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关键词： Cellular automata   chipless RFID   fractal tags   game of life  

摘要： In this paper, we propose a novel design of low-profile fractal chipless tags with unique specific electromagnetic responses. The tags are designed using cellular automata (Game of Life) technique to ensure the randomness of the generated fractal tags. The tags are simulated in CST Microwave Studio for the frequency range of 2 to 10 GHz. The tags are realized on FR4 substrate and their radar cross-section (RCS) characteristics are analyzed for the nine different tags for the three different polarizations (horizontal, vertical, and oblique). Each tag shows a unique signature resonance response. The obtained results of coding capacity (16-20 bits), coding spatial capacity (1-1.25 bits/cm(2)), coding spectral capacity (2.15-2.9 bits/GHz), and coding density (0.15-0.18 bits/GHz x cm(2)) of realized tags are very good. The presented tags could be used for the development of secure RFID systems. In this paper, we propose a novel design of low-profile fractal chipless tags with unique specific electromagnetic responses. The tags are designed using cellular automata (Game of Life) technique to ensure the randomness of the generated fractal tags. The tags are simulated in CST Microwave Studio for the frequency range of 2 to 10 GHz. The tags are realized on FR4 substrate and their radar cross-section (RCS) characteristics are analyzed for the nine different tags for the three different polarizations (horizontal, vertical, and oblique). Each tag shows a unique signature resonance response. The obtained results of coding capacity (16-20 bits), coding spatial capacity (1-1.25 bits/cm(2)), coding spectral capacity (2.15-2.9 bits/GHz), and coding density (0.15-0.18 bits/GHz x cm(2)) of realized tags are very good. The presented tags could be used for the development of secure RFID systems.

关键词： capacitors   miniaturised circularly polarised antennas   dispersion-engineered metamaterial transmission lines   UHF band RFID application   Antenna accessories   electromagnetic wave polarisation   microstrip-slot coupling excitation   metamaterial antennas   microstrip antennas   positive resonance-based antennas   CP antenna   CRLH-TL   dispersion curve   CP radiation   polarisation reconfigurable antenna   RFID systems   metal-insulator-metal capacitor   metamaterial-based antennas   frequency 902 MHz to 928 MHz   Single antennas   broadband antennas   transmission lines   antenna radiation patterns   metallic screws   crossed CRLH-TLs   UHF antennas   antenna feeds   radiofrequency identification  

摘要： Miniaturised circularly polarised (CP) antennas based on dispersion-engineered metamaterial transmission lines (TLs) are proposed and developed for RFID applications. It is first studied and developed based on the equivalent circuit and dispersion curves of composite right/left-handed TL (CRLH-TL), which is featured by a novel/low-cost double-layered 3D structure, including metallic screws, one ground layer and metal-insulator-metal (MIM) capacitor loaded on the top layer. CP radiation is achieved by two crossed CRLH-TLs with a microstrip-slot coupling excitation. One CP antenna and one polarisation reconfigurable antenna, which utilise CRLH-TLs are then implemented, respectively. Compared with the conventional right-handed (RH) TL-based antennas (positive resonance-based antennas), miniaturisation is achieved by pushing down the dispersion curve to a lower frequency using larger LH capacitance or/and inductance. Negative-order resonances could be successfully excited by cascading pi-type unit-cells. It shows similar radiation characteristics and additional size reduction as the positive resonance-based antennas. This antenna shows an electrical size of 0.24 lambda(0) x 0.24 lambda(0) x 0.03 lambda(0), a -10 dB bandwidth of 4.8%, and a peak gain of 4.2 dBic. It demonstrates advantages in terms of flexible size reduction, low cost, easy manufacturing, and good radiation performance, which are very suitable for 902-928 MHz UHF band RFID application.

关键词： Resonators   Antennas   Radiofrequency identification   Antenna measurements   Semiconductor device measurement   Scattering parameters   Resonant frequency   Chipless RFID   orientation sensor   RCS   scatterer   UWB  

摘要： This article presents a new reading method which is able to decode the backscattered signal of a chipless tag without any assumption on its orientation. The method is analytically justified by a model and can be applied to any known scatterers or chipless tags composed of multiple resonators. The presented approach is based on two orthogonal measurements in co-polarization on the reader part and can be optionally combined with time gating. Finally, read range is not reduced with this method since the entire energy of the chipless tag's antenna mode is exploited by the reader.

关键词： RFID   IoT   Mutual authentication   Lightweight  

摘要： Sensors and IoT (Internet of Things), which include RFID (Radio-Frequency IDentification) tags, have witnessed widespread adoption across a wide variety of application domains over the last two decades. These sensors and IoT devices are often a part of distributed sensor networks. As with any distributed processing scenario, there is a need to ensure that these devices provide required security and privacy to the tagged object as well as its bearer. Cryptography has been used to address the security and privacy aspects of RFID tags. Unlike a majority of other IoT devices, the commonly used passive RFID tags are extremely resource-constrained and therefore can accommodate only lightweight operations. Security and privacy concerns still need to be addressed as they remain significant regardless of implementation details. We evaluate RFID-based lightweight mutual authentication protocols that have been recently proposed and identify vulnerabilities.

关键词： Authentication   RFID   Wireless Body Area Network (WBAN)   Internet of Things (IoT)   Elliptic Curve Cryptography (ECC)  

摘要： Nowadays, Internet of Things (IoT)-based E-healthcare represents an emergent research field due to the fast development of wireless technologies and cloud computing. Radio Frequency Identification (RFID) is an integral technology in IoT thanks to its low cost and autonomous data collection and transfer. These features made it useful in Wireless Body Area Network (WBAN) for healthcare applications. However, data security and patient privacy remain major challenges in WBANs. In this context, many authentication protocols have been designed trying to satisfy both security and implementation requirements. Most recently, Naeem et al. have proposed an RFID authentication scheme for IoT which is claimed to be secure and provides scalability. Unfortunately, we have found that their protocol does not provide authentication and anonymity and it is vulnerable to numerous attacks. To overcome these security issues, we propose, in this paper, an efficient extended and improved IoT-based RFID authentication scheme for WBANs. Our proposed protocol could resist to various attacks and ensure mutual authentication from the tag to the medical server, in addition to patients data security. For this, elliptic curve cryptography (ECC) encryption mechanism and elliptic curve digital signature with message recovery (ECDSMR) have been adopted. Formal and informal analysis have proved that our proposed protocol succeeded to provide many security features and offer reliable data security with a considerably small computational and storage cost compared to existing schemes.

关键词： smart technologies   smart hangar   technical condition monitoring   UAV   RFID  

摘要： The new progressive smart technologies announced in the fourth industrial revolution in aviation-Aviation 4.0-represent new possibilities and big challenges in aircraft maintenance processes. The main benefit of these technologies is the possibility to monitor, transfer, store, and analyze huge datasets. Based on analysis outputs, there is a possibility to improve current preventive maintenance processes and implement predictive maintenance processes. These solutions lower the downtime, save manpower, and extend the components' lifetime;thus, the maximum effectivity and safety is achieved. The article deals with the possible implementation of an unmanned aerial vehicle (UAV) with an infrared camera and Radio Frequency Identification (RFID) as two of the smart hangar technologies for airframe condition monitoring. The presented implementations of smart technologies follow up the specific results of a case study focused on trainer aircraft failure monitoring and its impact on maintenance strategy changes. The case study failure indexes show the critical parts of aircraft that are subjected to damage the most. The aim of the article was to justify the need for thorough monitoring of critical parts of the aircraft and then analyze and propose a more effective and the most suitable form of technical condition monitoring of aircraft critical parts. The article describes the whole process of visual inspection performed by an unmanned aerial vehicle (UAV) with an IR camera and its related processes;in addition, it covers the possible usage of RFID tags as a labeling tool supporting the visual inspection. The implementations criteria apply to the repair and overhaul small aircraft maintenance organization, and later, it can also increase operational efficiency. The final suggestions describe the possible usage of proposed solutions, their main benefits, and also the limitations of their implementations in maintenance of trainer aircraft.

关键词： Ultra-High Frequency (UHF) RFID tag antenna   Impedance matching   Magnetic coupling   Dual resonance  

摘要： A novel low-profile metal mountable UHF RFID tag antenna is presented. The tag antenna design consists of two resonating patches with different resonant frequencies fed through a joint inductive loop. This design topology offers benefits such as bandwidth enhancement in the single band and the possibility of attaining a tunable dualband coverage in the UHF RFID band. The proposed antenna structure doesn't require any electrical connection (shorting pins/shorting plates/via holes) and therefore facilitates fabrication through a conventional RFID inlay manufacturing process. Fabrication and testing of a prototype of the proposed antenna design are carried out. The prototype antenna achieves free space and an on-metal reading range of better than 8 m and 11 m respectively in the US RFID band of 902-928 MHz.

关键词： Security   IoT   WSN   RFID  

摘要： The Internet of Things (IoT) has garnered significant attention from people with growing changes in human life over the last few years. IoT is a network of a group of smart devices that use sensors to collect information and conduct events in their environments. The information can then be shared on the Internet. IoT uses a range of technologies and finds various applications such as smart homes, environmental monitoring, and healthcare. In this paper, we conducted a comparative study to analyze the difference between two technologies-Wireless Sensor Networks (WSNs) and Radio Frequency Identification (RFID). It is pertinent to note that these technologies would not be effective without incorporating security aspects due to a potential number of threats and attacks on the network. This paper provides a comprehensive review of the recent approaches to securing RFID and WSNs. We have carefully chosen most of these studies to investigate only the recent technique from 2017 to 2020. The paper also highlights common attacks on RFID and WSNs and the secure authentication mechanisms on these technologies. It further provides a different way of detecting varying attacks in RFID and WSNs.

关键词： Bit error rate   Resonators   Scattering   Clutter   Radar cross-sections   Standards   RFID tags   Bit error rate (BER)   chipless RFID   communication systems   frequency-selective surfaces (FSSs)   radar cross section (RCS)  

摘要： The performance of different chipless RFID tag topologies is analyzed in terms of radar cross section (RCS) and bit error rate (BER). It is shown that the BER is mainly determined by the tag RCS once a standard reading scenario is considered and a fixed size of the tag is chosen. It is shown that the arrangement of the resonators in the chipless tag plays a crucial role in determining the cross-polar RCS of the tag. The RCS of the tag is computed theoretically by using array theory where each resonator is treated as a separate scatterer completely characterized by a specific reflection coefficient. Several resonators arrangements (periodic and nonperiodic) are compared, keeping the physical area of the tag fixed. Theoretical and experimental analyses demonstrate that the periodic configuration guarantees the maximum achievable RCS, thus providing a global lower BER of the chipless RFID communication system. We believe that the BER is the more meaningful and fair figure of merit (FoM) for comparing the performance of different tags than bit/cm(2) or bit/Hz since the increase in encoded information of the tag is useful only if it can be correctly decoded.

关键词： RFID   real-time locating   traceability   postal services   big data   analytics  

摘要： In this paper, we propose an RFID-based location-positioning platform for managing cart operations at vast and fast-moving distribution facilities. Our work was motivated by a real-world problem in a large airmail center. Our system requires that each cart is affixed with an active RFID tag, and RFID readers are installed at multiple locations of the facility. The locations of the tagged carts are determined by the estimated angles of arrival communication signals between the readers and the tags and the signal strengths, and the information about their positions are stored in the platform continuously. This platform enables the users to locate tagged objects in real time, thereby saving staff members a significant amount of time from searching for the right carts in the highly dynamic environment. Consequently, the mail facility can benefit from the increased efficiency. Furthermore, the system is also able to reduce the chance of having a delay in delivering mail bags to unit load device (ULD) area and misplacements of mail bags to ULDs. We further analyze the the huge amount of historical data collected from the RFID infrastructure of the airmail center for the cart movements within the facility and observed previously unrecognized operational issues. We also discuss some of the challenges and problems faced in this project. We believe that this application can bring huge benefits to businesses and organizations along supply chains by effectively anticipating the increasing demand for logistics services in the age of electronic retailing.