Design Method for UHF Class-E Power Amplifiers

This paper describes a method for designing single-ended high-efficiency switched-mode class-E UHF power amplifiers. The design procedure consists of a modified load pull transistor characterization from which a power/efficiency metric is calculated. Results for four prototypes using different device technologies are presented in detail. Amplifiers with Si-LDMOS, SiC-MESFET, GaN-HEMT on a Si substrate, and GaN-HEMT on a SiC substrate produce power over 40W with power-added efficiency greater than 75% and gain between 13 dB and 17 dB.