学科分类
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116 个结果
  • 简介:Thestructureoftheopticalwaveguideof2-bitelectroopticA/Dconverterwithproton-exchangemicroprismsisoptimizedbythefinite-differencebeampropagationmethod(FD-BPM).Theelectrodeparametersoftheconverterareoptimizedbyconformalmapping.Theoptimalparametersareahalf-wavevoltageofVπ=4.5VandabandwidthofΔf=1.4GHz.Anormalizedtransmittedpowerof69.75%isobtainedbyFD-BMPandtheoutputwaveguidegapis300μm.

  • 标签: 优化设计 数字变换器 光学波导 电磁传播
  • 简介:A2D-directionofarrivalestimation(DOAE)formultiinputandmulti-output(MIMO)radarusingimprovedmultipletemporal-spatialsubspacesinestimatingsignalparametersviarotationalinvariancetechniquesmethod(TS-ESPRIT)isintroduced.InordertorealizetheimprovedTS-ESPRIT,theproposedalgorithmdividestheplanararrayintomultipleuniformsub-planararrayswithcommonreferencepointtogetaunifiedphaseshiftsmeasurementpointforallsub-arrays.TheTS-ESPRITisappliedtoeachsub-arrayseparately,andinthesametimewiththeotherstorealizetheparallellytemporalandspatialprocessing,sothatitreducesthenon-linearityeffectofmodelanddecreasesthecomputationaltime.Then,thetimedifferenceofarrival(TDOA)techniqueisappliedtocombinethemultiplesub-arraysinordertoformtheimprovedTS-ESPRIT.Itisfoundthattheproposedmethodachieveshighaccuracyatalowsignaltonoiseratio(SNR)withlowcomputationalcomplexity,leadingtoenhancementoftheestimatorsperformance.

  • 标签: direction of ARRIVAL estimation (DOAE) temporal
  • 简介:0.概述近年来,中国的移动通信市场己开始从快速增长阶段进入到成熟阶段,随着3G的临近,新的运营商将会参与移动通信市场的竞争。面对日益激烈的竞争形势,中国移动作为国内移动通信市场占主导地位的运营商,如何处理现有GSM系统与3G之间的关系、制定合理的3G发展策略,以及顺利完成2G向3G过渡等,已成为面临的关键问题。

  • 标签: 中国移动 3G 策略研究 过渡 2G 移动通信市场
  • 简介:<正>2015年22日,笙科电子(AMICCOM)发表2.4GHz单向2Mbps无线发射SoC芯片,命名为A8325。A8325为A7325的SoC整合型芯片,RF效能与A7325相同。可与笙科的2.4GHzRF或SoC搭配使用。A8325的传输速度高达2Mbps,并支持FSK与GFSK调变,数字部份整合高效能的1TPipeline8051,内建8KbytesOTPMemory、1KbytesRAM,与12/8个GPIO与各种数字接口。2线式的ICE可搭配KeilC开发。

  • 标签: SOC芯片 无线发射 Hz bps PIPELINE 整合型
  • 简介:Anultra-highspeed1:2demultiplexerforopticalfibercommunicationsystemsisdesignedutilizingtheIHP0.25μmSiGeBiCMOStechnology.Thelatchofthedemultiplexercorecircuitisresearched.Basedonthecurrentmeasurementcondition,ahigh-gainandwide-bandwidthclockbufferisdesignedtodrivelargeload.Transmissionlinetheoryforultra-highspeedcircuitsisusedtodesignmatchingnetworktosolvethematchingproblemamongtheinput,outputandinternalsignals.Thetransientanalysisshowsthatthisdemultiplexercandemultiplexone100Gb/sinputintotwo50Gb/soutputs.Thechipareaofitis0.7mm×0.47mm,theinputandoutputdataarebothat400mVP-PPCMLstandardvoltagelevel,andthepowerconsumptionoftheICis900mWatthepowersupplyof-4V.

  • 标签: 集成电路 Gb 晶体管 BICMOS技术 信号分离器 超高速电路
  • 简介:已经有130多年历史的柯尼卡公司和70多年历史的美能达公司从2003年的秋天开始逐渐淡出人们的视野,真正成为“历史”,取而代之的是两者的“合壁”柯尼卡美能达(kenihminolta)。自今年1月发表经营合并以来,经过5月份股份交换合同的签定、6月份股东大会上对股份交换合同的表决认可,在8月5日通过交换股份方式实施了经营合并,10月1日实施了集团内事业的整合,日本柯尼卡株式会社和美能达株式会社的合并重组终于尘埃落定。

  • 标签: 股份 亚洲 经营 淡出 合并重组 有限公司
  • 简介:据《每日科学》报道,来自肯塔基大学、德国戴姆勒公司及希腊电子结构和激光研究所(IESL)的科学家们合作发现了一种单原子厚度的新型平面材料,该材料可替代石墨烯材料,并将推动数字技术的进步。尽管现在石墨烯备受瞩目,被认为是世界上最强韧的材料,但却有一个显见的不足——它不是半导体,这对其在数字产业的应用来说无疑是个打击。新材料由硅、硼、氮元素组成,3种元素都有重量轻、价格低、储量大的优点。此外,

  • 标签: 新材料 科学家 可替代 石墨 2D 元素组成
  • 简介:Thispaperpresentsanewarraystructureforestimatingtwo-dimensional(2-D)direction-of-arrivals(DOAs).ThestructureiscalledY-shapedarray,whichhas10%betteraccuracypotentialthanthenewly-developedL-shapedarray.Agreatmeritisitsabilitytoestimate2-DDOAswhicheverdirectionsthearrivingsignalscomefrom,comparedwithL-shapedarraywhoseperformancedependsonDOAs.Simulationresultsaregiventodemonstratetheperformanceofthenewarray.

  • 标签: DOA estimation ARRAY SIGNAL processing ARRAY
  • 简介:Aterahertz(THz)polarizerandswitchstructureisproposedbasedonthephasetransitionofvanadiumdioxide(VO2).WhenVO2isintheinsulationphase,theresonancefrequenciesoftheproposedstructureare1.49THzand1.22THzforthex-andy-polarization,respectively.ItcanperformasaTHzpolarizerwithextinctionratiosof52.5dBand17dBforthey-andx-polarization,respectively;WhenVO2transformsintometallicphase,theresonancefrequencyforx-polarizationwaveshiftsfrom1.49THzto1.22THz,whilethatremainsstillforthey-polarizationcomponent.Itmeansthatthestructurecanworkasapolarization-dependentTHzswitchwithahighextinctionratioof32dB.

  • 标签: 偏振开关 太赫兹 VO2 相变 偏振消光比 多用
  • 简介:AninitialstructuredesignofMMI1×8opticalpowersplittersisreported.ThewaveguidematerialisSi-basedSiO2Ge-dopedanddepositedbyPECVDmethod.Embeddedstripstructureisimpliedinthesectiondesign.ByusingBPM-CAD,afavorableresultisobtainedthatthisdevicehasasounduniformityandfairlylowloss.Meanwhile,simulationsofdesignswithcertainchangedparametersisalsoimplementedforabetterdesignconfiguration.

  • 标签: 光功率分配 多模干扰 波导 MMI
  • 简介:因特网已成为全球最大的信息基础设施,在全球宽带化、移动化、IP化、融合化、个性化大潮中,IPv6的海量地址支持及改进的业务解析能力与PeertoPeer(P2P)对等互联及有效宽带资源共享传送能力相组合,可以期望将会对开启未来信息通信网络新时代做出新的贡献!

  • 标签: 宽带网络 IPV6 P2P 信息基础设施 信息通信网络 解析能力
  • 简介:Silicon-on-insulator1×Y-junctionOpticalSwitchBasedonWaveguide-vanishingEfect①②ZHAOCezhou(Microelectron.Institute,XidianUnive...

  • 标签: Integrated Optics OPTICAL Switchs Y JUNCTION
  • 简介:UnipolarresistiveswitchingbehaviorsoftheZnOandAl2O3/ZnOfilmsfabricatedonflexiblesubstratesbypulselaserdepositionwerestudiedinthispaper.Thefilmsweredepositedatroomtemperaturewithoutpost-annealingtreatmentduringtheprocess.XraydiffractionresultsindicatedthatZnOfilmhasadominantpeakat(002).ScanningelectronmicroscopyobservationshowedacolumnargrainstructureoftheZnOfilmtothesubstrate.ThebilayerdeviceofAl2O3/ZnOfilmshadstableresistiveswitchingbehaviorswithagoodenduranceperformanceofmorethan200cycles,highresistiveswitchingratioofover103atareadvoltageof0.1V,whichisbetterthanthatofthesingleoxidelayerdeviceofZnOfilm.Apossibleresistiveswitchingfilamentarymodewasdemonstratedinthispaper.TheconductionmechanismsofhighandlowresistancestatescanbeexplainedbyspacechargelimitedconductionandOhmic’sbehaviors.Theenduranceofthebilayer(BL)devicewasnotdegradeduponbendingcycles,whichindicatesthepotentialoftheflexibleresistiveswitchingrandomaccessmemoryapplications.

  • 标签: FLEXIBLE PULSED laser DEPOSITION resistive switching
  • 简介:Thesilicon-on-insulator(SOI)1×2Y-junctionopticalwaveguideswitchhasbeenproposedandfabricated,whichisbasedonthelargecross-sectionsingle-moderibwaveguidecondition,thewaveguide-vanishingeffectandthefree-carrierplasmadispersioneffect.Intheswitch,theSOItechniqueutilizersiliconandsilicondioxidethermalbondingandback-polishing.Theinsertionlossandextinctionratioofthedevicearemeasuredtobelessthan4.78dBand20.8dBrespectivelyatawavelengthof1.3μmandaninjectioncurrentof45mA.Responsetimeisabout160ns.

  • 标签: 全光学 光切换 Y型连接 波导 硅上绝缘
  • 简介:Themixedl1/H2optimizationproblemforMIMO(multipleinput-multipleoutput)discrete-timesystemsisconsidered.Thisproblemisformulatedasminimizingthel1-normofaclosed-looptransfermatrixwhilemaintainingtheH2-normofanotherclosed-looptransfermatrixatprescribedlevel.ThecontinuitypropertyoftheoptimalvalueinrespecttochangesintheH2-normconstraintisstudied.Theexistenceoftheoptimalsolutionsofmixedll/H2problemisproved.Becausethesolutionofthemixedl1/H2problemisbasedonthescaled-Qmethod,itavoidsthezerointerpolationdifficulties.Theconvergentupperandlowerboundscanbeobtainedbysolvingasequenceoffinitedimensionalnonlinearprogrammingforwhichmanyefficientnumericaloptimizationalgorithmsexist.

  • 标签: MIMO 离散时间系统 混合l1/H2最优化 控制系统
  • 简介:Anultrahighvacuumchemicalvapordeposition(UHV/CVD)systemisintroduced.SiGealloysandSiGe/Simultiplequantumwells(MQWs)havebeengrownbycold-wallUHV/CVDusingdisilane(Si2H6)andgermane(GeH4)asthereactantgasesonSi(100)substrates.ThegrowthrateandGecontentsinSiGealloysarestudiedatdifferenttemperatureanddifferentgasflow.ThegrowthrateofSiGealloyisdecreasedwiththeincreaseofGeH4flowathightemperature.X-raydiffractionmeasurementshowsthatSiGe/SiMQWshavegoodcrystallinity,sharpinterfaceanduniformity.Nodislocationisfoundintheobservationoftransmissionelectronmicroscopy(TEM)ofSiGe/SiMQWs.TheaveragedeviationofthethicknessandthefractionofGeinsingleSiGealloysampleare3.31%and2.01%,respectively.

  • 标签: GESI 量子阱 UHV/CVD 透射电子显微镜
  • 简介:WefabricatepolycrystallineCu(In,Ga)Se2(CIGS)filmsolarcellsonpolyimide(PI)substrateattemperatureof450°Cwithsingle-stageprocess,andobtainapoorcrystallizationofCIGSfilmswithseveralsecondaryphasesinit.Forimprovingitfurther,thetwo-stageprocessisadoptedinsteadofthesingle-stageone.AnextraCu-richCIGSlayerwiththethicknessfrom100nmto200nmisgrownonthesubstrate,andthenanotherCu-poorCIGSfilmwiththicknessof1.5-2.0μmisdepositedonit.Withthemodificationoftheevaporationprocess,thegrainsizeofabsorberlayerisincreased,andtheadditionalsecondaryphasesalmostdisappear.Accordingly,theoveralldeviceperformanceisimproved,andtheconversionefficiencyisenhancedbyabout20%.

  • 标签: 薄膜太阳能电池 沉积过程 聚酰亚胺 CU 基板 GA