Analysis of the Split Ring Resonator (SRR) Antenna Applied to Passive UHF-RFID Tag Design

Abstract

Abstract-An electrically small planar passive UHF-RFID tag based on an edge-coupled split ring resonator (EC-SRR) antenna is presented in this work. In order to explore the potentiality and limitations of the SRR antenna and to aid the tag design, an analytical study of the SRR radiation properties at its fundamental resonance is presented for the first time. Radiation resistance, efficiency, polarization, bandwidth and impedance matching with the RFID ASIC are treated in the study. Based on such analysis, the tag design process is presented, and a tag prototype of size 30 mm × 30 mm (λ 0 /11 × λ 0 /11) is designed to operate in the North-American UHF-RFID band (902−928 MHz) and manufactured. The measured read range is in good agreement with the simulation, and reaches 9.3 m at 911 MHz. The tag also features a mitigation of the blind spots, providing a minimum measured read range of 4.2 m.Index Terms -Split ring resonators (SRRs), electrically small antennas (ESAs), radio frequency identification (RFID).

On‐metal UHF‐RFID passive tags based on complementary split‐ring resonators

“…Therefore, a resonance between the antenna and the ASIC is expected just below the CSRR resonance, in the resonator inductive region. At that frequency, the matching level depends on the ratio between Gc and Ga, which varies as a function of the position φp of the input port along the slot, as already reported in the case of moving the input port along the SRR ring [10]. Concretely, the NB-CSRR input conductance is raised when moving the port towards the ends of the slot, so that it is possible to obtain good impedance matching without introducing any a matching network.…”

“…matching and the radiation properties of reader [3][4][5] and tag [6][7][8][9][10] antennas. Also, their complementary counterparts, especially the complementary split-ring resonator (CSRR) and other structures derived from it, were used to obtain compact RFID tags, as follows.…”

A novel reverse design method of tag antenna based on image analysis

“…The size of antenna impedance can be known ð1 þ aÞ 2 Z A and Z t determined by equation (3). The impedance between the antenna and the chip is Z A and the impedance between the impedance loop and the antenna is Z t .…”

“…At present, the main research contents of UHF RFID tags are focused on RFID system application design, 1 tag chip research, and antenna optimization design. In terms of antenna design, it mainly focuses on the improvement of antenna performance, 2,3 such as antenna and chip impedance matching, 4 increasing the tag bandwidth and reducing the return loss. Although there are many UHF antenna structures, the main research object is the dipole tag antenna.…”

Passive UHF RFID Tags with Specific Printed Antennas for Dielectric and Metallic Objects Applications

“…In accordance to the literature, various configurations have been employed for the design of passive tag antennas, which aim at both satisfactory gain and matching to the IC be achieved: antennas, of simple dipole or monopole type [5], [6], of meandered line shape [7][8][9][10], of fractal shape [11][12][13][14], of metamaterial-inspired type [15][16][17] or based on Split Ring Resonator (SRR) concept [18]. Recently, published works for RFID tag antenna design propose coupled shorted patches, configured as step-impedance sections and being suitable for dielectric and metallic hosts [19].…”