Three Millimeter Wave Chaff Cloud Rcs Measurement Radar Signal Processor Developed

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.