资源描述：
《函数信号发生器设计外文资料及翻译》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、函数信号发生器设计外文资料及翻译英文资料原文WAVE-FORMGENERATORS1.TheBasicPricipleofSinusoidalOscillatorsManydifferentcircuitconfigurationsdeliveranessentiallysinusoidaloutputwaveformevenwithoutinput-signalexcitation.Thebasicprinciplesgoverningalltheseoscillatorsareinvestigated.Inaddition
2、todeterminingtheconditionsrequiredforoscillationtotakeplace,thefrequencyandamplitudestabilityarealsostudied.Fig.1-1showanamplifier,afeedbacknetwork,andaninputmixingcircuitnotyetconnectedtoformaclosedloop.Theamplifierprovidesanoutputsignalasaconsequenceofthesignalapp
3、lieddirectlytotheamplifierinputterminal.Theoutputofthefeedbacknetworkisandtheoutputlfthemixingcircuit(whichisnowsimplyaninverter)isFormFig.1-1theloopgainisLoopgain=Fig.1-1AnamplifierwithtransfergainAandfeedbacknetworkFnotyetconnectedtoformaclosedloop.Supposeitshould
4、happenthatmattersareadjustedinsuchawaythatthesignalisidenticallyequaltotheexternallyappliedinputsignal.Sincetheamplifierhasnomeansofdistinguishingthesourceoftheinputsignalappliedtoit,itwouldappearthat,iftheexternalsourcewereremovedandifterminal2wereconnectedtotermin
5、al1,theamplifierwouldcontinuetoprovidethesameoutputsignalasbefore.Note,ofcourse,thatthestatement=meansthattheinstantaneousvaluesofandareexactlyequalatalltimes.Thecondition=isequivalent8to,ortheloopgainmustequalunity.TheBarkhausenCriterionWeassumeinthisdiscussionofos
6、cillatorsthattheentirecircuitoperateslinearlyandthattheamplifierorfeedbacknetworkorbothcontainreactiveelements.Undersuchcircumstances,theonlyperiodicwaveformwhichwillpreserve,itsformisthesinusoid.Forasinusoidalwaveformtheconditionisequivalenttotheconditionthattheamp
7、litude,phase,andfrequencyofandbeidentical.Sincethephaseshiftintroducedinasignalinbeingtransmittedthroughareactivenetworkisinvariablyafunctionofthefrequency,wehavethefollowingimportantprinciple:Thefrequencyatwhichasinusoidaloscillatorwilloperateisthefrequencyforwhich
8、thetotalshiftintroduced,asasignalproceedfromtheinputterminals,throughtheamplifierandfeedbacknetwork,andbackagaintotheinput,ispreciselyzero
