共形双频带天线及多频带滤波器的设计与研究

发布时间：2018-09-14 16:34

【摘要】：随着无线通信系统的快速发展，多频带天线逐渐成为研究热点，鉴于与其它微波器件方便集成、便于携带等优点，共形天线受到越来越多人的关注。另一方面，作为新世纪的重点研究内容—频率选择表面（FSS），又可称为空间滤波器，其设计要求随着无线通信技术的发展越来越高，小型化、性能稳定和多频段是几大发展特点。而超材料（MM）作为一种特殊的空间滤波器受到越来越多学者的关注。近年来，国内外学者一直致力于多频、小型化的单元结构的研究，从而用于设计高性能的空间滤波器。此外，作为无线射频前端的关键部件—滤波器，其小型化、多频段和高性能成为研究热点。本论文主要从以下几个方面进行研究： (1)对传统的蝶形天线进行改进，提出了一种应用于WiMAX和X波段的柔性双频带天线，并对其进行了仿真、分析、加工及测试。该新型天线相较于传统的蝶形天线尺寸大幅度减小，，并且实现了双频带的效果。此外，该天线采用的是共面波导(CPW)馈电方式，方便与系统电路进行集成。最后，由于该天线采用的是柔性的材料作为介质基板，对其进行了弯折性测试，测试结果表明该天线对弯折状况不敏感，对未来柔性材料的应用奠定了一定的基础。 (2)在对传统分裂环谐振器(SRR)的基础上进行了改进，并设计了一款双频带空间滤波器。本文对一个柔性的双频带空间滤波器的传输特性、输入角度稳定性、电流分布进行了分析，并对加工制作出的双频带空间滤波器进行测试，测试结果和仿真结果吻合较好，从而验证了本文设计原理的有效性。该平面双频带空间滤波器采用了柔性介质板，方便加工和测试，并且易于与应用材料表面进行共形。总的来说，设计的柔性双频带空间滤波器对将来双频带或多频带的隐身介质和共形形状的空间滤波器研究具有推动作用。 (3)提出和设计了一个简单的三模非对称加载枝节谐振器(ASLR)单元，并对其等效电路和特性进行了详细的分析。在此基础上，将两个ASLR单元的枝节进行弯折并采用伪交趾方式耦合用于设计三频带带通滤波器，采用两阶谐振器的目的是提高通带的选择性，两旁的馈线通过缝隙耦合的方式耦合到谐振器。通过调节阻抗比和电长度比可以实现频率的控制，极大的提高了该款三频带滤波器的选择性。该滤波器设计的通带分别为GPS，4G和WiMAX频段，其电路尺寸小巧便于集成。最后经过滤波器实物制作和测试，实测结果和仿真结果吻合，证明了分析和设计理论的正确性和有效性。
[Abstract]:With the rapid development of wireless communication system, multi-band antenna has gradually become a research hotspot. Due to the advantages of convenient integration and portability with other microwave devices, conformal antenna has attracted more and more attention. On the other hand, as the important research content in the new century, frequency selective surface (FSS), can also be called spatial filter. With the development of wireless communication technology, its design requirements are more and more high, miniaturization, stable performance and multi-frequency band. As a special spatial filter, metamaterial (MM) has attracted more and more attention. In recent years, scholars at home and abroad have been devoted to the study of multi-frequency, miniaturized cell structures, so as to design high-performance spatial filters. In addition, as a key component of RF front-end, filter, its miniaturization, multi-band and high performance has become a research hotspot. This paper mainly studies the following aspects: (1) improve the traditional butterfly antenna, propose a flexible dual-band antenna used in WiMAX and X-band, and simulate, analyze, process and test it. Compared with the traditional butterfly antenna, the size of the new antenna is greatly reduced, and the effect of double band is realized. In addition, the antenna adopts coplanar waveguide (CPW) feed mode, which is convenient to integrate with the system circuit. Finally, because the antenna is made of flexible material as the dielectric substrate, the bending property of the antenna is tested. The test results show that the antenna is not sensitive to the bending condition. It lays a foundation for the application of flexible materials in the future. (2) based on the traditional split ring resonator (SRR), a dual-band spatial filter is designed. In this paper, the transmission characteristics, input angle stability and current distribution of a flexible dual-band spatial filter are analyzed. The validity of the design principle is verified. The planar dual-band spatial filter uses a flexible dielectric plate, which is easy to process and test, and is easy to conformal with the applied material surface. In general, The designed flexible dual-band spatial filter can promote the study of the future double-band or multi-band stealth medium and conformal spatial filter. (3) A simple three-mode asymmetric addition is proposed and designed. (ASLR) element with branch resonator, The equivalent circuit and characteristics are analyzed in detail. On this basis, the branches of the two ASLR elements are bent and the pseudo-cross-toe coupling is used to design a three-band bandpass filter. The purpose of using the two-order resonator is to improve the passband selectivity. The feeders on both sides are coupled to the resonator by slot coupling. By adjusting the impedance ratio and the electric length ratio, the frequency can be controlled, which greatly improves the selectivity of the three-band filter. The filter is designed in GPS,4G and WiMAX band, and its circuit size is small and easy to integrate. Finally, the experimental results are in good agreement with the simulation results, which proves the correctness and validity of the analysis and design theory.
【学位授予单位】：华东交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713

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