Printed Slotted Dual-Port Shared Radiator Circular Patch Antenna for Wideband Wearable Sub-6 GHz 5G Applications

This study presents a wideband, wearable dual-port antenna suitable for 5G sub-6 GHz communication and wireless body area networks (WBAN) applications. The innovation of this proposed work is in the usage of a thin, two-layer substrate combining thermoplastic polyurethane (TPU) and polyester, and fabricating silver ink conductive with screen-printing to provide a durable structure that is more suitable for industrial production. A protective coating is applied over the conductive layers to prevent oxidation and ensure long-term functionality. The antenna thickness is only 0.82 mm, where the polyester fabric substrate ensures seamless garment integration and allows the antenna to function like a printed logo on a T-shirt. Thus, the antenna exhibits the functionality as well as practicality of wearable 5G technology. The proposed shared-radiator dual-port design with a partial ground plane provides compact size and enhanced resonance. The antenna delivers a –10 dB bandwidth covering 5G FR1 spectrum, including typically challenging sub-1 GHz region alongside high frequencies. A slot is introduced in the radiator to reduce the mutual coupling and maintain isolation below –10 dB across the whole bandwidth. The antenna achieves a peak gain of 5.4 dBi and a maximum efficiency of 95.4%. Satisfactory robust performance is achieved under deformation, such as bending conditions and near human-body placement. Multi-port performance of the antenna was analysed through investigating diversity performance, i.e., envelope correlation coefficient (ECC) < 0.03 and diversity gain (DG) approaching 10 dB. Specific absorption rate (SAR) evaluations confirmed compliance with ICNIRP safety guidelines by remaining below 2 W/kg per 10 g tissue, ensuring safety of the user. These features demonstrate the antenna as a suitable wearable solution for both 5G sub-6 GHz communication and WBAN applications