room in 35K target
• Closer cooperation and system noise tests required
• And, Steve T, we indeed want to work in phase!
4th SKADS Workshop, Lisbon, 2-3 October 2008
LNA progress
Dr Danielle Kettle
7