L和S波段高頻收發(fā)前端研究.pdf

1、電子科技大學(xué)碩士學(xué)位論文L和S波段高頻收發(fā)前端研究姓名：杜清兆申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：電磁場(chǎng)與微波技術(shù)指導(dǎo)教師：謝俊20080301ABSTRACTMicrowavetransceiveriS觚importantcomponentinthesatellitecommunicationsystemThebasicfunctionoftransmitteriStoencodethebasebandinformantionontoahighf

2、requencysinewaveealTiersignalthatcanberadiatedmoreeffectivelythanthedirectradiationofthebasebandsignal，andtoamplifythemicrowavecarrierthepurposeofwhichistomeetdemandoflongdistancetransmissionThereceiverconvertsthehi曲micr

3、owavecartierfrequencytoalowintermediatefrequency(IF)byusingthelownoiseamplifier(LNA)andmixerandbandpassfilter(BPF)SomicrowavetransceiveristhehingeofsignalchaininthewirelesssystemThisthesisfocusesontheresearchanddesignoft

4、heLbandtransmitterandSbandreceiverfrontFirstlyinthisthesis，thehistoricaldevelopmentandfuturetrendsofmicrowavetransceiverfromcircuitartsandcrafts，tosystemare／ntroducedThen，asuperheterodynereceiverandanimproveddirectmodula

5、tiontechnologyareusedtocanyoutthetransceiverofthesatellitecommunicationSecondlysomekeytechnologiesinpractice，suchassensitivitylownoisefactorandphasenoise，linearitymicrowavedirectmodulationandlinearpoweramplifierarediscus

6、sed，andsometechnologiesareusedteachthetargetALNAwithalownoisefactorisdesignedtodeterminethenoisecharacteristicofwholereceiverThelowphasenoiseisreachedbyusingserial—digitalphaselockedloop(PLL)frequencysynthesizerInorderto

7、eliminatetheeffectof‘pull—push’fromalargetransmissionsignalinthemicrowavedirectmodulationsystemanimprovementthatthetransmissioncarrierdoublesthefrequencyoflocaloscillator(LO)isappliedtomicrowavetransmitterfrontAusefulapp

8、roachtothedesignandtuningcoupledresonatorfilterusinggroupdelayhasbeendescribedAndatappedI／Qcoupled—resonatorfilterwitlllowinsertionlossandnarrowbandhasbeensimulatedandtunedThirdlythemethodsoftuningandmeasuringtransceiver