Large-signal stability and spectrum characterization of a medium power HBT using active load-pull techniques

Abstract

Large-signal stability and spectrum characterizations of a half-watt HBT at 2 GHz for a class AB bias point are reported. Constant power, constant power-added efficiency, constant current gain contours, and second and third harmonic generation level contours over the whole Smith chart are presented. The characterization setup is an automated high power, multi-harmonic, active load-pull system that is based on six-port techniques and frequency discrimination using a controlled band pass YIG filter. >