Hybrid model chipless RFID tags based on the integration of filter theory and multi-resonator circuit

Abstract

In this paper, a hybrid model chipless radio frequency identification (RFID) tag is introduced. It is constructed by using multi -resonator circuit with a bandstop filter simultaneously. Bandstop filter section is conventionally designed by quarter -wave open -circuited stubs, while the multi -resonator circuit is developed by coupling dual -band codirectional split ring resonators (CDSRRs) to a feeding line. Each stub and CDSRR can provide two and four frequency codes, respectively. The open -circuited stubs can form the resonant frequencies within wide frequency range, while the CDSRRs have notch band characteristics. The proposed hybrid model approach has the ability of combining notch and wide band resonant frequencies on a single circuit. A 12 -bit chipless RFID tag is designed by locating two wideband monopole antennas vertically and horizontally at the end of the multi -resonator circuit. The monopole antennas are formed by using two orthogonal ellipses. 000000000000 and 100100100100 frequency coded two tags have been experimentally investigated.