Linearization of power amplifiers through injection of low-frequency second-order products

Abstract

This paper reports on a new linearization technique that is applicable to high power amplifiers used with digitally modulated single- or multi-carrier signals. The analysis and simulation results demonstrate that substantial improvement in intermodulation distortion (ACPR and CLR) can be achieved with relatively small signal processing overhead and minimal added hardware complexity. This paper attempts to present the underlying concept by applying frequency domain analysis to an amplifier modeled by a truncated power series. The technique has been successfully applied to EDGE and QPSK-modulated carrier signals. Simulation and practical results are presented to demonstrate its effectiveness.