Basic Nonlinear Analysis of Class-S Power Amplifiers based on GaN Switching Transistors

A Class-S Amplifier architecture theoretically offers high efficiency and nonlinearity resistance. Class-S idea is assumed to base on ideal switches which work in two states - ON and OFF, and these conditions enable nonlinearity resistance. Real implementations are based on switching transistors which suffer on many limits which can contribute to nonlinear effects. This paper includes basic nonlinearity considerations of Class-S amplifier architecture based on GaN switching transistors. The analysis is focused on evaluating the impact of transistors´ nonidealities on the nonlinearity of amplifier´s system. Simulations are performed for a carrier frequency of 890.88 MHz assuming a 2 tone input signal. This paper describes the basic method of nonlinearity analysis for Class-S amplifier.