Broadband Slot Antenna Design for On-Body UHF RFID Applications (Invited)

In this invited paper, a radio frequency identification (RFID) antenna working in the ultra-high frequency (UHF) band for on-body (wearable) applications is proposed. The UHF RFID proposed antenna is a slotted type that allows the RFID chip to be loaded into the center of the rectangular slot via two narrow feeding lines. The proposed wearable UHF RFID antenna has a small size of 45 mm × 15 mm × 1.6 mm (0.137 $\lambda_{0}$ × 0.046 $\lambda_{0}$ × 0.004$\lambda_{0}$, at center frequency 915 MHz). When placed on the wrist of a human hand, the measured results of the proposed UHF RFID antenna have exhibited 3-dB impedance bandwidth of 13.6% (870–997 MHz) and 10-dB impedance bandwidth of 4.13% (900–938 MHz), which is desirable for present UHF RFID applications working in the 902–928 MHz band.