Independent Dynamic Gate Bias for a Two-Stage Amplifier for Amplitude and Phase Linearization

Abstract

This work describes an analog linearization technique for two-stage power amplifiers using gate bias modulation. Independently driving the gates of the first and second stage with a signal dependent voltage allows for theoretically perfectly flat AM/AM, AM/PM while sacrificing average gain. Using a GaN 10 W MMIC driving and a custom built gate tracker, and a target NPR of 24 dB, dynamic gate tracking improves the average output power by 1.25 dB and raises the PAE more than 4 % points for a 5 MHz white noise signal.