HIGH-GAIN LOW SIDE LOBE LEVEL FABRY PEROT CAVITY ANTENNA WITH FEED PATCH ARRAY

Abstract

In this paper, a high gain, low side lobe level Fabry Perot Cavity antenna with feed patch array is proposed. The antenna structure consists of a microstrip antenna array, which is parasitically coupled with an array of square parasitic patches fabricated on a FR4 superstrate. The patches are fabricated at the bottom of superstrate and suspended in air with the help of dielectric rods at 0:5‚0 height. Constant high gain is obtained by resonating parasitic patches at near close frequencies in 5.725{5.875GHz ISM band. The structure with 9£9 square parasitic patches with 1:125‚0 spacing between feed elements is fabricated on 5‚0 £ 5‚0 square ground. The fabricated structure provides gain of 21.5dBi associated with side lobe level less than i25dB, cross polarization less than i26dB and front to back lobe ratio of more than 26dB. The measured gain variation is less than 1dB and VSWR is less than 2 over 5.725{5.875GHz ISM band. The proposed structures are good candidates for base station cellular systems, satellite systems, and point-to-point links.