A Novel Broadband UHF RFID Tag Antenna Mountable on Metallic Surface

A novel broadband UHF RFID tag antenna mountable on metallic surface is presented. The structures of T-matching network and double symmetrical radiating patches shorted to ground plane are employed. The proposed antenna has a half power bandwidth of 11.4% when placed in free air and covers two major segments of the UHF RFID band when mounted on metallic surface. The proposed antenna also has good radiation characteristics and cross-polarization performances in both conditions. The results show that the proposed antenna can work not only in free air but also on metallic surface for UHF RFID band.