Novel chipless tag with electromagnetic code

This paper presents a new radio frequency identification (RFID) chipless tag operating in the frequency span 4-7 GHz. The tag consists of triangle microstrip filter. The bits are encoded into the spectrum hence the tag has a unique spectral signature. The tag is less sensitive to tag orientation and has smaller size. A 6-bit chipless tag is designed. The simple opening of the triangle sides shifts the resonant frequency of the triangle resonator to an insignificant frequency, which is not used in the band. The curvature effects on the characteristics of the filter are analysed. The chipless tag is designed for advanced traffic and vehicle regulation, alarm and navigation. The finite-element method and the finite-integration technique are used to investigate the characteristics of the filter.