Experimental comparison of three electro-textile interfaces for textile UHF-RFID tags on clothes

Textile Ultra High Frequency (UHF, 865-868 MHz) Radio Frequency Identification (RFID) devices meet difficulties from connection of solid chips and textile antennas. In this work, three electro-textile interfaces integrated with the corresponding textile UHF-RFID antennas as the solutions are proposed and compared. The simulated and measured impedance curves of the corresponding antennas are all close and the radiation performance (realized gain) are designed to be near (about 1.4 dBi). According to the Friis formula, the simulated and measured read ranges of the interfaces with the corresponding antennas in air are obtained (all above 4.5 m). For reliability validation, mixed use feasibility tests are implemented and the results show the read ranges of each interface used on other two designs have tolerable read range decrease (< 2 m but all above 3.41 m).In addition, the read ranges of the designs on body are all above 2.05 m. Due to the small sizes of the interfaces, stable performance on body and good reliability, the proposed interfaces solutions are proved feasible.