Dual-band textile AMC integrated monopole antenna for SAR reduction

This paper presents a dual-band textile monopole antenna integrated with an artificial magnetic conductor (AMC) reflector, specifically aimed at minimizing the specific absorption rate (SAR) while enhancing radiation performance for wireless body area network (WBAN) and wireless local area network (WLAN) applications. The proposed antenna is designed to operate at the 2.4 GHz industrial, scientific, and medical (ISM) band and the 5.2 GHz wireless local area network (WLAN) band and is fabricated on a flexible felt substrate with a compact dimension of 30 × 50 mm2. To achieve dual-band operation and enhance radiation characteristics, a 3 × 3 AMC reflector composed of an optimized array of octagonal unit cells incorporating rhombus-shaped patches is employed, occupying an overall area of 111 × 111 mm2. The fabricated prototype exhibits measured impedance bandwidths of 25.27% (2.04–2.63 GHz) and 8.17% (5.05–5.48), with corresponding peak realized gains of 7.27 dBi at 2.4 GHz and 5.94 dBi at 5.2 GHz, respectively. Moreover, the specific absorption rate (SAR) values of the proposed antenna integrated with the AMC reflector are significantly reduced to 0.467 W/kg at 2.4 GHz and 0.205 W/kg at 5.2 GHz, both well below the international safety limit of 1.6 W/kg averaged over 1 g of tissue, thereby confirming its suitable and safe operation for on-body applications.