Wearable e-textile split ring passive UHF RFID tag: Body-worn performance evaluation

Abstract

We present a wearable e-textile passive UHF RFID tag based on a split ring resonator antenna. The antenna was optimised using a full-wave electromagnetic solver and the prototyped tag was tested in wireless measurements. The detection range of the tag is 2.8 metres at 915 MHz when affixed to the upper back of a person on a textile substrate with the thickness of only two millimetres. In the wireless measurement, we found a close match with the simulations where a homogenous dielectric cuboid representing the torso of a person and studied the impact of non-optimal antenna-body alignments and separations. Overall, the results indicate that the uniplanar split ring antenna achieves robust operation required in the practical wearable applications.