Frequency-coded chipless RFID tag based on spiral resonators

RFID has been widely used around the world and it is necessary and effective to lower the cost of RFID by removing inside chip. A novel frequency-coded chipless RFID tag is presented in this paper. It encodes data into the spectral characteristic by spiral resonators with different structures. The tag with six resonators can produce totally 64 IDs and each tag has its unique ID decided by unique size of spiral resonators. Some experiments have been implemented and the results show that tag has obvious frequency characteristic and can be accurately detected by reader. Results prove that this novel chipless tag has excellent performance in information coding.