畢業(yè)設(shè)計論文L波段接收機(jī)的設(shè)計學(xué)院年級專業(yè)2003級電子信息工程學(xué)生姓名指導(dǎo)教師專業(yè)負(fù)責(zé)人答辯日期2007年6月24日畢業(yè)設(shè)計論文任務(wù)書學(xué)院里仁學(xué)院系級教學(xué)單位電子工程系學(xué)號學(xué)生姓名專業(yè)班級電子信息工程1班題目L波段接收機(jī)的設(shè)計課題來源實(shí)踐主要內(nèi)容對接收機(jī)的噪聲、動態(tài)、增益的性能指標(biāo)設(shè)計對寬帶低噪聲放大器、電調(diào)衰減器、ITHELOWINTERMEDIATEFREQUENCYPLANALTHOUGHMAYREMARKABLEREDUCENEEDSTHEPARTNUMBER，BUTTHEHIGHSYSTEMGAINSIGNSNOTEASYTOASSIGN，MOREOVERTHISKINDOFSTRUCTUREREQUESTHASTHEVERYHIGHMIRRORIMAGESUPPRESSIONBUTTHEHETERODYNEPLANMAYTHEVERYGOODSOLUTIONMIRRORIMAGEQUESTIONANDTHEHIGHGAINQUESTIONAFTERCARRIESONTHREEKINDOFPLANSMEASURING，WEUSETRADITIONALTHEHETERODYNESTRUCTURETOTAKETHECHANNELRECEIVERTHEPLANINORDERTOSOLVETHISTOBECONTRADICTORY，WEFINALLYHAVEUSEDTWOUNDERFREQUENCYCONVERSIONSUPERHETERODYNERECEIVERSPLANINTHISKINDOFSTRUCTURE，THERADIOFREQUENCYSIGNALTHATCOMESINFORMTHEANTENNAAFTERTHEFILTER，THELOWNOISEAMPLIFIER，AFTERTHEMIXINGBECOMESTHEFIRSTINTERMEDIATEFREQUENCYSIGNAL，F(xiàn)IRSTINSPIRESINTHISISAFIXTUREAFTERTHEINTERMEDIATEFREQUENCYSIGNALPASSESTHROUGHONCEMORETHEFILTERANDTHEENLARGEMENTSENDSINTHESECONDLEVELOFMIXER，CHANGESTHESIGNALTOTHESECONDINTERMEDIATEFREQUENCYSIGNAL，THEINTERMEDIATEFREQUENCYAMPLIFIERGAINALSOMAYCONTROL，WHENSYSTEMWORKTHEGAINCONTROLSIGNALTHESIGNALWHICHDEMODULATESBYTHEREARENDDSPBASISPRODUCESINABOVEGROUPCHANNEL，THESIGNALAFTER2MHZSEVENSTEPSELLIPTICFUNCTIONLCFILTERLNACARRIESONTHEENLARGEMENTTOTHESIGNAL，F(xiàn)ROMTHREELEVELOFAGCREALIZATIONSYSTEMDYNAMIRANGETARGETREQUEST，F(xiàn)INALLYENLARGESAFTERWARDSTHESIGNALTOINTHEREQUESTLEVELOUTPUTSTHISGROUPCHANNELDOESNOTHAVEFREQUENCYCONVERSIONPROCESSING，BECAUSETHESIGNALINGFREQUENCYISLOWERTHAN2MHZ，MAYDIRECTLYCARRYONTOTHEOUTPUTSIGNALUSESTHEDIGITIZATION，THENCARRIESONBASEBANDPROCESSINGBYDSPTHISGROUPCHANNELMAINGUARANTEEDYNAMIRANGE，LINEAR，SENSITIVITYTARGETANDSOONSELECTIVITYFRONTENDUSESTHELOWNOISE，THEALTITUDE，HIGHINCREASESTHEFIELDEFFECTTUBETOTAKELNA，GUARANTEESTHECHANNELTHETOTALNOISEFACTORANDLINEARTHEAGCSTRUCTUREWITHFOLLOWINGGROUPCHANNELCONSISTENCY2MHZ30MHZCHANNELUSESTWOTIMESOFFREQUENCYCONVERSIONSUPERHETERODYNESTRUCTURES，THEFIRSTINTERMEDIATEFREQUENCYFORHIGHINTERMEDIATEFREQUENCY488MHZ，F(xiàn)RONTEDTHISKINDOFSTRUCTUREUNIONSIXGROUPOFASIANFREQUENCYMULTIPLICATIONBANDPASSFILTERMAYOBTAINTHEVERYGOODMIRRORIMAGETODAMPTHESYSTEMTOSATISFYTHESYSTEMTARGETREQUESTTHESIGNALFIRSTLOWLYINSERTSBY2M30MHZDAMAGESTHEFILTERTOTHEBELTOUTSIDETHESIGNALENERGYCARRIESONTHECERTAINSUPPRESSION，LNAISPUSHTHEPULLALTITUDESTRUCTURE，SELECTSTWOLOWNOISES，HIGHIP3，THEHIGHGAINFIELDEFFECTTUBECONSTITUTIONSUPPLEMENTARYSTRUCTUREENHANCESLINEARANDREDUCESTHEENTIREMACHINENOISE，SATISFIESTHESYSTEMTHESETWOTARGETSREQUESTAFTERLNAISAGROUPTHERESELECTWHICHCONSTITUTESBYSIXASIANFREQUENCYMULTIPLICATIONHIGHSELECTIVEBANDPASSLCFILTER，ENHANCESTHESYSTEMSELECTIVITYANDTHEANTIGAMBLINGABILITY，AFTERREDUCEINTHELEVELCHANNELDISORDERLYTHELEVEL，THERESELECTEDSIXTHROWSTHESWITCHBYTWOSINGLETOOLSTOCARRYONTHECONTROLCUTTHESIGNALDINEMIRAGEFROMREALIZESTHREETOFOURLEVELOFAGC，PULLEVENISINFRONTOFTHEFREQUENCYCONVERSIONTHESIGNALPOWERINTHEIDENTICALSTABLELEVEL，AFTERGUARANTEESTHEFREQUENCYCONVERSIONLINEARFIRSTLEVELOFAGCISTHEPINTUBEELECTRICITYADJUSTSTHEATTENUATORSSITUATIONAGC，THELATTERSEVERALLEVELSAREVGAAGCAFTERTHEDOUBLEBALANCEDMIXERTHREEFREQUENCYCONVERSIONENLARGESTHESIGNALTOTHEREQUESTLEVELLOSESLEAVESTHEFIRSTLEVELOFINTERMEDIATEFREQUENCYFILTERSELECTSTHERECTANGULARCOEFFICIENTTOBEGOOD，INTHEBELTRIPPLESMALLTABLESOUNDWAVESAWFILTERBANDWIDTH2MHZ，THESECONDINTERMEDIATEFREQUENCYFORCERAMICFILTERBANDWIDTH200KHZ，THETHIRDINTERMEDIATEFREQUENCYISTHE10KHZNARROWBANDCRYSTALFILTERASFORTHERECEIVERFREQUENCYSYNTHESIZER，CONSIDEREDTHESYSTEMREQUESTREALIZESTHE1HZFREQUENCYRESOLUTION，ATPRESENTONLYHASINTHEINFERIORFREQUENCYBANDFEASIBLEPLANUSESTHEDDSDIRECTNUMERALSYNTHESIS，WITHTHEDDSCHIPTOOKTHEFREQUENCYSYNTHESIZERTHECOREPART，PASSESSIDEANDSOONFREQUENCYMULTIPLICATIONTHETYPEREALIZESTHE1HZFREQUENCYRESOLUTIONWITH120MHZHIGHPURETHESTEADYCRYSTALOSCILLATORTOOKDDSTHEREFERENCEFREQUENCYSOURCE，F(xiàn)IRSTINSPIRESBECAUSEISONTHEFREQUENCYCONVERSIONREQUESTFREQUENCYISHIGHER，DDSDIRECTOUTPUTTHEUPPERFREQUENCYLIMITONLYCANARRIVETHEREFERENCEFREQUENCY04TIME，THEREFORENEEDSTOPASSTHROUGHTHEFREQUENCYMULTIPLICATION，OUTPUTS508MHZWHICHFIRSTINSPIRESNEEDS788MHZFREQUENCY，THELENGTHOFSTRIDEIS10KHZ，WHENSCANNINGTOOKTHICKLYSWEEPSPROVIDESSECONDTOINSPIRETHEFREQUENCYANOTHERDDSDIRECTOUTPUT，NEARBY381MHZCARRIESONBYTHE1HZ10HZLENGTHOFSTRIDETHINSWEEPSINORDERTOENHANCETHEMIXERBOOKTOINSPIRETHEMOUTHISOLATION，THESETWOGROUPSTHISINSPIRETHESIGNALTOWEAKENAFTERTHEENLARGEMENT，LIKETHISNOTONLYENHANCEDISOLATION，MOREOVERMAYTHISINSPIRETHESIGNALTOADJUSTTHEAPPROPRIATEBIGSIGNALTOCARRYONTHEMIXING，GUARANTEESMIXINGLINEARITYTHIRDINSPIRESFORFIXEDFREQUENCY10245MHZ，USESHIGHPURETHESTEADYCRYSTALOSCILLATORTHESYSTEMFREQUENCYCONTROL，CHANNELSSCANNING，THEFILTERSWITCHCUT，ASWELLASTHECHANNELCUTANDSOONTHEENTIREMACHINECONTROLREALIZESBYMCUTHROUGHTOTHEMCUPROGRAMMING，CONTROLSDDSBYTHEMCUOUTPUTTHEFCWFREQUENCYCONTROLWORD，THEFREQUENCYWHICHCAUSESDDSACCORDINGTOWHICHTOPREARRANGETHEREQUESTOUTPUTNEEDSTHECALCULATIONOFLINEARITYSYSTEMREQUESTSTHEENTIREMACHINEREALIZATIONTOOUTPUTTHREESTEPSINTERMEDIATIONTOMEASUREIP324DBM，THISTARGETWEIGHSASYSTEMLINEARITYMOSTIMPORTANTTARGET，MAINLYISDECIDEDINTHESYSTEMTHEAMPLIFIERANDMIXERLINEARALWAYSINPUTSTHREESTEPSINTERMEDIATIONQUANTITYFORMULAACCORDINGTOTHECASCADESYSTEMMAYCARRYONTHETHEORETICALCALCULATIONEACHLEVELOFACTIVESDEVICEINCLUDEDAMAGESCOMPONENTTHREESTEPSMUTUALLYTONEVALUESTHESYSTEMINTOSUBSTITUTETHEPREVIOUSTYPECOMPUTATION，MAYOBTAINTHESYSTEMINPUTENDALWAYSTOINPUTIP3THEVALUE，NEEDSSPECIALLYTOPAYATTENTION，USESINTHEPREVIOUSTYPECOMPUTATIONTHREESTEPSVALUETOHAVETOBEEACHCOMPONENTINPUTTHREESTEPSVALUE，INTHECOMPONENTMATERIALPRODUCESUSUALLYALLOUTPUTSTHREESTEPSVALUES，USESINTHEFORMULATOHAVETOSUBTRACTTHECOMPONENTTHEGAIN132121,NINIPGIPGIIMOREOVERMUSTCONVERTTHEACTUALPERFORMANCENUMBER，THEGAINALSOMUSTTRANSFORMINTOTHEACTUALMULTIPLE，CANNOTUSEADECIBELVALUETOCARRYONTHECOMPUTATION，AGAINWILLCALCULATETHEALWAYSINPUTTHREESTEPSPERFORMANCENUMBERSWILLTRANSFORMINTOTHELOGARITHMPERFORMANCENUMBERSYSTEMALWAYSIP3CALCULATESAGAINBASEDONTHUNDERTYPETHISFORMULACOMPUTATIONMAYSTRAIGHTTAKEOVERTHEUSEOFADECIBELVALUETOCARRYONTHECOMPUTATIONAFTERCOMPUTINGSYSTEMALWAYSIP327DBM24DBM，SATISFIESTHESYSTEMTARGETREQUESTCONCRETECOMPUTATIONTOBETEDIOUS，HEREONLYPRODUCESCOMPUTEDRESULTINSYSTEMMAJOREFFECTENTIREMACHINEIP3ISFIRSTLEVELOFLNA，THEMIXERANDLASTLEVELOFAMPLIFIERSLINEARTHEREFORETHETOPICINTHEDESIGN，F(xiàn)IRSTLEVELOFLNASELECTSOUTPUTSTHREESTEPSINTERMEDIATIONQUANTITYTOREACHASHIGHAS42DBMSUPERELEVATIONLINEARFET，THEMIXERSELECTSINPUTSTHREESTEPSFORTHE32DBMDOUBLEBALANCEDALTITUDEMIXER，INTHECHANNELAMPLIFIERSELECTSTHREESTEPSTOBEHIGHERTHANTHE30DBMAMPLIFYINGTUBESYSTEMTHEFRONTENDCHANNELCUTSINGLEPOLEDOUBLETHROWSWITCHSELECTSHITTITECORPORATIONHMC190MS8，IP350DBM，INSERTSDAMAGESONLY04DB，THESINGLETOOLWHICHTHEFILTERCUTSSIXTHROWSTHESWITCHTOUSLEHMC252QS24，IP346DBM，THEIRACTUALINFLUENCEISVERYSMALL，MAYIGNOREINFIRSTLEVELOFAGCTHEELECTRICITYADJUSTSTHEATTENUATORTHEPINTUBETOSELECTTHREESTEPSINTERSMODULATIONQUANTITYTOBEHIGHERTHAN60DBM，ALSOMAYNEGLECTTHEHIGHSENSITIVITYREALIZATIONRELIESONENTIREMACHINENOISEFACTORREDUCINGTHESYSTEMNOISECOEFFICIENTMAYCALCULATEBASEDONTHECASCADESYSTEMTOTALNOISEFACTORFORMULASIMILARLY，WHENCOMPUTATIONNEEDSALLLEVELSOFGAINSCONVERSIONFURTHERREALITYMULTIPLE，THETOTALNOISEFACTORWHICHWILLCALCULATEAGAINTOCONVERTADECIBELVALUEMAYSEEFROMTHEANALYSISFORMULA，IFTHECASCADESYSTEMFIRSTLGIPIN,31121FGFLEVELFORISINCREASINGTHECOMPONENT，GENERALLYISINRECEIVERLNA，IFITSGAINISG1ENOUGHBIG，THENINTHEFORMULATHEDENOMINATORWILLCONTAING1THEBEHINDITEMTOTHETOTALNOISEFACTORCONTRIBUTIONVERYSMALL，BASICWILLBEALLOWEDTONEGLECT，THENTHEENTIREMACHINENOISEFACTORONWILLBEBASICISTHELNANOISEFACTORADDSONINFRONTOFLNAWILLHAVEDAMAGESTHECOMPONENTINSERTSDAMAGESTHEREFORE，INRECEIVERLOWNOISEDESIGNTIME，F(xiàn)IRSTLEVELOFLNADESIGNESPECIALLYESSENTIAL，AFTERITSNOISEFACTORSHOULDASFARASPOSSIBLESMALLALSOTHEGAINMUSTTHEENOUGHBIGSUPPRESSIONTHELEVELNOISECONTRIBUTION，MOREOVERINFRONTOFTHELNAELECTRICCIRCUITINSERTSDAMAGESSHOULDBEASFARASPOSSIBLESMALLINFRONTOFTHISPROJECTLEVELSPDTSELECTSHITTITECORPORATIONLOWLYTOINSERTDAMAGESSWITCHHMC190MS8，INSERTSDAMAGESONLYIS04DB，IP350DBM，THEFIRSTLEVELOFLNANOISEFACTORIS12DB，THEGAINIS18DB，INFRONTOFLNA2MHZ30MHZSEVENSTEPSELLIPTICFUNCTIONFILTERINSERTSDAMAGESIS05DB，THECOMPUTATIONMAYRESULTINTHETOTALNOISEFACTORIS3DBACCORDINGTOSYSTEMSENSITIVITYFORMULAS174DBMNF10LOGBKSNKTHEACTUALCENTERUPPERLIMITMAYBEBIGGESTBYTHERECEIVEFUNCTIONRECEIVEANTISTOPSUPTHESIGNALTODETERMINETHAT，THELOWERLIMITDETERMINEDBYTHESYSTEMSENSITIVITY，BECAUSEINDESIGNTIME，INORDERTOENHANCERECEIVESTHEBIGSIGNALABILITY，JOINEDLEVELOFFUNCTIONSELECTRICCIRCUITSINFRONTENDADDTOBEPOSSIBLETOCUTTHEWEAKENELECTRICCIRCUIT，WHENSIGNALOVERSIZEDWASALLOWEDTOCUTTHEFIXEDWEAKEN，BUTWHENSMALLSIGNALNOWEAKENDIRECTLYPASSED，THEREFOREGREATLYENHANCEDTHESYSTEMDYNAMIRANGEUPPERLIMITUNIFIESTHREELEVELOFAGCTOBEALLOWEDTOREALIZEISBIGGERTHAN130DBTHEDYNAMIRANGESYSTEMNONMIXEDDISPERSESDYNAMIRANGESFDRALSOISWEIGHSTHESYSTEMOVERALLPERFORMANCETHEIMPORTANTTARGET，ISREFERSTOTHERECEIVERINPUTSIGNALFROMTOSURPASSNOISETHRESHOLD3DBPLACE，NAMELYMDS，TOHASNTHADTHREESTEPSINTERMEDIATIONMIXEDDISPERSESSOUNDSPOTPLACEBETWEENPOWERDYNAMIRANGENAMELYSFDR23IP3NF10LOGB171DBM95DBCONCRETEAGCREALIZATIONINNEXTSYSTEMREALIZATIONDETAILEDELABORATIONTHEMIRRORIMAGESUPPRESSIONANDTHEINTERMEDIATEFREQUENCYSUPPRESSIONTARGETSYSTEMDESIGNISTWOFREQUENCYCONVERSIONSUPERHETERODYNESTRUCTURES，F(xiàn)IRSTTIMEFORONFREQUENCYCONVERSION，TRANSFORMSTHESIGNALINGFREQUENCYTOHIGHINTERMEDIATEFREQUENCY488MHZON，THEGOALISFORENHANCETHEMIRRORIMAGESUPPRESSIONTHEMIRRORIMAGEFREQUENCYISTHESIGNALINGFREQUENCYTAKETHISINSPIRESTHEFREQUENCYSTHEAXISOFSYMMETRYMIRRORIMAGE，WHENTHESIGNALFREQUENCYBANDIES2MHZ30MHZ，F(xiàn)IRSTINSPIRESTHERANGEOFVARIATIONIS508MHZ788MHZTHENTHEMIRRORIMAGEFREQUENCYBANDIS996MHZ1276MHZ，F(xiàn)ARISHIGHERTHANRECEIVERFIRSTHIGHTHISINSPIRESTHEFREQUENCY，THEREFOREINTHERECEIVEREACHLEVELOFFILTERSALLHAVEABETTERSUPPRESSIONTOTHEMIRRORIMAGEFREQUENCYALSOFRONTENDINPUTSLEVEL2MHZ30MHZFILTERNOTONLYHASTHESUPPRESSIONTOTHEMIRRORIMAGEFREQUENCY，MOREOVERALSOHASABETTORSUPPRESSIONTOFIRSTINTERMEDIATEFREQUE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