Compact Physical Modeling of Trapping Effects for Microwave GaN HEMT

Physical modeling of GaN HEMT will help understand more physical features. This paper presents a large-signal model combining quasi-physical zone division (QPZD) drain-source current model and surface potential capacitance model. A Shockley-Read-Hall (SRH) based model is proposed to characterize the trapping effects. And the SRH model can be implemented into SPICE-like simulation software using a sub-network. Besides, a simplified ASM-HEMT capacitance model is proposed by neglecting the thermal voltage. An AlGaN/GaN HEMT with a large gate periphery of 2.4 mm is used for model validation. The results show that simulations and measurements have achieved a good agreement on pulse I-V, S parameters, and large signal performance.