Physical modeling of on-chip antenna for UHF RFID tags

Lumped-element models and parameter extraction methods for OCA are vital to successfully integrating OCA with RFID tags. In this paper, a compact model for OCA at UHF band is proposed. Metal loss (skin and proximity effects) and substrate coupling are taken into account. Meantime, a fast and physics meaningful parameter extraction method is presented. Two OCA prototypes and one fully-integrated UHF RFID tag chip have been designed and fabricated in SMIC 0.18μm CMOS RF process. Their measurement and simulation results verified the proposed OCA model and parameter extraction method. It is further demonstrated that the proposed model and extraction method can help to predict the tag read range.