摘要：为了解EMI滤波器性能的影响因素及其具体影响，以滤波器的插入损耗为研究对象，建立了电容和电感的高频等效电路模型，研究了滤波器电容和电感的分布参数、源端和负载端阻抗及滤波器级数对插入损耗的影响，结果表明：电容和电感的分布参数降低了滤波器的整体滤波效果，电容的分布电感主要影响电容支路谐振点之后的高频段部分的滤波性能，电感的分布电容值的改变没有明显改变插入损耗的值；滤波器源端匹配低阻抗时滤波性能较好，滤波器负载端匹配高阻抗时滤波性能较好；滤波器级数每增加一级，插入损耗值增加量约为一个单级时的值，但谐振点没有改变。本文的结论对于EMI滤波器的设计有一定参考价值。
关键词：电磁脉冲；电磁干扰；滤波器；分布参数；插入损耗

Abstract: In order to know the factors that affect the capability of EMI filter, the filters Insertion loss was chosen as the research object, the high frequency equivalent circuit model of capacitance and inductance were erected, then the effects of capacitances and inductances distribution parameters, the resistances of source end and load end and filters series on insertion loss were researched. Results show that capacitances and inductances distribution parameters depress the capability of filter, the capacitances distribution inductance mainly affects the high frequency capability of filter after resonance point in capacitances spur track, and the change of inductances distribution capacitance doesnt make a big effect on the insertion loss. When the source end of filter is low impedance, the filters capability is higher, while when the load end is high impedance, the filters capability is higher. When the series of filter increases one, the value of insertion loss increases that of a single seriess value, but the resonance point doesnt change. The results in this paper can be a reference to design a EMI filter.
Key words: electromagnetic pulse; electromagnetic interference(EMI); filter; distribution parameters; insertion loss(IL)