A Study Of The Cavity Backed Antenna Based On The Frequency Selective Surface

The frequency selective surface(FSS)has the ability to reduce the overall profile height and improve the gain of the antenna.In this paper,the cavity backed antenna based on frequency selective surface is researched.The main research results and work can be summarized as follows:A rectangular element periodic frequency selective surface is analysed,which is loaded on a slot antenna.The symmetrical gap gradient structure and exponential gradient of the Balun gradient structure were designed.The bandwidth for VSWR<2 is 0.6610GHz,which is increased by 10.2%.Secondly,the performance of the frequency selective surface slot antenna with the cavity backed was analyzed.When the cavity backed height is the quarter of the center frequency of the wavelength,the antenna has 9.6-10.33dB high gain and 25.6dB before-to-after ratio of bandwidth which increased by 30%.The bandwidth was 0.85GHz.when the cavity backed height decreased at 0.18 ?,the gain at the center frequency will produce a significant decline in 6dB.Finally,the analysis found that the placement of the patch-type FSS reflector can play an improved role for the antenna gain curve.The FSS is used to the cavity backed antenna to maintain effectively less deterioration of the gain with low back cavity height,9mm antenna cavity backed height is realized 6.125-7GHz VSWR<2 bandwidth,15.7dB before and after the ratio and 9-9.6dB gain.The cavity backed antenna with manufactured and experiment results is found to be consistent with simulation results.