复杂舰船环境下电磁场分布特性研究

硕士学位论文复杂舰船环境下电磁场分布特性研究RESEARCHOFELECTROMAGNETICFIELDDISTRIBUTIONCHARACTERISTICINCOMPLEXSHIPENVIRONMENT吴小川哈尔滨工业大学2010年7月国内图书分类号：TN822+.3学校代码：10213国际图书分类号：621.38密级：公开工学硕士学位论文复杂舰船环境下电磁场分布特性研究硕士研究生：吴小川导师：邓维波教授申请学位：工学硕士学科：信息与通信工程所在单位：电子与信息工程学院答辩日期：2010年7月授予学位单位：哈尔滨工业大学ClassifiedIndex:TN822+.3U.D.C:621.38DissertationfortheMasterDegreeinEngineeringRESEARCHOFELECTROMAGNETICFIELDDISTRIBUTIONCHARACTERISTICINCOMPLEXSHIPENVIRONMENTCandidate：WuXiaochuanSupervisor：Prof.DengWeiboAcademicDegreeAppliedfor：MasterofEngineeringSpeciality：InformationandCommunicationEngineeringAffiliation：SchoolofElectronicsandInformationEngineeringDateofDefence：July,2010Degree-Conferring-Institution：HarbinInstituteofTechnology哈尔滨工业大学工学硕士学位论文摘要舰船是有众多通信和无线导航系统林立的复杂平台，其上电磁环境异常复杂，通信系统(接收，发射)频率覆盖范围小到几千赫兹，大到40GHz。近几年有大量的研究发表以解决复杂电大结构上天线分析问题。对于舰载天线布局来说，金属结构(烟囱，桅杆等)对天线性能的影响以及舰船电磁兼容性问题的计算都是非常复杂的，而天线辐射方向图以及耦合的大量模型为天线的设计和排布提供了关键信息。众多理论方法如散射理论、互耦理论等可用以解决金属结构与附近天线的相互作用问题。然而，电大复杂平台上的天线辐射方向图的分析计算往往是既困难、又耗时，有时还无法实现。因此，利用数值方法或是渐进理论预估都是很好的解决方式。为了解决舰载平台下的多天线电磁兼容(EMC)问题，本文利用了自动分层的多层快速多极子方法(MLFMA)，并详细分析了该算法的原理和实现过程。然后介绍了模型建立的两种方式，并给出一艘典型舰船的建立模型。其次，本文分析了舰船甲板上频率为3~30MHz范围内的天线方向图及耦合度。为了分析天线间的耦合特性，本文运用微波网络理论给出了任意天线间的隔离度表达式。基于多层快速多极子算法，分析并仿真出舰载短波鞭天线的辐射远场图以及不同频率、天线高度、天线水平和垂直距离、极化方式等条件下的耦合强度。昀后，本文讨论了复杂平台下的天线辐射近场电磁场强特性，并比较了在不同舰体上层结构形状、天线位置、天线数量以及发射功率下的天线辐射特性，这为舰载短波通信天线的设计和布局提供了参考标准。除此之外，本文利用基于天线互耦矩阵特征值分解的算法实现天线的优化布局，该算法对优化舰载天线布局提供了合理的，可行性方案。关键词：电磁兼容；多层快速多极子方法；天线互耦；微波网络-I-哈尔滨工业大学工学硕士学位论文AbstractShipsarecomplexplatformshavingmanyantennaconnectedcommunicationandradionavigationsystems.Theelectromagneticenvironmentofawarshipisareasonablycomplexoneinvolvingthecommunicationsystems(receiver,transmitter)coveringafrequencyrangeofafewkHzto40GHz.Numerousstudieshavebeenissuedintheliteraturedealingwiththeanalysisoftheantennasmountedonalargecomplexstructureinrecentyears.Inthecaseofashipboardantennaconfiguration,computingtheeffectofmetalconstructions(funnel,mast,etc)ontheperformanceoftheantennas,consequentlyonthecharacteristicsofshipboardEMC,isparticularlycomplicated.Numericalmodelingfortheradiationpatternsandmutualcouplingbetweenthemofferscriticalinformationofdesigningandpositioningtheantennas.Varioustheoreticalmethods,suchasdiffractiontheory,mutualcoupling,areusedfortheevaluationoftheinteractionofantennaswithnearbymetalstructures.Theanalyticalcalculationofthepatternoftheantennasmountedonlargecomplexstructuresaredifficult,timeconsuming,andsometimesimpossible.Sopredictionsbyeithernumericalorasymptoticmethodsarepreferred.Inordertosolvetheelectromagneticcompatibility(EMC)problemsofmultipleantennasmountedonshipborneplatforms,bycomparingwithvarietyofelectromagneticalgorithms,themultilevelfastmutipolealgorithm(MLFMA)withadaptivenumberoflevelsisimplementedinthispaper.Thenitgivesananalysisofthetheoryandprocessofthisalgorithm,andbringsouttwokindsofmodelbuildingmethods.Subsequently,atypicalwarshipmodelisbuildandshowed.Secondly,theanalysispatternandmutualcouplingwhichhasbeenperformedinthe3~30MHzfrequencyrangeandantennasarelocatedonthetopsideoftheship.Fortheanalysisofthecouplingbetweenantennas,thedefinitionofarbitraryisolationbetweenantennasisputforwardaccordingtothemicrowavenetworktheoryconsidered.BasingonMultilevelFastMultipoleAlgorithm,thispaperanalyzed,calculatedandsimulatedtheradiationfieldofsinglewhipantennainshortwaveonwarship,andmutualcouplingindifferentconditionsincludefrequency,length,horizontalandverticaldistance,polarization,etc.Andthen,adestroyerissimulatedandanalyzed.Finally,thepaperdiscussthecharacteristicsofnear-fieldElectromagneticfield,andcomparedwiththeradiationcharacteristicsandlayoutoftheantennaswiththedifferentwarshipsuperstructuresize,antennapositions,antennanumbersandtransmitpower,whichprovidedonemeanstothedesignofthecommunicationwarship.Another,anantennaoptimizationlayoutalgorithmbasedontheeigenvalue-II-哈尔滨工业大学工学硕士学位论文decompositionofantennainter-couplingmatrixisimplemented,whichisrationalandapplicableforoptimizingthelayoutofmultipleantennasmountedonshipborneplatforms.Keywords:ElectromagneticCompatible,MultilevelFastMultipoleAlgorithm,MutualCouplingbetweenAntennas,MicrowaveNetwork-III-哈尔滨工业大学工学硕士学位论文目录摘要....................................................................................................................IAbstract................................................................................................................II第1章绪论..........................................................................................................11.1研究背景及意义..........................................................................................11.2国内外的研究状况......................................................................................21.3本文主要研究内容......................................................................................5第2章数值算法研究...........................................................................................62.1常规数值算法分析与比较...........................................................................62.1.1常规数值算法分析.....................................