1,721,131 research outputs found
Circularly-polarized SIW antenna for novel backscattering-based X-band communication systems
No full textRFID-inspired backscattering modulation implemented over other technologies promises low-power identification and communication among things. Recently, the feasibility of RFID over 10.525 GHz Microwave Motion Sensor (MMS) has been proved through the design and realization of a prototype of both reader and transponder. The former was provided with a simple and not particularly miniaturized 4-element array of patch antennas. In this work, a compact 10.525 GHz antenna in SIW technology conceived for MMS-compatible X-band transponder is presented. Both antenna directivity and circular polarization have been optimized to guarantee a robust communication while saving power. The antenna shows a very satisfying performance, with a-10 dB input matching frequency bandwidth equal to 130MHz, high efficiency, and an Axial-Ratio 3 dB bandwidth of lower than 5%
Reduction of Power-Discretization Effects in UHF RFID Tag Performance Estimation Systems based on Off-The-Shelf Programmable Readers
No full textThe rigorous electromagnetic characterization of passive UHF radio-frequency identification (RFID) tags is a challenging task. Among various solutions, in a previous work an automatic tool for the over-The-Air evaluation of significant RFID tag metrics has been presented. Once fixed the distance, the system, based on the estimation of the minimum power emitted by the interrogating reader capable to energize the tag under test, has an accuracy that, although adequate, is limited by the minimum power step at the reader side. In this work, a new platform implementing a smart method to overcome this limit while preserving flexibility and cost-effectiveness, is presented, implemented and tested. The platform can automatically vary with continuity the interrogating distance-which becomes hence a new degree of freedom-and it is able to estimate for each frequency the couple power-distance which annuls the estimation error due to the power-discretization
Single-Chip Gen2-Compliant UHF RFID Sensor Tags Based on Novel Pseudo-BAP Mode
No full textIn this work a new design strategy for UHF RFID tags mounting RFID chips with embedded sensor is proposed. In particular, a novel functioning mode named 'Pseudo-BAP' is introduced to solve the electromagnetic 'filed-off' problem and to allow for a fully Gen2-compliant tag interrogating sequence to retrieve sensor data. In particular, a prototype of Pseudo-BAP-empowered Tag testing board has been designed, fabricated in FR4 and fully tested from the electromagnetic point of view. At the end, the proposed approach allows for the passive RFID-based temperature data collection from sensor-provided RFID chips by using standard RFID readers, and appreciable working distances as large as 1.75 m have been obtained with the considered low-sensitivity chip
Design of UHF RFID devices based on 3D-printing technology
No full text3D-printing technology promises high added value in many scientific contexts, including that of new materials for electromagnetics. The joint use with Radio Frequency Identification (RFID) technology is very appealing for designing new RFID-based smart devices while maintaining cost-effectiveness. In this work a T-Resonator structure for the dielectric characterization of substrates, including 3D-printed ones, is firstly presented. Both permittivity and loss tangent of PLA substrates have been measured in the UHF RFID band when varying the air percentage in the printed material. On the basis on the characterized substrates, a wearable bracelet tag and a Yagi-Uda-inspired long-range tag, which exploit the peculiarities of 3D-printing, have been designed, realized, and validated. © 2017 Univeristy of Split, FESB
Passive and Contactless Complex Power Monitoring of Electrical Systems
No full textMaintaining the reliability of electric power infrastructure is essential for preventing outages, optimizing system performance, and quickly detecting faults across diverse industrial applications. Traditional monitoring methods typically require direct contact with power lines, presenting significant safety issues and creating difficulties in accessing hard-to-reach or buried cables. In some scenarios, the dependency on batteries of these power-monitoring systems can limit their sustainability and reduce their actual applicability. In response to these challenges, this article presents a novel solution: a fully passive and contactless, electric power monitoring system with near field communication (NFC) interface. The proposed system integrates a custom-designed contactless flexible, curved, ac voltage sensor and a Rogowski coil for current detection, combined with a signal conditioning circuit and a digital processing unit. The sensory circuit is energized by the high-frequency signal generated by an NFC reader, which also handles data exchange with the system. Furthermore, the system has been modeled using SPICE software, and metrics for measuring complex power, phase shift, frequency, voltage, and current of electrical systems have been implemented directly on the hardware. Finally, a proof-of-concept has been developed and successfully tested on real electrical loads, demonstrating the system functionality[Figure Presented]
The promising role of 3D-printed dielectric resonator antennas in the IoT framework
No full textOne of the most demanding frameworks is that of IoT and mobile applications. This determines a growing need for miniaturization, asking for smaller and smaller devices capable of intercommunicating with different transmission technologies like, for example, Bluetooth, WiFi, and the near-to-come 5G. To fulfill this demand, Dielectric Resonator Antennas (DRAs) can be used for their compact size, wide-band behavior, and high efficiency. However, these antennas are also expensive and difficult to produce. At this regard, Additive Manufacturing could grant improvements of different kind going from the reduction of production costs to the possibility of realizing complex shapes not achievable with a traditional manufacturing process. In this paper, a first example of a new design for a 3D-printable DRA, operating from 2.45 GHz to 3.75 GHz and realizable with a low-cost FFF (Fused Filament Fabrication) 3D printer, is presented and discussed as well as the ongoing research activity on the matter, carried on at University of Salento
Considerations on rigorous UHF RFID tag electromagnetic performance evaluation in non-anechoic environments
No full textThe rigorous electromagnetic characterization of passive UHF radio-frequency identification (RFID) tags is a challenging task which has been much discussed in literature over the years. The solutions to faced it up are both commercial and lab-made, but both use the same analytical model to describe the environment where to perform the measurement. In this work, some considerations about how a new metric called Saw-Tooth profile, introduced in a previous work, could be used in order to estimate how well the mathematical model matches the real measurement scenario, is proposed, in order to allow for rapid and rigorous performance evaluation of UHF RFID tags even in nonanechoic environments. The appropriateness of the proposed approach is demonstrated by comparing theoretical data with measurement performed in both anechoic chamber and in different non-anechoic environments
Circularly polarized antenna in 3d printing technology to feed a wearable fully-integrated WiFi-RFID reader for biomedical applications
No full textIn this work, a compact, low-profile, portable RFID reader suitable for medical applications has been proposed and its antenna designed, realized and tested. Specifically, a circularly polarized UHF RFID reader antenna conformal to a dielectrically controlled plastic support is proposed. The radiating element has been realized through a circular array of four inverted-F monopoles, where the array elements are excited with a 90-degree phase offset (sequential rotation feeding technique) through a microstrip feeding network. To allow for a friendly prototype realization, the antenna structure is thought to be shaped on adhesive copper and the dielectric support to be 3D-printed in Poly-Lactic Acid (PLA), opportunely selected due to interesting low losses properties. The very compact antenna (60mm x 60mm x 6.5mm), suitable for the desired portable Reader, has been characterized in terms of reflection coefficient, port isolation and radiation patterns
Exploiting 3D-printing in passive UHF RFID electromagnetic projects
No full textIn this work, the appropriateness of the combination of 3D-printing and RFID is faced. Firstly, a T-Resonator for the dielectric characterization of substrates, including 3D-printed ones, is presented, and the dependence on the air percentage of both permittivity and loss tangent of PLA substrates has been found in the UHF RFID band. Then, a wearable bracelet tag and a Yagi-Uda-inspired long-range tag, which exploit the peculiarities of 3D-printinted substrates, have been designed, realized, and validated
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