【摘要】：隨著電子技術(shù)向高頻化和高集成化發(fā)展,幾乎所有的設(shè)備都處于周圍電磁場(chǎng)的潛在影響中,電磁兼容越來(lái)越受到重視。金屬腔體具有良好的電磁屏蔽效果,是電磁兼容的重要手段。由于設(shè)備通風(fēng)、散熱以及外界觀察的需要,腔體上不可避免的存在開孔,而開孔是影響腔體屏蔽效能的關(guān)鍵因素。由于設(shè)備共存于一個(gè)緊湊的空間中,使得敏感設(shè)備常常處于干擾源的近場(chǎng)區(qū)。在近場(chǎng)區(qū),電磁場(chǎng)強(qiáng)度和波阻抗具有不均勻性,一些遠(yuǎn)場(chǎng)的結(jié)論不再適用,因此,研究開孔腔體的近場(chǎng)屏蔽效能具有十分重要的意義。本文基于時(shí)域有限差分法,分析了開孔腔體的近場(chǎng)屏蔽效能的影響因素及其規(guī)律�；谡辉囼�(yàn)法,分析了各因素對(duì)開孔腔體的近場(chǎng)屏蔽效能影響的主次順序,并對(duì)屏蔽效果進(jìn)行了優(yōu)化。論文主要從以下幾方面展開:首先,介紹時(shí)域有限差分法的基本原理及差分格式,Courant穩(wěn)定性條件。推導(dǎo)了自由空間與理想導(dǎo)體的邊界條件,并據(jù)此得出了屏蔽腔體的設(shè)置方法。深入研究了 Gedney完全匹配層,通過(guò)編制程序?qū)ξ招ЧM(jìn)行了驗(yàn)證。對(duì)激勵(lì)源的引入進(jìn)行了分析和研究,介紹了常用的隨時(shí)間變化的源和常用的激勵(lì)源的設(shè)置方法。其次,建立了開孔腔體的屏蔽效能分析模型,引入平面波,編制程序得到屏蔽效能的數(shù)值解,與等效傳輸線法的結(jié)論吻合,證明了算法的有效性。引入了電偶極子源,研究了開孔大小、開孔形狀、孔源距離、激勵(lì)源和觀察點(diǎn)偏移距離等不同因素對(duì)開孔腔體的近場(chǎng)屏蔽效能的影響。最后,設(shè)計(jì)了一套正交試驗(yàn),通過(guò)直觀分析和方差分析,得到了各因素對(duì)屏蔽效能影響的主次順序,確定了影響因素的最優(yōu)化水平組合,對(duì)屏蔽效能進(jìn)行了優(yōu)化。本文研究工作及成果為開孔腔體在近場(chǎng)環(huán)境中電磁兼容的設(shè)計(jì)提供了理論依據(jù),對(duì)工程實(shí)踐具有一定的指導(dǎo)意義。
[Abstract]:With the development of electronic technology towards high frequency and high integration, almost all equipments are affected by electromagnetic field, and EMC is paid more and more attention. Metal cavity has good electromagnetic shielding effect and is an important means of electromagnetic compatibility. Due to the need of ventilation, heat dissipation and external observation, there is an inevitable opening in the cavity, which is the key factor affecting the shielding effectiveness of the cavity. Because the devices coexist in a compact space, sensitive devices are often in the near field of the interference source. In the near field, the electric magnetic field intensity and wave impedance have inhomogeneity, and some far-field conclusions are no longer applicable. Therefore, it is of great significance to study the near-field shielding efficiency of the cavity. Based on the finite-difference time-domain method, the factors affecting the near-field shielding effectiveness of an open-hole cavity and its law are analyzed in this paper. Based on the orthogonal test, the primary and secondary order of the influence of various factors on the near-field shielding effectiveness of the cavity is analyzed, and the shielding effect is optimized. Firstly, the basic principle of FDTD method, the difference scheme and Courant stability condition are introduced. The boundary conditions of free space and ideal conductor are derived, and the method of setting shielding cavity is obtained. The perfectly matched layer of Gedney is studied in depth, and the absorption effect is verified by programming. The introduction of excitation sources is analyzed and studied, and the methods of setting up common sources with time and common excitation sources are introduced. Secondly, the shielding effectiveness analysis model of an open-hole cavity is established. The numerical solution of shielding effectiveness is obtained by introducing plane wave, which is in agreement with the conclusion of the equivalent transmission line method, and proves the validity of the algorithm. The influence of different factors, such as hole size, hole shape, hole source distance, excitation source and observation point offset, on the near-field shielding efficiency of an open-hole cavity is studied by introducing an electric dipole source. At last, a set of orthogonal experiment is designed. Through the analysis of visual analysis and variance, the primary and secondary order of the influence factors on shielding effectiveness is obtained, and the optimal level combination of the influencing factors is determined, and the shielding effectiveness is optimized. The research work and results in this paper provide a theoretical basis for the design of electromagnetic compatibility in the near-field environment of an open-hole cavity, and have a certain guiding significance for engineering practice.
【學(xué)位授予單位】：北京交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN03

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 吳剛;孫靖虎;李兵;張曉陽(yáng);;矩形金屬機(jī)殼孔縫電磁耦合特性研究[J];電波科學(xué)學(xué)報(bào);2015年06期

2 朱安石;陳自力;劉曉倩;甄云卉;楊勇;;單極天線和偶極子天線輻射特性數(shù)值計(jì)算[J];微波學(xué)報(bào);2015年02期

3 周海京;劉陽(yáng);李瀚宇;董燁;廖成;董志偉;莫?jiǎng)t堯;;計(jì)算電磁學(xué)及其在復(fù)雜電磁環(huán)境數(shù)值模擬中的應(yīng)用和發(fā)展趨勢(shì)[J];計(jì)算物理;2014年04期

4 吳博;王輝;黃志祥;吳先良;;三維FDTD方法中高效平面波源的引入[J];電子學(xué)報(bào);2014年06期

5 伍虹霖;尹浩;孟海軍;談學(xué)超;譚堅(jiān)文;;金屬艙近場(chǎng)孔縫耦合特性數(shù)值分析[J];電訊技術(shù);2014年03期

6 焦重慶;牛帥;;開孔矩形腔體的近場(chǎng)電磁屏蔽效能研究[J];物理學(xué)報(bào);2013年11期

7 何林濤;;基于HFSS的孔陣機(jī)殼近場(chǎng)屏蔽效能分析[J];工程設(shè)計(jì)學(xué)報(bào);2011年04期

8 柴焱杰;孫繼銀;孫東陽(yáng);胡寅;;平面波在時(shí)域有限差分法中的引入方法研究[J];電波科學(xué)學(xué)報(bào);2011年02期

9 石崢;杜平安;;孔陣結(jié)構(gòu)近場(chǎng)屏蔽特性有限元數(shù)值仿真[J];電子學(xué)報(bào);2009年03期

10 汪泉弟;朱蕾蕾;李彬;;一種計(jì)算屏蔽箱體外部輻射場(chǎng)的混合算法[J];電工技術(shù)學(xué)報(bào);2006年07期

相關(guān)碩士學(xué)位論文 前1條

1 史曉寧;基于屏蔽室法的材料電磁屏蔽效能的簡(jiǎn)易測(cè)試方法及影響因素分析[D];華北電力大學(xué);2015年

，

本文編號(hào)：2330131