基于人工电磁超表面的方向图可重构天线研究

发布时间：2018-08-27 20:11

【摘要】：天线作为通信、雷达系统中的关键部件,逐渐受到更多人的关注,同时人们也对其提出了更多的要求。为了简化天线系统、降低系统成本,可重构天线成为较好的选择。本文以人工电磁表面为基础对方向图可重构天线展开研究,主要内容包括以下几个方面:首先,本文介绍了人工电磁超表面的近几年研究现状及发展趋势,并简单介绍了人工电磁超表面及石墨烯材料的特有电磁特性。通过计算周期单元结构的等效阻抗,利用微波网络模型对人工电磁超表面的反射系数做了解析分析,并利用HFSS及CST软件对其进行了数值仿真分析。其次,基于FP谐振腔天线可重构原理,利用石墨烯材料设计了反射系数可调的部分反射表面和高阻抗表面,并据此构成FP谐振腔天线,通过改变石墨烯的偏置电压实现了天线方向图在±75°范围内的可重构,且天线最大方向图均超过5dBi,具有良好的辐射特性。然后,本文设计了一种工作于太赫兹频段的金属石墨烯混合组成的高阻抗表面,在其上方添加简单馈源天线,可实现天线方向图的可重构。石墨烯和电极之间加载不同的偏置电压,可导致高阻抗表面反射系数的不同,并最终改变整体天线的辐射方向。该天线工作于1.03THz,利用全波仿真软件CST对其进行仿真,其方向图可重构范围可达±75°。最后,本文提出了一种基于金属与石墨烯复合材料的方向图可重构微带准八木天线。在二氧化硅基板上表面印制左右对称的八木贴片天线单元,利用石墨烯材料将金属引向单元补偿至反向器长度,并在介质基板下表面间隔印制金属与石墨烯条带。通过联合控制上下表面的石墨烯偏置电压实现天线H面方向图在-70°至70°之间扫描。本文最后对全文进行了总结,并对下一步如何利用人工电磁超表面做了简单展望。
[Abstract]:As a key component of communication, antenna in radar system has attracted more and more attention. At the same time, people have put forward more requirements for it. In order to simplify the antenna system and reduce the cost of the system, reconfigurable antenna becomes a better choice. Firstly, the research status and development trend of artificial electromagnetic Supersurface in recent years are introduced, and the unique electromagnetic properties of artificial electromagnetic Supersurface and graphene materials are briefly introduced. Secondly, based on the reconfigurable principle of FP resonator antenna, the partial reflective surface and high impedance surface with adjustable reflective coefficient are designed by using graphene material, and then the FP resonator antenna is constructed. The antenna pattern is realized by changing the bias voltage of graphene. The antenna is reconfigurable in the range of The antenna operates at 1.03 THz and is simulated by full-wave simulation software CST. The reconfigurable range of the antenna pattern can reach (+) 75 degrees. Finally, a direction based on metal-graphene composites is proposed. Fig. 1 Reconfigurable microstrip quasi-Yagi antenna. Left-right symmetrical Yagi patch antenna elements are printed on the surface of silicon dioxide substrate. The metal lead element is compensated to the length of the reverser using graphene material. Metal and graphene strips are printed separately on the surface below the dielectric substrate. The graphene bias voltage on the upper and lower surfaces is controlled jointly. The H-plane pattern of the antenna is now scanned from - 70 to 70 degrees. Finally, the full text is summarized and a brief prospect of how to utilize the artificial electromagnetic Supersurface is given.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN820

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