等效导纳模型分析航天器VHF/UHF频段屏蔽效能

针对VHF/UHF频段航天器舱体屏蔽处理难度大的问题，提出一种基于等效导纳模型的屏蔽效能分析方法。该方法将屏蔽舱体孔缝等效为波导结构，基于变分法原理建立水平电容和垂直电感模型，对参数失配和舱体厚度影响进行导纳匹配和孔缝宽度参数修正。采用传输线理论建立屏蔽效能分析数学模型。算例对比表明算法具有较高的分析精度，可有效分析孔缝不位于舱体中心位置和孔缝长度非波长整数倍时的屏蔽效能，并可准确预测舱体的谐振效应。将其应用到航天器舱体屏蔽效能分析中，对比结果表明算法可有效满足工程应用要求。

Analysis of Spacecraft VHF/UHF Shielding Effectiveness Based on Equivalent Admittance Model

A shielding effectiveness analysis method based on the equivalent admittance model is proposed to overcome the difficulty of dealing with VHF/UHF shielding of spacecraft. The aperture is treated as a waveguide. The horizontal capacitive model and vertical inductive model are derived from the variation method. The parameter matching admittances and width correction method are also researched. The shielding effectiveness math model is researched based on the transmission line theory. It proves the accuracy of the method and usefulness in dealing with the aperture with arbitrary position and length-wavelength ratio, and it can analyze the resonant effect. The method has been used in analyzing the shielding effectiveness of a telecommunication cavity, and the result comparisons have demonstrated the effectiveness of the approach proposed.