Electronic multi-harmonic load-pull system for experimentally driven power amplifier design optimization

Abstract

This paper presents, for the first time, a multi-harmonic active envelope load-pull system allowing for the robust, high-speed characterization of devices used in modern microwave power amplifiers. Measurements of a commercially available 1W GaAs FET device demonstrate at least an eight-fold improvement in the measurement speed when compared to existing open-loop solutions. The developed active load-pull system, which instantly reacts, via baseband feedback, has the ability to set load impedances that are independent of changing device conditions. Thus it is similar to passive systems, but without the associated loss. This system is shown to be valuable in allowing the utilization of rapid, experimental, measurement driven optimization within the power amplifier design and yield analysis process.