基于Agrawal模型的双绞线受扰机理与场线配置

Disturbed mechanism and field-line configuration of Twisted-Wire Pair based on Agrawal model

摘要:

电磁环境日益复杂，电磁兼容性问题涌现，各类干扰对传输线信号传输造成的影响不容忽视。基于经典场线耦合Agrawal模型，结合时域有限差分法(FDTD)对双绞线(TWP)各场线参数的电磁耦合效应进行定量计算，为减少受扰的场线配置提出指导性意见。总结了各参数对双绞线电磁耦合效应的具体影响：线长会影响端接负载处的选频特性；节距影响较小，较小的节距会减小耦合；距地高度会显著影响电磁耦合，且高度越高耦合越强；决定入射方式的入射角、方位角和极化角对电磁耦合效应均有不同程度的影响，通过电场切向分量切片图可知，对某一角的分析需要考虑到其余两角的影响。双绞线传输线的电磁耦合效应与场线参数密切相关，各参数均有不同程度的影响，借助本文模型的计算与对结果的分析，可获得有效的低受扰双绞线传输线配置。

Abstract:

Due to the complex electromagnetic environment, Electromagnetic Compatibility(EMC) problems emerge, and the impact of interference on transmission lines can not be ignored. Based on the classical field-line coupling model―Agrawal model, this paper calculates the electromagnetic coupling effect of each field-line parameter of Twisted-Wire Pair(TWP) with Finite-Difference Time-Domain(FDTD), and gives guidance on the field-line configuration to reduce the disturbance. Finally, the influence of each parameter on the electromagnetic coupling effect of the interference source on the twisted pair is summarized: length will affect the frequency selection characteristic at the terminal load; the effect of pitch is small, and the shorter pitch will decrease the coupling; the height significantly affects the electromagnetic coupling, and the higher the height, the greater the coupling is; the incidence angle, azimuth and polarization angle all influence the electromagnetic coupling effect differently, and it can be seen from the tangential component of electric field's slice diagram that the analysis on one corner needs to take into account the influence of the other two corners. The electromagnetic coupling effect of TWP transmission line is closely related to the field line parameters, and each parameter shows different degrees of influence. Through the calculation of the model in this paper and the analysis on the results, an effective configuration of low-disturbed TWP transmission line can be obtained.