Design and Analysis of Compact Robust Chipless Tag Based OOK and FSK

A compact, frequency domain-based, data encoding structure amenable to be designed as a novel chipless RFID tag is proposed. The tag is a tiny trapezoidal lamina on which multiple L-shaped arc-angle resonators of different sizes are deployed to generate distinct one-to-one resonant frequencies corresponding to resonators. The material of the substrate is Rogers RT/Duroid®/5880 suitable for RFID tags. The 5 bits encoding is contained in a tag with OOK coding method and 2⁵ different items can be coded. The angle insensitivity (including polarization insensitivity and incident angle insensitivity) of the tag is verified to ensure that the tag can operate smoothly in different environments. Even more important, with FSK coding, the data capacity and bit density of the tag are doubled, and the number of encoded IDs increases exponentially. Hence, the realized tag with its small size, low cost, high robustness, and flexibility has the potential to replace the optical codes for the perception layer of IoT based smart applications.