An Industrially Scalable Embroidered Circularly Polarized Antenna with Reduced SAR for Wearable Applications

An industrially scalable, single-layer, embroidered circularly polarized (CP) textile antenna with a reduced profile and specific absorption rate (SAR) is proposed for 2.4 GHz ISM-band applications. The antenna is simply composed of a slotted substrate integrated cavity (SIC), featuring a simple configuration and low profile. The CP radiation is achieved by introducing a pair of ±45° asymmetrical crossed slots and a shorting pin. In addition, an auxiliary slot is etched near the probe feed to suppress the out-of-band radiation. Moreover, the antenna exhibits a super stability in terms of impedance/AR bandwidth, gain and radiation pattern under different conformal scenarios. The antenna is fabricated on a real industrial embroidery production line, enabling high repeatability, low production cost, and seamless compatibility with mass-manufacturing workflows. Thanks to the cavity-slot structure, the proposed antenna exhibits very low SAR values of 0.114 W/kg and 0.089 W/kg for 1-g and 10-g averaging when evaluated on a human phantom, demonstrating its suitability for safe and practical wearable deployment.