Modified rectangular resonator based 15-bit chipless radio frequency identification transponder for healthcare and retail applications

In this paper, a compact and fully passive chipless radio frequency identification planar tag is proposed based on a modified rectangular resonator. The tag is having a simple design and is fabricated using a low-cost FR4 substrate and acquires a physical footprint of 50 mm × 30 mm. The novelty of the proposed work describes a single passive tag having a reading distance of 84 cm with a 15-bit coding capacity in a compact profile. A spectral bit capacity of 2.727 bits/GHz is achieved in a wide range of frequencies from 0.5 to 6 GHz. A reference wideband horn antenna is used as the interrogator to study the tag detection procedure having gains of 6.6 and 18.77 dBi at 0.5 and 5.8 GHz respectively. The backscattered tag response is well suited to the measurement characteristic of the reader. The measurements are performed in a bistatic mode and the results confirm the 15-bit coding capacity of the chipless tag using frequency domain analysis with a maximum radar cross section of −15 dBsm. The multi-bit coded tag can be suitable for a wide range of wireless applications, viz. tracking, retailing, identification, and healthcare utilities.