Design of a Chipless RFID Tag by Using Notched Antenna and Closed- and Open-Loop Resonators

This letter presents a chipless radio frequency identification tag with increased coding capability by using a dual-mode loop resonator (closed- and open-loop resonator) and dual band-notch ultrawideband (UWB) antennas. 3N codes can be obtained by coupling N resonators of this kind with the microstrip. By introducing the two band notches on the UWB antenna, two more code bits can be performed without increasing the size of the tag. Band notches on the antennas are designed at a lower frequency for high space efficiency. For verification, tag prototypes are fabricated and measured. The measured results show that 6 bits can be achieved within the band range of 4.0 GHz–5.9 GHz.