Dual-band modified complementary split ring resonator (MCSRR) based multi-resonator circuit for chipless RFID tag

As chipless RFID technology has potential to offer ultra-low cost and fully printable tags, recently, there has been considerable interest on implementing a compact chipless RFID tag with adequate data capacity. In this paper, a compact multiresonator circuit for spectral signature based chipless RFID tag is proposed. The multiresonator circuit utilizes a number of modified complementary split ring resonators (MCSRR) placed along the transmission line as data bit encoding element. A novel resonance detuning mechanism proposed here allows the use of an MCSRR to independently encode two data bits instead of one bit. Besides, symmetricity of the MCSRR with respect to the feed line causes the disappearance of the second harmonic and hence the total realizable bandwidth for data bit encoding is also enhanced. The multiresonator circuit is based on coplanar waveguide (CPW) configuration and can be realized on flexible substrate with single sided metallization. Once incorporated with cross polarized UWB tag antennas, the proposed multiresonator circuit can be used for a compact fully printable chipless RFID tag that may replace barcode in the long run.