Small Size and Low Cost UHF RFID Tag Antenna Mountable on Metallic Objects

Abstract

Reducing tag size while maintaining good performance is one of the major challenges in radio-frequency identification applications (RFID), in particular when labeling metallic objects. In this contribution, a small size and low cost tag antenna for identifying metal objects in the European UHF band (865-868 MHz) is presented. The antenna consists of a transmission line mounted on an inexpensive thin dielectric which is proximity-coupled to a short-ended patch mounted on FR4 substrate. The overall dimensions of the tag are 33.5 × 30 × 3.1 mm. Experimental results show that, for an EIRP of 3.2 W (European regulations), such a small and cheap tag attains read ranges of about 5 m when attached to a metallic object.