非均匀耦合传输线瞬态响应灵敏度的分析方法

Sensitivity Analysis of the Transient Response of Nonuniform Coupled Transmission Lines

针对具有非线性负载的非均匀耦合传输线瞬态响应灵敏度分析困难的问题,提出了一种采用快速傅里叶变换的灵敏度分析方法——傅里叶变换法.该方法首先采用分段法将非均匀传输线均匀化,得到用无穷级数表示的非均匀传输矩阵,再通过对具有非线性负载的耦合传输线系统进行戴维宁等效,减少了瞬态响应非线性方程组数目,加快了计算的收敛速度,最后借助快速傅里叶变换得出时域内的传输线瞬态响应灵敏度.傅里叶变换分析法无需对耦合传输线进行解耦,能够分析任意类型传输线及任意负载.算例结果表明,在传输线分段数相同时,傅里叶变换法较微扰法的计算速度更快,当分段数大于16时,计算速度能提高37%以上.

Since the sensitivity of nonuniform coupled transmission lines with nonlinear loads is hard to analyze, a new method based on fast Fourier transform is proposed. Nonuniform transmission matrices expressed by infinite series form are derived by applying the piecewise decomposition technique. Based on the Thevenin＇s transmission equivalent network, the number of nonlinear equations of transient response is reduced, and the convergence performance is improved. The sensitivity of the transient response of transmission lines is finally obtained by employing the inverse fast Fourier transform. The proposed method can analyze all kinds of transmission lines and avoid complicated decoupled operations. Experimental results show that when the numbers of subsections are the same, the speed of the proposed method is faster than that of the perturbation method; and that the computing speed is increased by above 37% when the number of the subsections is more than 16.