楔体周期结构电磁波衰减的理论计算及数值模拟  

Theoretic Study and Numerical Solution for Periodic Wedge-Tapered Microwave Absorber

作　　者：罗志勇[1] 秦汝虎[2] 

机构地区：[1]中国计量科学研究院,北京100013 [2]哈尔滨工业大学,哈尔滨150006

出　　处：《微波学报》2006年第1期14-18,共5页Journal of Microwaves

基　　金：科学技术部资助课题(2002DEA20014)

摘　　要：微波吸收材料抑制表面对电磁波的反射有两种主要方法:一是根据传输线理论,通过材料配方改变材料电磁参数实现材料和空气的阻抗匹配;另一种是采用表面设计方法,包括复合结构层设计和将吸收表面设计成某种特殊的结构,实现对电磁波的回波衰减。本文采用等效传输线理论和几何光学原理分别对表面周期结构中的棱楔周期结构及其微波耗散机理进行了理论计算和数值模拟,得出了几点重要结论:(1)应使楔体周期宽度尽可能等于或接近电磁波波长,以实现良好的阻抗匹配;(2)楔体深度越大,阻抗匹配越好;(3)减小楔体夹角可增强回波衰减。以上结论对指导微波吸收材料的设计具有十分重要的意义。There is two kinds of way to reduce electromagnetic wave signal reflected from interface between air and absorbing materials, that is making a prescription and structure design of absorbing material. In this paper, the reflection coefficient of a plane electromagnetic wave incident on a Wedge-tapered absorbing structure is theoretically studied. The theoretical solution＇ is found in two asymptotic cases： the electromagnetic wavelength is longer than or equal to geometrical size of Wedge-Tapered and the electromagnetic wavelength is far shorter than geometrical size of Wedge-Tapered. In the former case, a transmission line analog result is setup while geometrical optical technique is applied in latter case. The main conclusions are： The electromagnetic wavelength should be equal or to approach to geometrical size of Wedge-Tapered for reducing electromagnetic wave signal reflected from interface between air and Wedge-Tapered efficiently.

关 键 词：棱楔 微波损耗 阻抗匹配 理论计算 几何光学 

分 类 号：O441.4[理学—电磁学] TM25[理学—物理]