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Electromagnetically metamorphic interfaces, objects and materials: An artificially intelligent substrate.

机译：电磁变质界面，对象和材料：人工智能基板。

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摘要

For general artificial multilayered structures (Photonic Band Gap (PBG) or Electromagnetic Band Gap (EBG) metamaterials) with centrosymmetric scattering matrices, the composite may be replaced by an equivalent homogeneous dispersive magneto-dielectric material and may be used for the design of integrated circuits, filters and antennas using standard methods. Otherwise, use of the scattering matrix approach to obtain the effective parameters is valid only for semi-infinite structures.;We present a novel semi-analytical methodology to analyze a periodic array of printed metallic closed ring elements in a multilayered dielectric structure. This approach is unique in that it is the first methodology capable in modelling structures with resonant implants and inter-element dimensions well beyond the Effective Medium Theory (EMT). In addition, it yields computational efficiency by two orders of magnitude over standard computational methods in computing the scattering parameters for a perfect electric conductor (PEC) closed ring multilayered periodic (EBG, PBG) structures. Moreover, it provides physical insight in the implementation of metallic implants for practical applications. This methodology satisfies the Kramers-Kronig relations and Causality and therefore allows for the development of semi-analytical expressions for the composite's wave impedance, index of refraction, as well as the permittivity and permeability parameters accounting for full dispersion. The upper band edge is determined by the host material uniquely, and the bandwidth is determined by the shunt susceptance for different PEC ring inclusions.;Electromagnetic metamorphism is defined in this study as the complete transformation of a scattering object of fixed shape and dimensions from one electromagnetic state to another (e.g. from a perfect electric conductor (PEC) to a perfect magnetic conductor (PMC)). Every scatterer may undergo five distinct metamorphic states, which are Perfect Electric Conductor, Perfect Absorber, Perfect Passive Magnetic Conductor, Perfect Active Magnetic Conductor and Perfect Amplifier. Furthermore, all scatterers with characteristic dimensions large compared to wavelength exhibit the same universal metamorphic response in the backscattering direction. The five metamorphic states are determined initially in terms of the backscattering properties of objects characterized by a continuously varying surface impedance. Subsequently, a PBG structure is considered with implant elements with variable electrical properties. The impact of metamorphism on the composite's effective parameters is studied and specific data are shown.;We also demonstrate that a metamaterial constructed by layered actively loaded array of PEC circular rings shows a negative index of refraction. The composite's effective parameters ne (index of refraction) and ze (wave impedance) are examined. Loss in the dielectric host plays an important role in the effective parameters of the composite material. The effective index of refraction exhibits a distinct behavior between the composites with a lossless and a lossy dielectric host, even if the loss is very small.;Finally, we demonstrate that size reduction of a electromagnetically metamorphic material can be realized by utilizing the spiral implants. A thin X-band microwave absorber has been designed and fabricated based on the spiral medium. Both the simulation and measurement results agree well.
机译：对于具有中心对称散射矩阵的常规人工多层结构（光子带隙（PBG）或电磁带隙（EBG）超材料），复合材料可以用等效的均质分散磁电介质材料代替，并且可以用于集成电路设计，滤波器和天线使用标准方法。否则，使用散射矩阵方法获得有效参数仅对半无限结构有效。我们提出了一种新颖的半分析方法，用于分析多层介电结构中印刷金属闭环元件的周期阵列。这种方法的独特之处在于，它是第一个能够对具有谐振注入和元素间尺寸的结构进行建模的方法，该方法远超出有效介质理论（EMT）。此外，在计算理想电导体（PEC）闭环多层周期（EBG，PBG）结构的散射参数时，与标准计算方法相比，它的计算效率高出两个数量级。此外，它为实际应用中的金属植入物的实现提供了物理见解。这种方法满足了Kramers-Kronig关系和因果关系，因此可以开发出复合材料的波阻抗，折射率以及介电常数和渗透率参数（完全分散）的半解析表达式。上边沿由主体材料唯一决定，带宽由不同PEC环内含物的分流率决定。电磁变质作用在本研究中被定义为固定形状和尺寸的散射对象从一个完整的转变。电磁状态（例如，从理想的电导体（PEC）到理想的磁导体（PMC））。每个散射体可能会经历五个不同的变质状态，分别是完美导电体，完美吸收体，完美无源磁导体，完美有源磁导体和完美放大器。此外，与波长相比具有较大特征尺寸的所有散射体在反向散射方向上均表现出相同的通用变质响应。最初根据以连续变化的表面阻抗为特征的对象的反向散射特性确定五个变质状态。随后，考虑使用具有可变电性能的植入元件的PBG结构。研究了变质对复合材料有效参数的影响，并显示了具体数据。我们还证明，由多层主动加载的PEC圆环阵列构成的超材料显示负折射率。检查了复合材料的有效参数ne（折射率）和ze（波阻抗）。介电基质的损失在复合材料的有效参数中起着重要作用。即使损耗非常小，有效折射率在具有无损和有损介电主体的复合材料之间也表现出独特的行为。最后，我们证明了通过利用螺旋注入可以实现电磁变质材料的尺寸减小。基于螺旋介质设计并制造了一种薄的X波段微波吸收器。模拟结果和测量结果均吻合良好。

著录项

  • 作者

    Liu, Yunhong.;

  • 作者单位

    University of California, Irvine.;

  • 授予单位 University of California, Irvine.;
  • 学科 Engineering Electronics and Electrical.
  • 学位 Ph.D.
  • 年度 2008
  • 页码 88 p.
  • 总页数 88
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 无线电电子学、电信技术;
  • 关键词

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