【作者】 张谅；

【导师】 吴群；

【作者基本信息】 哈尔滨工业大学 ， 微电子学与固体电子学， 2013， 博士

【摘要】 近年来，随着通信产业的发展，用户数量急剧增长，频谱资源日益紧张，为此，一系列新技术应运而生。其中智能天线技术可以有效改善信道链路性能，提升用户容量，提高频谱利用率，成为通信领域研究的热点前沿技术之一。常见的智能天线系统，在形式上多是线形或圆形阵列，通过控制阵元之间的相对相位来控制波束形成（Beam-forming）。对相位的控制一般利用移相器实现，并通过一系列相应的算法确定相对相位值，从而控制天线阵列辐射方向。对于整套智能天线系统来说，移相器的开销往往占据整套系统中的较大比重。因此，近年来很多学者开始研究无移相器的智能天线，或称为电扫描天线。本文针对基于有源频率选择表面结构的电扫描天线进行理论研究、仿真设计并加工实物测试验证了提出的设计方案和相关理论。提出了一种新颖的电扫描天线的结构及工作原理。该天线的电扫描能力是通过改变围绕在一全向天线周围的特殊的有源频率选择表面的工作状态，从而控制天线辐射方向来实现的。通过不同的配置方式，可以实现多种模式的单波束扫描，完成对整个水平面内各方向的平滑电控扫描。此外，还可以实现多波束的电控扫描。针对这种特殊形式的天线结构，本文进行了辐射特性的理论研究，将该天线的近场部分为行驻波区、功率交换区和二次辐射区。利用二次辐射的理论从线阵天线辐射开始展开理论推导，进一步推广至共形阵列天线的辐射理论，再进一步推导出ESRRA（Electronically steerable radiators and reflectors array）天线的辐射模型。从而建立了ESRRA天线辐射的阵因子模型。有源频率选择表面是实现天线电扫描能力的一种全新方法，本文针对其特殊性，分析了这种频率选择表面应具备的技术指标要求，提出了一系列不等式方程，建立了应用于ESRRA天线的有源频率选择表面的基础理论。有源频率选择表面面临的一个关键问题就是其复杂的馈电网络相互交织所引入的单元之间的阵列耦合和干扰，为了解决这个难题，本文提出了一种新颖的无偏置网络频率选择表面通用拓扑结构，并对其进行了仿真优化。分析结果表明这种拓扑结构不但解决了该问题，还具有很好的通用性。在此基础上为实现针对ESRRA天线的极化敏感方向的要求，首次提出了“磁环路陷阱”（Magnetic loop trap）结构。利用这一结构，很好地实现了前面所提出的窄带宽，反射带高反射率，通带高透过率以及极化方向与单元延伸方向一致等一系列要求。并且，较为系统的提出了一种新颖的有源频率选择表面偏置网络通用结构。这种结构通过电感的加载避免了其对天线工作频段的干扰。仿真和实测结果证明，这种有源频率选择表面很好的满足了前面设计理论所提出的指标要求。最后，为验证本论文提出的天线设计理论，加工制作了小型化和高增益两款典型天线实物进行测量。测量结果与理论分析一致。综上，通过本文的研究提出了一种新型电扫描天线的实现方法，并从理论分析到实验测试验证了这一方法。实验结果证明这种新型天线具有E面高增益、H平面全向灵活可控、平滑电扫、低功耗、低成本等一系列优点，体现了一种电扫描天线设计新思想。更多还原

【Abstract】 Recent years, with the development of communication industry, the amount of usersincreased significantly, frequency spectrum resource become more and more critical. Forthe very purpose, a serial new technology emerged. In many of these, smart antennabecome one of the frontier technologies by the means of user capacity and frequencyspectrum using efciency.In a common smart antenna system, a linear or circular array is always employed.Beam-forming ability is achived by cntrolling the relative phases of array elements. Phasecontrolling is usually realized by phase shifters, with a serial relative algorithm. Thus,radiation pattern is controlled. Phase shifters always contribute a lot to the total cost ofthe smart antenna system. For this reason, a lot researchs focused on the non-phase-shiftersmart antenna systems or so called electronically steerable antennas.In this essay, a research on the electronically steerable antenna based on active fre-quency selective surface is studied. The theoretically discussion, simulation and prototypetesting are token out to verificate the theory and design.A novel structure and relative theory is presented. The ability of electronically steer-ing is achived by controlling the status of the specially designed active frequency selectivesurface which surrounding a ominidirectional antenna. Single beam modes which coverthe whole horizontal plane and continuously tunable is achived by diferent configura-tions. Further more, multi-beam mode is also achived.Focusing on this special antenna structure, radiation feature is studied. Near field ofthis antenna is divided into three parts. Re-radiation theory is used to deduce the radiationfrom a common linear arry to circular array, further to a conformal array, and finally toESRRA (Electronically steerable radiators and reflector array) antenna. The array modleis established.Active frequency selective surface (AFSS) is a new method to realize electronical-ly steerable ability. In essay, the special requirements of AFSS for purpose of realizingESRRA antenna are studied and a serial of inequations are established. The basic theoryof AFSSes for ESRRA is established. A critical problem for AFSS is the couple inter-ference between unit cells caused by biasing network. To solve this problem, a novel non-biasing-network AFSS topology is presented. Relative simulation is accomplishedand the correctness of this design is proved. A novel magnetic loop trap structure is p-resented. An AFSS with narrow reflection band; high reflection rate in reflection band;high transmission rate in transparent band and polarization sensitive direction being thesame with the unit cells extend direction is achived. Furthermore, a new biasing networkis established systematically. Inductors are mounted on the gap of the biasing networkto isolation the interference. Both the simulation and tested results show that the AFSSmeets the requirements mentioned before.To prove the correctness of the theory, a compact an another high gain ESRRAantenna are fabricated. The test results perfectly meet the theory.In totally, a novel method to build electronically steerable antenna is established.Measured results show that this antenna is high gain in E-plane, flexible continuouslysteerable in H-plane, low power consumption and low cost.更多还原