RFID chipless tag based on multiple phase shifters

The RFID chipless tag presented in this article uses a new technique for data encoding. It is based on changing the phase of multiple resonators that behave as phase shifter. This technique brings a much higher reliability than for the actual absence/presence of resonance encoding way. The design proposed is based on 5 reflective strip resonators having resonant frequency starting from 2.5 GHz to 6.5 GHz. A capacity of 10 bits is reached within a reduced size of 20 × 40 mm². Tag made on this principle is potentially low cost because only one conductive layer is needed for its fabrication.