非线性微波电路的波形平衡分析法

A New Method for Analyzing Nonlinear Circuit without DFT (Discrete Fourier Transform)

提出了一种适用于单频和多频激励非线性电路分析的波形平衡法，导出了非线性电路的波形平衡方程，从而把求解非线性电路的问题转化成为求解一个非线性方程组的问题．文中导出的波形平衡方程是非线性电路特性的完型描述，计算中未用到ＤＦＴ．该方法具有简单，通用性强的特点。

Kundert et al in 1988, Hwang et al in 1989[2], and Ushida et al in 1989[4] all proposed methodsof analyzing nonlinear circuit. In the authors' opinion, their common deficiency is: for time-frequency transformation of almost periodic signals, such transformation is possible to perform but brings insome features not quite satisfactory.This deficiency, in the authors' opinion, occurs because DFT, not suitable for almost periodicsignals, were employed in Refs.[2-4].In this paper, the authors take continuous Fourier transform. The authors derive for time domain waveform balance equations, whose unknowns arc voltage phasors at all ports of circuit. Continuous Fourier transform can express satisfactorily continuous signals as compared with approximation unavoidable when DFT is used.As usual, Newton-Rapbson method is used to solve waveform balance equations.Numerical example indicates that the method proposed by the authors works out very well.