Electromagnetic Band Gap Structure for Microstrip Antenna Gain Enhancement at WLAN Band

Abstract

An array of 5 × 5 Electromagnetic Band Gap (EBG) structure based on the conventional microstrip patch antenna (MPA) for gain enhancement is presented in this paper. A single-layer of EBG structure mounted on semi-flexible FR-4 substrate and located above the radiating antenna patch with 70 mm. The proposed antenna based on the EBG structure is operating at 2.45 GHz for WLAN applications. CST MWS is utilized to evaluate the S11, matching impedance, resonant frequency, bandwidth, gain, and far-field radiation patterns. Parametric studies for the antenna design parameters with and without EBG planar array structure are investigated to obtain the optimal antenna performance at 2.45 GHz. The optimal antenna design based on the EBG array is fabricated on FR-4 substrate with maximum dimensions of 2.13λo × 2.13λo × 0.013λo mm3. It is noteworthy that introduced the EBG configuration significantly improves the antenna gain from 6.3 dBi to 13.4 dBi due to emerging the radiation beams towered the desired direction. Another achievement after adding the EBG structure is improving the aperture efficiency from 8.7% to 45.1% and increased the bandwidth by 18 MHz and enhanced the Half Power Beam Width (HPBW) from 77.1° to 42.1° and 118.9° to 35.8° along the elevation (θ) and azimuth directions (θ), respectively.