UC Davis

The authors present the design and development of a two stage Doherty power amplifier (DPA) in the Ka-band. The amplifier is fabricated in a 0.15-μm gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (pHEMT) process. The DPA has a centre frequency of 26.6 GHz, a measured small signal gain of 10.5 dB, output power at 1-dB compression point (P1 dB) of 26.9 dBm, maximum power added efficiency (PAE) of 42%, and PAE of 32% at 6 dB back-off power. To the best of the author's knowledge, this DPA is the first millimetre-wave (mm-wave) power amplifier to achieve a record 32% PAE at 6-dB back-off power from 26.9 dBm at Ka-band.