X-Band GaN-HEMT LNA performance versus robustness trade-off

In this paper design, fabrication and test of three X-Band robust LNA MMICs in microstrip GaN technology are presented to better understand the key aspects of performance versus robustness trade-off for said components. In particular LNAs with different number of amplification stages, input device gate peripheries and topologies have been evaluated with the objective of achieving in the 8–11 GHz frequency range a NF better than 2.5dB, associated gain of circa 20 dB and overdrive power survivability better than 38 dBm. On-wafer measurements of LNA performance and robustness have been carried out in order to evaluate the incident power failure mechanisms and to individuate the best design approach for optimum performance/robustness trade-off. With one of the three LNA designs a NF ass of 20 dB and P 1dB > 15dBm has been achieved in the entire 8–11GHz bandwidth. Said MMIC can withstand a 39dBm CW input power without any observable performance degradation.