Wearable Dual-Band Quasi-Yagi Antenna for UHF-RFID and 2.4 GHz Applications

A compact wearable dual-band quasi-Yagi RFID-reader antenna is designed for being incorporated into a smart glove. The antenna dual-band capability allows the integration of both the RFID reader at UHF band and a wireless data link at 2.4 GHz, into a single compact and wearable device. Dipole and loop antennas are combined into a quasi-Yagi structure to be placed on a hand back, in order to detect tagged objects close to the hand palm and fingers, during the operator normal activities. The dual-band driven element consists of a rectangular-shaped folded dipole (resonating at the ETSI UHF RFID band, 865-868 MHz) and a rhombus-shaped folded dipole (resonating at the WLAN band, 2400-2485 MHz). A few parasitic elements (reflector and directors) are included to focus the field in the required direction, namely out of the worker's hand. A prototype of the proposed textile antenna is developed on a stretchable fabric and its performance is measured in terms of read range and near-field distribution, at 868 MHz, and radiation pattern and gain at 2.45 GHz.