电子通讯专业英语UnitIII

2023电子通讯专业英语UnitIIICATALOGUE目录ElectromagneticFieldTheoryElectromagneticWavesElectromagneticShieldingElectromagneticCompatibility(EMC)CATALOGUE目录ElectromagneticPulse(EMP)ElectromagneticRadiationandHumanHealth01ElectromagneticFieldTheoryElectromagneticfieldtheoryisabranchofphysicsthatstudiesthebehaviorandinteractionofelectromagneticfields.DefinitionandPropertiesElectromagneticfieldsaregeneratedbychargedparticlesandarecharacterizedbytheirelectricandmagneticfieldcomponents.RelationshipwithElectricalEngineeringDevelopmentandApplicationElectromagneticfieldtheoryhasfoundnumerousapplicationsinmoderntechnology,includingwirelesscommunication,radar,television,andmicrowavecooking.02ElectromagneticWavesElectroma…Electroma…PolarizationFrequencythenumberofwavecyclesperunittime.DefinitionandCharacteristics010203040102Radiowaveslow-frequencyEMwavesusedforcommunication,radar,andbroadcastmedia.MicrowaveshigherfrequencyEMwavesusedforradar,satellitecommunication,andcooking.Opticalwav…X-rayshigherfrequencyEMwavesusedformedicalimagingandnon-destructivetesting.GammaraysthehighestfrequencyEMwavesusedforradiationtherapyandsterilization.TypesofElectromagneticWaves030405CommunicationUsesandImpactsofElectromagneticWavesImagingandS…ThermalEffec…HealthImpacts03ElectromagneticShieldingPrinciplesandMethodsMetals,conductiveplastics,carbonfibers,etc.arecommonlyusedconductivematerials.ShieldingmethodsincludeFaradaycage,conductivecoating,conductivegasket,etc.Electromagnetics…Conductivemateri…ShieldingmethodsElectricalequip…ApplicationsinElectricalEquipmentElectromagnetic…Shieldingmethod…Thehousingofelectricalequipmentcanbemadeofconductivematerialstoachieveelectromagneticshielding.EnvironmentalimpactHealthimpactControlmeasuresEnvironmentalandHealthImpacts04ElectromagneticCompatibility(EMC)EMCreferstotheabilityofelectronicdevicestofunctionproperlywithoutunacceptabledegradationinperformanceduetoelectromagneticinterference(EMI)fromotherdevicesorfromtheenvironment.DefinitionandPrinciplesEMCregulationsaresetbygovernmentagenciesandtypicallyrequireproductstocomplywithcertainEMCstandardsbeforebeingsoldorused.EMCstandardsarecrucialforensuringcompatibilityandreliableoperationofelectronicdevices.EMCStandardsandRegulationsEMCDesignandTestingMethods05ElectromagneticPulse(EMP)1DefinitionandProperties23突然爆发的强电磁场，可在短时间内对电子设备造成破坏。EMP可由核爆炸、高能量雷击、或其他电磁脉冲产生器产生。EMP来源具有高强度、宽频带、传播距离远等特点。EMP特点EMPProtectionMethods采用金属外壳或金属网包裹电子设备，以阻隔EMP辐射。EMP屏蔽EMP滤波EMP接地EMP备份在电源和信号线路上安装滤波器，以削弱EMP干扰。将电子设备与大地相连，以泄放EMP能量。采用多路备份电源和数据存储，以防止EMP造成系统瘫痪。EMPEffectsonElectronicSystemsEMP可造成电源电压波动、电流冲击和电磁短路等问题。电源系统EMP可导致数据传输错误、网络中断和设备间通信失败等问题。数据通信EMP可干扰控制信号传输，导致系统失控或不安全运行。控制系统EMP可造成程序错误、乱码或死机等现象，影响系统正常运行。微处理器06ElectromagneticRadiationandHumanHealthElectromagneticradiationsourcesincludenaturalandman-madesources.ElectromagneticRadiationSourcesMan-madesourcesincludeelectronicdevices,suchascomputers,mobilephones,andpowerlines,aswellasmicrowaveovensandradarsystems.Naturalsourcesincludethesun,theEarth'smagneticfield,andlightning.Electromagneticradiationhasbothbeneficialandharmfuleffectsonhumanhealth.EffectsofElectromagneticRadiationonHumanHealthAtlowlevels,itcanbebeneficialfortherapeuticpurposes,suchasusingmicrowavetherapytotreatjointinflammation.Itisimportanttotakeprecautionstominimizeexposuretoelectromagneticradiation.