Near-Field UHF RFID Transponder with a Screen-Printed Graphene Antenna

As a method of producing RFID tags, printed graphene provides a low-cost and eco-friendly alternative to the etching of aluminum or copper. The high resistivity of graphene, however, sets a challenge for the antenna design. In practice, it has led to using very large antennas in the UHF RFID far field tags demonstrated before. Using inductive near field as the coupling method between the reader and the tag is an alternative to the radiating far field also at UHF. The read range of such a near field tag is very short, but, on the other hand, the tag is extremely simple and small. In this paper, near field UHF RFID transponders with screen-printed graphene antennas are presented and the effect of the dimensions of the tag and the attachment method of the microchip studied. The attachment of the microchip is an important step of the fabrication process of a tag that has its impact on the final cost of a tag. Of the tags demonstrated, even the smallest one with the outer dimensions of 21 mm * 18 mm and the chip attached with isotropic conductive adhesive (ICA) was readable from a distance of 10 mm with an RF power marginal of 19 dB, which demonstrates that an operational and small graphene-based UHF RFID tag can be fabricated with low-cost industrial processes.Comment: 8 pages, 9 figures. IEEE Transactions on Components, Packaging and Manufacturing Technology, 201

Customizing 3D-Printing for Electromagnetics to Design Enhanced RFID Antennas

none5This document discusses some of the advances in additive manufacturing 3D-printing for electromagnetic applications that have been investigated in the literature in the last few years. Starting from the research activity of the authors on this topic, this work summarizes and showcases the effectiveness of the 3D-printing technology in electromagnetics, with reference to UHF RFID technology. Specifically, the first part of the work deals with Fused Deposition Modeling (FDM) printing technique and faces the problem of the characterization of 3D-printable materials using a made-in-lab instrument based on the T-Resonator theory, which has been purposely designed to be 3D-printed. Once verified the dielectric properties of substrates realized with common 3D-printable materials, two techniques to improve their electrical permittivity are explained. Moreover, the possibility to realize fully 3D-printed RFID devices based on the use of novel 3D-printable materials with noteworthy conductive properties is discussed. Then, two new 3D-printed antennas are presented and discussed highlighting some of the advantages of 3D-printing in electromagnetics. Finally, the application in RFID of another promising 3D-printing technology called Digital Light Processing (DLP) and based on the photopolymerization of liquid resins is discussed as well.openR. Colella ; F. P. Chietera ; F. Montagna ; A. Greco ; L. CatarinucciColella, R.; Chietera, F. P.; Montagna, F.; Greco, A.; Catarinucci, L

RFID Enabled Health Monitoring System for Aircraft Landing Gear

RFID has been used in the aviation industry to track and identify emergency equipment and other in-cabin assets on commercial aircraft for some time. Recently, the industry is looking to expand the use of RFID to more demanding parts and surfaces both inside and outside of an aircraft’s cabin, where RFID tags face much harsher conditions. The lLanding gear (LG) is one of the critical subsystems of an aircraft that plays an essential role in dispersing the energy of landing events and taxiing. Health monitoring of the LG has been suggested to help reduce both operational and maintenance costs, and extend the life of the LG beyond its current, fixed, designed service life. In this paper, we propose such a health monitoring system using a combination of active wired sensors and passive RFID tags. We present the measurement of UHF RFID tags on an aircraft landing gear using an aircraft-mounted fixed RFID reader. The results indicate that all major landing gear components and assemblies are shown to be identifiable by their EPC, and a 7 dB system margin has been achieved using 2 RFID reader antennas. Such a margin will tolerate degradations caused by harsh environments (e.g. low temperatures and high humidity) and enable update of information (e.g. flight count) to be stored on the RFID tags

RFID-based smart shelving storage systems

In recent years, RFID systems that are widely applied for the identification of objects and people in radio frequency, are also going to be applied used for localization purposes. In indoor applications (apartments, shopping malls, airports), conventional solutions can use a number of signal parameters: instant of arrival ( Time of Arrival , Time Difference of Arrival, TOA, TDOA), angle information (Angle of Arrival, AOA), phase information (Phase Difference of Arrival , PDOA ) or the amplitude of the received signal (Received Signal Strength Indicator, RSSI). There are also some scenarios with small dimensions where the location can be extremely useful. For example, in a hospital, a better service could be offered through RFID technology, as it can add more control to prevent human errors. Indeed, RFID technology can be useful for correct patient drug supply, dose recording, accurate dispensing, anti-counterfeiting as well as replenishment ordering; besides, it simplifies the information transfer between doctors and nurses (e.g. allergic reactions or drug treatment). In retail industry, real-time inventory based on RFID allows to monitor actual customer demand for products, to prevent an out-of-stock situation by timely replenishing orders, to increase sales through additional services (e.g. fitting rooms with smart mirrors providing suggestions to the customer). In food and restaurant industry, RFID technology allows for a better food control, as for example avoiding expired products sale. In this framework, RFID-based smart shelves, smart freezers, and proximity point readers have been developed in libraries, hospitals and retail industries. In Chapter I, a brief introduction on RFID systems will be presented, in particular describing the main components involved and the principle of operation. It will be described what is proposed in literature about RFID smart shelf and localization algorithms, with particular attention to the methods exploiting the RSSI information. In Chapter II, an exhaustive experimental study by using off-the-shelf reader, antennas and tags, will be presented with reference to a wooden drawer filled with drug boxes. The LDA algorithm (supervised classifier) will be compared with the K-Means clustering algorithm (unsupervised classifier), to validate the proposed method. The procedure to get several RSSI average samples during the drawer sliding actions is described, and classification performance is investigated. First of all, an RSSI analysis is described with reference to a static configuration of the drawer (not sliding). Then, two classification algorithms are compared by considering a different number of drawer sub-regions. In the second part, the algorithm exploiting the drawer sliding is described and system performance is illustrated to verify the classification capability in a two-region drawer. In Chapter III, a localization technique for smart bookshelves based on UHF-RFID systems is presented. Two off-the-shelf reader antennas attached to the bookshelf columns, one in front of the other, are used as an alternative to large-area thin planar antennas integrated onto the shelf top. Two scenarios were considered: the first one with a shelf that is D = 97 cm long, and the second one with D = 150 cm. Exploiting RSSI data acquired by the two antennas, a clustering algorithm is implemented to classify tagged books within one of the regions the shelf has been subdivided into. Preliminary results of the system performance analysis have been compared with simulations to demonstrate that is possible to create an interference region in different sectors on the shelf, through a proper phase shift between the feed currents of the two antennas. The system requires a power divider, a switch, variable phase shifters and finally a fixed or variable power attenuator based on the size of the shelf. In Chapter IV the algorithm implemented will be described and then the performance results (in terms of normalized confusion matrix) will be presented and discussed. Finally, a preliminary analysis has been presented considering different tags, even if it is still under developing

Characterization and Design Methodologies for Wearable Passive UHF RFID Tag Antennas for Wireless Body-Centric Systems

Radio Frequency Identification (RFID) is a wireless automatic identification technology that utilizes electrically active tags – low-cost and low-power wireless communication devices that let themselves transparently and unobstructively be embedded into everyday objects to remotely track information of the object’s physical location, origin, and ownership. At ultra-high frequencies (UHF), this technology uses propagating electromagnetic waves for communication, which enables the fast identification of tags at large distances. A passive RFID tag includes two main components; a tag antenna and an RFID integrate circuit (tag IC). A passive tag relies solely on the external power harvested from an incident electromagnetic wave to run its circuitry and for data transmission. The passiveness makes the tag maintenance-free, simple, and low-cost, allowing large-scale commercial applications in the supply chain, ticketing, and asset tracking. The future of RFID, however, lies in the transition from traditional embedded applications to wearable intelligent systems, in which the tags are seamlessly integrated with everyday clothing. Augmented with various ambient and biochemical sensors, the tag is capable of detecting physical parameters of its environment and providing continuous monitoring of human vital signs. Tremendous amount of tagged entities establish an intelligent infrastructure that is personalized and tailored to the needs of each individual and ultimately, it recedes into the background of our daily life. Although wearable tags in intelligent systems have the enormous potential to revolutionize the quality of human life, the emerging wearable RFID applications introduce new challenges for designers developing efficient and sophisticated RFID systems. Traditional tag design parameters and solutions will no longer respond to the new requirements. Instead, the whole RF community must adopt new methods and unconventional approaches to achieve advanced wearable tags that are highly transparently integrated into our daily life. In this research work, an empirical as well as a theoretical approach is taken to address the above-mentioned wearable RFID tag challenges. Exploiting new analysis tools in combination with computational electromagnetics, a novel technique to model the human body in UHF applications for initiating the design of optimized wearable tags is developed. Further, fundamental unprecedented UHF characteristics of advanced wearable electronics materials – electro-textiles, are established. As an extremely important outcome of this research work, innovative optimization methodologies for the promotion of novel and advanced wearable UHF antennas are proposed. Particularly, it is evidenced that proper embroidery fabrication techniques have the great potential to realize wearable tag antennas exhibiting excellent RF performance and structural properties for the seamless integration with clothing. The kernel of this research work is the realization of a flexible and fully embroidered passive UHF RFID patch tag prototype achieving optimized performance in close vicinity of the high-permittivity and dissipative human body. Its performance may be considered as a benchmark for future wearable antenna designs. This shows that this research work outcome forms an important contribution to the state of the art and a milestone in the development towards wearable intelligence

Wireless sensor system for infrastructure health monitoring

In this thesis, radio frequency identification (RFID)-based wireless sensor system for infrastructure health monitoring (IHM) is designed and developed. It includes mountable semi-passive tag antenna integrated sensors capable of measuring critical responses of infrastructure such as dynamic acceleration and strain. Furthermore, the system is capable of measuring structural displacement. One of the most important parts of this system is the relatively small, tunable, construction material mountable RFID tag antenna. The tag antenna is electronically integrated with the sensors. Leading to the process of developing tag antenna integrated sensors having satisfactory wireless performance (sensitivity and read range) when mounted on concrete and metal structural members, the electromagnetic performance of the tag antenna is analyzed and optimized using both numerical and experimental procedures. Subsequently, it is shown that both the simulation and the experimental measurement results are in good agreement. The semi-passive RFID-based system is implemented in a wireless IHM system with multiple sensor points to measure dynamic acceleration and strain. The developed system can determine the natural frequencies of infrastructure and identify any state changes of infrastructure by measuring natural frequency shifts. Enhancement of the spectral bandwidth of the system has been performed under the constraints of the RFID hardware. The influence of the orientation and shape of the structural members on wireless power flow in the vicinity of those members is also investigated with the RFID reader-tag antenna system in both simulation and experiments. The antenna system simulations with a full-scale structural member have shown that both the orientation and the shape of the structural member influence the wireless power flow towards and in the vicinity of the member, respectively. The measurement results of the conducted laboratory experiments using the RFID antenna system in passive mode have shown good agreement with simulation results. Furthermore, the system’s ability to measure structural displacement is also investigated by conducting phase angle of arrival measurements. It is shown that the system in its passive mode is capable of measuring small structural displacements within a short wireless distance. The benchmarking of the developed system with independent, commercial, wired and wireless measurement systems has confirmed the ability of the RFID-based system to measure dynamic acceleration and strain. Furthermore, it has confirmed the system’s ability to determine the natural frequency of an infrastructure accurately. Therefore, the developed system with wireless sensors that do not consume battery power in data transmission and with the capability of dynamic response measurement is highly applicable in IHM

Experimental validation of a SAR-Based RFID localization technique exploiting an automated handling system

The synthetic aperture radar (SAR) approach has attracted a considerable interest in the context of phase-based techniques for the localization of UHF-RFID passive tags. In this letter, the results of an extensive experimental activity are presented, when the reader antenna is moved in front of a set of static passive UHF-RFID tags by means of a planar handling system. Measured performance is evaluated with respect to several system parameters: tag number and typology, tag reciprocal distance and orientation, trajectory and speed of the moving reader antenna. It is shown that the SAR processing can guarantee an accurate two-dimensional localization of multiple tags, with a localization error comparable to the size of typical commercial tags, by using a single reader antenna and without the need for any reference tag

Chipless RFID sensor systems for structural health monitoring

Ph. D. ThesisDefects in metallic structures such as crack and corrosion are major sources of catastrophic failures, and thus monitoring them is a crucial issue. As periodic inspection using the nondestructive testing and evaluation (NDT&E) techniques is slow, costly, limited in range, and cumbersome, novel methods for in-situ structural health monitoring (SHM) are required. Chipless radio frequency identification (RFID) is an emerging and attractive technology to implement the internet of things (IoT) based SHM. Chipless RFID sensors are not only wireless, passive, and low-cost as the chipped RFID counterpart, but also printable, durable, and allow for multi-parameter sensing. This thesis proposes the design and development of chipless RFID sensor systems for SHM, particularly for defect detection and characterization in metallic structures. Through simulation studies and experimental validations, novel metal-mountable chipless RFID sensors are demonstrated with different reader configurations and methods for feature extraction, selection, and fusion. The first contribution of this thesis is the design of a chipless RFID sensor for crack detection and characterization based on the circular microstrip patch antenna (CMPA). The sensor provides a 4-bit ID and a capability of indicating crack width and orientation simultaneously using the resonance frequency shift. The second contribution is a chipless RFID sensor designed based on the frequency selective surface (FSS) and feature fusion for corrosion characterization. The FSS-based sensor generates multiple resonance frequency features that can reveal corrosion progression, while feature fusion is applied to enhance the sensitivity and reliability of the sensor. The third contribution deals with robust detection and characterization of crack and corrosion in a realistic environment using a portable reader. A multi-resonance chipless RFID sensor is proposed along with the implementation of a portable reader using an ultra-wideband (UWB) radar module. Feature extraction and selection using principal component analysis (PCA) is employed for multi-parameter evaluation. Overall, chipless RFID sensors are small, low-profile, and can be used to quantify and characterize surface crack and corrosion undercoating. Furthermore, the multi-resonance characteristics of chipless RFID sensors are useful for integrating ID encoding and sensing functionalities, enhancing the sensor performance, as well as for performing multi-parameter analysis of defects. The demonstrated system using a portable reader shows the capability of defects characterization from a 15-cm distance. Hence, chipless RFID sensor systems have great potential to be an alternative sensing method for in-situ SHM.Indonesia Endowment Fund for Education (LPDP