简介:Anew140GHz/2MW/3selectroncyclotronresonanceheating(ECRH)systemcomposedoftwounitsisnowbeingconstructedonHL-2A.Asapartofthesystem,twotransmissionlinesmarkedNo.7&8playtheroleofcarryingmicrowavepowerfromtwogyrotronstothetokamakport.Basedontheoversizedcircularcorrugatedwaveguidetechnology,anevacuatedtransmissionsystemwithhighpowercapabilityandhightransmissionefficiencyisdesigned.Detailsarepresentedforthedesignofthecorrugatedwaveguide,thelayoutoftheproposedlinesandthevacuumpumpingsystem.Thenmodeconversionlossesduetocoupling,misalignment,bendsandgapsarediscussedtoserveasareferenceforanalyzingthetransmissionefficiencyandalignment.Finally,adual-modespropagationcaseconsistingoftheHEnandLPnevenmodesisdiscussed
简介:摘要:170GHz-260Ghz倍频器是微波扩频模块的核心模块,其性能直接决定着扩频模块的指标。本文通过对一种170GHz-260Ghz倍频器的二极管发热进行仿真,发现温度升高对模块指标影响巨大,对不同功率的二极管进行仿真,二极管温升满足产品的要求,实现了高性能倍频器的设计,满足了扩频模块整机的要求。
简介:Thispaperpresentsthedesignandsimulationofseveralfixed-tunedsub-harmonicmixerscoverfrequenciesfrom110GHto130GHz,215GHto235GHz,310GHto350GHz,and400GHto440GHz.Amongthem,120GHz,225GHz,330GHzsubharmonicmixersaredesignedwithflip-chippedplanarschottkydiodemountedontoasuspendedquartz-basedsubstrate,the225GHzand425GHzsubharmonicmixersareGaAsmembraneintegrated,andthe115GHzsubharmonicmixerhasbeenfabricatedandtestedalready.
简介:Inthispaperweusea10-layerradiationtransfermodeltosystematicallyinvestigatetherelationbetweenbrightnesstemperatureandtherainfallratesat37GHz,includingvariousviewingofmicrowave(MW)remotesensinganddifferentsurfacecondition,withmainfocusontheinfluenceofthestructureofice-phaselayer.Theresultsshowthatthequantitativerainfallmeasurementcannotbereliablyobtainedoverthelandfromspuceborneradiometeratthiswavelengthandthestructuresoficelayerareveryimportantindeterminingthe"observed"brightnesstemperatureforthespaceborneMWremotesensing.
简介:Thesingle-carrierblocktransmission(SCBT),a.k.a.,single-carrierfrequency-domainequalization(SC-FDE),isbeingconsideredasanoptiontechniqueforthewirelesspersonalareanetwork(WPAN)operatingat60GHz.Itisfoundthatforresidentialenvironment,innon-line-of-sight(NLOS)multi-pathchannels,theSCBTismuchmoreeffectivetocombattheinter-symbolinterference(ISI)comparedwithorthogonalfrequencydivisionmultiplexing(OFDM).Low-densityparity-check(LDPC)codesareaclassoflinearblockcodeswhichprovidenearcapacityperformanceonalargecollectionofdatatransmissionandstoragechannelswhilesimultaneouslyadmittingimplementabledecoders.TofacilitateusingLDPCcodesforSCBTsystem,anewlog-likelihoodratio(LLR)calculationmethodisproposedbasedonpilotsymbols(PS).GolaySequenceswhosesumautocorrelationhasauniquepeakandzerosidelobeareusedforcreatingthePS.ThepositionandlengthofthePSarenotfixedinthedatablocks.ThesimulationresultsshowthattheproposedmethodcansignificantlyimprovetheLDPCdecodingperformanceinSCBTsystem.Thisisverypromisingtosupportultrahigh-data-ratewirelesstransmission.
简介:Weexperimentallydemonstratea4-Gb/sradio-over-fiber(RoF)systemwith40-kmfiberand2-mwirelessdistancedownstreamat100-GHzcarrier.Tothebestofourknowledge,thisisforthefirsttimeinChinatorealizeopticalwirelesslinkat100GHz.Inthisletter,simpleintensitymodulatorwithdirectdetector(IM-DD)modulationisemployedandopticalpowerpenaltyafter40-kmsinglemodefiber(SMF)-28and2-mairlinkis3.2dBwithbit-error-rate(BER)at1×109.
简介:台湾的VIATechnology公司目前公开了预计在2001年第3季度出厂的86系列互换微处理器(开发代码名:C5X)的大致规格。其工作频率为1.2GHz.与基于现行体系结构的“C5C”相比.工作频率提高了40%。该处理器的发布会是由美国Centaur技术公司(该公司由VIA于1999年8月从IDT手中收购)总裁GalenHenry主持进行的.C5X由于工作频率大幅提高.所以其流水线段数也相应地从C5C的12段增加到17段.并且在一个周期内可进行译码的指令数日增加到2个关于整数运算指令和MMX指令,在一个周期内最大可以执行2个指令。
简介:Inthispaperwedescribeafull-integratedcircuitcontainingallbuildingblocksofacompletedPLL-basedsynthesizerexceptforlowpassfilter(LPF).Thefrequencysynthesizerisdesignedforafrequencyhopping(FH)transceiveroperatingupto1.5GHzasalocaloscillator.ThearchitectureofVoltageControlledOscillator(VCO)isoptimizedtogetbetterperformance,andaphasenoiseof-111.85-dBc/Hz@1MHzandatuningrangeof250MHzaregainedatacentrefrequencyof1.35GHz.AnovelDual-ModulusPrescaler(DMP)isdesignedtoachieveaverylowjitterandalowerpower.ThesettlingtimeofPLLis80μswhilethereferencefrequencyis400KHz.ThismonolithicfrequencysynthesizeristointegrateallmainbuildingblocksofPLLexceptforthelowpassfilter,withamaximumVCOoutputfrequencyof1.5GHz,andisfabricatedwitha0.18μmmixedsignalCMOSprocess.Lowpowerdissipation,lowphasenoise,largetuningrangeandfastsettlingtimearegainedinthisdesign.