A novel, frequency selective surface (FSS) based, data encoding structure amenable to be used as a chipless RFID tag is proposed. The data encoding structure is made up of finite repetitions of a unit cell fabricated on commercially available grounded FR4 substrate having physical dimensions of 15 × 15 mm2. The unit cell is composed of numerous T-shaped resonant elements arranged as two atypical sets of concentric nested loops. Alteration in geometry of the encoding circuit, attained by inclusion or omission of nested resonators, corresponds to a particular data sequence. Each encoded data sequence is manifested in the frequency domain as a distinct spectral signature. The proposed 10-bit tag is both compact and robust, and remains interrogable in response to illuminating electromagnetic waves at various angles of incidence.
2017 by The Institute of Electronics, Information and Communication Engineers