采用电荷控制理论和载流子速度饱和理论的物理分析方法 ,并结合 Statz、Angelov等经验模型的描述方法 ,提出了常温下针对 4 H- Si C射频功率 MESFET的大信号非线性电容模型 .此模型在低漏源偏压区对栅源电容 Cgs强非线性的描述优于 Statz、Angelov等经验模型 ,计算量也远低于基于器件物理特性的数值模型 ,因而适合于大信号的电路设计与优化 A large-signal nonlinear capacitance model for a 4 H-Si C RF power MESFET at ambient temperature is proposed using the charge control theory and the physical analysis of the carrier-based speed saturation theory, combined with the description of empirical models such as Statz and Angelov. The non-linearity of the gate-source capacitance Cgs in the low-drain source bias region is better than that of Statz, Angelov and other empirical models, and the computational load is much lower than the numerical model based on the physical properties of the device. Therefore, it is suitable for the design of large-signal circuits optimization