Performance Improvement of a Dual-Band Textile Antenna for On-Body Through Artificial Magnetic Conductor

Abstract

The increasing demand for wireless communication in wearable devices has led to the need for wearable antennas with a low profile, flexibility, robustness, low SAR, and acceptable on-body performance for WBAN applications. This study presents a low-profile dual-band wearable antenna for WBAN applications operating at 2.45 and 5.8 GHz. The antenna is integrated with a $3\times3$ artificial magnetic conductor array to reduce backward radiation and improve performance when worn on the human body. It is designed and fabricated on a 2 mm-thick flexible felt substrate with a relative permittivity of 1.3 and loss tangent of 0.044. A 0.17 mm-thick superconductive shieldit material is used as conductive material for the antenna and AMC array. The proposed antenna and AMC array have overall volumes of $0.41\lambda _{0} \times 0.45\lambda _{0} \times 0.016\lambda _{0}$ and $0.83\lambda _{0} \times 0.83\lambda _{0} \times 0.016\lambda _{0}$ , respectively. Results indicate that the AMC structure enhances the antenna's gain, radiation efficiency, and bandwidth. The use of AMC reduced the SAR by greater than 98% for 1 and 10 g of human tissue at 2.45 and 5.8 GHz. The proposed design is suitable for WBAN applications due to its low profile, flexibility, robustness, low SAR, and acceptable on-body antenna gain and bandwidth.