分形天线的小型化分析-信息与通信工程专业论文.docxVIP

摘 要 分形是通过迭代函数系统产生的具有自相似的分数维结构，分形的概念可用 于天线设计以实现天线的尺寸减缩和多频特性，这在军用和民用方面都有着非常 广泛的应用前景。 绪论部分介绍了分形天线的产生背景、优点及其应用，国内外研究概况以及 本论文的基本结构与框架。 接着在第二章里，作者详细阐述了分形的概念和和定义，并结合迭代函数系 统分析了几种典型的分形天线的生成，指出分形天线在国外的研究有着良好的发 展趋势，在国内稍有落后。 第三部分主要介绍了一种新型分形结构在低剖面天线中的应用。设计出了一 种新型分形低剖面天线，并完成了仿真和加工测试等工作。最终结果表明，加工 测试结果和仿真结果基本吻合，尺寸减缩效果明显。 在第四部分中，提出了一种准分形结构。针对偶极子的辐射特点，设计出新 型准分形结构，研究了各阶分形对尺寸减缩的影响。 在介绍了前面各部分的基础上，本论文在第五部分对课题阶段所做的工作进 行了总结，并对后续研究工作进行了展望。 关键词：分形天线 天线小型化 电小天线 Abstract A “fractal” is a recursively generated structure by iterated function systems. It has a fractional dimension and possesses a self-similarity property. The concept of a “fractal” has been applied to antenna design in order to reduce the size of antenna and obtain multi-band frequency operation. Fractal antennas have broad application prospect in military and civil application. First of all, the dissertation presents some basic knowledge about the reconfigurable antennas, including the background, advantages, applications, the development sketch of this project in the worldwide . Ultimately introduces the framework and content of this thesis. In the second chapter following, the author elaborates on the concept of a “fractal” . Simultaneity, iterated function systems is applied to analysis this transforming process of a few representative “fractal” antennas. In the end of this chapter, the author summarizes the developing situation and point out that the “fractal” antennas have been obtained a great deal of production in the overseas while beginning in our country. In the third part, the applications of a novel fractal iteration technique in the design of low-profile antenna is presented. A novel fractal low-profile antenna is designed. The proposed antennas are fabricated and measured. It is shown that the measured results are in good agreement with the simulation results. The novel fractal characteristics reduce the size of the antenna obviously. In the fourth part, the author put forward a quasi-fractal construction. Based on