FSS inspired polarization insensitive chipless RFID tag

Abstract

A polarization insensitive, compact, fully-passive bit encoding structure exhibiting 1 : 1 resonator-to-bit correspondence is presented. Inspired by frequency selective surface (FSS) based microwave absorbers, the structure readily operates as a chipless radio frequency identification (RFID) tag. The unit cell is composed of several concentric hexagonal loops. Finite repetitions of the unit cell constitute the proposed RFID tag in its entirety. The required bit sequence is encoded in the frequency domain by addition or omission of corresponding nested resonant elements. A functional prototype is fabricated on a commercial-grade grounded FR4 substrate, occupying a physical footprint of 23 × 10 mm 2 while offering a capacity of 14 bits. The proposed tag boasts a minuscule profile, and demonstrates polarization insensitivity as well as stable oblique angular performance.

Novel Butterfly Slot Based Chipless RFID Tag

“…However, spectral efficiency (bits/GHz) is often not taken into consideration, that may result in high reader setup cost. Although, hexagonal loop resonator based tag [24] offers a slightly higher bit density, its spectral efficiency is less than half to that of the proposed design. Furthermore, it requires a wide band of 4-19 GHz that requires a more sophisticated setup to operate.…”

“…Although RCS based chipless RFID tags offer low-cost solution for mass production, enhancement of bit capacity and density are constrained due to multiple reasons, such as: limited operating frequency band [22], inter-resonator coupling [15], [21], and presence of higher order harmonics [23]. Although recently proposed RCS based chipless RFID tags [15,20,24] are compact having low production cost, spectral efficiency has not been taken into consideration. Operating over a wide band at higher frequencies requires advanced reading system, resulting in higher reader setup cost.…”

Novel QR-incorporated chipless RFID tag

“…Chipless variants of radio frequency identification (RFID) tags have received considerable research interest in recent past [2,3,4,5]. Both time domain [2] and frequency domain-based chipless RFID tags have been designed, with the latter encoding data in spectral domain and offering advantages such as ease of manufacturing, polarization insensitivity and design compactness [3,4,5]. QR codes and RFID tags, when unified, can act as an effective security contraption offering multi-layer authentication.…”

A novel miniaturized-element frequency selective surface with a second-order bandpass response

“…Frequency selective surface (FSS) is a one-dimensional or two-dimensional periodic structure with bandpass or bandstop spatial filtering properties which can propagate or prevent the electromagnetic wave through space. FSSs are widely used in many fields including radar cross section (RCS) reduction of the military objects, electromagnetic compatibility, microwave absorbers and lenses, reflectarrays, RFID tag and so on [1,2,3,4,5].…”