Doherty power amplifier : comparison between standard Doherty and Bias Tunning Doherty

Abstract

The goal of this project is the design, implementation and characterization of a Doherty Power Amplifier (DPA) with bias tuning at 3.5 GHz. The transistor used is a commercial GaN HEMT from Cree inc., with a class AB for the main and a changing class C to AB for the peak. The maximum power provided by the DPA is 28.5W. The efficiency is 67.7% at saturation, and 60.3% at 6 dB back-off. The maximum gain is 14.7 dB with a more linear function than the standard DPAs