Comparison of wearable passive UHF RFID tags based on electro-textile dipole and patch antennas in body-worn configurations

We present the comparison of wearable passive UHF RFID tags based on dipole and patch antennas made of textile materials. The tags' wireless performance was evaluated when attached to the upper back of a test subject. Despite the fundamentally different structures and electromagnetic operation mechanisms of the antennas, both tags attained read ranges of several meters. In the optimized configuration, the patch tag achieved slightly higher performance, but was found to be more sensitive toward variable antenna-body separation.