Comparison of static and memory predistortion in envelope tracking system

Abstract

This paper concentrates on finding optimal yet simple predistorter for an amplifier in envelope tracking (ET) system. The scope is to linearize AM-AM error statically by maintaining constant compression by polynomial fit to the envelope path. For static AM-PM predistortion, the path delay between RF and envelope paths is fixed. A set complex memory predistorters were also tested and compared to the static prediction. It was found that the ET transmitter linearity can be further improved by a simple memory predistorter by taking the path timing into account.