中文摘要：

当AlGaN/GaN HEMT输出高功率密度时,器件沟道温度的升高将引起电流的下降（自热效应）。提出了一种针对AlGaN/GaN HEMT改进的大信号等效电路模型,考虑了HEMT自热效应,建立了一种改进的大信号I-V特性模型,仿真结果与测试结果符合较好,提高了大信号模型的精度。

英文摘要：

The high power operation of AlGaN/GaN HEMTs may result in high junction temperature in the conduction channel and output current decreasing,which is commonly known as the self-heating effect.Based on an improved AlGaN/GaN HEMT large-signal model equivalent circuit,a new large-signal I-V model considering the self-heating effect has been presented in this paper.A good agreement between the model and experimental results is obtained.