非均匀多导体传输线高频场线耦合分析中的边界条件

场线耦合问题是电磁兼容分析与电磁效应评估中的重要课题。经典场线耦合模型受限于准TEM波近似，在较高频率时将导致不可接受的模型误差。传输线超理论（TLST）建立了高频场线耦合模型，解决了经典场线耦合模型的困难。基于TLST介绍了非均匀多导体传输线的高频场线耦合模型，提出了三种不同终端负载情况下对应边界条件的设置方法。最后通过具体算例对比了高频模型和经典模型以及全波分析计算结果，证实了高频场线耦合模型的普遍适用性、边界条件设置的有效性和数值实现过程的准确性。

Boundary condition in analysis of high-frequency electromagnetic field coupling to non-uniform multi-conductor transmission line

Field coupling to transmission line is an important subject for electromagnetic compatibility analysis and electromagnetic effect evaluation. The classical models of field-to-transmission line coupling are limited by the quasi-TEM wave approximation, which leads to unacceptable model errors at higher frequencies. The transmission line super theory (TLST) has established the model of high frequency field-to-transmission line coupling and solved the difficulty of the classical models. Based on TLST the model of high frequency field coupling to the non-uniform multi-conductor transmission line is introduced in this paper. The boundary conditions in three cases of different terminal loads are also proposed. Finally, the results of some numerical examples of high frequency model are compared with the results of the classical models and the full wave analysis, which shows the universal applicability of the high frequency model, the validity of the boundary conditions setting and the correctness of the numerical implementation.