Efficient high gain wideband antenna with circular array of square parasitic patches

This article proposes a low cost, high gain and wideband Fabry-Perot Cavity antenna with circular array of square parasitic patches on a superstrate layer. The antenna structure consists of a microstrip antenna, which feeds circular array of 18 square parasitic patches fabricated on a low cost FR4 superstrate. The patches are at the bottom of superstrate and suspended in air at 0.5λ₀ height. The structure provides gain of 16.5 dBi with 3 dB gain bandwidth of 14.6% and impedance bandwidth of 13.5%, which covers 5.15-5.875 GHz ISM band. Radiation patterns are nearly stable over the entire frequency band. The antenna provides more than 85% antenna efficiency, Side Lobe Level (SSL) less than -20 dB and Front to Back lobe ratio (F/B) of 20 dB with cross polarization less than -18 dB. The measured VSWR is less than 2 over the frequency band of interest. The proposed antenna is an attractive solution for several wireless communication systems.