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1、分类号 密 级 秘 密 异向介质的电磁特性及其应用研究学 科 专 业： 指挥信息系统工程研 究 方 向： 通信战术与特殊装备研究作 者 姓 名： x导 师 姓 名： x 教授论文提交日期： 年 月独 创 性 声 明本人声明所呈交的论文是我个人在指导老师指导下进行的研究工作及取得的研究成果。尽我所知，除了文中特别加以标注和致谢的地方外，论文中不包含其他人已经发表或撰写过的研究成果，也不包含为获得 x 或其它教育机构的学位或证书而使用过的材料。与我一同工作的同志对本研究所做的任何贡献均已在论文中作了明确的说明并表示了谢意。本人如违反上述声明，愿意承担以下责任和后果：1交回学校授予的学位证书；2学校
2、可在相关媒体和单位对本人的行为进行通报；3本人应按照学校规定的方式，对因不当取得学位给学校造成的名誉损害进行公开道歉；4本人负责论文后果不实产生的各种法律纠纷。本人签名：日 期： 关于论文使用授权的说明本人完全了解 x 有关保留、使用学位论文的权利，即：学校有权保留送交论文的复印件，允许论文被查阅或借阅； 学校可以公布论文的全部或部分内容，可以采用影印、缩印或其他复制手段保存论文。(保密的论文在解密后应遵守此规定保密的论文在解密后应遵守此规定)本人签名： 导师签名：日 期： x 学士学位论文异向介质的电磁特性及其应用研究Study on the Electromagnetic Characte
3、ristics and Applications of the Metamaterials指导教师姓名、专业技术职务 学 科 专 业 论文答辩日期 学位授予单位和日期 答辩委员会主席 答辩委员会委员 分类号 密 级 秘 密 摘 要异向介质（Metamaterials）是指介电常数和磁导率全部为负值的人工合成介质，其相关研究被Science评为了 2003 年和 2006 年年度十大科技进展。本论文立足于部队“打赢高技术条件下的现代战争”和“信息化建设”的要求，对异向介质的电磁特性以及在电磁隐身方面的应用进行深入的研究。主要通过对异向介质实现的理论分析和数值仿真两个方面，研究了异向介质的传输特性
4、以及覆盖隐身目标的电磁散射特性，根据理论推导分析预测，结合数值仿真加以验证。研究结果对异向介质的结构设计和电磁隐身等工程应用具有一定的参考价值。首先，用 CST 仿真软件设计和计算了异向介质的基本结构，并研究其传输特性。通过仿真实现了等效介电常数和等效磁导率为负值的异向介质模型。推导了 NRW 参数反演方法的递推式，利用计算结果反演提取了介电常数、磁导率和折射率的实部，验证了负折射率的存在。其次，提出了一种新型的集电谐振和磁谐振于一体的双开口谐振环异向介质单元模型。通过仿真验证了新型结构的“双负效应” ，针对这一模型分析讨论了参数变化对其传输特性的影响。验证了新型双开口谐振环单元周期排列组成的
5、异向介质在特定频带内存在负的折射率。最后，研究了异向介质在电磁隐身方面的应用。基于时域有限差分法（FDTD） ，用有耗 Drude 色散介质模型模拟异向介质，计算结果表明，异向介质覆盖金属圆柱使其前向散射增加，后向散射减小。计算了异向介质覆盖战斗机机头的三维模型的电磁散射。结果表明，异向介质覆盖后使电大目标的后向散射减小，从而验证了异向介质在电磁隐身应用中的可行性。通过选取不同介质参数，计算了异向介质的介质参数为单负或双负时的雷达散射截面（RCS） ，分析对比三种人造介质的散射特性。讨论了介质参数实部不变时虚部对异向介质散射特性的影响。结果表明，选取适当的异向介质覆盖层，可以在特定的宽频段内减
6、小目标的后向 RCS 并增大前向 RCS，起到良好的电磁波隐身作用。关键词：异向介质；双开口谐振环；时域有限差分方法；目标隐身；电磁散射IABSTRACTMetamaterials are artificially structured materials with simultaneous negative permittivity and permeability. Some relevant research achievements were selected as one of the top ten Research High Lights by “Science” in 2003
7、 and 2006 respectively. This paper is based on the army requirement that we should win the modern war under high-tech and informationization construction conditions. Some electromagnetic characteristics of metamaterials and their applications in stealth technique are studied thoroughly. The electrom
8、agnetic wave transmission of metamaterials and scattering characteristics of stealth targets coated with metamaterials are investigated with theoretical analysis and numerical simulation. Prediction is made according to theoretical derivation analysis. Conclusions are verified by numerical simulatio
9、n. The results are of certain reference values in the design of the metamaterial structure and engineering applications such as electromagnetic stealth.First, the basic structure of metamaterials are designed and simulated with CST software to study its transmission characteristics, achieving the ne
10、gative effective permittivity and negative effective permeability of the metamaterial model. Recursion relations of the NRW parameter inversion are derived, and the computational results are used to extract the real part of permittivity, permeability and refractive index. The existence of negative r
11、efractive index is verified.Second, a new type of metamaterial is proposed, which is made up of two split ring resonators and has electrical resonance and magnetic resonance in one structure. Its “double-negative effects” are verified by means of numerical simulation. The effects of parameter change
12、 on its transmission characteristics are analyzed and discussed. It is validated that the new metamaterial structure which is made up of two new types of split ring resonators has negative refractive index in a specific frequency range.Finally, the applications of metamaterials in the electromagneti
13、c stealth technique are presented based on finite-difference time-domain method (FDTD), and metamaterials are simulated with the lossy Drude dispersion model. The calculation IIresults show that different metal cylinder coated with metamaterials could increase forward scattering and decrease backwar
14、d scattering. The electromagnetic scattering characteristics of a fighter aircraft coated with metamaterials of three-dimensional model are computed. The results indicate that metamaterials cause the back scattering of the target to decrease. The feasibility of metamaterials in the electromagnetic s
15、tealth applications is verified. By selecting different medium parameters the electromagnetic scattering is computed when the relative permittivity or relative permeability is negative or both are negative and the scattering properties of three artificial media are analyzed and compared. The effects of the imaginary part of medium parameters on the scattering property of metamaterials are discussed with the real part of medium parameters unchanged. The results show that selecting appropriate medium coverage of the metamaterial layers could increase
