A simplified switch-based GaN HEMT model for RF switch-mode amplifiers

A simplified switch-based model is proposed for GaN-HEMTs, which is suitable for the design of switch-mode-type amplifiers, in both time and frequency domain. The model is validated using a current-mode class-S circuit, for signals up to 5 Gbps. This amplifier structure allows to check two important characteristics of this model: its capabilities to operate as a switch between two digital states and the broadband capabilities. Though much simpler than the conventional nonlinear HEMT models the simplified model shows very good agreement with measurements and excellent stability in time-domain simulations.