资源描述：
《等离子鞭天线及米波超短间距八木天线性能研究》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、上海交通大学硕士学位论文等离子鞭天线及米波超短间距八木天线性能研究姓名：孙杰申请学位级别：硕士专业：电磁场与微波技术指导教师：袁斌20070101上海交通大学硕士学位论文THERESEARCHOFPERFORMANCEOFPLASMAWHIPANTENNASANDCLOSELY-SPACEDYAGIANTENNASFORMETERWAVESABSTRACTInthisthesis,thereconfigurabilityandstealthperformanceofplasmawhipantennaarestudied,
2、aswellascloselyspacedYagiantennasformeterwaves.Basedontheseresearch,thetwo-foldedplasmaYagiantennaformeterwavesispresentedforthefirsttime,andthisprovidestheoreticalandtechnologicalsupportforthewide-banddual-frequency,dual-polarization,cross-polarizationreceiving,
3、meterwaveplasmaYagiantennasystems,andalsoprovidesaneffectivetoolfordetectionofthehard-to-detecttargetsandespeciallyforprotectionagainsttheheavyEMattackinVHFrange.Accordingtotheresultofthisthesis,whenincidentEMwavefrequencyωbelowplasmafrequencyω，plasmapresents‘met
4、al-like’characteristicandcanformplasmapantennawhichisreplacementofmetalantenna,however,itisagainststealth.Bychangingplasmadensitytomakeωbelowω,stealthperformanceandself-protectionagainstphighEMinterferencearerealized.Ifwelldesigned,two-foldedYagiantenna,usedinthe
5、rangeof100MHzand300MHz,canachieveexcellentimpedancematchingtothe50Ωtransmissionline,withdirectivityhigherthan5.4dBd,whilethespacebetweenelementsisonly0.02λ,thusgreatlysatisfyingtheneedsoftrendsnowadayswhichrequireantennastobemuchsmaller.III上海交通大学硕士学位论文Theresearch
6、backgroundandnecessityofplasmaantennasarediscussedfirstinthisthesis.Theninchaptertwo,basedonbasictheoriesofplasmawireantenna,reconfigurabilityissummarizedandconcluded,thatisplasmalengthcanbecontrolledbytheinputRFpowerandfarfieldcanbecontrolledbyplasmadensity.Inch
7、apter3,twodifferentbasictheoriesforplasmastealth—refractionandabsorptionattenuation,aredemonstrated;thenRCSofplasmaantennasaregiven.Inchapter4,theoriesandsimulationsofcloselyspacedYagiantennaformeterwavesarestudied.Itisshowedthattwo-foldeddipolesat100MHz,228.5MHz
8、,300MHz,formingYagiantennasin0.02λ,achieveexcellentimpedancematchingandhighdirectivity.Atlast,two-foldedplasmaYagiantennaformeterwaveisprimarilystudied,andthes
