Design of a Hexagonal-shaped Split Resonators Based Chipless RFID Tag

The main objective behind the design of chipless RFID tags for communication systems is to obtain a compact size, high capacity, and low-cost tag. In this work, a multiresonator based chipless RFID tag is represented. Multiresonators are equivalent to series and parallel LC resonators. A chipless RFID tag with hexagonal-shaped split resonator is proposed. The tag encodes N-data bits using N half-wavelength hexagonal-shaped split resonators operating at different resonant frequencies fi, where i = 1, 2, 3…, N. The split gap in each resonator is rotated by an angle θ=2π/N, where N is the number of resonators. The proposed chipless RFID tag has dimensions of 26 mm × 40.78 mm and operates over a frequency band 0.889 GHz and 2.202 GHz. Each hexagonal-shaped split resonator represents a logic state ‘1’ when interrogated with an incident wave. When the resonator is removed then the logic state will be changed to ‘0’. The proposed chipless RFID tag is printed on FR-4 substrate with a thickness of 1.6 mm and a dielectric constat (permittivity) of 4.3. The structure design, simulation and analysis are carried out using Microwave Studio CST software.