基于超材料的太赫茲吸波體理論與工藝研究
發(fā)布時間：2018-10-22 06:59
【摘要】：超材料是一種新型的人工電磁材料,其結(jié)構(gòu)一般由周期陣列單元構(gòu)成,其電磁特性高度依賴于所設(shè)計(jì)的器件結(jié)構(gòu)。太赫茲(terahertz:THz)電磁波具有安全性好、光譜信息含量高、穿透性強(qiáng)和頻帶寬等優(yōu)點(diǎn),在通信、生物醫(yī)學(xué)、物質(zhì)識別和國防軍事等方面的應(yīng)用前景極其廣闊。隨著微納加工工藝和太赫茲技術(shù)的飛速發(fā)展,基于微納加工工藝的超材料太赫茲吸波體研究,成為太赫茲功能器件領(lǐng)域的一個研究熱點(diǎn)。本文首先基于時域有限積分方法,設(shè)計(jì)了一種新穎的三層結(jié)構(gòu)太赫茲寬帶吸波體,并詳細(xì)分析了吸波體的電磁吸收機(jī)理和吸收曲線受不同參數(shù)影響情況。仿真結(jié)果表明,該寬帶吸波體其吸收率在80%以上對應(yīng)的帶寬為1.2THz,其半峰全寬(FWHM)為1.6THz,最大吸收率可達(dá)98.7%,對太赫茲波的偏振方向不敏感,且能實(shí)現(xiàn)大入射角吸收。若按比例改變該寬帶吸波體的結(jié)構(gòu)尺寸,則吸波體的工作頻段也可以擴(kuò)展到微波和紅外等波段,其在電磁隱身、測輻射熱的探測和寬帶通信等領(lǐng)域具有潛在的應(yīng)用價值。然后,詳細(xì)介紹了MEMS微加工工藝流程和特點(diǎn),并簡要介紹了吸波體結(jié)構(gòu)的設(shè)計(jì)方法。最后,在利用CST軟件設(shè)計(jì)出了太赫茲可調(diào)吸波體后,采用MEMS工藝制作出了可調(diào)吸波體樣片,分析了可調(diào)吸波體的電磁損耗機(jī)理以及吸收曲線受不同參數(shù)的影響情況,并實(shí)驗(yàn)驗(yàn)證了吸波體吸收峰的調(diào)制特性。仿真結(jié)果表明,該吸波體的低頻吸收峰出現(xiàn)紅移,且調(diào)制度為2.2%,吸收率的幅度變化為0.5%;中頻吸收峰的調(diào)制度為5.7%,吸收率變化幅度為7.4%;高頻吸收峰的調(diào)制度為0.65%,吸收率變化幅度為3%。實(shí)驗(yàn)結(jié)果表明,吸波體的低頻吸收峰出現(xiàn)了明顯的紅移,且調(diào)制度為0.7%,吸收率變化了0.5%;中頻吸收峰的調(diào)制度為3.9%,吸收率變化了1%;高頻吸收峰的調(diào)制度為1.4%,吸收率變化了8%。該吸波體的仿真結(jié)果與實(shí)驗(yàn)結(jié)果基本吻合。該THz可調(diào)吸波體可用作THz調(diào)制器,在頻率選擇性光譜探測、THz開關(guān)和多譜成像等方面的應(yīng)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.
【學(xué)位授予單位】：桂林電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：O441.4
本文編號：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.
【學(xué)位授予單位】：桂林電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：O441.4
【參考文獻(xiàn)】
相關(guān)期刊論文 前2條
1 陳順兵;張文濤;何曉陽;陳琦;;THz波段Metamaterial吸波材料研究現(xiàn)狀[J];信息與電子工程;2011年03期
2 顧超;屈紹波;裴志斌;徐卓;劉嘉;顧巍;;Multiband terahertz metamaterial absorber[J];Chinese Physics B;2011年01期
，本文編號：2286437
本文鏈接：http://sikaile.net/kejilunwen/dianzigongchenglunwen/2286437.html
最近更新
教材專著
