宽带侦察DBF技术研究

发布时间：2019-06-17 18:41

【摘要】：为了同时应对更大频宽,更多类型的雷达信号,雷达侦察接收机采用宽带数字波束形成(DBF)技术,通过数字信号处理获得良好的瞬时空间覆盖和高分辨特性,这对于电子侦察十分有利。但是宽带侦察DBF的突出问题是:目标信号的工作带宽可能覆盖若干个倍频程,如果按照最高工作频率不发生栅瓣的要求设计阵元间距(最小间距),则对低频段信号不仅难以设计结构,还会出现严重的阵元间互相耦合;而如果按照最低频率不发生阵元间互相耦合设计阵元间距(最大间距),则对高频段信号会出现严重的栅瓣。本文首先介绍了研究背景以及分析了抑制栅瓣对宽带侦察DBF的重要意义。然后,本文研究了宽带数字波束形成的方法和最优波束准则,同时理论分析了栅瓣问题产生的原因,并且通过仿真验证了波束方向图的栅瓣与阵元间距、主瓣指向等参数的关系。最后,本文重点研究了宽带波束栅瓣抑制的技术。针对宽带信号波束的栅瓣问题,研究了基于频率加权的宽带波束合成器技术,并且仿真分析了该宽带波束合成器抑制栅瓣的性能。针对超宽带信号波束的栅瓣问题,本文提出了局部均匀组合阵列技术和栅瓣等波动阵列技术两种方法抑制栅瓣。通过将基于频率加权的宽带波束合成器应用到局部均匀组合阵列设计中,分频段处理超宽带信号达到了栅瓣抑制的效果;通过对栅瓣等波动阵列设计的理论分析和实验仿真,论证了其抑制超宽带信号波束栅瓣的效果。本文对局部均匀组合阵列技术和栅瓣等波动阵列设计的两种方法进行了比较,分析得出了它们的优缺点。
[Abstract]:In order to deal with more types of radar signals with larger bandwidth and at the same time, the radar reconnaissance receiver adopts broadband digital beamforming (DBF) technology to obtain good instantaneous spatial coverage and high resolution characteristics through digital signal processing, which is very beneficial to electronic reconnaissance. However, the outstanding problem of broadband reconnaissance DBF is that the working bandwidth of the target signal may cover several octaves. If the array element spacing (minimum spacing) is designed according to the requirement that the gate lobe does not occur at the highest operating frequency, it is not only difficult to design the structure for the low frequency band signal, but also serious coupling between the array elements will occur. If the array element spacing (maximum spacing) is designed according to the lowest frequency, there will be a serious gate lobe for the high frequency band signal. In this paper, the research background is introduced and the significance of gate lobe suppression for broadband reconnaissance DBF is analyzed. Then, the method of broadband digital beamforming and the optimal beam criterion are studied in this paper. At the same time, the causes of the gate lobe problem are analyzed theoretically, and the relationship between the gate lobe of the beam pattern and the parameters such as array element spacing and main lobe direction is verified by simulation. Finally, this paper focuses on the broadband beam gate lobe suppression technology. Aiming at the gate lobe problem of broadband signal beam, the technology of broadband beamsynthesizer based on frequency weighting is studied, and the performance of the broadband beamsynthesizer in suppressing gate lobe is simulated and analyzed. In order to solve the gate lobe problem of ultra-broadband signal beam, two methods, local uniform combination array technique and gate lobe wave array technique, are proposed to suppress the gate lobe. By applying the broadband beamsynthesizer based on frequency weighting to the design of local uniform combined array, the ultra-broadband signal is processed in frequency band to achieve the effect of gate lobe suppression, and the effect of suppressing the gate lobe of ultra-broadband signal beam is demonstrated through the theoretical analysis and experimental simulation of the wave array design such as gate lobe. In this paper, two methods of wave array design, such as local uniform combination array technique and gate lobe, are compared, and their advantages and disadvantages are analyzed.
【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】：TN971

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