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Electromagnetic scattering characteristics of metamaterials in the presence of conducting objects and surfaces.

机译:在存在导电物体和表面的情况下,超材料的电磁散射特性。

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摘要

The study of the electromagnetic (EM) scattering characteristics of metamaterials in the vicinity of conducting geometries is of tremendous interest to the scientific community. The objective of this thesis is to present a theoretical analysis of the scattering characteristics of these metamaterials in the vicinity of conducting surfaces for different geometries and arrangements. This thesis will contribute towards advancements in the areas of cloaking, low observable antenna design, remote sensing and sensor devices in the microwave regime (operating between 1 - 10 GHz). The metamaterials considered in this study are of both dispersive and non-dispersive types. The dispersive type metamaterials are simulated by substituting the Drude/Lorentz model for the permittivity and the permeability of the material. The non-dispersive type has fixed values for the same parameters for the entire spectrum. In the first part of the analysis, the scattering characteristics of a metamaterial coated conducting cylinder with an intervening air gap will be presented. Subsequently, the scattering characteristics of a metamaterial coated conducting sphere with an intervening air gap will be presented. In reality, these air gaps may be implemented by styrofoam which has approximately the same dielectric characteristics as that of air (&egr;r=1.03). For both cylindrical and spherical cases, plane wave incidence has been considered. It can be shown that broadband reduction of backscattering and reduction of total scattering for a broad range of scattering angles are possible to achieve, thus giving astonishing results for cloaking and scattering reduction applications. In the final portion of this thesis, the scattering characteristics of a dispersive and lossy or non-dispersive metamaterial sphere or metamaterial coated conducting sphere in the vicinity of a conducting surface with the surrounding medium being air is presented. A technique based on method of images and multipole expansions is utilized to obtain the scattering characteristics for a circularly polarized (left or right) incident beam. The results show interesting possibilities for remote sensing and low observable antenna and radar applications for maritime purposes.
机译:对超导体在导电几何形状附近的电磁(EM)散射特性的研究对于科学界非常感兴趣。本文的目的是对不同几何形状和布置的导电材料附近这些超材料的散射特性进行理论分析。本论文将为掩盖,低可见天线设计,微波状态(在1-10 GHz之间工作)的遥感和传感器设备领域的发展做出贡献。本研究中考虑的超材料是分散型和非分散型的。通过用Drude / Lorentz模型代替材料的介电常数和磁导率来模拟分散型超材料。对于整个频谱,相同参数的非色散类型具有固定值。在分析的第一部分中,将介绍带有中间气隙的超材料涂覆的导电圆柱体的散射特性。随后,将介绍具有中间气隙的超材料涂覆的导电球体的散射特性。实际上,这些气隙可以由聚苯乙烯泡沫塑料实现,该泡沫塑料具有与空气的介电特性大致相同的介电特性(例如,r = 1.03)。对于圆柱和球形情况,均已考虑了平面波入射。可以证明,对于宽范围的散射角,宽带散射的减小和总散射的减小是可能实现的,因此对于隐身和散射减小应用给出了惊人的结果。在本文的最后部分,提出了一种分散的,有损的或非分散的超材料球或涂覆有超材料的导电球在导电表面附近且周围介质为空气的散射特性。利用基于图像和多极扩展方法的技术来获得圆偏振(左或右)入射光束的散射特性。结果表明,对于航海目的,遥感和低可观测天线和雷达应用具有有趣的可能性。

著录项

  • 作者

    Jamil, Adnan Golam.;

  • 作者单位

    University of Massachusetts Lowell.;

  • 授予单位 University of Massachusetts Lowell.;
  • 学科 Electrical engineering.
  • 学位 Ph.D.
  • 年度 2016
  • 页码 135 p.
  • 总页数 135
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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