A compact split-ring resonator using spiral technique for UHF RFID tag

In this paper, the development of a compact tag antenna based on Split Ring Resonator with spiral technique printed on flexible Arlon CuClad 250LX substrate is proposed to operate at North-American UHF-RFID band (902-928 MHz). The spiral technique is used to reduce the passive SRR tag antenna, providing proper impedance matching with the RFID chip. The antenna presents compact size with total dimensions of 16.17mm × 16.17mm (λ/20 × λ/20). The antenna was designed and fabricated on Arlon CuClad 250LX substrate. The RFID IC chip Alien Higgs 3 was soldered directly to the antenna and the read range of the prototype was measured, reaching 4 m. The measurements are in good agreement with simulated results.