A compact Doherty power amplifier for massive multi‐input multi‐output applications

Abstract

A Doherty power amplifier composed of GaAs IPDs (Lange coupler and Doherty combiner) and GaN MMICs (carrier amplifier and peaking amplifier) is presented for 5G massive multi‐input multi‐output (MIMO). No input phase compensation circuit and no output offset lines were used for a compact design and the assembled Doherty power amplifier is as small as 6.6 mm × 3.6 mm with a saturation output power of 46 dBm. The asymmetric Doherty power amplifier exhibits a gain greater than 27.8 dB, PAE greater than 39.8% at average output power of 38 dBm, and ACLR less than −27.7 dBc using a 20 MHz LTE signal with 7.5 dB PAR across 3.6‐3.8 GHz.