双绞传输线电磁兼容特性的FDTD分析

将曲线坐标系中的时域有限差分法（FDTD）拓展到空间为任意媒质情形，然后针对双绞传输线的特殊结构综合运用曲线坐标系、圆柱坐标系、旋转坐标系和子域连接法进行空间网格划分、FDTD建模，并通过求解双绞传输线和平行传输线的特性阻抗对该建模的准确度进行了验证，最后在空间线源激励下对双绞线和平行线的电磁兼容特性进行了比较，可以看出双绞线对空间电磁场的耦合能力远远低于平行线。

The analysis of twisted-pair transmission lines′ EMC property by using FDTD method

First, the finite difference time domain (FDTD) method in curvilinear coordinates is extended to a space with arbitrary medium. Then, for the special structure for twisted pair transmission line, curvilinear coordinates, cylindrical coordinates, rotational coordinates and sub region connection method are used partition and it is modelled for FDTD calculation. The precision of this model is tested by calculating the characteristic impedances of twisted pair transmission line and parallel transmission line. At last, a comparison between the electromagnetic compatibility (EMC) for twisted line and parallel line is made, and the results clearly show that coupling ability of twisted line is far smaller than that of parallel line.