ROBUST WEARABLE TEXTILE ANTENNAS ON OPTIMIZED SUBSTRATES FOR BIOMEDICAL BODY AREA NETWORKS: EXCEPTIONAL PERFORMANCE, MECHANICAL STABILITY UNDER BENDING, AND REGULATORY SAR COMPLIANCE

Abstract

We provide a detailed design, simulation, fabrication and experimental validation of flexible textile-structured antennas for continuous biomedical monitoring in Wireless Body Area Networks (WBANs) in this paper. The ISM bands (2.435 GHz and 5.54 GHz) based dual-band antennas and ultra-wideband antennas (3.1–10.6 GHz) were designed and methodically demonstrated on seven textile substrates (jeans, flannel, leather, washed cotton, cotton, polyester, and polyimide) and five conductive materials (copper, chromium, gold, nickel, silver). The optimized dual-band ISM antenna on denim substrate has a high impedance matching at |S₁₁| = −40.179 dB at 2.435 GHz and −38.731 dB at 5.54 GHz, fractional bandwidth value of 1.27% and 0.85% and radiation efficiencies of 50.3% and 55%, respectively. The UWB circular patch antenna on polyimide shows |S₁₁| = −43.076 dB, 92.24% radiation efficiency, and it has a good bending stability. The robust SAR results from a three-layer (skin-fat-muscle) phantom demonstrate adherence to FCC (1.6 W/kg) and ICNIRP (2.0 W/kg) standards for 10–500 mW input power and significant safety margins for standard biomedical telemetry. On-body measurements with different curvatures (wrist, arm, chest) show excellent performance. This project contributes to the practical materials database and design guideline for the bridging of flexible electronics with the biomedical work. Keywords: Wearable antennas, Textile substrates, ISM/UWB, SAR, Flexible electronics, Body area networks, Biomedical telemetry.