Channel Temperature Analysis and Nonlinear Thermal Model of AlGaN/GaN HEMTs Including Steady-State and Transient

The thermal analysis of GaN-based high electron-mobility transistors (HEMTs) is carried out from steady-state and transient aspects, respectively. An improved closed-form nonlinear thermal model based on device structure is proposed. In the steady-state case, the plane layer is added on the basis of the original partition, and the effect of thermal boundary resistance on channel temperature is also considered. In addition, the operating temperature of each gate finger is predicted based on the thermal coupling, and the nonlinear thermal model is extended to the transient by combining the thermal time constant. The validity of our presented model is verified by comparing the simulation results with the experimental data. Furthermore, this model is also embedded in the surface-potential-based current model to verify the self-heating effect in the circuits.