三毫米波箔条云RCS测量雷达信号处理机的研制

【作者】 夏礼雄；

【导师】 汪学刚；

【作者基本信息】 电子科技大学 ， 信号与信息处理， 2007， 硕士

【摘要】 RCS测量对目标识别与分类、雷达对抗、飞行器隐身及雷达反隐身等具有重要意义。基于毫米波的RCS测量特性有着许多区别于厘米波段的特性，这些特性对RCS测量精度有着直接的影响。本文介绍了一种三毫米波箔条云RCS测量雷达信号处理机的实现方案。本方案信号处理模块采用实时数据采集与离线信号处理相结合的方法，即对持续测量时间内的中频信号进行实时采集，然后由计算机对其进行离线处理，因此硬件部分主要完成数据的采集工作，而信号处理部分在计算机上完成。RCS测量雷达工作的大致过程为，从目标散射回来的三毫米回波信号，经射频前端模拟下变频之后输出30MHz中频信号，这个信号实际因受测量物体多谱勒频率及接收机相位噪声等因素的影响，中频输出考虑在30MHz±0.3MHz波动的点频信号。而信号处理机的任务就是通过对中频单频正弦波输入信号进行处理，该正弦波的幅度反映了箔条云RCS的大小，信号处理机通过精确地估计该正弦波的幅度，实现对箔条云RCS的测量。本文的工作主要分硬件设计、调试和外场实验等几个部分。硬件设计的内容主要包括AD中频信号采集、基于HSP50214B的数字下变频以及基于CY7C68013的USB2.0数据传输这几个部分。调试分FPGA配置HSP50214B，FPGA与CY7C68013的接口控制、CY7C68013固件程序调试和驱动程序调试等。外场实验主要有微波暗室实验和空旷场地实验两个部分。微波暗室实验完成对金属球定标体近距离的标定工作，而空旷场地实验则完成远距离的标定工作。实验结果显示在微波暗室中定标测量波动在0.5dB以下，而在外场中明显高于这个数值。主要原因是外场中情况复杂，测量结果受各种杂波影响较大，如大气衰减、云或雾、定标金属球的波动、地面杂波等，因此在实际测量中应考虑这些因素，并做出相应的修正处理。更多还原

【Abstract】 RCS measuring is important to object recognition and classification, radarcountermeasure, aerocraft stealth and radar anti-stealth. The RCS measuring based onthe millimeter wave has some special traits compared with centimeter wave band,andthese traits have a direct influence to RCS measure precision.This thesis introduces an implement scheme of 3mm chaff cloud RCS measuringradar signal processing machine.The signal processing module has an combination ofreal time data acquisition and offline signal processing.It means that a real timeacquisition to IF signal during persistent measuring and an offiine processing oncomputer. So the hardware part mainly do the work of data acquisition and the computerfinish the signal processing.The 3mm echo signal from object scattering outputs 30MHz IF signal after analogdown conversion from RF front-end. The intermediate frequent is considered a singlefrequence signal during 30MHz minus plus 0.3MHz because of the influence ofDoppler frequence of measuring object and phase noise of receiver.The main task ofsignal processing machine process the single frequence sine wave of IF.The amplitudeof sine wave reflects the RCS value of chaff cloud and signal processing machinerealize the measure of chaff cloud RCS via accurately estimate the amplitude of sinewave.The main work of this thesis consists of hardware design and debugging andoutfield experiment.Hardware design mainly include AD IF signal acquisition, thedigital down conversion based on HSP50214B and USB2.0 data transfers based onCY7C68013.Debugging parts are composed of HSP50214B configuration viaFPGA,the interface control between FPGA and CY7C68013 and CY7C68013firmware program debugging and driver program debugging.Outfield experimentsmainly have microwave darkroom experiment and open field experiment.Microwavedarkroom experiment finishes the work of near field scale of metal ball, and open fieldexperiment finishes the work of far field scale.Experiment result shows that scalemeasuring fluctuating below 0.5dB in microwave darkroom,however the fluctuating value is much higher in open field experiment.The main reason is that the condition ismore complicated in open field,and measuring result is much more easily influenced bysome kinds of clutters,like atmosphere attenuation,cloud or fog,the fluctuating of scaleobject and ground clutter and so on.So these factors should be taken into account inpractical measuring,and make some amending processing.更多还原