High-efficiency power amplifier MMICs in 100 nm GaN technology at Ka-band frequencies

Three power amplifier MMICs at Ka-band frequencies are reported in this paper. The MMICs are realized using AlGaN/GaN HEMTs with a gate length of 100 nm. Two single-stage amplifiers are presented to highlight the potential of this GaN technology. A dual-stage amplifier is designed to reach high power performances. In continuous-wave (CW) operation, MMICs have provided up to 1.4 W, 2.4 W and 4.7 W of output power associated with (in this order) 41%, 33%, and 28% of PAE, respectively. The dual-stage MMIC delivered an output power higher than 4 W, associated with 27% of PAE and 9.8 dB of power gain from 29 GHz to 31 GHz.