An Improved Nonlinear I-V Model for GaN HEMTs

In this article, an improved nonlinear model for gallium nitride high-electron-mobility transistors (GaN HEMTs) is proposed. Aiming at the problem of insufficient accuracy of the nonlinear DC model caused by the self-heating effect and trap effect in the traditional model, this thesis uses the Softplus function to improve the traditional nonlinear DC model and establishes a nonlinear DC model including the self-heating effect, which is verified by the three GaN HEMT devices of different sizes. The MSE of I_ds is less than 2.44 × 10⁻⁶. The traditional empirical basis model needs to calculate the partial derivative of the current expression with respect to V_ds, which is tedious and complicated. The proposed model can be directly used to fit the G_m. The verification results show that the MSE of the G_m is less than 1.07 × 10⁻⁴, which proves the effectiveness of the equation.