Flicker noise reduction using GaAs microwave feedforward amplifiers

Abstract

This paper describes the analysis and design of a microwave feedforward power amplifier optimised for maximum close to carrier flicker noise suppression. Three amplifier topologies are analysed with respect to system noise figure and ease of production. Potential problems affecting error signal cancellation are highlighted and discussed. A feedforward 1 W power amplifier offering 20 dB flicker noise power reduction over 1-30 kHz offset from a 7.7 GHz carrier has been produced.