摘要频率选择表面(Frequency Selective Surfaces,简称FSS)是周期性排列的金属贴片或有缝隙的金属板。它可以在两侧或者一侧加载介质,其本质特征就是能够对不同频率、不同入射角和不同极化状态下的电磁波呈进行空间滤波。为了达到传输或者阻隔某个频段的信号这一目的,就可以通过设计频率选择表面(如带通、带阻)来实现。而在低频范围内时,各个通信频段的带宽很窄且相距很近,就需将中心谐振频率的误差降到最小,因此为了设计出性能较好的频率选择表面,必须消除各个单元间的耦合。基于此,本课题将法拉第笼结构引入到设计中以消除这种相互影响。本课题通过Ansoft HFSS软件设计出了引入法拉第笼结构的方形缝隙环频率选择表面,并分析讨论不同尺寸参数对频率选择表面性能的影响,最后分析了加载集总元件电容之后对频率选择表面性能的影响。86542
毕业论文关键词:方形缝隙环;频率选择表面;法拉第笼;集总元件
Abstract The frequency selective surface (FSS) is formed by the periodic arrangement of the slot units of the metal patch or the metal screen。 It can be loaded on both sides or one side of the medium, its essential feature is to be able to present space filtering when the incident wave frequencies, incidence angles or polarization state of the electromagnetic wave are different。 Through the reasonable design of different functions (such as band-pass, band-stop) frequency selective surface, it can effectively transmit or block the signal of different frequency。 And in the low frequency band of microwave applications, due to the communication frequency band, the bandwidth is really narrow and the band is very close, the resonant frequency must be designed very accurate, thus eliminating coupling between elements is really useful to design excellent performance of frequency selective surface accurately。 So the Faraday cage structure is introduced to eliminate this kind of interaction。 This thesis applies Ansoft HFSS to design the Square loop slot FSS based on Faraday Cage structure, and analyzes the influence of different parameters on the frequency selection surface。 Finally, we analyze the influence of frequency selective surface when loading lumped element capacitors。
Key words: square loop slot-FSS; frequency selective surface; faraday cage; lumped elements
目 录
第一章 绪论 1
1。1 频率选择表面概述 1
1。2 课题研究的背景及意义 3
1。3 课题研究的主要内容 4
第二章 频率选择表面理论分析方法 6
2。1 频率选择表面的原理与性能 6
2。2 频率选择表面的理论分析方法 7
第三章 频率选择表面的模式匹配分析法 10
3。1 Floquet模 10
3。2 介质加载的频率选择表面 12
3。2。1 栅瓣现象 12
3。2。2 场分析法 15
3。3 HFSS软件仿真法 18
3。3。1 Floquet 端口 18
3。3。2主从边界条件 19
第四章 基于法拉第笼结构的方形缝隙环的频率选择表面研究 21
4。1 法拉第笼对方形缝隙环频率选择表面的影响 21