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1、IntroductiontoradiatedEmissions1Introductiontoradiatedemissions1.IntroductiontoEMC•TermsandDefinitionsoftheEMIEnvironment•TermsanddefinitionsofEMCEngineering•dBconversiontoelectricalterms2IntroductiontoradiatedemissionsTermsandDefinitionsoftheEMIEnvironmen
2、t•ElectroMagneticSpectrum–FromULFtoEHF,0.01HztoTeraHz•RadioFrequencySpectrum–9kHzto40GHz•RadioFrequencyInterference–RFI,RadiatedemissionwhichcompromisetheuseoftheRadioSpectrum3IntroductiontoradiatedemissionsTermsoftheEnvironment•Electromagneticfieldunits:•
3、ElectricFieldE(V/m)orμV/mordB/(μV/m)•Farfield,distance>λ/(2π)or300/(2πf)meterMHz4IntroductiontoradiatedemissionsThedB•NamedafterAlexanderGrahamBell,Inventorofthetelephone,andusedforacousticpressuremeasurements,dBA•dB=10log10(P2/P1)•P=V2/R•dB=10log(V22/R/V1
4、2/R)=20log(V2/V1)•(A*B)dB=AdB+BdB,(A/B)dB=AdB-BdB•AgeindBisgood,salaryisnot!5IntroductiontoradiatedemissionsTranslatingThedB•E=20log(E/1μV/m)=E(dBμV/m)dB•Realvalue=10(dB/20)•0dB=1•6dB=2-6dB=0.5•20dB=10-20dB=0.1•30dB=30-30dB=0.03•40dB=100-40dB=0.016Introduc
5、tiontoradiatedemissions2.Standards•StandardsforradiationcontrolforRFSpectrumconservation•MeaningoftheEMCStandardsforSanDiskDesignerstomeetthematOEMProducts•Impactofgettingtheradiationunderthelimits7IntroductiontoradiatedemissionsIntentoftheStandards•Keepth
6、eEMEnvironmentopenforcommunication,industrial,medicalandScientificuse•Controlledbyinternationalfrequencymanagementagreements–ITU-R•ControlledbynationalstandardsforEMI8IntroductiontoradiatedemissionsEmissionControlStandards•USAFCCPart15.109,InformationTechn
7、ologyEquipment•European,InternationalEN55022(CISPR22)•ClassA–IndustrialAreas,notforresidentialareas•ClassB–ForuseinresidentialAreas9IntroductiontoradiatedemissionsRadiatedLimitsoftheStandardsEN55022ClassBat3mFrequencyμV/mdBμV/mMHz30-881004088-21615043.5216
8、-96020046Above9605005410IntroductiontoradiatedemissionsTheMeaningofthecompliancewiththestandards•OEMProductsmustcomplywiththestandards•AdditionalCards,accessories,andSanDiskproducts,notofferedwiththeOEMproduc
