UHF-HF RFID integrated tag for moving vehicle identification

In this work, the development of a UHF RFID passive tag for moving vehicle identification and access control is presented. It is composed by both a UHF meander dipole antenna and an ISO 15693 commercial tag arranged in two separate sections on an equivalent ISO 7810 ID-1 card space. The UHF antenna has been designed and optimized to provide small size, proper conjugate-matching to high-capacitive input impedance of the tag IC and omnidirectional pattern in a plane perpendicular to the antenna plane. The design process of the UHF antenna has taken into account both the presence of a commercial ISO 15693 tag allocated in the HF section and the presence of the car glass. UHF antenna characteristics including both the return loss with respect to the IC input impedance and radiation pattern are investigated.