An Ultralong-Range, Wideband Planar UHF RFID Tag With Two Split Arcs

A wideband planar passive UHF radio frequency identification (RFID) tag with an ultralong range is proposed in this letter. It is electrically small with a compact footprint of 59.6 mm × 33.3 mm (0.18
$\lambda$
× 0.10
$\lambda$
). The tag is designed based on a T-matching network, and two split arcs are introduced to adjust the resistance and reactance of the tag for the first time. Due to the almost perfect conjugate matching, the power transmission coefficient of the proposed tag reaches 99.63
$\%$
. Finally, it has been fabricated and tested. The measured read range of the tag is greater than 6.2 m within the whole UHF-RFID band (860–960 MHz) with a maximum value of 21.3 m at 910 MHz (with 4 W effective isotropic radiated power).