| This thesis has been done with the scientific research projects.The research workcan be divided into three parts.1. It has designed and analysised a “MovingConmunication” vehicle mounted antenna which bases on plane spiral antenna andoperates from400MHz to5GHz.2. It has designed a UWB(ultra wide band)miniaturization and polarization antenna which operates from2GHz to18GHz.3. Itdesigned and realized a conformal array GPS antenna on frustum with a particularradiation pattern.The main content of this paper is listed below:Firstly, a spiral antenna of compound structure has been designed. The diameterof antenna is300mm.A wideband balun is mentioned to realize impedance matching.In order to enhancing the antenna gain by using backward radiation energy, the thesisalso proposed a particular backed-cavity with a ladder-shaped reflection,which alsocontributes to realize unidirectional radiation.Secondly, a miniaturization compound spiral antenna working from2GHz to18GHz is designed in this part. Its diameter is30mm. The antenna feeds by anultra-wideband balun and uses a cavity which is filled with absorbing materials toretrain backward radiation. At last, the antenna physical prototype is manufactured andmeasured. The measuring results indicate that the simulation results agree mainly withthat of testing. Accordingly, it has proved the feasibility of design proposal.Lastly, a conformal array antenna on cone platform which works at1.575GHz±3MHz has been designed and manufactured. The microstrip antennas areused as two units of the conformal array and these two units are placed on a coneplatform symmetrically. The antenna feeded by a “T”-shaped power divider. At last,the antenna physical prototype is manufactured and measured. The measuring resultsof the antenna show a good performances about VSWR，polarization characteristicsand radiation pattern. And these testing results are agree well with the simulation datas. |
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