Exploration of printing-friendly RFID antenna designs on paper substrates

Printed RFID antenna is a promising solution for itemlevel tagging applications. In order to integrate the antenna printing with the package printing process, it is highly preferred that antenna geometries are printed on paper substrates. However, the electromagnetic property and thickness of paper substrates are subject to change. Thus wideband and material-insensitive printed RFID antennas are desired. This paper presents an analytical model for wideband tag antenna designs. Two matching scenarios, i.e. single-tuned match and double-tuned match, are particularly discussed in detail. Two slim-line antennas printed on paper with screen printing technique are proposed. They benefit from the single-tuned/double-tuned bandwidth optimization and demonstrate a great potential in conductive ink saving. Influences of dielectrics on the bandwidth performance are also studied. It is demonstrated that the proposed double-tuned antenna can cover the whole UHF RFID band, and can tolerate a considerable variation in the permittivity like 1∼9 on thin paper substrates.