【作者】 张立晔；

【导师】 齐晓辉；

【作者基本信息】 哈尔滨工业大学 ， 信息与通信工程， 2011， 硕士

【摘要】 在现代战场中,雷达接收机面临的战场电磁环境日益恶劣。进入雷达接收机的信号既包括目标信号,又包括杂波和敌方干扰信号,各种信号相互叠加使得接收机发生饱和,难以正常工作,有时甚至损坏接收机。因此,研制能够适应复杂电磁环境条件的接收机已成为现代雷达系统的研究重点之一。作为有效地解决手段之一,自动增益控制(Automatic Gain Control, AGC)技术已成为研究的热点。针对这一问题,本文对数字AGC系统进行了定量研究。给出了系统的设计指标,确定了系统各模块的算法。研究了基于级联梳状滤波器的数字检波技术,对级联梳状滤波器进行了仿真,分析了级联梳状滤波器检波性能;研究了坐标旋转数字计算机算法,分析了圆周坐标系统下的不同工作模式,推导了坐标旋转数字计算机算法的系统公式,得到了基于坐标旋转数字计算机算法的正交通道数据处理方法;对数字AGC系统使用的增量式PID算法进行了研究,分析了算法中各系数对增量式PID算法结果的影响,仿真结果表明该算法对信号的波动能产生快速的响应;对固定增益跟踪滤波算法在数字AGC系统中的应用进行了研究,通过理论分析和仿真,得到了αβ滤波器具有良好的滤波效果的结论。本文还对数字灵敏度时间控制(Sensitivity Time Control,STC)技术进行了研究,得到了数字STC技术的距离-衰减量和距离-控制电压曲线。基于理论分析和仿真结果,设计并制作了数字AGC系统的硬件实验平台,在平台上对数字AGC系统进行了系统级半实物仿真调试。利用VHDL语言和流水线技术完成了级联梳状滤波器、坐标旋转数字计算机算法、增量式PID算法,实验结果验证了理论分析结论。通过理论分析和系统测试,结果表明基于级联梳状滤波器、坐标旋转数字计算机算法、增量式PID算法的数字AGC系统具有资源占用少、输出稳定等优点,能够有效保护接收机,这对于接收机分辨和跟踪目标有重要意义。研究成果可广泛应用于各种体制雷达系统中,具有较广的应用前景。更多还原

【Abstract】 In the modern battlefield, the radar receiver facing increasingly harsh electromagnetic environment. The signals which come into the radar receiver are not only target signal, but also the clutter and jamming signals, the signals superimposed on each other makes the receiver blocking, there may even damage the receiver. Therefore, the development of modern radar system to adapt to complex electromagnetic environment is research priorities.As an effective solution, Automatic Gain Control(AGC) technology has become a research hotspot.For this problem, the digital AGC system is quantitatively researched.In the study of digital AGC system, the algorithms of each module of system are designed based on identified indicators. Digital detector technology is researched based on Cascaded Integrator-Comb filter (CIC), the CIC filter is simulated and the performance of CIC filter is analyzed; the coordinate rotation digital computer (CORDIC) algorithm is studied, different modes of the circular coordinate system are analyzed, the CORDIC algorithm system formula is derived and orthogonal channels data processing mehtod based on CORDIC algorithm is gotted; the incremental PID algorithm is analyzed, the affect of the factors on results of PID algorithm is studied and simulation results show that the algorithm can produce rapid fluctuations in the signal response and fully filled with system design requirements; the fixed-gain tracking filter was discussed, theαβfilter method and the advantages and disadvantages are given in this paper, the conclusion that the filter has goog filter effect is gotted. The digital STC technology is also studied and Distance-Attenuation and Distance-Control voltage curves are obtained.Based on the theoretical analysis and simulation results, the digital AGC system hardware test platform is designed and production, and the digital AGC system is debugged in the platform. The CIC filter, CORDIC algorithm and incremental PID algorithm are completed with VHDL language and pipeline technology, and the theoretical analysis of the results are verified by experimentation data.Experimental results show that digital AGC syste based on CIC filter, CORDIC algorithm and incremental PID algorithm has mang admvantages, such as fewer resources are needed, outputs are stable. It can effectively protect the receiver, which is important for the receiver to identify or track targets. The research results can be widely used in mang radar systems, and it has a widely application.更多还原