Design of a miniaturized UHF tag antenna for global usage

Based on coupled split ring resonators, a new broadband small tag antenna is proposed to overcome compatibility problem of the global usage of ultra-high frequency radio frequency identification(UHF RFID)tags. As the criteria of voltage standing wave ratio (VSWR) is less than 1.22, the antenna can operate well in the frequency range 790 to 960 MHz, which covers all the licensed UHF RFID frequencies globally. As an experimental demonstration, we fabricated a RFID tag with the proposed antenna and a commercial RFID microchip. Tested by a RFID reader in an anechoic chamber, the RFID tag demonstrates good performances, which agree with simulation results and prove the usage of the tag in some different working environments. The tag antenna has the advantages of small volume, simple structure, low cost and easy of fabrication.