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关键词： Sensors   Temperature sensors   Radiofrequency identification   Temperature measurement   Resonant frequency   Resonators   Mathematical model   Chipless   crack sensor   internet of things (IoT)   radio frequency identification (RFID)   sensor applications   temperature sensor   vertically polarized  

摘要： Nowadays, structural health monitoring and thermal contemplation of remote places are of serious significance. In this scenario, chipless radio frequency identification (RFID) sensors are the vital enablers to monitor remote circumstances in the low-cost pervasive network. This letter presents a compact 7-bit chipless RFID multiparameter sensor designed on smart Rogers RT/Duroid((R)) 6010.2LM material. The material alters its dielectric properties concerning temperature fluctuations. Six inverted "U" and "L" shaped resonators are designed with specific length and width to resonate within the desired frequency band of 2-8 GHz. A circular microstrip patch antenna is used for the characterization of the crack. The measurements are performed outside the anechoic chamber in an electromagnetically quiet environment. The realized novel smart sensor can be attached to monitor any crack in the metal surface, where temperature monitoring is also crucial. The proposed state-of-the-art robust multisensor is suitable for long-term applications.

关键词： absorbed dose   Gafchromic EBT3   gamma radiation   ID card   personal dosimetry   personnel monitoring   radiochromic film   RFID   X-ray  

摘要： Purpose: This paper is aimed at investigating the feasibility of developing a personal dosimeter of cumulative radiation dose which would incorporate the following features: 1) a small size compared to that of a proximity ID card;2) instant dose readout;3) no power source;4) moderate cost. The dosimeter is proposed as a potential replacement for TLD and OSL dosimeters used by nuclear industry workers and some medical staff groups. Methods: An original detector design is developed containing a two-color LED, two photodetectors located in one plane covered with a mirror coating. The power necessary for the operation comes from an RFID reader. A small (5x5 mm) piece of Gafchromic EBT3 photochromic film sensitive to both X-ray and gamma radiation is used as a sensor. Irradiation of samples under X-ray and gamma radiation is carried out in the dose range of 0.1 cGy-1 Gy. The transmittance spectra are measured in the 300 nm-1100 nm spectral range. Results: Several prototypes of the dosimeter are presented, the distinctive features of which are the absence of the power source, easy transmitting of the dosimetric data via a RF channel, and a slim form factor. Several sources of dose uncertainties are analyzed and ways to eliminate them are outlined. The average dose confidence interval (alpha = 0.05) calculated from the response curve is shown to equal 0.02 cGy. This makes it possible to reliably measure doses as low as 0.1 cGy, which corresponds to the minimum value claimed for Gafchromic EBT3. Conclusions: The proposed idea of an ID-card-size dosimeter is feasible and has a number of advantages over TLD and OSL dosimeters, in particular, instant reading of the dose data using RFID/NFC readers, and a possibility of integrating into ERP systems. (C) 2021 American Association of Physicists in Medicine

关键词： Metal-mountable   narrow footprint   RFID antenna   tag antenna   UHF tag antenna  

摘要： A slim and semi-flexible UHF RFID tag antenna, which has a compact dimension of 40 mm x 5 mm x 3.2 mm (0.1221 lambda x 0.0153 lambda x 0.0098 lambda), is proposed for tagging on metallic industrial tools with a narrow footprint. For a metal-mountable tag antenna, the unwanted electromagnetic antennametal interaction can deteriorate the tag read performances and it is particularly pronounced when the tag is attached to a narrow industrial tool. To achieve a size-reduction, the proposed tag is made of an inlay comprising a very compact 3-layer structure with two radiating patches. The currents on the top and middle patches can be made in phase for enhancing the radiated fields. Digital serrations, inductive stubs, and open slots loading have been studied for optimizing the antenna resonant frequency efficiently. With the use of the tuning mechanisms, when being tested on a narrow-body metal tool, the antenna impedance can be fully matched with the RFID microchip impedance, resulting in a good power transmission coefficient of similar to 1. Despite its compactness, the proposed tag antenna is readable from 11.0 m with an EIRP of 4W. To the best of our knowledge, the proposed tag antenna has a much better aspect ratio between its read distance and tag volume than most of the commercially available on-metal tags and it can be used for tagging on narrow metallic surfaces.

关键词： Antennas   Radiofrequency identification   Magnetic separation   Loaded antennas   Magnetic resonance   Transponders   Mathematical model   Magneto-inductive waveguide   near-field communication   RFID   travelling wave antenna  

摘要： Efforts to increase read range in passive HF RFID systems are hampered by the poor range scaling law of inductive coupling. An alternative approach to enlarging capture volume-increasing the lateral extent of the antenna-is proposed, using a magneto-inductive (MI) travelling wave arrangement to allow larger antenna sizes. A theory of load modulation in MI systems is first presented, together with field simulations in the capture volume. A 2.3 metre-long MI antenna is then constructed, and an active tag emulator is used to demonstrate load modulation. RFID is then demonstrated, with the antenna in both reflection and transmission modes, using a custom reader constructed from laboratory equipment. A transverse read range of 0.5 m is obtained using commercial off-the-shelf RFID cards with 10 W RF power, with high uniformity along the length of the antenna.

关键词： Authentication   IoT   Passive tag   RFID  

摘要： Internet of things (IoT) contains a massive number of “things” that are connected to the internet and communicates without human interaction. In these IoT devices, Radio frequency identification is used to detect the location of devices in communication networks. However, the RFID tag contains a low power battery and low memory capacity (i.e., few KB). Hence, it requires a lightweight or ultra-lightweight solutions for these RFID tags. This paper proposes a novel ultra-lightweight authenticate approach for a passive tag that uses XOR and rotate operations. This scheme contains three different phases: tag identification, mutual authentication, and pseudonyms and key updating phases. The first phase comprises the identification of the tag. After that, the second phase performs mutual authentication between the tag and the reader. The last phase involves the updating of the key between the tag and the reader. This scheme also defines the function “MIX” to enhance the security of the protocol. This scheme analyses in terms of communication cost between tag and reader, and storage cost for a passive tag. © 2021, Bharati Vidyapeeth's Institute of Computer Applications and Management.

关键词： Chipless tag   dual-CP   liquid differentiation   RFID   wideband  

摘要： To wirelessly differentiate specified liquid samples, this article presents a radio-frequency identification (RFID) front-end including wideband reader antenna with chipless tag. The proposed reader antenna employs left-handed circularly-polarized (LHCP) antenna for transmitter (Tx) and right-handed circularly-polarized (RHCP) antenna for receiver (Rx), to improve the Tx-Rx isolation and also liberate the orientation and polarization of chipless tags. This dual circularly-polarized (dual-CP) configuration also features wide bandwidths of impedance and axial ratio, by using sequentially-rotated structure. Moreover, the proposed chipless tag has three resonances, among them, one independent resonance provides a lookup table for fast and easy identification, and another two resonances can be used to reconfirm the identification results. For validation, dual-CP reader antenna array and chipless tag are numerically optimized, experimentally measured, and also in-vivo demonstrated to wirelessly differentiate liquid samples.

关键词： chipless RFID tags   conductive inks   industry laminates   screen printing   sintering temperature  

摘要： A chipless radio frequency identification (RFID) tag is a suitable low-cost alternative to any chip-based RFID one. The flexibility to use low-cost printing techniques makes chipless RFID a competitive technology. In this paper, we report an evaluation of the microwave performance of two different screen-printed chipless tags in the 3-6 GHz range. The tags were designed and screen printed on industry packaging laminates using nanoparticle conductive ink-paste supplied by ANP and InkTec companies. The measured microwave performance of tags was compared with simulated performance and printing parameters that influence the print quality, and eventually, the microwave response of the tags are discussed.

关键词： Machining   Radiofrequency identification   Employee welfare   Monitoring   Computational modeling   Data processing   error accumulation   error estimation   graphical models   machining   process control   production control   quality management   radio-frequency identification (RFID) tags  

摘要： Interpreting the mechanism of machining errors' accumulation (MEA) is hard in multistage machining processes. This article addresses a novel three-dimensional graphical model named RFID-MEA for quantitating MEA inspired by the radio-frequency identification (RFID) graphical deduction computing model. RFID-MEA aims at revealing the MEA's mechanism instead regarding the machining process as a traditional "black box" model. First, Taylor's second-order expansion is employed to advise the mathematical representation of MEA and its calculation formula. Then, RFID data are collected to bond the MEA formula's variables with certain data silos in the right type at the right time. After that, raw not only structured query language (NoSQL) data computing is executed in edge nodes for assigning values to variables of the MEA formula accurately. Finally, machining errors are estimated by solving the MEA formula. By illustrating an industrial case, it is shown that the RFID-MEA has better performance in estimating machining errors, as well as with higher reliability and interpretability.

关键词： Flexible electronics   Wireless communication   Radio frequency   Wireless sensor networks   Tactile sensors   RFID tags   Production  

摘要： Recently, the field of flexible electronics has received significant research attention, primarily in response to the growing market for lightweight and compact devices. The low-cost mass fabrication of these flexible-electronic printed products, such as RF identification (RFID) tags, wireless sensors, conductive tags and readers, touchpads for keyboards, and display applications, all require knowledge of additive production techniques and appropriate substrates.

关键词： IoT   RFID   Security   Confidentiality   Integrity   Availability   Authorization  

摘要： Internet of things (IoT) is made up of many devices like sensors, tags, actuators, mobile devices, and many more. These devices interact with each other without human interaction. Radio-frequency identification (RFID) devices are used to track people, assets, objects, etc. Along with the small memory capacity and low-power battery issues, these devices suffer from various security-related issues. These security threats include attacks such as replay, disclosure, tracking, offline guessing, denial of service attacks, and many more. In the last few decades, the researchers have suggested various security approaches to overcome these vulnerabilities. Hence, this paper discusses various possible attacks that can occur on an RFID system, and several security schemes that have been proposed to handle these attacks. First, the works presents the architecture of IoT in detail. Second, all possible attacks are described by categorizing them into confidentiality, integrity, and availability. Then, taxonomy of various security schemes, to deal with these attacks, is discussed under the criteria cryptography approaches, privacy, authentication, authorization, and availability. Finally, the paper describes various issues and challenges to have a better understanding of scope of the future research in the field of RFID security.