有孔箱体的电磁屏蔽分析
摘要：通过对电磁干扰、屏蔽及有孔箱体的实际屏蔽进行了系统全面地介绍。列举电磁干扰的几条主要危害，让人们认识到防电磁干扰的重要性，从而具体深入地研究防电磁干扰的重要方法——屏蔽。本文的研究重点是对电小孔的耦合理论进行了总结，给出了计算具有电小孔的无限大金属导体板屏蔽效能的1般计算方法，讨论和分析了在平面波源情况下，椭圆孔导体板对磁场的屏蔽特性，并用计算机模拟作图，根据图象具体分析其屏蔽特性。并将同面积的矩形孔进行对比。分析了不同情况下各种形状的优越性，对设计具有1定的指导意义。另外还模拟了相同面积情况下圆形与正方形的屏蔽特性曲线，并将它们进行分析与对比。还综合分析了不同形状的孔的屏蔽特性的相似点。最后将相同面积的孔阵与孔进行对比，介绍孔阵的优越性。并结合机箱的实际孔缝情况，对机箱的电磁屏蔽做了较全面的介绍。
关键词：电磁干扰；电磁耦合；屏蔽效能；孔；孔阵；金属导体板
Analysis of Electromagetic Shielding of cavity with Aperture
Abstract: This paper recommends. Electromagetic interference、shielding and the pragmatic shielding of cavity with aperture roundly and systemtically. The paper enumerates several main damage of electromagetic interfernence andd then inputs an important method of fighting against the electromagetic interference—shielding. This paper summarizes the theory dealing with electromagnetic penetration through electrical small aperture in conducting surfaces. A general method for calculating shielding effectireness of infinite metallic plale with small aperture is investigated. The case of plane wave soure is computed and the effects of ellipse aperture on shielding effectiveness are discussed, and use the computer to simulate the graph, and then analyse the shielding characteristic concrelely according to the graph. Through contrasting with the same area of rectangle aperthre, analysed the superiority of different shape apertures. This has some guilding significance to design. Besides simulating the graph of the shielding characteristics curve of the same area square and circular, we examines the resemblances of different shape apertures through contrasting the graphes. Finally, we contrast the same area of aperture and the aperture arrays, then presents the advantage superiorily of the aperture arrays. Integrating the practical situation of carity with aperture, the round presentations of electromagetic shielding of cavity are mentioned.
Keywords: electromagnetic interference, electromagnetic coupling, shielding effectiveness,aperture, aperture arrays, metallic plate
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