标签: measure

DoesMeasurementMeasureUp-HowNumbersRevealandConcealtheTruth

Timecursorstomeasureelapsedtime

1HowtoMeasuretheLoopTransferFunctionofPowersupplyies.pdfLM22670,LM22671,LM22672,LM22673,LM22674,LM22675,LM22676,LM22677,LM22678,LM22679,LM25005,LM3578A,LM5000,LM5001,LM5002,LM5005ApplicationNote1889HowtoMeasuretheLoopTransferFunctionofPowerSuppliesLiteratureNumber:SNVA364HowtoMeasuretheLoopTransferFunctionofPowerSuppliesNationalSemiconductorHowtoMeasuretheLoopApplicationNote1889TransferFunctionofPowerFrederikDostal……

测噪声_measure_NF_with_sa用频谱仪测量噪声系数September,20061NoiseFigureDefinitionBPF1LNABPF2MixerBPF3IFAmpDemodulatorLORFReceiver,DUT(DeviceunderTest)NF=SNRinSN=ininSNRoutSoutNoutNF(dB)=Nout(dBm/Hz)Nin(dBm/Hz)Gain(dB)Gain=10*log(Sout/Sin)因此需要测三个参数Gain,Nin,Nout来算出NF2GainPowerGainvs.VoltageGain因为测量系统都用50欧姆,如非特指,以下所说的Gain均指功率增益(PowerGain).但是一般的接收机的输入输出并非50欧姆,因此有必要考虑电压增益(VoltageGain)outVoltageGain=PowerGain+10log(ZZin)举个例子说,一个将50欧姆转换到100欧姆的Balun,如果损耗是0.5dB,我们可以认为其功率增益为-0.5dB,而电压增益为-0.5+10*log(100/50)=2.5dB3输入噪声密度Nin(1)Nin=10log(kT)=-174dBm/Hz注:对于变频系统而言,需要考虑镜像频率转换后是否落在测量频带内1.零中频系统举例说明,WCDMADirectconversionreceiver,RFBW2110-2170MHz,BasebandBW1.92MHzSignalfreq=2140.1MHzLOfreq=2140MHzImag……

NFMEASUREMETHODFROMMAXIMMaxim/Dallas>AppNotes>BASESTATIONS/WIRELESSINFRASTRUCTUREWIRELESS,RF,ANDCABLEKeywords:rf,rfic,wireless,noisefiguremeasurement,gain,meter,yfactor,rfics,rficsNov21,2003APPLICATIONNOTE2875ThreeMethodsofNoiseFigureMeasurementAbstract:Threedifferentmethodstomeasurenoisefigurearepresented:Gainmethod,Y-factormethod,andtheNoiseFigureMetermethod.Thethreeapproachesarecomparedinatable.IntroductionInwirelesscommunicationsystems,the"NoiseFigure(NF),"ortherelated"NoiseFactor(F),"definesthenoiseperformanceandcontributestothereceiversensitivity.Thisapplicationnotedescribesthisimportantparameteranddetailswaystomeasureit.NoiseFigureandNoiseFactorNoiseFigure(NF)issometimesreferredtoasNo……

powernoisemeasureAPPLICATIONNOTEHOWTOTESTOUTPUTRIPPLEANDNOISEOFPOWERSUPPLIESTheswitchingpowersupplies(eitherstep-downregulators,orisolatedDC-DCconverters,orOFFLINEpowersupplies)havethefundamentaladvantageofhighefficiencyi.e.lowpowerdissipationwhencomparedtolinearvoltageregulation.Howevertheswitchingtechnique,thatisbeneficialtoraisetheefficiency,hasanassociatedweaknessi.e.theoutputvoltagehasalwaysanACcontent.Thetypicaloutputrippleandnoiseofaswitchingpowersupplyisasshowninfig.1.Figure1.OutputrippleandnoiseofaswitchingpowersupplyFourACcomponentscanbeidentified:lowfrequencyrippleat2fbeingftheACmainsfrequencyhighfrequencyrippleduetoPulseWidthModulation(PWM)toobtaintherequiredlinean……

RF_impedance_measure_basic5),PSHGDQFH0HDVXUHPHQW%DVLFV*UHJ$PRUHVHHewlett-PackardCompanyKobeInstrumentDivision1400FountainGroveParkwaySantaRosa,California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……