Power amplifier design considerations using a simplified model for the transistor

This paper discusses the use of a simplified static model for representing high-frequency transistors in the initial stage of power amplifier design. Focusing on gallium nitride high electron mobility transistors, the application of the model to two different scenarios is shown. Firstly, the model is proven to be effective in initiating the design of a broadband PA for Ku-band, and results are compared to the use of a full non-linear model showing a good agreement. Secondly, the model is used to analyze the sensitivity to load mismatch of different PA architectures, including balanced, Doherty, and load-modulated balanced amplifiers and offering some interesting insight into this very relevant problem in modern wireless transmitters.