人工磁导体结构的研究及在天线中的应用

【作者】 王倞婧；

【导师】 盛卫星； 王昊；

【作者基本信息】 南京理工大学 ， 电磁场与微波技术， 2012， 硕士

【摘要】 近年来,人工磁导体作为当前微波毫米波领域研究的热点之一,得到了学术界的广泛关注。该结构具有结构简单,容易制备的特点,主要用于提高射频部件的性能。本论文研究了人工磁导体结构在微带天线单元和阵列中的应用。本论文首先从人工磁导体基本特性的研究入手,给出人工磁导体的反射相位带隙以及电磁带隙结构阻带带隙的分析方法,并由此设计出所需要频段的人工磁导体。其次将人工磁导体结构应用于微带天线单元及其阵列的设计中。在单元设计研究方面,将AMC替代原来微带天线单元的地板,仿真结果表明人工磁导体结构的加载对提高天线的增益及带宽效果明显,与相同介质基板情况下的天线单元相比,带宽增加了250%,增益提高了1.41dB；在此基础上,本文针对加载人工磁导体的2×2微带天线阵列的三种情况进行讨论和分析,这三种情况分别是：(1)AMC结构仅加载至微带贴片下方,馈线下方不加载AMC结构；(2)微带贴片及馈线下方均加载AMC结构；(3)AMC结构仅加载至微带贴片下方,同时馈线下方金属地板被抬高。通过AMC结构的加载,三种情况的带宽及增益均有明显增大。仿真结果显示,三个阵列天线的相对带宽均大于17.64%,由于馈线下方AMC结构的加载,使得实例2的相对带宽达到20.04%；三个阵列天线的最高增益均大于14dBi,由于馈线下方地板的抬高,使得实例3的馈线损耗明显降低,增益最大值达到15.29dBi；同时与实例1、实例2相比,实例3的方向图的对称性最好。最后,对性能最好的实例3进行加工和实测。天线实物测试的回波损耗工作频带相对带宽为20.45%,驻波频带内增益最大值为15.95dBi。更多还原

【Abstract】 In recent years, the artificial magnetic conductor (AMC) structure as one of hot topics has been investigated in the research area of microwave and millimeter wave technology. The structure is simple and easily manufactured, which is mainly used to improve the performances of RF components. In this thesis, the applications of the AMC structure on the microstrip antenna have been presented.Firstly, the method analyzing the reflected phase band-gap of the AMC structure has been presented. Furthermore, focusing on the Electromagnetic band-gap (EBG), one structure of AMC, the investigations of its stop-band have also been given. Secondly, the applications of AMC structure to microstrip patch antenna and antenna array are researched in this thesis. For the application of microstrip antenna element, the AMC structure has been used to instead the ground plane of the antenna. With this modification, the high-gain and wide-band antenna element is achieved. Compared with the conventional patch antenna using the same thickness dielectric substrate, the simulated results of this novel patch element show that the bandwidth is increased by 250%, and the gain is increased by 1.41 dB. Further, three cases of 2X2 antenna array utilizing the AMC are discussed. The three cases are listed:case 1 is the AMC only insteading the ground plane of the antenna elements of 2×2 array; case 2 is the AMC structure insteading the ground plane of the 2×2 array; case 3 is the AMC only insteading the ground plane of antenna elements, however, the ground plane of feeding network has been elevated. The VSWR, radiation patterns and gains of three cases are compared. Among them, the best one has been fabricated and tested. The measured results show approximately 20.45% relative bandwidth and the maximum gain in the frequency working band is 15.95dBi.更多还原