Design of Wearable Radio Frequency Identification Antenna

This paper focuses on the development of a wearable radio frequency identification (RFID) antenna to be embedded on shirt collars or cuffs. Wearable RFID tags tend to be conformal, and are required to reasonably meet design specifications even when under deformation. A simple circular dipole structure was selected as the base design for the antenna. Operating in the ultra-high frequency band at 866 MHz and over an operating range of around 5 m, the antenna is versatile enough to be used for a number of applications such as the tagging of patients in a hospital or for workers on dangerous construction sites. The designs presented account for the complex input impedance generally observed in RFID systems and the final design employs an intricate spiral structure to accommodate longer wavelengths. This resulted in a compact portable antenna able to meet device specifications.