太赫兹准光天馈系统空间耦合技术研究

发布时间：2018-01-29 06:50

本文关键词： 太赫兹成像准光技术天馈系统空间耦合技术　出处：《北京理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：太赫兹准光天馈系统是太赫兹无线系统中的重要组成。太赫兹准光天馈系统空间耦合技术是太赫兹无线系统研究中的关键技术。本文基于太赫兹成像的应用背景,对太赫兹准光天馈系统中的馈源、准光聚焦元件及两者空间耦合方案开展了研究。针对不同具体应用需求和加工工艺,分别对线极化和圆极化工作方式的馈源天线进行了研究。对于太赫兹准光聚焦元件,给出以高斯波束变化为设计起点的透镜设计流程,验证了高斯波束理论在透镜天线设计中的正确性。主要研究内容如下:1、太赫兹准光天馈系统的馈源设计与实现:(1)设计并优化一系列可覆盖220GHz~500GHz(增益分别为15dB、20d B和30dB)的线极化多模金属喇叭馈源,该喇叭馈源具有结构相对简单、波束对称性好和高斯效率高的特点。在国内目前测试条件下,对220GHz频段天线进行了驻波比测试。在缺少太赫兹标准增益天线的情况下,采用三天线法和比较法对220GHz频段喇叭天线进行了增益标定。仿真结果与测试结果吻合良好。测试结果表明该系列馈源达到了可替代同类进口多模金属喇叭馈源的水平。(2)基于体硅MEMS干法刻蚀工艺,提出一种新型圆极化器结合平面波纹加载的圆极化平面波纹天线方案。该方案解决了二维低剖面条件下天线的圆极化工作和高增益辐射问题。研究表明通过加载平面波纹的方法可有效提高天线的增益,通过控制新型圆极化器与馈电波导之间的夹角可有效改变轴比特性。分别在ka波段和THz波段进行了加工、测试和验证工作,仿真结果与测试结果吻合度较好,验证了该方案的正确性,说明了MEMS工艺可以满足THz频段该新型天线的制备需求。2、太赫兹准光天馈系统馈源与准光聚焦元件的空间耦合设计。基于高斯波束束腰变换理论,给出了上述馈源与准光聚焦元件的空间耦合方案。研究表明,透镜照明面和阴暗面的双面曲率函数对波束束腰敏感,对其控制和优化可有效增加波束的可控性。进而设计仿真了双异双曲面介质透镜,利用该透镜与馈源共同搭建了一套天馈系统,在仿真层面验证了馈源与准光聚焦元件的空间耦合设计方案的有效性与合理性。
[Abstract]:Terahertz quasi-optical space-fed system is an important component of terahertz wireless system. The spatial coupling technology of terahertz quasi-optical space-fed system is the key technology in the research of terahertz wireless system. This paper is based on the application background of terahertz imaging. . The feeders, quasi-light focusing elements and their spatial coupling schemes in terahertz quasi-optical antenna feed system are studied. The feed antenna of linear polarization and circular polarization is studied respectively. For terahertz quasi-light focusing element, the design flow of lens with Gao Si beam change as the starting point is given. The correctness of Gao Si beam theory in the design of lens antenna is verified. The main research contents are as follows: 1. Design and implementation of Terahertz Quasi-Optical Sky Feed system: 1) Design and optimize a series of covers of 220GHz / 500GHz (gain 15dB respectively). 20dB and 30dB) linear polarization multimode metal horn feed, which has the characteristics of relatively simple structure, good beam symmetry and high efficiency of Gao Si. The standing wave ratio of the 220GHz band antenna is tested in the absence of terahertz standard gain antenna. The gain calibration of the loudspeaker antenna in 220GHz band is carried out by using the three-antenna method and the comparison method. The simulation results agree well with the test results. The test results show that the series of feeders can replace the imported multi-mode metals of the same kind. Level of horn feed. 2) based on bulk silicon MEMS dry etching process. A new type of circular polarizer with plane ripple loading is proposed, which solves the problem of circular polarization and high gain radiation under the condition of two-dimensional low profile. The method of plane ripple can effectively improve the gain of antenna. By controlling the angle between the new circular polarizer and the feed waveguide, the axial ratio characteristics can be changed effectively. The processing, testing and verification are carried out in the ka band and the THz band, respectively. The simulation results are in good agreement with the test results, which verifies the correctness of the scheme. It shows that the MEMS process can meet the THz frequency band of the new antenna preparation requirements. 2. Based on Gao Si beam waist transformation theory, the spatial coupling scheme between the feed and the quasi-light focusing element is presented. The double curvature function of the illumination surface and the dark side of the lens is sensitive to the beam waist, and the control and optimization of the lens can effectively increase the controllability of the beam. Furthermore, the hyperboloid dielectric lens is designed and simulated. A space feed system is built by using the lens and the feed, and the validity and rationality of the spatial coupling design of the feed and the quasi-light focusing element are verified at the simulation level.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN820

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