Chapter 7 - Class-E with quarterwave transmission line

Abstract

This chapter presents the results of exact time-domain analysis of the switchmode Class-E power amplifiers with a quarterwave transmission line. The load network parameters are derived analytically. The ideal collector voltage and current waveforms demonstrate a possibility of 100% efficiency without overlapping each other. The load network implementation including output matching circuit at RF and microwave frequencies using lumped and transmission-line elements is considered with accurate derivation of the matching circuit parameters. The switchmode Class-E power amplifiers with a quarterwave transmission line offer a new possibility for RF and microwave power amplification to provide the high-efficiency and harmonic-suppression operation conditions simultaneously. Design examples of 10-W 2.14-GHz Class-E GaN HEMT power amplifiers with parallel quarterwave transmission line and transmission-line filter are given and analyzed.