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:战术级一体化联合作战作为未来战争重要形式之一,对通信网络设计提出了较高要求。由于战术通信网络具备多手段、弱连接和拓扑快速变化的特点,因此需解决快速接入和组网问题。另外,联合作战模式引入了更多类型的作战应用,不同作战应用具有不同通信网络需求。为了适应战术通信环境,实现通信资源的灵活调度,保障不同类型业务的服务质量,对战术通信网络特点以及在战术通信环境下第5代移动通信技术(5G)需求和军用化方式进行了分析,并进一步在5G网络架构与技术架构基础上,给出了5G通信技术战术应用研究方向。
简介:Themixedl1/H2optimizationproblemforMIMO(multipleinput-multipleoutput)discrete-timesystemsisconsidered.Thisproblemisformulatedasminimizingthel1-normofaclosed-looptransfermatrixwhilemaintainingtheH2-normofanotherclosed-looptransfermatrixatprescribedlevel.ThecontinuitypropertyoftheoptimalvalueinrespecttochangesintheH2-normconstraintisstudied.Theexistenceoftheoptimalsolutionsofmixedll/H2problemisproved.Becausethesolutionofthemixedl1/H2problemisbasedonthescaled-Qmethod,itavoidsthezerointerpolationdifficulties.Theconvergentupperandlowerboundscanbeobtainedbysolvingasequenceoffinitedimensionalnonlinearprogrammingforwhichmanyefficientnumericaloptimizationalgorithmsexist.