数字波束形成（DBF）校准网络研究

【作者】 王嫣然；

【导师】 盛卫星； 王昊；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2012， 硕士

【摘要】 DBF (Digital Beamforming数字波束形成)是通过控制各个阵元的权向量来实现空域滤波,以达到增强有用信号,同时抑制掉干扰信号的目的。但在实际工作中,常常存在各种误差。由于这些误差的存在,会使阵列方向图旁瓣过高或者使得主波束产生畸变,从而使得DBF性能下降,甚至失效,从而限制了这些技术的应用。因此,对阵列校准技术的研究具有重大意义。本文的内容概括如下：1)针对项目指标要求,设计了针对10×10 DBF天线阵列的内校准网络,通过在天线阵面上设计耦合口和天线阵列与校准网络之间对穿的绝缘子完成这两部分的能量传递以实现内校准。在仿真中对2×2校准网络、弱耦合天线以及2×2的子系统的性能进行讨论；并通过仿真模拟系统加工可能导致的某些天线阵元的弱耦合较弱和安装过程中可能碰到的端口匹配不好、天线单元接地不好、耦合微带线接地不好以及对穿的绝缘子有空气间隙等情况进行,详细的论证了系统的稳定性。从仿真结果来看,该DBF校准网络的稳定性良好,系统稳健。2)对DBF校准网络实测时发现,系统存在各阵列单元间的串扰严重和微带校准网络辐射较大两个不良现象。针对以上现象,依照能量传输路径依次实验,最终给出了能够保证系统正常工作的指导意见。同时讨论了T/R组件的屏蔽性,给出如何判定接收组件屏蔽性良好的依据。针对微带校准网络辐射较大会对接收组件产生不利影响的现象,提出了几种有效减少辐射的改进方案。更多还原

【Abstract】 In order to enhance the useful signals and suppress the interfering signals, the Digital Beamforming (DBF) technology can achieve spatial filtering by controlling the weight vector of each array element. However, in practical work, the system usually have different kinds of errors. To achieve the desired radiation pattern, such as main beam shape and low sidelobes, it is necessary for the array to be well calibrated. So the research of array calibration technique has great significance.The main work has been concluded in the following:1) According to the project requirements, a 10×10 calibration array has been designed. Through the coupling structure in the microstrip antenna, energy can be transferred between the antenna aperture and the calibration network. Furthermore, the errors of the calibration network have been investigated in this thesis, such as the fabrication errors and the fix errors. Form the simulated results, the performances of the DBF calibration system are stable.2) From the measured results, the mutual coupling between the antenna elements and microstrip calibration network affect the accuracy of the calibration. To improve the performance of the calibration network, a series of experiments have been done. Some methods have been proposed as a guideline to guarantee the accuracy of the calibration network. Furthermore, the shielding of the T/R module is discussed. Several methods have been presented to reduce the radiation of the microstrip calibration network.更多还原