学科分类
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3 个结果
  • 简介:Theeffectofsystemmismatchesonanadaptivelinearconstrainedgeneralizedsidelobecanceller(LC-GSC)isdiscussedinthispaper.Basedonthearraygainindex,twoclassicsystemmismatches,thedirectionofarrival(DOA)mismatchandthemismatchesarisingfromarraydisturbance,arestudied,respectively.Toobtaintheeffectivemethodsforcompensatingforthesystemmismatches,weanalyzetheperformanceoftheimprovedLC-GSCwiththediagonalloadingandadditionalconstraints(suchasthedirectionalconstraintsandderivativeconstraints).Thecomputersimulationsshowthatthetechniquesofdiagonalloadingandadditionalconstraintscaneffectivelycompensateforthesystemmismatches.Thelossofarraygainscanbecontrolledwithin3dBinthepresenceof20%ofarraydisturbancesorDOAmismatchwhenthesignal-to-noiseratioislessthan10dB.Theanalysisillustratesthattheproposedcompensationmethodsarevalidandfeasible.

  • 标签: 性能分析系统 补偿方法 不匹配 自适应 旁瓣 广义
  • 简介:Thispaperpresentsaschemetoidentifyandcompensatethetimingmismatchesbetweentwochannelsfortimeinterleavedphotonicanalog-to-digitalconverters(TIPADCs).Theimpactofelectro-opticsamplingisremovedbypreprocessingfirstly.ThenacalibrationmethodcombiningchoppingprocessingandaHilberttransformisproposedtoidentifythetimingmismatches,whichcanbefurthercompensatedbyusingvariousmaturecompensationalgorithms.Theprincipleoftheproposedmethodisderivedtheoretically.Theperformanceoftheschemeisanalyzedbysimulation.Theresultsshowthattheharmonicinducedbytimingmismatchescanbesuppressedbymorethan30dBusingtheproposedcorrectionscheme.

  • 标签: CORRECTION PHOTONIC analog-to-digital CONVERTERS TIMING
  • 简介:Inthispaper,6mmthick2219-T6aluminumalloywasjoinedbymeansofvariablepolaritytungsten-arcwelding(VP-TIG)andtheinfluenceofgradientmismatchesonVP-TIGjointsisinvestigated.Theaveragetensilestrengthofthejointsreduces32%,53%and59%,whenthemismatchofthejointwas0.635mm,1.44mm,1.83mm,respectively.Incompletepenetration,additionalbendingmoment(Ma)anddecreaseofeffectiveloadregionareaareconsideredtoexplainthisphenomenon.Thefracturelocationoftensilespecimensoccurredattheweldzone(WZ)closetopartialmeltzone(PMZ),correspondingtoasharpdeclineofmicrohardnessfromPMZtoWZ.Theoriginalpositionoffractureisfoundatweldtoe,whereincompletepenetrationformsduetotheintroductionofgradientmismatches.

  • 标签: 2219-T6 aluminum alloy VP-TIG GRADIENT MISMATCHES