小型化双频导航天线设计

发布时间：2018-08-18 08:20

【摘要】：目前同时存在多种卫星导航系统,包括GPS,Galileo、GALLONASS以及我国的北斗导航。如果能够同时在两个或多个导航模式工作,将有效改善导航系统的性能和兼容性。为此,需要应用天线的多频技术。针对微带天线的小型化技术和多频技术进行研究分析和总结,本文提出一种双层贴片组成的叠层结构天线,对上层贴片馈电,对下层贴片通过电磁耦合馈电,同时工作在GPS的L1频段和GALLONASS的L2频段。首先介绍了微带天线工作原理,分析了其辐射机理与常用馈电方法,分析了天线的多频技术、宽带技术在天线的设计中的应用,以及实现圆极化的方法和设计过程。根据天线设计的相关技术,提出天线模型,并运用电磁仿真软件HFSS分析了天线特性,重点研究了天线的各个设计参数对天线特性的影响及设计参数的优化。其中,主要分析了影响天线驻波比的两个因素,馈电位置和基片厚度,通过参数优化,使天线的带宽和驻波比等参数符合设计指标要求。通过仿真天线的辐射方向图结果,分析其圆极化性能,重点分析天线的切角微扰尺寸对圆极化特性轴比特性的影响,并优化分析了天线切角尺寸参数,使天线的带宽在双频工作频段。此时天线的工作带宽和轴比带宽在要求范围内,并且辐射电磁波为右旋圆极化波。为了进一步展宽天线带宽,优化参数结果,满足设计指标要求,通过分析基片和厚地板面积两个参数对带宽的影响,并通过优化这两个参数,改进天线的介质基片的结构,改善了天线的特性。考虑到实际安装环境可能存在反射波,还对天线在带反射板的条件下进行建模仿真,并总结得出反射板存在影响天线辐射电磁波。此外,基于敏感度分析,研究了天线性能对天线设计参数的敏感程度;基于统计分析,研究了天线加工公差对天线性能的影响。根据优化后的设计参数制作实物,并在电波暗室环境下,在有无金属反射板的两种情况下,测量了在天线的回波损耗、驻波比与方向图等相关参数,分析了天线实际参数性能与仿真结果的差异原因,测试结果与仿真结果基本一致,验证了设计方案的有效性。
[Abstract]:At present, there are many satellite navigation systems, including GPS Galileo GALLONASS and Beidou navigation in China. If you can work in two or more navigation modes at the same time, you will effectively improve the performance and compatibility of navigation systems. Therefore, it is necessary to apply the multi-frequency technique of antenna. The miniaturization technology and multi-frequency technology of microstrip antenna are analyzed and summarized. In this paper, a laminated antenna composed of double-layer patch is proposed, which feeds the upper layer patch and the lower layer patch through electromagnetic coupling. It also works in L1 band of GPS and L2 band of GALLONASS. Firstly, the working principle of microstrip antenna is introduced, the radiation mechanism and common feeding method are analyzed, the multi-frequency technology of antenna, the application of broadband technology in antenna design, and the method and design process of realizing circular polarization are analyzed. According to the related technology of antenna design, the antenna model is put forward, and the antenna characteristics are analyzed by using electromagnetic simulation software HFSS. The influence of antenna design parameters on antenna characteristics and the optimization of design parameters are studied emphatically. Two factors affecting the antenna standing wave ratio (VSWR), feed position and substrate thickness, are analyzed, and the bandwidth and VSWR parameters are optimized to meet the design requirements. By simulating the radiation pattern of the antenna, the circular polarization performance is analyzed, and the influence of the shearing angle perturbation size on the axial ratio characteristics of the circular polarization characteristic is analyzed, and the parameters of the antenna tangent angle dimension are optimized. Make the bandwidth of the antenna work in the dual frequency band. The operating bandwidth and axial ratio bandwidth of the antenna are within the required range, and the radiated electromagnetic wave is a right-handed circular polarization wave. In order to further widen the antenna bandwidth, optimize the results of the parameters and meet the design requirements, by analyzing the influence of the substrate and the area of the thick floor on the bandwidth, and by optimizing these two parameters, the structure of the dielectric substrate of the antenna is improved. The characteristics of the antenna are improved. Considering that there may be reflected waves in the actual installation environment, the antenna is modeled and simulated under the condition of the reflector, and it is concluded that the reflector has an effect on the radiation electromagnetic wave of the antenna. In addition, the sensitivity of antenna performance to antenna design parameters is studied based on sensitivity analysis, and the effect of antenna processing tolerance on antenna performance is studied based on statistical analysis. According to the optimized design parameters, the parameters such as echo loss, standing wave ratio and pattern of antenna are measured in the environment of anechoic chamber and without metal reflector. The reasons for the difference between the actual antenna parameters and the simulation results are analyzed. The test results are in good agreement with the simulation results, and the effectiveness of the design scheme is verified.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN965.2

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