Metamaterial-Inspired Dual-Band Flexible Textile Antenna Using Wool-Felt Substrate for Body-Centric Wireless Electronics

Flexible textile-based electronic systems are emerging as promising candidates for next-generation wearable technologies due to their mechanical compliance, lightweight nature, and seamless integration into garments. In this work, a metamaterial-inspired dual-band flexible textile antenna based on a wool-felt substrate is presented for body-centric wireless applications. The proposed device is designed as a flexible electronic structure integrating coplanar waveguide (CPW) feeding with symmetric square-ring resonators to enable compact size and dual-band electromagnetic functionality. The wool-felt substrate serves as a functional textile material offering low density, high flexibility, and stable dielectric behavior under mechanical deformation. The fabricated structure exhibits an overall dimension of 40 × 52 mm2, making it suitable for garment-integrated electronic systems. Experimental results demonstrate two impedance bandwidths of 3.11–3.70 GHz and 5.52–6.89 GHz (|S11| < −10 dB), covering sub-6 GHz 5G and ISM wireless communication bands. The proposed flexible electronic system achieves measured gains of 1.81 dBi and 4.35 dBi at the lower and upper frequency bands, respectively, with good agreement between simulated and experimental results. Mechanical bending analysis confirms stable electromagnetic performance, with resonance shifts below 1%, indicating robust mechanical–electromagnetic coupling under deformation. Furthermore, specific absorption rate (SAR) analysis verifies compliance with international safety standards for on-body wireless operation. Owing to its combination of a functional textile substrate, compact architecture, and stable dual-band performance, the proposed wool-felt-based flexible antenna represents a promising candidate for wearable and body-centric electronic systems.