Dedicated Large-Signal GaN HEMT Model for Switching-Mode Circuit Analysis and Design

A novel large-signal gallium nitride (GaN) high electron mobility transistor (HEMT) model that focuses on and improves analysis and design of switching-mode power amplifiers (PAs) is presented in this letter. The proposed model can be constructed using standard dc and ac characterization measurements and easily implemented in any computer-aided design (CAD) software to simulate and design switching-mode amplifiers. The model can predict the behavior of a switching-mode PA accurately at saturation and, due to the proposed approach, also well in the weak compression region. Using the developed model, an inverse class-F PA is designed and fabricated for validation purposes. The prototype developed using the proposed model achieved power-added efficiency (PAE) of 67% for an output power of 36.7 dBm at 2.35 GHz. Comparison between simulation and measured results of the manufactured PA proves the validity and accuracy of the proposed model.