二維電磁晶體之散射特性分析~實驗驗證

Abstract

本篇論文中，我們研究了二維電磁晶體之電磁散射特性，此二維電磁晶體由多層一維金屬線條陣列塗佈於介質材料所堆疊而成。為了量測電磁晶體的穿透特性，我們使用向量網路分析儀作閉路式量測，同時設計並製作一量測設備，主要包含兩個寬頻號角天線以及微波光罩來產生一涵蓋有限面積之均勻平面電磁波以入射該電磁晶體。此外，我們將這些量測設備放置於無反射實驗室以避免外界干擾，同時亦可消除多重路徑反射之電磁波。經由精密之實驗量測，獲得與經由精確波模匹配理論計算相當一致之結果，該研究除了證實此量測工作的標準性及一致性之外，同時亦證明該量測製具之準確性。

In this thesis, we have studies the scattering characteristics of a two-dimensional Electromagnetic (EM) crystal made up of metal strips arrays. To measure the transmittance of the EM crystal, we have setup a test fixture containing two wide-band double ridged horns and a microwave mask employed to generate a finite size uniform plane wave for illuminating the EM crystal. Besides, we have put this test fixture in an anechoic chamber to avoid the interference and, meanwhile, to suppress the multiple scattering. We have taken numerous measurements by changing some structural parameters in conjunction with the 2-D EM crystal. The good agreement between those measured data and the theoretical computation based on the program ECMRY [18] prove the standard and consistent measurement in this research work.