Super Long Range Small Empty Cavity UHF RFID Tag Antenna Design for a Metal Cart

This paper presents an UHF (Ultra High Frequency) band small empty cavity structured RFID (Radio Frequency Identification) tag antenna with a super long reading range, designed to apply on metal cart for auto-parts logistics. The size of tag antennas is 140×60×10 mm3, attached on an exporting metal cart, and it can give the information of inventory and logistics of carts. By collecting the exported carts and increasing the recovery rate of missing carts or pallets, the paid import tax can be refunded when the carts are returned back to the manufacture. The tag antenna is made by a PLA plastic cover to prevent damage, and help to make the cavity antenna; the dielectric constant of the cover is considered for the simulation. The copper material is attached on four side of the plastic; the reading range of the tag antenna is almost 21m using LP (Linear Polarization), 10 m with CP (Circular Polarization) reader antennas. This 920 MHz UHF RFID cavity tag ensures the long reading distance of the antenna regardless of the material of the object where it is attached.