U slot multi-resonator RFID tag with enhanced bit encoding capacity

Multi-resonator based 6 bit chipless RFID tag using U slot resonators is presented in this paper. The multi-resonators are designed and fabricated on substrate C-MET LK4.3 of dielectric constant 4.3 and loss tangent 0.0018. The tag identity can be encoded in the spectral domain either using absence/presence encoding technique or Frequency Shift coding technique. Bistatic measurement is used to decode the tag identity from either the amplitude,phase or group delay information. The tag consists of two cross polarised wide band antennas integrated to multi-resonator, for transmission and reception of signals. Various RFID tags are designed and tested using bistatic measurement setup. Measurement results on realized prototypes are provided to ensure the reliability of the proposed design.