Modified Square Split Ring Resonator-Based Chipless RFID Tag for Biomedical Applications

This paper presents a modified square split ring resonator-based chipless radio frequency identification (RFID) tag having with a coding capacity of 5 bits. A compact physical footprint of 39 mm × 39 mm with a frequency band from 2 GHz to 8 GHz makes the tag well-suited for multifarious applications in which 2.4 GHz and 5.8 GHz ISM bands can be widely utilized in biomedical scenarios. The resonant structure is developed on an FR4 substrate material which has a dielectric constant and a loss tangent value of 4.3 and 0.02 respectively. The nonexistence of a ground plane potentially lowers the fabrication price. Moreover, the windowing technique is implemented for the encoding of bits.