Fabry-perot Cavity Antennas To Optimize The Design Study

The Fabry-Perot (F-P) cavity has frequency selection function to electromagnetic waves. When the resonance condition of the cavity is satisfied, transmitted electromagnetic waves superpose in phase and become stronger, so that the directivity of the antenna can be significantly improved.In this paper, the radiation principle of Fabry-Perot cavity antennas is discussed and the performances of gain, bandwidth and aperture efficiency are intensively investigated. Parametric studies are conducted to validate theoretical analysis and achieve optimized design of the F-P cavity antenna. Engineering applications of the dual polarized F-P antenna are also explored. In chapter 1 and 2, the state of the art on the main properties and applications are presented. The radiation mechanism, analysis models and input impedance of the Fabry-Perot cavity antenna are illustrated and studied in detail. In chapter 3, the study on aperture efficiency of the F-P antenna is carried out. A Fabry-Perot cavity antenna is designed with a rectangular patch antenna as the primary radiator and a Frequency Selective Surface (FSS) as Partially Reflecting Surface (PRS) cover. The defect modes model is performed to analyze the frequency selective property of the cavity with particular FSS. Based on above research, effects of the cavity height, primary source and FSS cover on the aperture efficiency are investigated in detail. In chapter 4, bandwidth enhancement techniques of the F-P antenna are researched, and corresponding effects on the aperture efficiency are discussed. A Fabry-Perot cavity antenna at15GHz is designed with a 2-D taped-sized FSS as cover, a U-slot patch antenna as primary radiator. Simulated results validate the desired bandwidth and gain. Finally in chapter 5, a dual-polarized Fabry-Perot cavity antenna is developed to meet the demand of high gain and dual-polarization for the particular application.The whole similation study is conducted with CST Microwave Studio. A dual-polarized Fabry-Perot cavity antenna is fabricated and measured, which has a maximum gain of 20.5dB, a aperture efficiency of 52.5%, a port isolation of -30dB and a cross polarization of -15dB. This design has broad application prospects.