数字阵列天线自适应单脉冲算法研究与实现

发布时间：2018-05-15 04:10

本文选题：阵列天线 + 互耦　；参考：《南京理工大学》2017年硕士论文

【摘要】：复杂电磁环境下的快速目标检测和跟踪已经成为未来雷达系统研制和装备必须考虑的核心技术之一,数字阵列雷达采用自适应波束形成技术,可以有效抑制空域强干扰。本文主要针对数字阵列雷达存在旁瓣和主瓣干扰情况下快速、精确的目标角度估计的需要,完成了阵列天线建模和四通道快速自适应单脉冲算法研究,进而针对某二维数字阵列雷达的实际要求,研制了96通道中频采样数字波束形成电路硬件平台,完成了硬件电路调试测试,根据系统的多模式工作要求完成了采用四通道自适应单脉冲技术的相关硬件程序实现,采用动态重配置技术有效的提高了系统多模式交替工作情况下FPGA资源利用和功耗降低。本文的主要工作如下:首先,完成了一维线性阵列建模仿真,对互耦条件下的阵列天线进行建模,阐述了互耦对方向图的影响。给出了一种采用离线存储HFSS仿真结果快速准确逼近实际阵列天线方向图的优化计算方法,仿真分析了算法的高效性和有效性;接着,开展了改进的降维四通道和差单脉冲角度估计方法研究。该算法对正方形栅格平面阵按行列降维进行自适应处理,并在降维之前进行干扰方向的快速估计以选择最佳降维维度。算法结合了主瓣保形的自适应旁瓣干扰抑制,以及主瓣干扰自适应和差对消,以形成主旁瓣干扰抑制的四通道波束,并用于单脉冲角度估计。算法引入了一种基于主瓣子空间的主瓣保形自适应方法,该方法在进行主瓣保形时,无需获取主瓣干扰的准确方向。最后,针对某二维数字阵列雷达的实际要求,研制了一款同时对96通道中频模拟信号进行高速、同步采样,采用V7系列FPGA和8核DSP进行高性能信号处理的数字波束形成电路硬件平台。针对电路设计中的电源、时钟、配置、数据处理等电路的原理图和PCB版图进行优化设计。完成了电路电源调试测试、时钟调试测试和模数转换数据传输接口的调试测试。FPGA中数字下变频、波束形成模块的实测结果验证了相关程序设计的正确性。
[Abstract]:Fast target detection and tracking in complex electromagnetic environment has become one of the core technologies to be considered in the development and equipment of radar systems in the future. Digital array radar uses adaptive beamforming technology, which can effectively suppress strong interference in airspace. Aiming at the need of fast and accurate target angle estimation in digital array radar with sidelobe and main lobe interference, the array antenna modeling and four-channel fast adaptive monopulse algorithm are studied in this paper. Furthermore, according to the practical requirements of a two-dimensional digital array radar, a 96 channel if sampling digital beamforming circuit hardware platform is developed, and the hardware circuit debugging and testing is completed. According to the requirements of multi-mode operation of the system, the hardware program is implemented using four-channel adaptive monopulse technology. The dynamic reconfiguration technology can effectively improve the utilization of FPGA resources and reduce the power consumption under the condition of multi-mode alternation. The main work of this paper is as follows: firstly, the one-dimensional linear array modeling and simulation are completed, the array antenna under the condition of mutual coupling is modeled, and the influence of mutual coupling on the direction graph is discussed. In this paper, an optimization method for fast and accurate approximation of the actual array antenna pattern by off-line storage HFSS simulation results is presented, and the efficiency and effectiveness of the algorithm are analyzed. The improved dimensionality reduction four channel and differential monopulse angle estimation method are studied. The algorithm adaptively processes the dimensionality reduction of square raster plane array according to the row and column, and estimates the interference direction quickly before reducing the dimension to select the best dimension reduction degree. The main lobe conformal adaptive sidelobe interference suppression and the main lobe interference adaptive and differential cancellation are combined to form a four-channel beam for the main sidelobe interference suppression and it is used to estimate the angle of a single pulse. The algorithm introduces a principal lobe shape preserving adaptive method based on the principal lobe subspace. This method does not need to obtain the accurate direction of the main lobe interference when the main lobe is conserved. Finally, according to the practical requirements of a certain two-dimensional digital array radar, a high-speed and synchronous sampling of 96 channels if analog signals is developed at the same time. Digital beamforming circuit hardware platform using V7 series FPGA and 8 core DSP for high performance signal processing. The schematic diagram and PCB layout of power supply, clock, configuration, data processing and so on in circuit design are optimized. The circuit power supply debugging test, clock debugging test and analog to digital conversion data transmission interface debugging test. FPGA digital downconversion. The experimental results of beamforming module verify the correctness of the related program design.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN820

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