| The technology of modern radar,electronic eountermeasures,satellite communication and remote sensing has a booming development.Antennas play a very important role on these electronic devices,which are required to work in multi-band or wide band in the modern wireless system.Due to the advantages of simple sturture,high gain and simple feeding network,the Fabry-Perot cavity resonant antennas have become a popular topic in the research area.In this dissertation,the deign methods of dual-band and tri-band Fabry-Perot antenna are studied.The wideband circularly polarized Fabry-Perot antenna and the wideband dual-poalrized Fabry-Perot antenna are researched as well.The author's main contributions are outlined as follows:1.The study of the dual-band Fabry-Perot antenna based on two FSS layers.The method for achiving dual-band Fabry-Perot antenna using two FSS layers is researched.To realize dual-polarization,a dual-band dual-polarized feeding antenna is designed.The coupling between two antenna elements in the Fabry-Perot cavity is studied.To study the beam steering of this proposed antenna at the both working frequencies,this dual-band Fabry-Perot antenna fed by a sparse array is situmated and analysised,respectively.2.The study of the dual-band Farby-Perot antenna based on one Farby-Perot resonant cavity.The resonant condition making two frequencies resonate in one Fabry-Perot cavity is derived.Based on the resonant condition,a partially reflective surface?PRS?with the property of the artificial magnetic conductor?AMC?reflection phase is designed for achieving dual-band Fabry-Perot antenna.The frequency tunning independently of this proposed antenna is studied as well.Moreover,the beam scanning in the two operating frequencies is studied.3.The method of achieving tri-band Fabry-Perot cavity antenna is studied.This method is based on two FSS layers.The study of how to achive the third working frequency is presented.The frequency tunning independently is studied carefully.4.The study of wideband circularly polarized Fabry-Perot antenna.The resonant condition improving the gain bandwidth is addressed,then the PRS layer satisfying the condition is designed.To achieve wideband circular polarization,a 90o wideband phase shifter is studie to integrate with the feeding network.5.The study of wideband dual-polarized Fabry-Perot antenna.The PRS consists of the patch and cross-strip is studied firstly.Then a microstrip antenna with dual-polarization is designed for feeding the proposed Fabry-Perot antenna.To achieve higher realized gain with keeping the gain bandwidth,a 1×2 feed array instead of a single feed is employed as the primary source. |
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