word文檔可自由復(fù)制編輯word文檔可自由復(fù)制編輯 介質(zhì)諧振器及寬帶印刷縫隙天線研究StudyofDielectricResonatorAntennasandBroadbandPrintedSlotAntennasAthesissubmittedtoXIDIANUNIVERSITYinpartialfulfillmentoftherequirementsforthedegreeofMasterofPhilosophyByZhangsan(ElectronicsandCommunicationEngineering)Supervisor:LisiWangwuApril2011摘要近年來，介質(zhì)諧振器天線（DielectricResonatorAntenna，DRA）和寬帶印刷縫隙天線由于其良好的性能受到了學(xué)者的廣泛關(guān)注。介質(zhì)諧振器天線具有頻帶寬、效率高及激勵(lì)簡單等諸多優(yōu)點(diǎn)，在毫米波段中具有良好的應(yīng)用前景。寬帶印刷縫隙天線以其低剖面、加工簡單以及易于與電路集成等優(yōu)點(diǎn)，在現(xiàn)代無線通信中得到了廣泛的應(yīng)用。本文對介質(zhì)諧振器天線及寬帶印刷縫隙天線進(jìn)行了系統(tǒng)的研究，所取得的主要研究成果為：對寬帶印刷縫隙天線進(jìn)行了研究。針對無線通信系統(tǒng)的要求，提出了一種覆蓋IMT-2000、WiMAX和WLAN等頻段的共面波導(dǎo)饋電的寬帶印刷縫隙天線。通過改變縫隙和共面波導(dǎo)的結(jié)構(gòu)參數(shù)來調(diào)節(jié)天線的諧振頻率，再引入一段阻抗變換器來實(shí)現(xiàn)寬帶阻抗匹配。還提出了一種微帶饋電的超寬帶橢圓形印刷寬縫天線，通過調(diào)整橢圓形縫隙和橢圓環(huán)形貼片長短軸的比例來實(shí)現(xiàn)寬帶阻抗匹配。對寬帶介質(zhì)諧振器天線進(jìn)行了研究?；谌N展寬帶寬的方法，即引入空氣層減小介質(zhì)諧振器天線的內(nèi)在Q值，選擇合適的空氣層厚度使之工作于輻射特性類似的多種模式，以及在饋線末端加六邊形枝節(jié)對介質(zhì)諧振器天線進(jìn)行阻抗匹配，設(shè)計(jì)了一種縫隙耦合饋電的寬帶圓柱形介質(zhì)諧振器天線。采用月牙形印刷單極天線與介質(zhì)諧振器的混合結(jié)構(gòu)，設(shè)計(jì)了一種共面波導(dǎo)饋電的超寬帶介質(zhì)諧振器天線。實(shí)驗(yàn)結(jié)果表明，這兩種介質(zhì)諧振器天線具有良好的寬帶性能。對寬帶圓極化及高隔離度雙線極化介質(zhì)諧振器天線進(jìn)行了研究。提出了一種環(huán)形縫隙耦合饋電的寬帶圓極化介質(zhì)諧振器天線。利用介質(zhì)諧振器天線和環(huán)形縫隙的雙諧振工作得到寬帶圓極化特性，并加入匹配網(wǎng)絡(luò)實(shí)現(xiàn)了寬帶阻抗匹配。提出了一種覆蓋5.2GHzWLAN頻段的高隔離度雙線極化矩形介質(zhì)諧振器天線。采用探針與縫隙分別對兩個(gè)端口饋電實(shí)現(xiàn)了高隔離度，并通過雙探針等幅反相饋電技術(shù)避免了單個(gè)探針饋電的方向圖不對稱性。對小型化介質(zhì)諧振器天線進(jìn)行了研究。介紹了幾種小型化介質(zhì)諧振器天線的設(shè)計(jì)方法，并對其中的一種方法加以改進(jìn)，設(shè)計(jì)出一種改進(jìn)型小型化介質(zhì)諧振器天線。通過與多個(gè)天線的對比表明，使用金屬柱代替金屬面來減小天線的尺寸能避免輻射方向圖畸變，降低交叉極化電平。對高增益介質(zhì)諧振器天線直線陣列進(jìn)行了研究?；诰匦谓橘|(zhì)諧振器天線高次模的分析結(jié)果，選取一種高增益介質(zhì)諧振器天線單元，設(shè)計(jì)了一個(gè)8單元高增益介質(zhì)諧振器天線直線陣列。分析了陣列間距對天線陣增益的影響，通過比較發(fā)現(xiàn)該介質(zhì)諧振器天線直線陣列的增益要高于相同口徑的微帶貼片天線直線陣列。最后，結(jié)合饋電網(wǎng)絡(luò)實(shí)際加工了一個(gè)8單元介質(zhì)諧振器天線直線陣列的實(shí)驗(yàn)?zāi)Ｐ?，?shí)測結(jié)果驗(yàn)證了該設(shè)計(jì)方法的可行性和有效性。關(guān)鍵詞：XXX，XXX，XXX，XXX，XXX（一般為3～5個(gè)）論文類型：應(yīng)用基礎(chǔ)研究類（或基礎(chǔ)研究類）（注：全日制工程碩士學(xué)位論文類型分為8種）word文檔可自由復(fù)制編輯ABSTRACTInrecentyears,dielectricresonatorantennas(DRA)andbroadbandprintedslotantennashavebeenwidelystudiedowingtotheirgoodperformances.Duetotheirseveraladvantagessuchaswidebandwidth,highefficiencyandeaseofexcitation,DRAshavebeenwidelyusedinmillimeterwaveregions.Broadbandprintedslotantennasarewidelyusedinmodernwirelesscommunicationsduetotheiradvantagesoflowprofile,simplefabricationprocessandeaseofintegrationwithcircuits.ThisdissertationismainlyconcernedwiththedesignandimplementationofvariousDRAsandbroadbandprintedslotantennas.Theauthor’smajorcontributionsareoutlinedasfollows:1.Twobroadbandprintedslotantennashavebeenstudied.Firstly,accordingtotherequirementsofwirelesscommunicationsystems,acoplanarwaveguide(CPW)fedbroadbandprintedslotantennacoveringIMT-2000,WiMAXandWLANbandsisdesigned.Theresonantfrequenciesoftheantennaareadjustedbychangingthestructuresoftheslotandthecoplanarwaveguide.Animpedancetransformerisintroducedtorealizebroadbandimpedancematch.Secondly,amicrostripfedprintedellipticalwide-slotantennaisproposedforultra-widebandapplications.Theultra-widebandimpedancematchisachievedbyadjustingtheaxialratiooftheellipticalslotandtheellipticalannularpatch.2.TwobroadbandDRAshavebeenstudied.Firstly,aslot-fedbroadbandcylindricalDRAisdesignedbyusingthefollowingthreemethods:introducingairgaptoreducetheinternalQ-factoroftheDRA,choosingtheappropriatethicknessoftheairgaptomaketheDRAworkingatseveralmodeswithsimilarradiationpatterns,andaddinghexagonstubattheendofthefeedlinefortheDRAimpedancematch.Secondly,aCPW-fedultra-widebandDRAisproposedbyusingthecombinationofcrescent-shapedprintedmonopoleandDRA.Theexperimentalresultsshowthatthesetwoantennashavegoodbroadbandperformance.3.Abroadbandcircularly-polarized(CP)DRAandaduallinear-polarizedDRAwithhighisolationhavebeenstudied.Firstly,abroadbandcircularlypolarizedcylindricalDRAexcitedbyannularslotcouplingisproposed.ThebroadbandCPradiationhasbeenachievedbyusingtwoCPradiators,DRAandannularslot.Inaddition,animpedancetransformerisintroducedtoimprovetheimpedancebandwidth.Secondly,aduallinearlypolarizedrectangulardielectricresonatorantennawithhighisolationoperatingataround5.2GHzforWLANapplicationshasbeenpresented.Thehighisolationisachievedbyusingtwohybridfeedingmechanism:oneporthavinganH-shapedaperturecoupledfeedandtheotherwithprobefeed.Twoout-of-phaseprobefeedisusedtoavoidtheasymmetricradiationpatterncausedbysingleprobefeed.4.AcompactDRAhasbeenstudied.SeveraltechniquesusedforreducingthesizeofaDRAarediscussed.Byusingtheshortingposts,amodifiedcompactDRAisdesigned.Comparingwithseveralexistingantennas,theradiationpatternsdeformationandcouldbeavoidedandthecrosspolarizationlevelsarereduced,byusingshortingpostsinsteadofshortingplate.5.Ahigh-gainDRAlineararrayhasbeenstudied.Basedontheanalysisresultsofthehigh-ordermodesoftherectangularDRA,ahigh-gainDRAelementisselectedtodesignan8-elementhigh-gainDRAlineararray.Theeffectofspacingbetweenadjacentelementsonthegainofthearrayisanalyzed.Inaddition,itisfoundthatthegainoftheproposedDRAlineararrayishigherthanthemicrostrippatchlineararraywiththesameaperturearea.Finally,an8-elementDRAlineararrayprototypeisconstructedtovalidatethefeasibilityandefficiencyofthedesign.Keywords:XXX,XXX,XXX,XXX,XXXTypeofDissertation:AppliedBasicResearch(orBasicResearch)插圖索引圖序號(hào)圖名稱 X 表格索引表格序號(hào)表格名稱 X 符號(hào)對照表符號(hào)符號(hào)名稱XXXXXXXXXXXXXXXXXX…………縮略語對照表縮略語英文全稱中文對照XXXXXXXXXXXXXXXXXXXXXXXXXXX………………目錄摘要 ⅠABSTRACT Ⅲ插圖索引 Ⅴ表格索引 Ⅵ符號(hào)對照表 Ⅶ縮略語對照表 Ⅷ目錄 Ⅸ第一章緒論 11.1選題緣由和意義 X1.1.1介質(zhì)諧振器天線的研究進(jìn)展 X1.1.2寬帶印刷縫隙天線的研究進(jìn)展 X1.2國內(nèi)外研究現(xiàn)狀分析 X1.2.1國外學(xué)者的研究 X1.2.2國內(nèi)學(xué)者的研究 X1.2.3存在的主要問題 X1.3論文的主要研究思路和研究方法 X1.3.1研究思路 X1.3.2研究方法 X……第八章結(jié)論和展望 X8.1研究結(jié)論 X8.2研究展望 X參考文獻(xiàn) X致謝 X作者簡介 X1.基本情況 X2.教育背景 X3.攻讀碩士學(xué)位期間的研究成果 X第一章緒論無線通信系統(tǒng)的飛速發(fā)展，對作為其關(guān)鍵部件的天線提出了小型化、寬頻帶、高效率等高性能要求。各種各樣的微帶貼片天線因其剖面低、質(zhì)量輕等優(yōu)點(diǎn)，已經(jīng)得到了深入的研究和廣泛的應(yīng)用。然而，由于微帶貼片天線存在高頻段金屬歐姆損耗高、低頻段天線幾何尺寸較大的兩個(gè)關(guān)鍵性技術(shù)瓶頸，一定程度上限制了其發(fā)展和應(yīng)用。近年來，一種新型天線——介質(zhì)諧振器天線（DielectricResonatorAntenna,DRA）由于自身所具有的良好性能受到了國外學(xué)者的關(guān)注和研究ADDINEN.CITEADDINEN.CITE.DATA[1-5]。1.1選題緣由和意義1.1.1介質(zhì)諧振器天線的研究進(jìn)展XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX1.1.2寬帶印刷縫隙天線的研究進(jìn)展XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX表1.SEQ表格\*ARABIC1雙極化DRA激勵(lì)方式的性能對比饋電方式電性能參數(shù)探針環(huán)形縫隙探針和縫隙縫隙和CPW探針縫隙縫隙CPW諧振頻率9.5GHz8.8GHz9.4GHz9.8GHz9.2GHz9.3GHz帶寬（|S11|<-10dB）7.3%4.5%6.9%6.8%4.9%5.3%隔離度（帶內(nèi)最差）-16.5dB-17dB-31dB-22dB方向圖不對稱對稱不對稱對稱對稱對稱交叉極化電平高低高低低低第八章結(jié)論和展望8.1研究結(jié)論XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX8.2研究展望XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX