超材料结构电磁-热性能研究

论文总字数：26652字

摘 要

人工复合的材料，即所谓的超材料。超材料具有一系列特殊的物理性质，例如负介电常数、负磁导率、负折射率、反多普勒效应和电磁隐身等。虽然最初对超材料的兴趣大多是出于它们能够表现出天然材料无法实现的独特电磁效应，但它们确实非常适合用来制造电磁波吸收器。

但是到目前为止，超材料吸波结构的吸收机理仍需要进一步探索。一般认为吸收由表面金属膜层的欧姆损耗和电介质层的介质损耗组成。目前学术界对超材料电磁-热互作用比较少，且缺少比较全面的总结和分析，特别是对于温度对超材料比较消极性、负面性甚至是破坏性的研究比较少进行，这就意味着在超材料系统中缺乏对电磁波热效应的定量评估，这可能极大地阻碍器件设计和优化。本论文就针对此问题进行研究分析，提出了一种人工超材料吸波结构，并且构成了适用于金属矩形波导的超材料吸波器。接着对适用于金属矩形波导的超材料吸波器进行了电磁仿真和温度分布仿真，提出影响超材料结构热性能的三个因素进行总结和分析。

第一章中简单介绍了人工超材料的背景及发展。第二章总结了近年来有关超材料结构光热效应的实验，为本论文提供理论基础。第三章提出了一种超材料吸波结构，并且将其横向排列放入金属矩形波导形成超材料吸波器，接着对该吸波器进行了电磁仿真。第四章首先在第三章的基础之上对该吸波器进行了温度分布仿真，接着提出了三个影响吸波器温度的影响因素分别为功率，照射时长，背景温度。最后分析总结了这三个因素对吸波结构的热能的具体影响。

关键词：超材料 吸波器 温度分布 热性能

Abstract

Artificial composite materials, or so-called metamaterials. Metamaterials have a series of special physical properties, such as negative dielectric constant, negative permeability, negative refractive index, anti-Doppler effect and electromagnetic stealth. Although most of the initial interest in metamaterials was due to their ability to exhibit unique electromagnetic effects that natural materials could not achieve, they are very suitable for making electromagnetic wave absorbers.

But up to now, the absorption mechanism of metamaterial absorbing structure still needs to be further explored. It is generally believed that absorption consists of ohmic loss of surface metal film and dielectric loss of dielectric layer. At present, there are few studies on the Electromagnetic-Thermal interaction of metamaterials in academia, and there is a lack of comprehensive summary and analysis. Especially, there are few studies on the negative or even destructive effects of temperature on metamaterials. This means that there is a lack of quantitative evaluation of the thermal effects of electromagnetic waves in metamaterials systems, which may greatly hinder the design and optimization of devices. In this paper, a kind of artificial supermaterial absorbing structure is proposed, and a supermaterial absorber suitable for metal rectangular waveguide is constructed. Then the electromagnetic simulation and temperature distribution simulation of the supermaterial absorber suitable for metal rectangular waveguide are carried out, and three factors affecting the thermal performance of the supermaterial structure are summarized and analyzed.

In the first chapter, the background and development of artificial metamaterials are briefly introduced. Chapter 2 summarizes recent experiments on photothermal effects of metamaterial structures, which provide theoretical basis for this paper. In the third chapter, a metamaterial absorbing structure is proposed, and the transverse arrangement of the structure is put into a metal rectangular waveguide to form a metamaterial absorber. Then the electromagnetic simulation of the absorber is carried out. Chapter 4 firstly simulates the temperature distribution of the absorber on the basis of Chapter 3. Then three factors affecting the temperature of the absorber are proposed, which are power, irradiation time and background temperature. Finally, the specific effects of these three factors on the thermal energy of the absorbing structure are analyzed and summarized.

Key words: metamaterials Absorber temperature distribution thermal property

目 录

摘要....................................................................................................................................................Ⅰ

Abstract...............................................................................................................................................Ⅱ

第一章 绪论........................................................................................................................................1

1.1引言.....................................................................................................................................1

1.2人工超材料.........................................................................................................................1

1.2.1超材料背景与应用前景............................................................................................1

1.2.2超材料吸波结构介绍................................................................................................3

1.3电磁热-性能.......................................................................................................................4

1.4小结.....................................................................................................................................5

第二章 超材料结构电磁-热性能研究理论基础..............................................................................6

2.1光热效应............................................................................................................................6

2.2 CST仿真方法......................................................................................................................7

2.3小结.....................................................................................................................................7

第三章 适用于金属矩形波导的超材料吸波器................................................................................8

3.1适用于金属矩形波导的超材料吸波结构.........................................................................8

3.2超材料吸波器仿真分析...................................................................................................10

3.2.1吸波原理..................................................................................................................10

3.2.2超材料吸波器电磁仿真分析..................................................................................11

3.3小结...................................................................................................................................17

第四章 吸波结构的电磁-热性能分析............................................................................................18

4.1吸波结构热仿真分析.......................................................................................................18

4.1.1吸波结构温度分布仿真（瞬态）…..........................................................................18

4.1.2吸波结构不同功率下的温度分布..........................................................................20

4.1.3吸波结构不同照射时长下的温度分布..................................................................23

4.2小结...................................................................................................................................25

第五章 总结与展望..........................................................................................................................26

5.1全文总结...........................................................................................................................26

5.2展望...................................................................................................................................27

参考文献............................................................................................................................................28

致谢....................................................................................................................................................29

1. 绪论
   1. 引言

人工复合的材料，即所谓的超材料。虽然最初对超材料的兴趣大多是出于它们能够表现出天然材料无法实现的独特电磁效应，但它们确实非常适合用来制造电磁波吸收器。超材料具有一系列特殊的物理性质，例如负介电常数、负磁导率、负折射率、反多普勒效应和电磁隐身等^[1]。一开始科研人员们主要研究超材料的特殊物理性质，但是进一步研究发现超材料之所以能实现对电磁波的完美吸收是利用超材料与电磁波相互作用的过程中，产生电场的局域性增强，导致电磁能量消耗增加。超材料所表现出的最突出的特征是，与天然材料不同，超材料的电磁特性是由其几何形状而非化学成分或频带结构决定的。到2008年, Landy等基于超材料电磁耦合谐振特性, 提出了一种具有极好吸波性能的超材料吸波结构。该超材料吸波结构是由电谐振、 介质和金属微带线构成的。该超材料吸波结构的面世，引起了科研人员们的关注。在这之后科研人员们陆续提出了一系列极化不明显、多频带、宽频带的超材料吸波结构，虽然越来越多的超材料吸波结构被提出，但是如何提高超材料结构的吸波性能，仍需要进一步总结分析^[2]。

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