Wide Band Microstrip Patch Antenna with Enhanced Gain using FSS Structure

Abstract

— This paper suggests a slotted ground ‘S’-shaped low profile planar microstrip patch antenna for wideband and high gain operation. The suggested antenna has physical dimensions of 𝟐𝟎𝐦𝐦 × 𝟏𝟒𝐦𝐦 × 𝟏. 𝟔𝐦𝐦 having a fractional bandwidth of 111% having the operating impedance bandwidth 22.55GHz (9.12 GHz to 31.67 GHz). At 19 GHz, maximum gain of 3.9 dBi is attained. An equivalent circuit model corresponding to suggested antenna is designed by ADS software and assessed with the simulated and measured antenna results. Frequency Selective Surface (FSS) of single layer has been placed at optimum position at a distance of 15 mm below the antenna for further improvement of the overall gain of the suggested antenna. Combination of suggested antenna and 𝟔 × 𝟔 FSS configuration increases peak gain to 9.4 dBi maintaining the same antenna bandwidth. The FSS unit cell of dimension 𝟔. 𝟓𝐦𝐦 × 𝟔. 𝟓𝐦𝐦 × 𝟏. 𝟔𝐦𝐦 is used. Design of the antenna is done using commercially available electromagnetic simulator (CST Microwave Studio), and the simulated results are verified by suitable antenna measurement technique using standard microwave test bench. Given FSS integrated antenna has an overall physical volume of 𝟑𝟗𝐦𝐦 × 𝟑𝟗𝐦𝐦 × 𝟏𝟓𝐦𝐦 which makes it ideally suited for high-gain long-range applications.