简介:ToovercomethelimitationoflowimagesignalswingrangeandlongresettimeinfourtransistorCMOSactivepixelimagesensor,achargepumpcircuitispresentedtoimprovethepixelresetperformance.Thechargepumpcircuitconsistsoftwostageswitchcapacitorserialvoltagedoubler.Cross-coupledMOSFETswitchstructurewithwellcloseandopenperformanceisusedinthesecondstageofthechargepump.Thepixelresettransistorwithgatevoltagedrivenbyoutputofthepumpworksinlinearregion,whichcanaccelerateresetprocessandcompleteresetisachieved.Thesimulationresultsshowthatoutputofthechargepumpisenhancedfrom1.2to4.2Vwithvoltageripplelowerthan6mV.Thepixelresettimeisreducedto1.14nsindark.Imagesmearduetonon-completelyresetiseliminatedandtheimagesignalswingrangeisenlarged.ThechargepumpissuccessfullyembeddedinaCMOSimagesensorchipwith0.3×106pixels.
简介:Thecoupling-waveequationsofphotorefractivewaremixingprocessenin-cludingtwo-andfour-wavemixingareexpressedasanunifiedmatrixequationintheun-depletedpumpapproximation.Thelosslessgeneralsolutionofthematrixequationisob-tained.Thepreviousformulasoffivewave-mixingprocessesintheundepletedpumparederivedfromthesolutionwhentheirboundaryconditionsareused.
简介:Becauseofthezerodispersionwavelength(ZDWL)randomfluctuations,thegainandnoisefiguresdeteriorateinopticalparametricamplifiersbasedonhighlynonlinearfibers(HNLFs).ThedetrimentalroleofZDWLfluctuationsonthegainandnoiseperformanceindual-pumpfiberopticalparametricamplifiers(FOPAs)ispresented.Numericalinvestigationsofnoisefigure(NF)fordifferentfiberswithrandomfluctuationareanalyzed.Thenoisefiguresfordifferentfibersarevaryingeveniftherandomfluctuationissmall.ThroughchoosingHNLFswithlowZDWLfluctuationandlargenonlinearcoefficient,high-gainandlow-noiseperformancecanbeobtained.
简介:摘要:深入贯彻落实军民融合发展战略是推进新时代军事斗争准备的重要举措。军民融合模式下组织国防光缆建设运用,有助于释放民用通信资源巨大潜能,更好促进国防光缆保障战备训练和作战指挥需求,为军队战斗力提升做出实质性贡献。
简介:她在报告中回顾了功率变换技术的发展历史,对如何获得高效、优波负载适应性和强鲁棒性的综合特征进行了阐述。效率、优波、负载鲁棒性以及对负载尖刺的危害等问题的合理解决,关键是如何得到与输出波形同步、同形、同频、同相的纹波供电电压波形,并始终跟随其幅频变化,保持线性功率管工作在临
简介:采用磁控溅射法在阳极氧化预处理过的铝板上沉积氮化铝薄膜,制备氮化铝-铝复合基板。制备的氮化铝为非晶态,抗电强度超过700V/μm,阳极氧化铝抗电强度达75V/μm。当阳极氧化铝膜厚约10μm、氮化铝膜约1μm时,制备的复合封装基板击穿电压超过1350V,绝缘电阻率1.7×106MΩ·cm,氮化铝与铝板的结合强度超过8MPa;阳极氧化铝膜作为缓冲层有效缓解了氮化铝与铝热膨胀系数失配的问题,在260℃热冲击下,铝板未发生形变,氮化铝膜未破裂,电学性能无明显变化。氮化铝与阳极氧化膜的可见光高透性保持了镜面抛光金属铝的高反射率,当该复合基板应用于LED芯片COB封装时,有助于提高封装光效。