《U型寄生贴片微带天线,原文的》由会员分享，可在线阅读，更多相关《U型寄生贴片微带天线,原文的（8页珍藏版）》请在金锄头文库上搜索。
1、AnalysisandDesignofANovelSmallMicrostripPatchAntennaABSTRACT:Microstripantennashavebeenwidelyusedincommunicationsystems.DesignandanalysisofawidebandU-shapedparasiticMicrostripPatchAntennawhichiscoupledbythemainpatchandU-shapedparasiticpatchesispresentedinthispaper.Twoparasiticelementsareincorporated
2、intotheradiatingedgesofarectangularpatchwhoselengthandwidthareg/2andg/4,respectively,inordertoachievewidebandwidthwithrelativelysmallsize.Theproposedantennaisdesignedandfabricatedonasmallsizegroundplane(25mm30mm)forapplicationofcompacttransceivers.Themeasuredbandwidthis1.5GHz(4.78-6.28GHz)withtwosep
3、arateresonantfrequenciesat5.12and6.08GHz.Themeasuredradiationpatternsaresimilartothoseofaconventionalpatchantennawithslightlyhighergainsof6.4dBand5.2dBateachresonantfrequency.KEYWORD:Parasiticpatchantenna,U-shapedparasiticpatches,widebandwidth.1. INTRODUCTIONInhigh-performanceaircraft,spacecraft,sat
4、ellite,andmissileapplications,wheresize,weight,cost,performance,easeofinstallation,andaerodynamicprofileareconstraints,low-profileantennasmayberequired.Presentlytherearemanyothergovernmentandcommercialapplications,suchasmobileradioandwirelesscommunications,thathavesimilarspecifications.Tomeetthesere
5、quirements,microstripantennas1-38canbeused.Theseantennasarelowprofile,conformabletoplanarandnonplanarsurfaces,simpleandinexpensivetomanufactureusingmodernprinted-circuittechnology,mechanicallyrobustwhenmountedonrigidsurfaces,compatiblewithMMICdesigns,andwhentheparticularpatchshapeandmodeareselected,
6、theyareveryversatileintermsofresonantfrequency,polarization,pattern,andimpedance.Inaddition,byaddingloadsbetweenthepatchandthegroundplane,suchaspinsandvaractordiodes,adaptiveelementswithvariableresonantfrequency,impedance,polarization,andpatterncanbedesignate,39-44.Demandforcompactandmultifunctional
7、wirelesscommunicationsystemshasspurredthedevelopmentofmultibandandwidebandantennaswithsmallsize.Microstrippatchantennasarewidelyusedinthisregardastheyoffercompactness,alowprofile,lightweight,andeconomicalefficiency.However,themicrostrippatchantennaislimitedbyitsnarrowoperatingbandwidth.Therearenumer
8、ousandwell-knownmethodstoincreasethebandwidthofantennas,includingincreaseofthesubstratethicknestheuseofalowdielectricsubstrate1,theuseofvariousimpedance-matchingandfeedingtechniquestheuseofmultipleresonators3-7,andtheuseofslotantennageometry8.However,thebandwidthandthesizeofanantennaaregenerallymutu
9、allyconflictingproperties,thatis,improvementofoneofthecharacteristicsnormallyresultsindegradationoftheother.Recently,severaltechniqueshavebeenproposedtoenhancethebandwidth.In9-11,utilizingtheshortingpinsorshortingwallsontheunequalarmsofaU-shapedpatch,U-slotpatch,orL-probefeedpatchantennas,widebandan
10、ddual-bandimpedancebandwidthhavebeenachievedwithelectricallysmallsize.Inthiswork,awidebandmicrostrippatchantennaemployingparasiticelementsisinvestigated.TwoU-shapedparasiticelementsareincorporatedalongtheradiatingedgesofaprobefedrectangularpatchantennasoastoobtainwidebandoperatingfrequency.Inadditio
11、n,theantennaisrelativelysmallincomparisonwiththeconventionalparasiticpatchantennadescribedin4,5.Performanceoftheproposedantennaiscalculatedandmeasured.ThemethodsofanalysisformicrostripantennasisgiveninSection2.TheproposedantennageometryisdescribedinSection3.Thefabricatedantennaandexperimentalvalidat
12、ionsarepresentedinSection4.2. METHODSOFANALYSISTherearemanymethodsofanalysisformicrostripantennas.Themostpopularmodelsarethetransmission-line16,35,cavity12,16,18,35,andfullwave(whichincludeprimarilyintegralequations/MomentMethod)22,26,71-74.Thetransmission-linemodelistheeasiestofall,itgivesgoodphysi
13、calinsight,butislessaccurateanditismoredifficulttomodelcoupling75.Comparedtothetransmission-linemodel,thecavitymodelismoreaccuratebutatthesametimemorecomplex.However,italsogivesgoodphysicalinsightandisratherdifficulttomodelcoupling,althoughithasbeenusedsuccessfully8,76,77.Ingeneralwhenappliedproperl
14、y,thefull-wavemodelsareveryaccurate,veryversatile,andcantreatsingleelements,finiteandinfinitearrays,stackedelements,arbitraryshapedelements,andcoupling.Howevertheyarethemostcomplexmodelsandusuallygivelessphysicalinsight.Inthischapterwewillcoverthetransmission-lineandcavitymodelsonly.Howeverresultsan
15、ddesigncurvesfromfull-wavemodelswillalsobeincluded.Sincetheyarethemostpopularandpractical,inthischaptertheonlytwopatchconfigurationsthatwillbeconsideredaretherectangularandcircular.Representativeradiationcharacteristicsofsomeotherconfigurationswillbeincluded.ANTENNADESIGNFig.1.Geometryoftheproposedm
16、icrostripGnd.patchantennawithU-shapedparasiticelements.Fig.1depictsthetopandsideviewsoftheproposedantenna.Theproposedantennaconsistsofaprobefedhalf-wavelengthrectangularpatchandtwoU-shapedparasiticelementsincorporatedaroundtheradiatingedgesoftherectangularpatch.Ingeneral,thelengthandwidthoftherectangularpatchantennaareclosetohalf-wavelength.However,thelength(LR)andwidth(WR)ofthemainpatchvaryfromthepropo
