Switch-based GaN HEMT model suitable for highly-efficient RF power amplifier design

A new approach to accurately model the transistor performance in radio frequency (RF) switching-mode operation is proposed. The purpose of the presented switch-based model is to facilitate and speed up considerably extraction and implementation of large-signal device models for computer added design (CAD). Only a small number of DC and low-frequency small-signal S-parameter measurements are required for the extraction of the complete set of element parameters of the model. Accuracy and efficacy of the nonlinear model in predicting the performance of a single-ended RF power amplifier (PA) is demonstrated by experimental results. For a PA based on a commercial GaN HEMT, measured output power and efficiency match with simulations over a broad frequency range. Moreover, robustness of the developed switch-based model is demonstrated by the design of a voltage-mode class-D PA.