We present a wearable passive UHF RFID tag based on a slotted patch antenna comprising only textile materials (e-textile, textile substrate, and conductive yearn). As a novel manufacturing approach, we realize the patch-to-ground and antenna-to-IC interfaces using only conductive thread and a sewing machine. We outline the electromagnetic optimization of the antenna for body-worn operation through simulations and present a performance comparison between the e-textile tag and a tag produced using regular electronics materials and methods. The measured results show that the textile tag achieves the electrical performance required in practical applications and that the slotted patch type antenna provides stable electromagnetic performance in different body-worn configurations.
Virkki, J., Wei, Z., Liu, A., Ukkonen, L., & Björninen, T. (2017). Wearable passive E-textile UHF RFID tag based on a slotted patch antenna with sewn ground and microchip interconnections. International Journal of Antennas and Propagation, 2017. https://doi.org/10.1155/2017/3476017