High-gain, Compact UWB Antenna for Wireless Power Transfer Based Wearable Applications

The advancement of wearable ultra-wideband (UWB) antennas for wireless power transmission (WPT) requires a compact antenna design with high gain and wide bandwidth capability. A wearable UWB antenna is fabricated that is intended for wireless power transfer applications. A comparative analysis is presented with respect to the fabricated antenna’s gain, bandwidth, and power transfer capability with the antenna in the air and when placed on the human skeletal muscle tissue phantom. The fabricated UWB antenna has a resonating frequency of 3.11 GHz. The designed UWB antenna has realized a gain of 6.35 dBi with fractional bandwidth (FBW) of 69.93%. The measured nearfield S21 parameter portrayed a maximum power transfer efficiency (PTE) efficiency of 66.3% for a 0.3λ transfer distance along with the estimated specific absorption rate (SAR) value of 0.794 W/kg when averaged over 10 g tissue and 1.02 W/kg when averaged over 1 g tissue portrays that the proposed design is safe and suitable for wearable applications.