环形波导阵列金属银膜的电磁特性研究.doc

摘要：左手材料是指同时具有负电容率和负磁导率的人工复合材料。电磁波在这样的材料中传播时，电场、磁场和波矢的方向成左手螺旋关系，所以这种材被称为左手材料。左手材料，自2001年被实验实现以来，已经成为世界上物理、光学、材料、电子学等领域的研究热点。

　　　本文主要通过左手材料的研究，介绍了左手材料具有许多独特的电磁特性，其中最重要的是负折射。此外，左手材料还具有逆Doppler效应、反常Cherenkov辐射等性质。还介绍了参数的提取方法和Ansoft HFSS软件的应用和数值模拟。应用Ansoft HFSS软件对环形波导阵列金属银膜材料的进行数值模拟和计算。我们通过改变模型的厚度，绘制出对应的透射光谱图，从图可知该模型具有法布里-珀罗共振。再通过提取材料的S参数，得出材料的折射率、波阻抗、有效电容率和有效磁导率。模拟结果显示具有高透过率负折射带位于130THz到145THz，在频率为140THz处品质因数FOM的值达到27.35。大量的模拟验证了只要通过简单地调谐模型厚度就能够很容易地获得具有高透过率的不同的负折射带。

关键词：左手材料，负折射，品质因数

Abstract: The left-handed material is an artificial composite material with simultaneously negative permittivity an negative permeability. For electromagnetic waves propagating in such materials, the electric field E，magnetic field Ｈand wave vector K form a left-handed triplet of vectors and so such materials are called LHMs. After the first realization in 2001, LHMs have been the hot topic in physics, optics, materials, and electronics and so on in the word. 

     According to the study of LHMs, LHMs exhibit many unique electromagnetic properties, among which the most well-known is negative refraction. So, LHMs are also called as negative-index materials. Other properties include reversed Doppler effects, reversed Cherenkov radiation, and so on. We also introduced the extraction method of parameters and application of Ansoft HFSS software. Through the thickness of the change model, draw out the corresponding transmission spectra, from graph, this model has known Fabry-perot resonance. Simulating the S parameters, we retrieve the refractive index, wave impedance, effective permittivity, and effective permeability. The retrieved results show that the negative-index band with high transmission ranges roughly from 130THz to 145THz, and FOM (−Re(n)/ Im(n)) reaches 27.25 at the frequency of 140THz. Our additional large numbers of simulations testify that different negative-index bands with high transmission can be obtained by simply tuning the mode width. 

Keywords: left-handed materials, negative refraction, figure of merit