机载分布式相控阵波束合成方法研究

发布时间：2018-01-16 15:00

本文关键词：机载分布式相控阵波束合成方法研究　出处：《重庆大学》2015年硕士论文　论文类型：学位论文

【摘要】：由于雷达技术、光电技术和数字技术的飞速发展,21世纪机载任务设备的性能将有质的飞跃,例如探测距离大幅度增加、灵敏度更高、分辨率更细、质量更小。在军事方面,航空通信显得尤为重要,在通信天线中,相控阵天线是通常的选择。而分布式相控阵天线,可以巧妙地把大口径相控阵,划分为多个小口径的子相控阵。对于飞机而言,每个子相控阵可以安装在飞机机翼的不同位置,既保证了天线的增益,也不影响飞机的气动力学要求,同时又巧妙地解决了天线在飞机上的安装问题。因此分布式相控阵的研究对于飞机的天线设计有着广阔前景。故本论文就是针对机载的分布式相控阵波束合成的方法进行研究,研究内容主要包括四个部分:①研究了相控阵子阵的设计方法。对相控阵原理进行学习研究,弄清天线的各项基本参数包括方向图、波束范围、定向性、增益等等。对相控阵天线的信号模型进行分析,对其指标进行了解分析,据此设计机载相控阵的均匀平面子阵。②研究了角度校正的方法。由于每个子阵安装在机翼上,机翼的变形使得每个阵面相对于卫星或者地面站的角度是不相同的。需要通过一定的方法,对每个阵面的信号的波达方向(Direction of arrival,DOA)进行计算。于是给出一种坐标变换的方式来校正角度,并且将校正方法进行实验仿真,验证其正确性。③分析了多子阵的信号合成方法。信号合成的目的,就是校正每个子阵输出信号的延时差,使得这些信号可以实现同相叠加,从而进一步提高信号的SNR。采用自适应滤波的方法,通过对信号进行加权求和,完成信号合成。不同的信号采用的合成方式也不同。等输入SNR下的信号合成要分成两类,一类是高SNR下的信号合成,另一种是低SNR下的信号合成。对于较大SNR下的信号,我们可以采用基于功率倒置准则的自适应LMS滤波算法,实现信号合成。对于低SNR下的信号合成,可以借鉴深空通信中的天线组阵方法。因此选择SUMPLE算法。将选择的方式进行实验仿真,验证其可行性。不等输入SNR下的信号合成需要对多路数据进行两次加权后再求和。第一次加权算法同等输入SNR的信号合成算法相同,采用SUMPLE算法求其权矢量,校正每个子阵输出信号的延时差,使得第一次加权输出的各路数据可同相叠加。第二次加权先采用谱估计方法对各路数据进行SNR估计,然后通过最大比合并算法进行加权求和。根据方法进行实验仿真,验证方式的可行性。④系统方案利用研究的信号处理方法进行系统方向图仿真。每个子阵分别通过两种方式进行波束合成,一种是在没有进行角度矫正情况下进行的,另一种是在进行了角度校正的情况下进行的。同样地,信号合并也分两种情况,一种是各子阵输出SNR相等且SNR值比较大,对所有信号采用基于有用信号的PI算法进行信号合并,另一种是各子阵输出SNR不相等时先采用SUMEPLE算法进行延时校正,后通过SNR估计及最大比合并进行信号合并。观察其整体的系统方向图,验证系统的可行性。
[Abstract]:Due to rapid development of radar technology, photoelectric technology and digital technology, the performance of airborne mission equipment in twenty-first Century will have a qualitative leap, such as the detection distance is greatly increased, higher sensitivity, resolution and more fine, the quality is smaller. In the military, aviation communication is particularly important in communication antenna, phased array antenna is usually chosen while distributed phased array antennas, can skillfully put large aperture phased array, is divided into a plurality of small caliber sub phased array. For aircraft, each sub phased array can be installed in different locations of the aircraft wing, both to ensure the antenna gain, does not affect the aerodynamic requirements of the aircraft, but also solves the problem of installation the antenna on the aircraft. So the research on distributed phased array has broad prospects for antenna design of aircraft. This thesis is aiming at airborne distributed phased array beam combination Research into the method, the research content mainly includes four parts: the design method of phased array array. Study on phased array principle, the basic parameters including antenna pattern clear, directional beam range, gain and so on. Analyze the signal model of phased array antenna, know analysis the index, according to the design of uniform plane sub array. The airborne phased array method of angle correction. Because each sub array mounted on the wing, the wing deformation makes each array relative to the satellite ground station or the angle is not the same. Through a certain method, direction of arrival of each array signal (the Direction of arrival, DOA) were calculated. Then gives a coordinate transformation approach to correction angle, and the correction method of simulation to verify the correctness of the analysis of the. Signal synthesis method of the sub array. The signal is synthesized, correction of each subarray output signal delay difference, the signal can realize in-phase superposition method so as to further improve the signal by SNR. adaptive filter, the signal through the weighted sum of completion signal synthesis. Synthesis of different signals using the different input signal. The synthesis of SNR should be divided into two categories, one is the synthesis of high SNR signal, the other is a synthetic signal under low SNR. For large signal SNR, we can use the adaptive LMS filter algorithm based on the power inversion criterion, realize signal synthesis. For the synthesis of low SNR signal next, can be used in deep space communication antenna array method. So the choice of the SUMPLE algorithm. The selection method of simulation to verify its feasibility. The signal synthesis requires different input SNR for multi-channel The data of the two weighted sum. After the signal synthesis algorithm of weighted algorithm equivalent input SNR same first, using SUMPLE algorithm to solve the weight vector, correction of each subarray output signal delay difference, the first time the various data output can be weighted stacking. Second weighted by SNR spectral estimation method. Estimation on the various data, and then through the maximal ratiocombining weighted sum. According to the simulation method, verify the feasibility of the system. The system simulation using signal processing methods. For each subarray beamforming respectively through two ways, one is in no angle correction the other is in the angle correction case. Similarly, the signal merger is divided into two kinds, one is the sub array output and the value of SNR is equal to SNR And of all signals by signal with PI algorithm based on the useful signal, the other is the first using SUMEPLE algorithm for time delay correction of each subarray output is not equal to SNR, through the SNR estimation and the maximum ratio combining signal combination. To observe the overall direction of the system diagram, verify the feasibility of the system.

【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V243

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