251 research outputs found

    Performance Analysis of a Compact UHF RFID Ceramic Tag in High-Temperature Environments

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    In this paper an experimental analysis of the effect of high temperature on the performance of a compact UHF RFID tag is described and discussed. The tag is designed to be integrated into small cavities carved out of metal objects to identify themselves during the entire fabrication and assembly line. Since the UHF RFID tag is applied just after the die casting operations needed to model the metal component, it must be robust to high temperature manufacturing environments and processes. Tests demonstrated a significant chip input impedance variation by increasing the surrounding temperature, with a consequent read-range reduction. However, the considered ceramic tag can be detected at a satisfactory distance of 30 cm when employed with temperatures so high as up to 120 degrees C

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

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    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

    Passive low frequency RFID for non-destructive evaluation and monitoring

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    Ph. D ThesisDespite of immense research over the years, defect monitoring in harsh environmental conditions still presents notable challenges for Non-Destructive Testing and Evaluation (NDT&E) and Structural Health Monitoring (SHM). One of the substantial challenges is the inaccessibility to the metal surface due to the large stand-off distance caused by the insulation layer. The hidden nature of corrosion and defect under thick insulation in harsh environmental conditions may result in it being not noticed and ultimately leading to failures. Generally electromagnetic NDT&E techniques which are used in pipeline industries require the removal of the insulation layer or high powered expensive equipment. Along with these, other limitations in the existing techniques create opportunities for novel systems to solve the challenges caused by Corrosion under Insulation (CUI). Extending from Pulsed Eddy Current (PEC), this research proposes the development and use of passive Low Frequency (LF) RFID hardware system for the detection and monitoring of corrosion and cracks on both ferrous and non-ferrous materials at varying high temperature conditions. The passive, low cost essence of RFID makes it an enchanting technique for long term condition monitoring. The contribution of the research work can be summarised as follows: (1) implementation of novel LF RFID sensor systems and the rig platform, experimental studies validating the detection capabilities of corrosion progression samples using transient feature analysis with respect to permeability and electrical conductivity changes along with enhanced sensitivity demonstration using ferrite sheet attached to the tag; (2) defect detection using swept frequency method to study the multiple frequency behaviour and further temperature suppression using feature fusion technique; (3) inhomogeneity study on ferrous materials at varying temperature and demonstration of the potential of the RFID system; (4) use of RFID tag with ceramic filled Poly-tetra-fluoro-ethyulene (PTFE) substrate for larger applicability of the sensing system in the industry; (5) lift-off independent defect monitoring using passive sweep frequency RFID sensors and feature extraction and fusion for robustness improvement. This research concludes that passive LF RFID system can be used to detect corrosion and crack on both ferrous and non-ferrous materials and then the system can be used to compensate for temperature variation making it useful for a wider range of applications. However, significant challenges such as permanent deployment of the tags for long term monitoring at higher temperatures and much higher standoff distance, still require improvement for real-world applicability.Engineering and Physical Sciences Research Council (EPSRC) CASE, National Nuclear Laboratory (NNL)

    Design And Analysis Of Reconfigurable Sensing Antennas For Wireless Sensing Applications

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    Reconfiguration sensing antenna (rsa) is a novel antenna concept, which not only can transmit or receive radio waves but also can sense the surrounding environment. The environment sensing is realized by reconfiguring the antenna\u27s characteristics, such as resonant frequency, and radar cross section (rcs). The rsas possess the advantages of passive and low cost, which make them suitable for the large-scale wireless sensing networks (wsns) deployment. In this dissertation, the rsas concept is demonstrated, and two sensing mechanisms performed in the rsas are investigated. In order to verify these sensing mechanisms, four rsas are designed, analyzed, and measured. All the rsa designs in this dissertation are temperature monitoring rsas, and they realize the temperature sensing by reconfiguring the antenna resonant frequency. About the two sensing mechanisms, one utilizes the electrical properties of materials, and the other utilizes thermal properties of the materials. For each sensing mechanism, there are two rsa designs using different sensing materials. As sensing antennas, sensitivity is a crucial factor in the rsa designs. Thus, a sensitivity evaluation method is also defined in this dissertation. There are three factors used to evaluate the rsa performance, which are realized gain, and realized gain bandwidth. For the sensing mechanism using electrical properties of materials, water and high density polyethylene-ba0.3sr0.7tio3 (hdpe-bst) are investigated and selected as the sensing materials. Patch antennas are properly designed to easily implement these sensing materials as their substrate. Simulation and measurement results show that these two designs provide 4mhz/10â°c and 8mhz/10â°c frequency shift with temperature, respectively. Their realized gain is -3.2db with 4.33

    Design and development of novel radio frequency identification (RFID) tag structures

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    The objective of the proposed research is to design and develop a series of radio frequency identification (RFID) tag structures that exhibit good performance characteristics with cost optimization and can be realized on flexible substrates such as liquid crystal polymer (LCP), paper-based substrate and magnetic composite material for conformal applications. The demand for flexible RFID tags has recently increased tremendously due to the requirements of automatic identification in various areas. Several major challenges existing in today's RFID technologies need to be addressed before RFID can eventually march into everyone's daily life, such as how to design high performance tag antennas with effective impedance matching for passive RFID IC chips to optimize the power performance, how to fabricate ultra-low-cost RFID tags in order to facilitate mass production, how to integrate sensors with passive RFID tags for pervasive sensing applications, and how to realize battery-free active RFID tags in which changing battery is not longer needed. In this research, different RFID tag designs are realized on flexible substrates. The design techniques presented set the framework for answering these technical challenges for which, the focus will be on RFID tag structure design, characterization and optimization from the perspectives of both costs involved and technical constraints.Ph.D.Committee Chair: Tentzeris, Manos; Committee Member: DeJean, Gerald; Committee Member: Ingram, Mary; Committee Member: Kavadias, Stylianos; Committee Member: Laskar, Jo

    Development of Sensor Integrated and Inkjet-Printed Tag Antennas for Passive UHF RFID Systems

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    Radio frequency identification (RFID) is a form of automated identification technology that is nowadays widely used to replace bar codes in asset tracking and management. Looking ahead to the future, our lives will be surrounded by small, embedded and wireless electronic devices that provide information about everything for everybody through pervasive computing. At the core of this vision lie two key concepts of ubiquitous sensing and the Internet of Things. RFID technology is seen as one of the most prominent technologies of today for the implementation of these future concepts. Ubiquitous sensing describes a situation, where small embedded sensors monitoring various environmental parameters are found everywhere. The second concept, the Internet of Things, requires that all objects, even the most insignificant everyday items, surrounding us should encompass computing and communication capabilities of some sort. In its simplest form, such computing could be a transponder that allows the unique identification and tracking of the item. Together these future concepts could truly revolutionize our lives by delivering significantly more information from our living environment. The objectives of this thesis are twofold. Firstly, passive ultra-high frequency (UHF) RFID technology is utilized to develop low cost, completely passive, wireless sensor devices for ubiquitous sensing applications. Secondly, inkjet-printed passive UHF RFID tag antennas are developed and optimization techniques are presented to lower the cost of such tag antenna implementations. The latter objective aims to facilitate the advancement of the Internet of Things by enabling tag antennas to be directly printed on or in to various objects. As a result of the research work presented in this thesis, three different passive UHF RFID based sensor tags were developed. Two of these designs monitor temperature and one is developed for relative humidity measurements. For the first time, the applicability and accuracy of such passive sensor tags was demonstrated. The results show that UHF RFID sensor tags have potential to be utilized as low cost sensor devices in ubiquitous applications. In addition, this thesis presents methods to lower the costs of inkjet-printed tag antennas. A technique was developed to reduce the ink consumption significantly to produce high performance tag antennas. Moreover, a special type of tag antenna design consisting of very narrow lines was developed. Finally, novel electronic materials were used as tag antenna substrate materials for inkjet-printed tag antennas. The use of a high permittivity ceramic-polymer composite, wood veneer, paper and cardboard were demonstrated. In each case, it was shown that inkjet-printing is a feasible form of fabrication on such materials, producing passive UHF RFID tags with long read ranges. This shows that tag antennas can be inkjet-printed directly on to various items to advance the realization of the Internet of Things

    Wearable flexible lightweight modular RFID tag with integrated energy harvester

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    A novel wearable radio frequency identification (RFID) tag with sensing, processing, and decision-taking capability is presented for operation in the 2.45-GHz RFID superhigh frequency (SHF) band. The tag is powered by an integrated light harvester, with a flexible battery serving as an energy buffer. The proposed active tag features excellent wearability, very high read range, enhanced functionality, flexible interfacing with diverse low-power sensors, and extended system autonomy through an innovative holistic microwave system design paradigm that takes antenna design into consideration from the very early stages. Specifically, a dedicated textile shorted circular patch antenna with monopolar radiation pattern is designed and optimized for highly efficient and stable operation within the frequency band of operation. In this process, the textile antenna's functionality is augmented by reusing its surface as an integration platform for light-energy-harvesting, sensing, processing, and transceiver hardware, without sacrificing antenna performance or the wearer's comfort. The RFID tag is validated by measuring its stand-alone and on-body characteristics in free-space conditions. Moreover, measurements in a real-world scenario demonstrate an indoor read range up to 23 m in nonline-of-sight indoor propagation conditions, enabling interrogation by a reader situated in another room. In addition, the RFID platform only consumes 168.3 mu W, when sensing and processing are performed every 60 s
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