硅微波功率静电感应晶体管(SIT)非线性失真特性分析

Analysis of Nonlinear Distortion Behaviors in Silicon Microwave Power Static Induction Transistors(SIT)

本文讨论了介质盖栅SIT的基本特性。在SIT小信号S参数和静态特性的基础上,得到了SIT非线性等效电路模型。采用Volterra级数法,分析了包含三种主要非线性源的SIT微波功放的互调失真和增益压缩特性。指出引起SIT互调失真和增益压缩的主要原因是跨导G_m的非线性,其次是栅源电容C_(gs)的非线性变化和漏电导G_d的非线性变化的作用。还指出了SIT非线性失真与输入功率电平和偏置条件的关系。分析结果得到了实验的证实。

The basic features of gate-insulator-covered type SIT are discussed in this paper, A nonlinear equivalent circuit model of SIT is developed on the basis of small-signal S parameters and static characteristics of SIT.Adopting Volterra-series, we analyzed the intermodulation distortion and gain compression behaviors of a SIT microwave power amplifier, in which three main nonlinear sources are included. It is pointed out that the intermodulation distortion and gain compression of SIT are mainly caused by the nonlinearity of transconductance G_m, then by those of gate-source capacitance C_(gs) and drain conductance G_d in order. The dependence of the sIT nonlinear distortion on input power levels and bias conditions are investigated. The analytical results have been experimentally verified.