Dual-Band Metamaterial-Based EBG Antenna for Wearable Wireless Devices

In this paper, a wearable dual-band T-shaped antenna using a coplanar waveguide (CPW) fed operating at 2.4 GHz and 5.2 GHz bands is proposed for onbody wireless communications applications. Without the metamaterial-based electromagnetic bandgap (EBG) layer, the original antenna covers two bands from 1.96 GHz to 2.77 GHz and from 5.07 GHz to 5.35 GHz. The antenna efficiency decreases when it is placed on the human arm due to the interference from the human body to the antenna, as shown by a high specific absorption rate (SAR) value. These SAR values are reduced to 77.1% at 2.4 GHz and 91.7% at 5.2 GHz by the proposed EBG. The antenna gain is therefore improved to 1.4 dBi at 2.4 GHz and 6.25 dBi at 5.2 GHz. The antenna prototype is evaluated using a Wi-Fi wearable device, resulting in an improved signal-to-noise ratio (SNR) of 6-12 dB.