周期结构二维左手材料的设计与实现

发布时间：2018-02-25 06:06

本文关键词： 左手材料二维阵列结构宽频带　出处：《杭州电子科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：左手材料是一类新型人工构造的电磁材料,具有特异的电磁性能,在一定的频率范围内同时具有负的介电常数ε和负的磁导率?,对电磁波的传播形成负折射率。这种材料的奇异特性能够在微波、天线、射频和光学等领域发挥重要的作用。作为一种人工材料,左手材料的制备通常在一般媒质中嵌入设计的几何谐振结构,组合形成天然媒质不具有的电磁特性。本文围绕左手材料的设计,提出了一种新型矩形阵列结构左手材料,具有二维各向同性、频带高适应性等优点,并研究了所设计结构的参数与材料的电磁特性之间关系。论文的主要工作有:1、详细阐述了左手材料的研究背景及其基本特性,通过复现验证经典的Smith结构,介绍和验证了左手材料的建模、电磁仿真流程以及S参数法等效本构参数提取,研究了利用基于Kramers Kronig关系式改进参数反演算法解决传统参数反演算法中选取折射率计算结果支路的算法缺陷。将算法公式在MATLAB程序中编程,计算出S参数数据分别对应的等效介电常数、等效磁导率、折射率和阻抗。2、设计了一种新型宽频带,低损耗二维双面矩形阵列左手材料,可在两个方向上产生各向同性的等效负介电常数和等效负磁导率。材料由两种规格的矩形金属片阵列蚀刻在FR4介质板两面,结构简单,易于加工,材料在二维方向上通带带宽达到6.4GHz。3、进一步研究了材料的结构尺寸与材料本构参数的关系。验证了周期结构左手材料单元间距从1mm递增到2mm,材料左手特性实现了2.3GHz的频率偏移;验证了构成左手材料结构的矩形金属片的宽度分别增减0.4mm,实现左手特性0.8GHz的频率偏移。进一步解决了目前左手材料频带窄,适应性差的缺点。4、对材料进行工业加工制备,通过波导-矢量网络分析仪测量系统测试验证制备材料的性能,将材料放置在波导内,通过同轴线连接矢量网络分析仪提取出材料S参数,进一步反演参数验证了材料的左手特性。本文的研究为左手材料的应用提供了一种易于加工,高性能,频带高适应性的可行性方案。
[Abstract]:Left-handed material is a new type of artificial electromagnetic material with special electromagnetic properties. It has negative permittivity 蔚 and negative permeability in a certain frequency range at the same time. The singular properties of this material can play an important role in the fields of microwave, antenna, radio frequency and optics. The preparation of left-handed materials is usually embedded in a general medium with a geometric resonant structure, which combines to form electromagnetic properties that natural media do not have. A new type of left-handed material with rectangular array structure is proposed around the design of left-handed materials in this paper. It has the advantages of two-dimensional isotropy, high adaptability in frequency band, and studies the relationship between the parameters of the designed structure and the electromagnetic properties of the material. The main work of this paper is: 1. The research background and basic characteristics of left-handed materials are described in detail. The classical Smith structure is verified by reproducing, and the modeling of left-handed material, electromagnetic simulation flow and the extraction of equivalent constitutive parameters by S-parameter method are introduced and verified. An improved parameter inversion algorithm based on Kramers Kronig relation is proposed to solve the problem of selecting the branch of refractive index calculation in the traditional parameter inversion algorithm. The algorithm formula is programmed in MATLAB program. The corresponding equivalent permittivity, equivalent permeability, refractive index and impedance of S parameter data are calculated respectively. A novel broadband, low-loss two-dimensional two-sided rectangular array left-handed material is designed. Isotropic equivalent negative permittivity and equivalent negative permeability can be produced in two directions. The material is etched on both sides of the FR4 dielectric plate by two kinds of rectangular metal sheet arrays. In the two-dimensional direction, the passband bandwidth reaches 6.4 GHz 路3. The relationship between the structure size and the constitutive parameters of the material is further studied. It is verified that the cell spacing of the left-handed material increases from 1 mm to 2 mm, and the left-handed characteristic of the material achieves a frequency shift of 2.3 GHz. It is verified that the width of rectangular metal sheet composed of left-handed material structure increases or decreases by 0.4mm respectively, and the frequency offset of left-handed characteristic of 0.8GHz is realized. Further, the defect of narrow band and poor adaptability of left-handed material is solved, and the material is manufactured by industrial processing. The properties of the prepared materials were tested by the wave-vector network analyzer system. The materials were placed in the waveguide and the S parameters were extracted by the coaxial vector network analyzer. Further inversion parameters verify the left-handed properties of the material. This study provides a feasible scheme for the application of left-handed materials, which is easy to process, high performance and high adaptability in frequency band.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM27

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