便携式移动定位系统前端设计

发布时间：2018-05-01 07:27

本文选题：移动定位 + 和差波束　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：随着移动通信技术的发展,移动定位技术成为人们研究的热点。目前,移动定位技术提供的服务范围集中在位置查询、周边信息查询、地图导航、人员定位等。但是,当用户处于大楼、大厦、商场等三维立体场所时,确定用户的高度信息才能对用户进行准确定位。特别是,在紧急救援、犯罪分子追踪等情况下,快速定位的实现非常重要。为此,本文结合实际项目的需求,对便携式移动定位系统及其关键技术进行研究,实现了大楼用户的准确定位。本文主要设计了用于便携式移动定位系统的两单元和四单元单脉冲天线阵列,实现了宽频带工作;研究了和差波束天线的宽频带馈电网络技术,基于椭圆缝隙耦合技术设计出宽频带的3dB电桥和宽频带的移相器。为了实现精确定位,研究了天线单元的宽波束和波束对称性,以及天线阵列相位中心等关键技术。本文主要完成的工作如下:1.宽频带领结状渐变平面单极子定向辐射天线单元的设计,采用U型地板对天线的方向图进行修正。天线的回波损耗在650MHz-2175MHz频段均大于10dB,很容易扩展到GSM/DCS/PCS/UMTS/CDMA/WiMAX/LTE等频段。对影响天线带宽、辐射方向图的对称性以及波瓣宽度等的因素进行了研究;2.宽频带和差波束馈电网络的设计,包括宽频带的正交定向耦合器和宽频带移相器设计。耦合器和移相器均采用宽边耦合来实现较高的耦合度,采用椭圆缝隙耦合来实现宽频带性能并对影响定向耦合器和移相器带宽的因素进行了研究。由于定向耦合器及移相器均采用开放性的耦合结构,因此金属环境对馈电网络的性能有较大影响。本文对金属环境中的馈电网络的S参数及相位和幅度平衡度进行了仿真分析。为了实现工程可应用的宽带馈电网络,必须消除金属环境的影响及耦合器与移相器之间的耦合。通过对在良好接地的金属盒子中的耦合器和移相器的仿真分析,本文提出了在不同模块之间采用良好接地的金属盒子进行屏蔽,来消除天线对馈电网络的影响及耦合器与移相器之间的耦合,并进行了仿真分析。3.本文对和差波束阵列天线的相位中心与阵列排布的关系进行了探究。为了精确定位,需要保证和波束最大辐射方向和差波束的最小辐射方向重合在参考方向上,也就是说天线阵列的相位中心与几何中心重合。本文研究了不同的阵元排布方式对相位中心的位置及稳定度的影响,并给出了优化的阵列排布方式。4.本文对双天线和差波束阵列天线及其馈电网络进行了仿真,并给出了仿真结果;同时,本文对四天线和差波束阵列天线及其宽频带馈电网络进行了联合仿真,并进行了工程实现,通过对采用去耦技术的馈电网络的测试,验证了上述的原理分析。本文所设计的四天线和差波束阵列及其馈电网络的测试结果与仿真结果吻合良好,具有较高的工程应用价值。
[Abstract]:With the development of mobile communication technology, mobile positioning technology has become a hot topic. At present, mobile location technology provides a range of services focused on location query, peripheral information query, map navigation, personnel positioning and so on. However, when the user is in the building, building, shopping mall and other three-dimensional space, determine the user's height information can accurately locate the user. In particular, in emergency rescue, criminal tracking and other situations, the realization of rapid positioning is very important. In this paper, the portable mobile positioning system and its key technologies are studied according to the requirements of the actual project, and the accurate location of building users is realized. In this paper, a two-unit and four-unit monopulse antenna array for portable mobile positioning system is designed to realize broadband operation, and the broadband feed network technology of sum and differential beam antenna is studied. A wide band 3dB bridge and a wide band phase shifter are designed based on elliptical slot coupling technique. In order to achieve accurate positioning, the key techniques such as wide beam and beam symmetry of antenna elements and phase center of antenna array are studied. The main work of this paper is as follows: 1. In the design of wideband bandnecked planar monopole directional radiation antenna unit, the pattern of the antenna is modified by using U-shaped floor. The echo loss of the antenna is larger than 10 dB in the 650MHz-2175MHz band, which can be easily extended to the GSM/DCS/PCS/UMTS/CDMA/WiMAX/LTE band. The factors affecting antenna bandwidth, symmetry of radiation pattern and width of lobe are studied. The design of wide band and differential beam feeding network includes the design of wide band orthogonal directional coupler and wide band phase shifter. Both coupler and phase shifter adopt wide edge coupling to realize higher coupling degree, elliptical slot coupling is used to realize wide band performance, and the factors affecting the bandwidth of directional coupler and phase shifter are studied. Because both directional coupler and phase shifter adopt open coupling structure, metal environment has great influence on the performance of feed network. In this paper, the S parameters, phase and amplitude balance of feed network in metal environment are simulated and analyzed. The influence of metal environment and the coupling between coupler and phase shifter must be eliminated in order to realize the wideband feed network which can be used in engineering. Through the simulation and analysis of couplers and phase shifters in well-grounded metal boxes, this paper proposes to shield metal boxes with good grounding between different modules. To eliminate the effect of antenna on the feed network and the coupling between coupler and phase shifter. The relationship between phase center and array arrangement of sum difference beam array antenna is discussed in this paper. In order to locate accurately, it is necessary to ensure that the maximum radiation direction of the beam and the minimum radiation direction of the difference beam coincide with the reference direction, that is to say, the phase center of the antenna array coincides with the geometric center. In this paper, we study the influence of different array arrangement modes on the position and stability of phase center, and give the optimized array arrangement mode .4. In this paper, the dual antenna and differential beam array antenna and its feed network are simulated, and the simulation results are given, at the same time, the four antenna and differential beam array antenna and its broadband feed network are simulated jointly. The above principle analysis is verified by testing the feed network using decoupling technology. The test results of the four-antenna and differential beam array and its feed network designed in this paper are in good agreement with the simulation results and have high engineering application value.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5

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