【作者】 李凡；

【导师】 刘英；

【作者基本信息】 西安电子科技大学 ， 电磁场与微波技术， 2013， 硕士

【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。更多还原

【Abstract】 A“fractal” is a recursively generated structure by iterated function systems. It has afractional 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 obtainmulti-band frequency operation. Fractal antennas have broad application prospect inmilitary and civil application.First of all, the dissertation presents some basic knowledge about thereconfigurable antennas, including the background, advantages, applications, thedevelopment sketch of this project in the worldwide. Ultimately introduces theframework 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 processof a few representative “fractal” antennas. In the end of this chapter, the authorsummarizes the developing situation and point out that the “fractal” antennas have beenobtained 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 designof low-profile antenna is presented. Anovel fractal low-profile antenna is designed. Theproposed antennas are fabricated and measured. It is shown that the measured results arein good agreement with the simulation results. The novel fractal characteristics reducethe size of the antenna obviously.In the fourth part, the author put forward a quasi-fractal construction. Based on thecharacteristic of the dipole, the author put forward a novel quasi-fractal construction.The application of different orders on size reduction has been researched.Finally, the summary about the research of the project and the expectation aboutthe future work are presented.更多还原