资源描述：
《外文翻译--频率范围》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、英文原文RFIDFrequencyRangesUsedBecauseRFIDsystemsgenerateandradiateelectromagneticwaves,theyarelegallyclassifiedasradiosystems.ThefunctionofotherradioservicesmustundernocircumstancesbedisruptedorimpairedbytheoperationofRFIDsystems.ItisparticularlyimportanttoensurethatRFIDsy
2、stemsdonotinterferewithnearbyradioandtelevision,mobileradioservices(police,securityservices,industry),marineandaeronauticalradioservicesandmobiletelephones.Theneedtoexercisecarewithregardtootherradioservicessignificantlyrestrictstherangeofsuitableoperatingfrequenciesava
3、ilabletoanRFIDsystem(Figure1-1).Forthisreason,itisusuallyonlypossibletousefrequencyrangesthathavebeenreservedspecificallyforindustrial,scientificormedicalapplications.ThesearethefrequenciesclassifiedworldwideasISMfrequencyranges(Industrial–Scientific–Medical),andtheycan
4、alsobeusedforRFIDapplications.InadditiontoISMfrequencies,theentirefrequencyrangebelow135kHz(inNorthAndSouthAmericaandJapan:<400kHz)isalsosuitable,becauseitispossibletoworkwithhighmagneticfieldstrengthsinthisrange,particularlywhenoperatinginductivelycoupledRFIDsystems.Th
5、emostimportantfrequencyrangesforRFIDsystemsaretherefore0–135kHz,andtheISMfrequenciesaround6.78(notyetavailableinGermany),13.56MHz,27.125MHz,40.68MHz,433.92MHz,869.0MHz,915.0MHz(notinEurope),2.45GHz,5.8GHzand24.125GHz.AnoverviewoftheestimateddistributionofRFIDtransponder
6、satthevariousfrequenciesisshowninFigure1-2.AVAILABLE&PRACTICALRFIDFREQUENCIESFigure1-1ThefrequencyrangesusedforRFIDsystemsrange.ThefrequencyrangesusedforRFIDsystemsrangefromthemyriametricrangebelow135kHz,throughshortwaveandultrashortwavetothemicrowaverange,withthehighes
7、tfrequencybeing24GHz.Inthefrequencyrangeabove135kHztheISMbandsavailableworldwidearepreferred.Figure1-2Theestimateddistributionoftheglobalmarketfortranspondersoverthevariousfrequencyrangesinmilliontransponderunits(Krebs,n.d.)1Frequencyrange9–135kHzTherangebelow135kHzishe
8、avilyusedbyotherradioservicesbecauseithasnotbeenreservedasanISMfrequencyrange.Thepropagationconditionsinthislo
