Accurate modeling of the electrothermal effects of GaN electronic devices is critical for reliability de- sign and assessment. In this paper, an improved temperature-dependent model for large signal equivalent circuit modeling of GaN HEMTs is proposed. To accurately describe the thermal effects, a modified nonlinear thermal sub-circuit which is related not only to power dissipation, but also ambient temperature is used to calculate the variations of channel temperature of the device; the temperature-dependent parasitic and intrinsic elements are also taken into account in this model. The parameters of the thermal sub-circuit are extracted by using the numerical finite element method. The results show that better performance can be achieved by using the proposed large signal model in the range of-55 to 125℃ compared with the conventional model with a linear thermal sub-circuit.
针对氮化镓高电子迁移率晶体管(GaN High Electron Mobility Transistor,GaN HEMT)小信号等效电路模型参数提取和优化过程中存在的误差累计问题,基于GaN HEMT 19元件小信号模型,提出了一种扫参与迭代相结合的参数提取算法.该算法在迭代过程中,每次使用比前一次更准确的元件值进行计算,可使结果趋向最优解.通过Matlab编程实现后计算结果表明,仿真与实测S参数在0.1~40GHz频率范围内吻合良好.
