Chipless RFID Tag using a Quad Bridge Complimentary Split Ring Resonator

A 2-bit Chip less RFID tag is developed using a modified quad coupled resonator. The feedline is specially modified for exciting a rectangular complimentary split ring resonator between 5 to 7 GHz. The tag consists of two CSRR resonating at 5.78 GHz and 6.43 GHz where each resonator encodes bits of information with a dedicated frequency allocation for data encoding. The improved prototype provides an improvement of 800 MHz compared to a conventional circular split ring resonator. This is mainly because of an enhanced coupled due to the specially modified quad feed line exciting the rectangular resonator in the ground plane. The RFID tag is designed in CST MWS and a detailed analysis is carried out for the developed prototype.