超材料吸波体及左手材料的研究

发布时间：2018-04-17 15:40

  本文选题：超材料 + 吸波体　； 参考：《北京化工大学》2015年硕士论文

【摘要】：超材料(metamaterial)是一种亚波长结构周期排列而成的人工材料,拥有常规材料不能实现的奇异电磁特性,在隐身斗篷、纳米光学成像、微型谐振器、定向发射天线、热辐射探测器、太阳能转换器、弯曲波导等领域具有极大的应用潜力。本文以发展新型超材料为目标,系统研究了三角型吸波体、“丰”型零折射超材料、“回”型负折射超材料、双“E”型超材料、“中”型负折射超材料和铜钱型超材料等六种材料,计算了其等效电磁参数,分析了结构与电磁特性的依赖关系,揭示了这些超常电磁特性的微波响应机理。其中重点开展了三角型超材料吸波体和铜钱型超材料的电磁特性研究。对于三角型超材料吸波体：三角型MMA厚度为波长的1/8,远小于普通电损耗吸波介质厚度(λ/4),并且吸收性能得到了极大提高。吸收峰频率随介质厚度和金属厚度的减小而蓝移,与原胞间缝宽成线性关系,这种吸波性能对缝宽的线性依赖关系使得调控微波吸收频带更为简便。该吸波体的损耗以介质损耗为主,欧姆损耗为辅,在热探测器、传感器、微波衰减器件上具有潜在的应用前景。铜钱型结构的超材料呈现出一个负折射带(品质因数为5.6)和两个零折射带(一个宽频带和一个低损耗频带),在多频段、多功能、不同损耗微波器件应用中具有明显优势。我们深入探讨了铜钱环、金属线与共振频率的关系,建立了铜钱型超材料的电等离子体频率和磁等离子体频率模型,分析了铜钱型超材料负折射和零折射的产生机理,为新型超材料研究与发展提供了参考；基于零折射特性的研究结果,提出了实现零折射率的通用判据,即同时满足条件ε'μ"+μ'ε"≈0和μ'ε'-ε"μ"0,为宽带零折射超材料的设计提供了理论依据。此外,研究了零折射超材料在弯曲同轴波导、T形微带线、喇叭天线中的应用。
[Abstract]:Metamaterial) is an artificial material with a periodic subwavelength structure, with singular electromagnetic properties that cannot be achieved by conventional materials, in stealth cloaks, nano-optical imaging, microresonators, directional emission antennas, thermal radiation detectors.Solar energy converter, curved waveguide and other fields have great application potential.Aiming at the development of new metamaterials, this paper systematically studies the triangular absorber, "Feng" type zero refraction supermaterial, "return" type negative refraction supermaterial, and double "E" type supermaterial.Six kinds of materials, such as "medium" negative refraction metamaterials and copper-Qian metamaterials, are calculated. The dependence of structure on electromagnetic properties is analyzed, and the microwave response mechanism of these supernormal electromagnetic properties is revealed.The electromagnetic properties of triangular supermaterials and copper-Qian supermaterials are studied.For triangular supermaterial, the thickness of triangular MMA is 1 / 8 of the wavelength, which is much smaller than that of ordinary dielectric absorber (位 / 4), and the absorption performance is greatly improved.The absorption peak frequency shifts blue with the decrease of the dielectric thickness and the metal thickness, and is linearly related to the original intercellular slit width. The linear dependence of the absorption performance on the slit width makes it easier to control the microwave absorption band.The loss of the absorber is mainly dielectric loss, ohmic loss is auxiliary, and has potential application prospect in thermal detector, sensor and microwave attenuation device.The copper-Qian type metamaterials show a negative refraction band (quality factor 5.6) and two zero refraction bands (one wide band and one low loss band), which have obvious advantages in the application of multi-band, multi-function and different loss microwave devices.The relationship between copper ring, wire and resonance frequency is discussed in depth. The electric plasma frequency and magnetic plasma frequency model of copper Qian type supermaterial are established, and the generation mechanism of negative refraction and zero refraction of copper Qian type supermaterial are analyzed.It provides a reference for the research and development of new metamaterials, and based on the research results of zero refraction, a general criterion for realizing zero refraction index is proposed.The conditions 蔚'渭 "渭'蔚" 鈮，

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