A text-meandered RFID tag implemented with conductive threads

ABSTRACT We present a wearable RFID tag implemented on a fabric, comprising four alphabet texts embroidered by conductive threads. The tag is optimized to provide a conjugate match to the RFID chip impedance at the operation frequency, 910 MHz. Various tags with different stitching patterns and thread diameters are examined in simulation and a number of tags are measured using two‐port differential probe suitable for balanced tag structures. The measured results of tag impedance show good agreements to the simulation results with slight errors caused by imperfection in probe calibration. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1978–1984, 2016