Dr Danielle Kettle1 LNA progress 4 th SKADS Workshop, Lisbon, 2-3 October 2008 LNA progress

Dr Danielle Kettle2 LNA progress 4 th SKADS Workshop, Lisbon, 2-3 October 2008 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 single- ended design in fabrication Characterising devices at various possible operating temperatures (including commercial devices) Testing and test plan issues Array cross-coupling

Dr Danielle Kettle3 LNA progress 4 th SKADS Workshop, Lisbon, 2-3 October 2008 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

Dr Danielle Kettle4 LNA progress 4 th SKADS Workshop, Lisbon, 2-3 October 2008 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

Dr Danielle Kettle5 LNA progress 4 th SKADS Workshop, Lisbon, 2-3 October 2008 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

Dr Danielle Kettle6 LNA progress 4 th SKADS Workshop, Lisbon, 2-3 October 2008 Array cross-coupling Noise implications of antenna array cross-coupling –Investigating fundamental principles –Developing ADS model –Performing measurements on commercial packages LNAs

Dr Danielle Kettle7 LNA progress 4 th SKADS Workshop, Lisbon, 2-3 October 2008 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!