标签: 路带

锁相环环路带宽的测量AppliedRadioLabswww.radiolab.com.auMeasuringtheLoopBandwidthofaPLLDesignFile:DN00315October1999IntroductionManymoderncommunicationsystemsutilisePLLfrequencysynthesizers.ThePLLisafeedbackloop,andthefrequencydomaincharacteristicsofthelooptransferfunction(gainandphaseresponse)havesignificanteffectonthePLLoperation,forexample:§§§Lockingtimes(e.g.overshootandringingforpoorphasemargin)Phasenoise‘ears’ifphasemarginispoorFrequencyresponseofmodulation/demodulationLink1VCOFoutMainDivider1/NKv/sF(s)PhaseDetectorKd1/MReferenceDividerFrefLoopFilterFigure1-PLLSynthesizerMeasuringtheLoopBandwidthForthePLLinFigure1,weinsertalow-passfilterinplaceofLink1.Asuitablefilterist……