Chipless RFID based on group delay encoding

A two bit planar chipless RFID tag based on group delay encoding has been presented in this paper. This chipless tag encodes data in the phase signature. The data encoding has been done by using C-sections formed by coupling the cascaded transmission line sections at alternative ends. The tag produces two different delays for two specific frequencies corresponding to the two different lengths of the transmission line sections. A measurable amount of delay has been obtained. The new approach has been validated with simulation results in frequency and temporal domain and with measurement results in frequency domain.