Equivalent circuit model of GaN high electron mobility transistor with consideration of non-ideal effects using genetic algorithm

Abstract

This work proposes a semi-physical equivalent circuit model for GaN-based high electron mobility transistors (GaN HEMTs), taking into account the non-ideal effects of both the current source and resistance–capacitance components. The current source model is built based on both device operation and multiple model interfaces setup for important non-ideal effects, such as self-heating effects, channel length modulation, short channel effects, and so on. Moreover, according to the improved Meyer capacitance model with fringe capacitances, the non-linear capacitances of the GaN HEMT are modeled with a dependence on the bias voltages and gate geometry. The extraction of the model parameters is implemented accurately and efficiently in MATLAB through a genetic algorithm. Moreover, the capacitance model is established to be mathematically simple and Simulation Program with Integrated Circuit Emphasis (SPICE)-compatible for the design of GaN-based integrated circuits (ICs). The static and dynamic characteristics of GaN ICs were simulated and found to be in excellent agreement with the experimental results, validating that the established and well-packaged equivalent circuit model can be of great help to GaN HEMT development and IC design.