基于多功能可调电磁超材料的波束可控天线研究

Novel electromagnetic metamaterials have remarkable electromagnetic characteristics, however, the singular character of their function and non-tunable property seriously restrict their applications in steerable beam antennas. Multifunction tunable electromagnetic metamaterials (TEMM) is the main research object of this proposal. "multifunction" means that the transfer in metamaterials could be made among double positive (DPS), double negative (DNG), single negative (SNG, including MNG and ENG), and near zero index metamaterial (ZIM) under the control of electronic controlled element (ECE). Besides, through the theoretical modeling and optimization simulation of the TEMM, the equivalent circuit method could be developed and the corresponding relations of parameters of ECE, medium parameters, and structural parameters could be established, which lays the foundation for the design of metamaterials antenna with steerable beam; Then, on the basis of existing parallel plate waveguide for the measurement of metamaterails, the improvement and design of a set of TEMM test system will be implemented; Finally, based on the theoretical and experimental research achievements, and under the application motivations of specific problems from wireless communications and other multiple fields, we emphasize on the research of steerable beam antennas base on multifunction TEMM, which means that we manipulate the width and angle of radiated beam from antenna making use of the tunable property of multifunction TEMM, and improve other performance indicators of the antenna, such as bandwidth, gain, etc..

新型电磁超材料具有新颖的电磁特性，但是其功能的单一性以及非可调特性严重制约其在波束可控天线中的应用。本项目正是以多功能可调电磁超材料为主要研究对象，“多功能”是指在电控元件的控制下使超材料在双正、双负、单负(包括磁负和电负)以及近零折射率材料之间转换。此外，对多功能可调电磁超材料进行理论建模与优化仿真，发展等效电路方法并建立电控元件参数、媒质参数、及结构参数之间的对应关系，为波束可控超材料天线设计奠定基础；其次，在现有的超材料平板波导测量系统的基础上，改进并设计一套可调电磁超材料测试系统；最后，基于理论和实验的研究成果，以无线通信等多个领域中的具体问题作为应用背景，重点研究基于多功能可调电磁超材料的波束可控天线，利用多功能超材料的可调特性来操控天线辐射波束的宽度和角度，同时改进天线的带宽、增益等其它性能指标。

超材料的理论和应用研究是近年来国内外物理和电磁领域的研究热点问题之一。通过亚波长单元和阵列排布设计，超材料可在微波、太赫兹、光波等频段获得传统媒质所不具有的新颖特性，但同时其色散、损耗等问题严重制约了其应用范围。本项目尝试通过将有源器件与超材料相结合，提升传统超材料性能的同时并增加其功能，主要研究内容为可调电磁超材料的理论研究与分析，具体包括可调电磁超材料的等效电路模型以及超材料与有源器件的一体化设计仿真；多功能高性能超材料天线及器件，具体包括多频带多极化电磁超材料天线设计，波束可调/高增益电磁超材料天线，超材料应用器件；携带轨道角动量的涡旋电磁波特性研究，具体包括多模态涡旋电磁波物理机理研究，产生多模态多波束涡旋电磁波的反射型超表面天线和天线阵列。.本项目所取得的一些代表性研究成果发表在了应用物理快报、IEEE天线与传播快报等国际知名期刊杂志上，这些研究成果为超材料在多个领域中的理论研究和工程应用提供了潜在的新方法和新思路。