Wearable Textile Antenna Magnetically Coupled to Flexible Active Electronic Circuits

This letter proposes wearable electronic modules on textile, suitable for garment integration, based on antennas magnetically coupled to the active circuitry. The coupling mechanism is based on a heterogeneous transformer with the primary and secondary windings implemented in the antenna and in the circuitry substrate (hybrid or monolithic), respectively. The proposed coupling topology avoids galvanic contacts between the antenna and the active circuitry, allowing for interconnecting the antenna by a mere placing and gluing process. Bonding and soldering processes, often critical for textile materials, are thus avoided. The proposed innovation, mitigating the industrial realization constraints posed by textile implementation of active antennas and radio frequency identification (RFID) tags, should unsurprisingly enable and foster industrial developments of garment RFID, wearable electronics and body-centric communications systems. A patch antenna with transformer based on textile materials and operating in the frequency band 2.4-2.4835 GHz is designed, realized, and measured.