A Ka-Band High Efficiency Doherty Power Amplifier MMIC using GaN-HEMT for 5G Application

Abstract

This paper has reported a Ka-band (27-40GHz) high efficiency doherty power amplifier (DPA) MMIC (Monolithic Microwave Integrated Circuit) using GaN-HEMT for 5G application. To realize a high power and high efficiency DPA in Ka-band, a parasitic output capacitance (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ds</sub> ) is compensated by shunt inductor through resonance using high accuracy large-signal model. As a result, the fabricated 2-stage DPA using GaN-HEMT achieves a measured saturation output power of 35.6dBm (3.6W) and peak PAE of 25.5%. PAE of 22.7% and 19.5% are obtained at 6dB and 8dB back-off, respectively. In addition, the measured ACLR is -25/-27dBc and PAE is 20.5% at average output power of 27.6dBm under 100MHz 64QAM modulated signal. To the best of author's knowledge, the developed DPA is state-of-the art 5G amplifier at Ka-band.