A low-profile FSS-based high capacity chipless RFID tag for sensing and encoding applications

Abstract

This paper presents a polarization-independent 11-bit chipless RFID tag based on frequency-selective surface which has been designed for encoding and relative humidity (RH) sensing applications. The 10 exterior U-shaped resonators are used for item encoding whereas Kapton has been incorporated with the interior resonator for RH sensing. This radio-frequency identification (RFID) tag operates in S- and C-frequency bands. The proposed design offers enhanced fractional bandwidth up to 88% with the density of 4.46 bits/cm2. Both single- and dual-layer tags have been investigated. The simulated results are in good agreement with measured results and a comparison with existing literature is presented to show the performance. Simple geometry, high code density, large frequency signature bandwidth, high magnitude bit, high radar cross-section, and angular stability for more than 75° are the unique outcomes of the proposed design. In addition, RH sensing has been achieved by integrating the Kapton on the same RFID tag.

Impact of dielectric substrates on chipless RFID tag performance

“…The tag was placed 70 cm distance ( d ) away from the probe in the z + direction. The distance “ d ” was calculated using equation (2), where “ D ” is the maximum dimension of tag and “ λ ” is the central wavelength (0.0952 m) of the used central operating frequency (3.15 GHz) [2]. In our proposed tag each side of the tag is 1.5 cm ( a = 15 mm); below calculation was used to find the maximum dimension ( D ) of the hexagonal shape tag [21], and distance ( d ) between probe and tag.…”

“…Equation (1) was used for calculating resonance frequencies (or slot size) for circular shape slots reported in [19]. The obtained values from equation (1) are not in accordance with simulated and measured values of hexagonal shape tag [2]. Probably this equation is designed only for “U-shape” tag.…”

“…All tags had the same geometry, which is 0.5 mm slot width and gapes between slots, except having different substrates. To observe and analyze the substrate impact on the tag's spectral signature, the designed tag's backscattered S 21 response was measured using the same setup as elaborated in [2]. The backscattered S 21 response presents the impact of different substrates in terms of shifts in spectral signatures.…”

“…Chipless radio frequency identification (C-RFID) technology is of increasing interest to both industry and academia due to its ability to track the object, monitor object health, and various environmental parameters at low cost. The use of RFID tags in tracking systems, industry, telecommunication, commerce, and health monitoring has significantly increased due to their low cost, simple circuitry, and data-sensing abilities [1,2]. Additionally, sensors have been reported [3] for monitoring environmental parameter variations such as temperature, ambient humidity, pressure, gas, strain, and crack sensing.…”

High capacity chipless RFID tags for biomass tracking application

“…A radio-frequency identification (RFID) tag is a wireless data-capturing device that utilizes radio frequency (RF) signal power for recognition of remotely located objects. It has various advantages over barcode technology [8, 9], such as long-read range, no need for line-of-sight detections, and automatic identification.…”