Glove-Integrated Textile Antenna with Reduced SAR for Wearable UHF RFID Reader

We present a wearable slotted patch antenna embedded in a glove for wearable UHF RFID reader. The antenna is fully-textile based, small enough to fit on the area in the back of the hand and achieves the realized gain of -1.3 dBi at 866 MHz in body-worn configuration. The paper outlines the numerical optimization of the antenna using a layered hand model and assessment of the specific absorption rate to determine the maximum output power of the reader that complies with the SAR safety limits. As a novel feature, we have designed an isolator layer of conductive textile that is adhered inside the glove underneath the antenna to achieve 10 percent reduction in the specific absorption rate (SAR) and 1.14 dBi improvement in the realized gain compared to our earlier work. With these marked improvements, the output power of the reader is not limited by SAR, but by the regular RFID emission limit. In the wireless testing, we have verified a detection range of 4.7 meters for a regular dipole type RFID tag with 3.19 WEIRP.