基于超材料的太赫兹吸波体理论与工艺研究
发布时间：2018-10-22 06:59
【摘要】：超材料是一种新型的人工电磁材料,其结构一般由周期阵列单元构成,其电磁特性高度依赖于所设计的器件结构。太赫兹(terahertz:THz)电磁波具有安全性好、光谱信息含量高、穿透性强和频带宽等优点,在通信、生物医学、物质识别和国防军事等方面的应用前景极其广阔。随着微纳加工工艺和太赫兹技术的飞速发展,基于微纳加工工艺的超材料太赫兹吸波体研究,成为太赫兹功能器件领域的一个研究热点。本文首先基于时域有限积分方法,设计了一种新颖的三层结构太赫兹宽带吸波体,并详细分析了吸波体的电磁吸收机理和吸收曲线受不同参数影响情况。仿真结果表明,该宽带吸波体其吸收率在80%以上对应的带宽为1.2THz,其半峰全宽(FWHM)为1.6THz,最大吸收率可达98.7%,对太赫兹波的偏振方向不敏感,且能实现大入射角吸收。若按比例改变该宽带吸波体的结构尺寸,则吸波体的工作频段也可以扩展到微波和红外等波段,其在电磁隐身、测辐射热的探测和宽带通信等领域具有潜在的应用价值。然后,详细介绍了MEMS微加工工艺流程和特点,并简要介绍了吸波体结构的设计方法。最后,在利用CST软件设计出了太赫兹可调吸波体后,采用MEMS工艺制作出了可调吸波体样片,分析了可调吸波体的电磁损耗机理以及吸收曲线受不同参数的影响情况,并实验验证了吸波体吸收峰的调制特性。仿真结果表明,该吸波体的低频吸收峰出现红移,且调制度为2.2%,吸收率的幅度变化为0.5%;中频吸收峰的调制度为5.7%,吸收率变化幅度为7.4%;高频吸收峰的调制度为0.65%,吸收率变化幅度为3%。实验结果表明,吸波体的低频吸收峰出现了明显的红移,且调制度为0.7%,吸收率变化了0.5%;中频吸收峰的调制度为3.9%,吸收率变化了1%;高频吸收峰的调制度为1.4%,吸收率变化了8%。该吸波体的仿真结果与实验结果基本吻合。该THz可调吸波体可用作THz调制器,在频率选择性光谱探测、THz开关和多谱成像等方面的应用前景十分巨大。
[Abstract]:Metamaterials are a new type of artificial electromagnetic materials. Their structures are generally composed of periodic array elements and their electromagnetic properties are highly dependent on the designed device structures. Terahertz (terahertz:THz) electromagnetic wave has many advantages, such as good security, high spectral information content, strong penetration and frequency bandwidth, etc. It has a very broad application prospect in communication, biomedicine, material recognition and national defense and military. With the rapid development of micro and nano processing technology and terahertz technology, the research of terahertz absorbers based on micro and nano processing technology has become a research hotspot in the field of terahertz functional devices. In this paper, a novel terahertz wideband absorber with a three-layer structure is designed based on the time-domain finite integral method. The electromagnetic absorption mechanism of the absorber and the influence of different parameters on the absorption curve are analyzed in detail. The simulation results show that the absorption rate of the broadband absorber is more than 80%, the corresponding bandwidth is 1.2 THZ, the half peak full width (FWHM) is 1.6 THZ, and the maximum absorptivity can reach 98.7, which is insensitive to the polarization direction of terahertz wave and can achieve high incidence angle absorption. If the structure size of the broadband absorber is changed proportionally, the working frequency band of the absorber can also be extended to the microwave and infrared bands. It has potential application value in the fields of electromagnetic stealth, radiometry and broadband communication. Then, the process and characteristics of MEMS micromachining are introduced in detail, and the design method of absorbing body structure is briefly introduced. Finally, after designing the terahertz tunable absorber by using CST software, the tunable absorber sample sheet is made by MEMS process. The electromagnetic loss mechanism of the adjustable absorber and the influence of different parameters on the absorption curve are analyzed. The modulation characteristics of the absorption peak of the absorber are verified experimentally. The simulation results show that the low-frequency absorption peak of the absorber is red-shifted. And the modulation system is 2.2, the absorptivity range is 0.5, the medium frequency absorption peak is 5.7and the absorptivity is 7.4. the modulation system of the high frequency absorption peak is 0.65 and the absorptivity is 3. The experimental results show that the low frequency absorption peak of the absorber appears obvious red shift, and the modulation system is 0.7 and the absorptivity changes 0.5%, the intermediate frequency absorption peak is 3.9, the absorption rate changes 1, and the modulation system of the high frequency absorption peak is 1.4 and the absorptivity changes 8%. The simulation results of the absorber are in good agreement with the experimental results. The tunable THz absorber can be used as a THz modulator. It has great application prospect in frequency selective spectrum detection, THz switch and multispectral imaging.
【学位授予单位】：桂林电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O441.4
本文编号：2286437
[Abstract]:Metamaterials are a new type of artificial electromagnetic materials. Their structures are generally composed of periodic array elements and their electromagnetic properties are highly dependent on the designed device structures. Terahertz (terahertz:THz) electromagnetic wave has many advantages, such as good security, high spectral information content, strong penetration and frequency bandwidth, etc. It has a very broad application prospect in communication, biomedicine, material recognition and national defense and military. With the rapid development of micro and nano processing technology and terahertz technology, the research of terahertz absorbers based on micro and nano processing technology has become a research hotspot in the field of terahertz functional devices. In this paper, a novel terahertz wideband absorber with a three-layer structure is designed based on the time-domain finite integral method. The electromagnetic absorption mechanism of the absorber and the influence of different parameters on the absorption curve are analyzed in detail. The simulation results show that the absorption rate of the broadband absorber is more than 80%, the corresponding bandwidth is 1.2 THZ, the half peak full width (FWHM) is 1.6 THZ, and the maximum absorptivity can reach 98.7, which is insensitive to the polarization direction of terahertz wave and can achieve high incidence angle absorption. If the structure size of the broadband absorber is changed proportionally, the working frequency band of the absorber can also be extended to the microwave and infrared bands. It has potential application value in the fields of electromagnetic stealth, radiometry and broadband communication. Then, the process and characteristics of MEMS micromachining are introduced in detail, and the design method of absorbing body structure is briefly introduced. Finally, after designing the terahertz tunable absorber by using CST software, the tunable absorber sample sheet is made by MEMS process. The electromagnetic loss mechanism of the adjustable absorber and the influence of different parameters on the absorption curve are analyzed. The modulation characteristics of the absorption peak of the absorber are verified experimentally. The simulation results show that the low-frequency absorption peak of the absorber is red-shifted. And the modulation system is 2.2, the absorptivity range is 0.5, the medium frequency absorption peak is 5.7and the absorptivity is 7.4. the modulation system of the high frequency absorption peak is 0.65 and the absorptivity is 3. The experimental results show that the low frequency absorption peak of the absorber appears obvious red shift, and the modulation system is 0.7 and the absorptivity changes 0.5%, the intermediate frequency absorption peak is 3.9, the absorption rate changes 1, and the modulation system of the high frequency absorption peak is 1.4 and the absorptivity changes 8%. The simulation results of the absorber are in good agreement with the experimental results. The tunable THz absorber can be used as a THz modulator. It has great application prospect in frequency selective spectrum detection, THz switch and multispectral imaging.
【学位授予单位】：桂林电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O441.4
【参考文献】
相关期刊论文 前2条
1 陈顺兵;张文涛;何晓阳;陈琦;;THz波段Metamaterial吸波材料研究现状[J];信息与电子工程;2011年03期
2 顾超;屈绍波;裴志斌;徐卓;刘嘉;顾巍;;Multiband terahertz metamaterial absorber[J];Chinese Physics B;2011年01期
，本文编号：2286437
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