小型化宽带天线及koch分形天线分析-analysis of miniaturized wideband antenna and koch fractal antenna.docx

I 摘要  PAGE 2 小型化宽带天线及 Koch 分形天线研究 摘要 论文结合科研项目进行选题研究，主要研究工作分为两个部分，第一部分工 作为研制了两款分别工作于UHF频段和S频段的小型化宽带遥测天线的工程样机， 测量结果表明所设计的这两款天线均满足指标要求，已交付甲方使用，使用效果 良好；第二部分工作为设计了两款分别应用于UWB和WLAN/WiMAX 频段的Koch 分形单极子天线，测量结果表明所设计的这两款天线均达到了设计要求，对于将 分形结构应用于天线设计的探索研究具有一定的参考意义。 论文的主要研究内容为： 首先，结合小型化宽带UHF天线的工程要求，论述了UHF天线的定义，阐述 了UHF天线的发展历史和研究现状，讨论了UHF天线的设计方法。在此基础上设 计了两款分别工作于UHF频段和S频段的小型化宽带天线。采用Ansoft HFSS仿真软 件对天线进行仿真设计，在仿真的基础上研制了天线的实验样机，并对其电性能 进行了测量。测量结果表明，所设计的两款天线电压驻波特性良好，实现方位面 全向辐射的设计要求，并且达到8%以上的阻抗带宽。可见文中提出的两款天线具 有一定的工程应用价值。 随后，为了研究了Koch分形边界对单极子天线性能的影响，本文设计了两款 不同用途的Koch分形单极子天线。采用Ansoft HFSS软件进行了仿真分析，在仿真 的基础上加工了天线的实验样机，并对其电性能进行了测量。测量结果表明，分 形边界可以有效减小天线尺寸，并且研制的两款天线分别适用于UWB频段和 WLAN/WiMAX频段。 关键词：小型化 宽频带 Koch 分形 单极子天线  Abstract III  PAGE 4 小型化宽带天线及 Koch 分形天线研究 Abstract The research works are made with scientific projects. The major works can be divided into two parts: the engineering samples of two compact broadband antennas work at two different frequences are made in the first part and the measured results show good agreement with the requirements, the antennas have been applied to practical application and achieved a good use effect; and in the second part, two engineering models of Koch fractal monopole antennas suit for UWB and WLAN/WiMAX applications are proposed and the measured results indicate the antennas are suitable for broadband wireless communication application. The main research works of this thesis are as following: Firstly, with the project requirements of compact broadband UHF antenna, the definition of the UHF antenna are illustrated, the research status and the history of the UHF antenna are presented, and the design methods of the UHF antenna are discussed. The antennas are simulated by Ansoft HFSS. On the basis of the simulation, the prototype of antennas are fabricated and measured. The measured results show that the two designed antennas can obtain favorable VSWR and omnidirectional radiation characteristics in azimuth plane; whats more, they achieved 8% impedance b