A compact flexible ultra-wide band slot antenna with semi-circular partial ground for wearable applications

Abstract This paper introduces a novel Ultra-Wideband (UWB) slot antenna configuration designed for wearable applications. The design involves a flexible substrate made from denim jeans, integrating both a slotted patch and a slotted semi-circular partial ground structure. The optimized position of slots across the length of the patch by narrowing its width helps achieve a wide operational band and also, a rectangular slot is introduced in the center to improve the return loss and to reduce the overall size of the design. The ground structure on the other side is semi-circular with a little I-shaped stub. These two constructions yield a bandwidth of over 22.31 GHz (2.69 GHz–25 GHz), covering the UWB spectrum while resonating at 3.1 GHz and 18.5 GHz. A moderate gain and stable radiation characteristics across the entire operational bandwidth are achieved for the proposed design. In addition to the bending robustness, the function of the antenna under human loading, and the Specific Absorption Rate (SAR) on the human body are investigated, and it was found to be satisfying. Due to its flexible characteristics, compact size, ease of fabrication, the UWB technology spectrum capability, and very high impedance bandwidth, the antenna can serve a multitude of wearable applications such as Wireless Local Area Networks (WLANs), Wireless Body Area Networks (WBANs), Wi-Max and Ku band applications.