简介:ThebasicschemeoftheorientationdetectionsystemusingL-shapereticleisintroduced.Thedimensionofthepatternsonthereticleofthesysteminpracticalapplicationsisdesignedandananalysisoftheprincipleofabstractingtheorientationinformationofthetargetandtheeffectsandformationmethodofself-adaptingtrackinggateispresented.TheresearchresultshowsthattheorientationdetectionsystemusingL-shapereticlehasagoodeffectonspace-filtering,thesignalsthattheorientationdetectionsystemsendsoutareeasytobeprocessedbycomputer,itsself-adaptingtrackinggatehasastronganti-interferenceability,andthewholesystem’ssearchingandtrackingperformancesarequitehigh.
简介:Thispaperpresentsthesimulationandmeasuredresultsofatriple-bandL-shapedmonopoleantennawithdefectedgroundplaneforapplicationsinwirelesslocalareanetworks(WLANs)andworldwideinteroperabilityformicrowaveaccess(WiMAX)bands.Thetriple-bandL-shapedmonopoleantennawithdefectedgroundplanewasfabricatedonaFR4substrate.Thelowerbandisassociatedwiththeshortedparasiticstripintheprotrudingstubofthegroundplane;themiddlebandisexpectedtobecontrolledbythelongerstripofL-shapedmonopoleinthefrontside,whilethehigherbandisassociatedwiththeshortstripofL-shapedmonopoleinthefrontside.Theproposedantennahasagoodagreementbetweenthemeasuredandthesimulationresults.Ithasa10dBreturnlosswiththebandwidthof250MHz(2270MHzto2520MHz)inthelowerband,600MHz(3320MHzto3,920MHz)inthemiddleband,and1110MHz(5030MHzto6140MHz)inthehigherband.TheproposedantennacoverstheISM(industrial,scientificandmedical),HIPERLAN(highperformanceradiolocalareanetwork),UNII(unlicensednationalinformationinfrastructure),andWiMAXbands.
简介:Themixedl1/H2optimizationproblemforMIMO(multipleinput-multipleoutput)discrete-timesystemsisconsidered.Thisproblemisformulatedasminimizingthel1-normofaclosed-looptransfermatrixwhilemaintainingtheH2-normofanotherclosed-looptransfermatrixatprescribedlevel.ThecontinuitypropertyoftheoptimalvalueinrespecttochangesintheH2-normconstraintisstudied.Theexistenceoftheoptimalsolutionsofmixedll/H2problemisproved.Becausethesolutionofthemixedl1/H2problemisbasedonthescaled-Qmethod,itavoidsthezerointerpolationdifficulties.Theconvergentupperandlowerboundscanbeobtainedbysolvingasequenceoffinitedimensionalnonlinearprogrammingforwhichmanyefficientnumericaloptimizationalgorithmsexist.
简介:目前PSWF的脉冲产生方法在硬件实现方面有着编程复杂,计算量大,资源消耗多等制约因素,因此亟需一种适合实时产生PSWF脉冲信号的方法。通过分析Walsh函数系的特点和产生原理,提出了一种基于Walsh函数系的PSWF脉冲波形重构方法。其中,Walsh系数可以通过已有的PSWF数值点与P编号的Walsh矩阵求解得出,再截取所需精度的Walsh系数参与重构PSWF脉冲波形,从而达到降低存储量的目的。由于Walsh码型中的±1与数字电路中的01有着天然对应的关系,重构时只需将Walsh系数相加减,从而降低计算量。仿真结果表明,利用Walsh函数系可以较好地重构PSWF脉冲波形,且算法简单,避免了乘法运算,降低了计算量和存储量,有利于工程实现。