Rectangular Microstrip Slot Antenna with EBG Structure for Wearable WLAN/WiMAX Applications

A rectangular coplanar ground antenna is proposed for wearable applications. The rectangular patch antenna of size 31 mm
$\times 24$
mm is designed to have a low profile and wide bandwidth. The antenna is designed on an FR4 substrate of thickness 1.6 mm. To investigate the effect of slots on the radiation performances, multiple antennas have been designed with varying slot areas. An EBG structure with a suppression bandwidth of 3.5 GHz is employed to reduce the back radiation of the antenna. Both structures are designed independently to operate in the 2–6 GHz range, to be employed in devices operating in WLAN/WiMAX frequencies. The antenna is integrated with the EBG structure of a
$2\times 2$
square unit cell array and the radiation characteristics are observed. The back radiation of the antenna has been reduced significantly due to the EBG structure. The integrated structure has enhanced gain, directivity and low Specific absorption rate. The effect of the conductor, which reflects the radiation of the antenna with a phase difference and then destructively get added to the antenna's forward radiation, is removed with an EBG structure with full ground structure. The EBG structure has enhanced the antenna's effectiveness by reflecting radiation in phase with the antenna's forward radiation. In this work, the effect of EBG on the antenna radiation pattern is analysed to reduce SAR and make the antenna suitable for wearable applications.