利用超表面材料合成90度轉彎之伊頓透鏡

Abstract

由於超材料可以產生使用者想要的介電常數和導磁率，超材料已經被學術界廣泛的應用。在本篇論文我們將超材料製作成平面，並且以週期性排列方式作成伊頓透鏡。由伊頓透鏡的折射率公式決定了電磁波轉彎的特性，依照公式可分成許多彎曲角度的伊頓透鏡，我們調查90度轉彎的伊頓透鏡。我們將先介紹色散與折射率間的關係，然後使用CST電磁模擬軟體及MATLAB取得所需折射率，如此可將伊頓透鏡折射率進行離散化分析及合成透鏡。 接下來我們將模擬電磁波在伊頓透鏡轉彎的效果，當中包含我們所遇到的問題以及提出來改善能量損耗和能量集中的方法，然後應用於伊頓透鏡合成，比較其中的效果差異。

Metamaterials had been investigated for many years. They can be manufactured for specific properties. In this thesis, we propose an Eaton lens synthesized by periodic structure. We use the two-dimension of metamaterial to synthesize the 90-degree Eaton lens. Because refractive index of Eaton lens varies in radial direction, it makes electromagnetic fields bent. We introduce the relation of the dispersion and the refractive index. We find the dispersion for different patch sizes of the unit cell. We use the CST software to find dispersion. Then we transform the dispersion into the refractive index. Then we synthesize the Eaton lens by discretization synthesis distributed diagram. We simulate initial Eaton lens bending effect. And we propose improvement bending effect methods. We point out that the incident angle affect refractive index.