Advanced GaN/(In)AlGaN MMICs for applications in space from K-band to W-band frequencies

This paper describes recent advances in GaN/AlInGaN monolithically microwave integrated circuits (MMICs) on semi-insulating SiC for the frequency range from 18 GHz to 94 GHz based on the GaN25 and GaN10 technologies with gate lengths of 250 nm and 100 nm, respectively, High-power operation has been demonstrated in this work at K-band frequencies (downlink bands around 20 GHz, e.g. for multi-feed applications) and at Ka-band frequencies (around 30 GHz) in CW-operation with MMICs with very good gain beyond 20 dB and efficiencies (beyond 30 % at Ka-Band) which are very competitive to export controlled US processes on MMIC level. For even higher frequencies at V-(50-75 GHz) and E-band (71-84 GHz), a series of MMICs has been designed and realized which all produce measured output power levels beyond 27 dBm (500 mW). An E-band MMIC with 15 dB of gain produces more than 28 dBm of output power at 74 GHz, e.g. suitable for inter-satellite communication. The reliability of the GaN10 process with the small GaN10 gates (100 nm) has improved significantly after systematic re-evaluation for operation bias of 10-15 V and for typical GaN channel temperatures.