A Study of UHF RFID Metallic Tag Design for Long Reading Range Using a Cavity Structure

This paper shows an UHF RFID metallic tags using a Cavity structure for a long reading range. The reading range of a general passive tag is limited because the EIRP of a reader system is limited as 36㏈m by ISO 18000-6. To extend the reading range, the tag antenna should have a high gain antenna structure. The designed tag antenna is recognized over 10m range with a Cavity structure. The directivity pattern and the performance of the tag with the Cavity structure is stable when it is attached to a metallic object. The designed tag antenna has two kinds as cavity thickness. The sizes of designed tag antennas are and They can be attached to a large metallic materials and heavy equipments. The measured reading ranges of the tags are about 11m and 15m when they are attached to a metallic object.