A Ka-Band doherty power amplifier with 25.1 dBm output power, 38% peak PAE and 27% back-off PAE

Abstract

We present the design and development of the first fully integrated, two stage Doherty power amplifier (DPA) in the Ka-Band. The DPA is fabricated in a 0.15-μm GaAs pseudomorphic high electron mobility transistor (pHEMT) process. At 26.4 GHz, the amplifier achieves measured small signal gain of 10.3 dB, output power at 1-dB compression point (P1dB) of 25.1 dBm, peak power added efficiency (PAE) of 38%, and PAE of 27% at 6 dB back-off power. To the best of the author's knowledge, this Doherty circuit is the first fully integrated millimeter-wave amplifier that achieves the highest power and a recorded 27% PAE at 6-dB back-off and each unit amplifier has 2 stages.