433 research outputs found

    Antenna Design for Semi-Passive UHF RFID Transponder with Energy Harvester

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    A novel microstrip antenna which is dedicated to UHF semi-passive RFID transponders with an energy harvester is presented in this paper. The antenna structure designed and simulated by using Mentor Graphics HyperLynx 3D EM software is described in details. The modeling and simulation results along with comparison with experimental data are analyzed and concluded. The main goal of the project is the need to eliminate a traditional battery form the transponder structure. The energy harvesting block, which is used instead, converts ambient energy (electromagnetic energy of typical radio communication system) into electrical power for internal circuitry. The additional function (gathering extra energy) of the transponder antenna causes the necessity to create new designs in this scope

    Definition, Characteristics and Determining Parameters of Antennas in Terms of Synthesizing the Interrogation Zone in RFID Systems

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    The radio frequency identification (RFID) systems are gaining in popularity in automated processes of object identification in various socioeconomic areas. However, despite the existing belief, there is no universal RFID system on the commercial market that could be used in all user applications. All components of a developed solution should be carefully selected or designed according to the specification of objects being recognized and characteristics of their environment. In order to determine parameters of propagation or inductively coupled system, especially when it is dedicated to uncommon applications, a multiaspect analysis has to be taken into consideration. Due to complexity, the problem is reduced to analytical or experimental determination of RFID system operation range and a “trial and error” method is mostly used in the industry practice. In order to cope with the barriers existing in the RFID technology, the authors give the review of latest achievements in this field. They focus on the definition, comprehensive characteristics and determination of the antenna parameters. They also pay attention to the 3D interrogation zone (IZ) that is the main parameter in which multitude technical aspects of the RFID systems are gathered simultaneously, as regards the theoretical synthesis as well as market needs

    UHF Power Transmission for Passive Sensor Transponders

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    Passive transponder tags operating in the ultra high frequency (UHF) range receive their power supply from the electromagnetic carrier wave from a remote base station. The maximum range is largely determined by the circuits’ current consumption and the rectifier efficiency. Reading ranges of several meters have recently been reported for several state of the art RFID (Radio frequency IDentification) tags [1]. The presented UHF transponder chip with integrated temperature sensor was designed for a 0.35 ?m CMOS process with EEPROM, Schottky diodes, and double poly layers. Due to a more complex architecture and additional functionality, the power consumption of the presented sensor transponder tag is significantly larger than that of simple RFID tags. The A/D conversion requires a stable, ripple-free supply voltage with a relatively large DC value. A novel rectifier circuit generates the supply voltage from the high frequency antenna signal. The circuit requires only -11.4 dBm input power and is insensitive to temperature and process variations. The maximum operating distance is approximately 4.5 m

    Spatial Identification Methods and Systems for RFID Tags

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    DisertačnĂ­ prĂĄce je zaměƙena na metody a systĂ©my pro měƙenĂ­ vzdĂĄlenosti a lokalizaci RFID tagĆŻ pracujĂ­cĂ­ch v pĂĄsmu UHF. Úvod je věnovĂĄn popisu současnĂ©ho stavu vědeckĂ©ho poznĂĄnĂ­ v oblasti RFID prostorovĂ© identifikace a stručnĂ©mu shrnutĂ­ problematiky modelovĂĄnĂ­ a nĂĄvrhu prototypĆŻ těchto systĂ©mĆŻ. Po specifikaci cĂ­lĆŻ disertace pokračuje prĂĄce popisem teorie modelovĂĄnĂ­ degenerovanĂ©ho kanĂĄlu pro RFID komunikaci. Detailně jsou rozebrĂĄny metody měƙenĂ­ vzdĂĄlenosti a odhadu směru pƙíchodu signĂĄlu zaloĆŸenĂ© na zpracovĂĄnĂ­ fĂĄzovĂ© informace. Pro Ășčely lokalizace je navrĆŸeno několik scĂ©náƙƯ rozmĂ­stěnĂ­ antĂ©n. Modely degenerovanĂ©ho kanĂĄlu jsou simulovĂĄny v systĂ©mu MATLAB. VĂœznamnĂĄ část tĂ©to prĂĄce je věnovĂĄna konceptu softwarově definovanĂ©ho rĂĄdia (SDR) a specifikĆŻm jeho adaptace na UHF RFID, kterĂĄ vyuĆŸitĂ­ bÄ›ĆŸnĂœch SDR systĂ©mĆŻ značně omezujĂ­. DiskutovĂĄna je zejmĂ©na problematika prĆŻniku nosnĂ© vysĂ­lače do pƙijĂ­macĂ­ cesty a poĆŸadavky na signĂĄl lokĂĄlnĂ­ho oscilĂĄtoru pouĆŸĂ­vanĂœ pro směơovĂĄnĂ­. PrezentovĂĄny jsou tƙi vyvinutĂ© prototypy: experimentĂĄlnĂ­ dotazovač EXIN-1, měƙicĂ­ systĂ©m zaloĆŸenĂœ na platformě Ettus USRP a antĂ©nnĂ­ pƙepĂ­nacĂ­ matice pro emulaci SIMO systĂ©mu. ZĂĄvěrečnĂĄ část je zaměƙena na testovĂĄnĂ­ a zhodnocenĂ­ popisovanĂœch lokalizačnĂ­ch technik, zaloĆŸenĂœch na měƙenĂ­ komplexnĂ­ pƙenosovĂ© funkce RFID kanĂĄlu. Popisuje ĂșzkopĂĄsmovĂ©/ĆĄirokopĂĄsmovĂ© měƙenĂ­ vzdĂĄlenosti a metody odhadu směru signĂĄlu. Oba navrĆŸenĂ© scĂ©náƙe rozmĂ­stěnĂ­ antĂ©n jsou v zĂĄvěru ověƙeny lokalizačnĂ­m měƙenĂ­m v reĂĄlnĂœch podmĂ­nkĂĄch.The doctoral thesis is focused on methods and systems for ranging and localization of RFID tags operating in the UHF band. It begins with a description of the state of the art in the field of RFID positioning with short extension to the area of modeling and prototyping of such systems. After a brief specification of dissertation objectives, the thesis overviews the theory of degenerate channel modeling for RFID communication. Details are given about phase-based ranging and direction of arrival finding methods. Several antenna placement scenarios are proposed for localization purposes. The degenerate channel models are simulated in MATLAB. A significant part of the thesis is devoted to software defined radio (SDR) concept and its adaptation for UHF RFID operation, as it has its specialties which make the usage of standard SDR test equipment very disputable. Transmit carrier leakage into receiver path and requirements on local oscillator signals for mixing are discussed. The development of three experimental prototypes is also presented there: experimental interrogator EXIN-1, measurement system based on Ettus USRP platform, and antenna switching matrix for an emulation of SIMO system. The final part is focused on testing and evaluation of described positioning techniques based on complex backscatter channel transfer function measurement. Both narrowband/wideband ranging and direction of arrival methods are validated. Finally, both proposed antenna placement scenarios are evaluated with real-world measurements.

    Baseband-processor for a passive UHF RFID transponder

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    This paper describes the design of a digital processor targeting the Class-1 Generation-2 EPC Protocol for UHF RFID transponders, and proposes different techniques for reducing its power consumption. The processor has been implemented in a 0.35ÎŒm CMOS technology process using automatic tools for both the logic synthesis and layout. Post-layout simulations confirm the fully functionality of the prototype and predict a worst-case power consumption of only 2.9ÎŒA at 1.2V supply.Ministerio de EducaciĂłn y Ciencia TEC2006-03022, TEC2009-08447Junta de AndalucĂ­a TIC-0281

    Smart RFID Tags

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    Embedded system for networked real-time RFID reader

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    Erilaisia tuotantoprosessiin liitettÀviÀ jÀljitettÀvyysketjuja on kÀytössÀ useilla eri teollisuudenaloilla. JÀljitettÀvyydellÀ pyritÀÀn sekÀ parantamaan tuotantoprosessia ettÀ liittÀmÀÀn enemmÀn prosessitietoa itse lopputuotteeseen. Huomattavista sÀÀstömahdollisuuksista huolimatta koko puunjalostusprosessin kattavaa jÀljitettÀvyyttÀ ei metsÀteollisuuteen ole kuitenkaan toteutettu. TÀmÀ diplomityö on toteutettu osana suurta kansainvÀlistÀ Indisputable Key -projektia, jossa tÀhdÀtÀÀn puutavaran jÀljitettÀvyyden parantamiseen ja jÀljitettÀvyystiedon hyödyntÀmiseen kÀytÀnnössÀ. TÀssÀ työssÀ suunnitellaan ja toteutetaan RFID lukijan sulautettu jÀrjestelmÀ. RFID-lukija suunnitellaan VTT:llÀ, ja sitÀ kÀytetÀÀn metsÀkoneen harvesteripÀÀssÀ osana puutavaran jÀljitettÀvyysketjua. KÀyttöympÀristö ja -tarkoitus asettavat RFID-lukijalle ja sulautetulle jÀrjestelmÀlle vaatimuksia sekÀ kommunikointiin ja kÀytettyihin rajapintoihin ettÀ myös radiotaajuisen elektroniikan hallintaan. Toteutettu sulautettu jÀrjestelmÀ hoitaa RFID-lukijan kommunikoinnin isÀntÀjÀrjestelmÀn kanssa kÀyttÀen metsÀkoneen CAN-vÀylÀÀ. LisÀksi myös sarjamuotoinen kommunikointi toteutetaan lukijan testaamista ja esittelyÀ varten. SekÀ isÀntÀ-lukija-rajapinnassa ettÀ ilmarajapinnassa kommunikoinnissa sulautetun jÀrjestelmÀn ja muun jÀljitettÀvyysketjun vÀlillÀ hyödynnetÀÀn yleisesti laajassa kÀytössÀ olevia RFID-standardeja. LisÀksi sulautettu jÀrjestelmÀ hoitaa RFID-lukijan sisÀistÀ toimintaa ja elektroniikan hallinnan. Työn tuloksena saadaan sulautettu jÀrjestelmÀ, joka on testaamalla ja mittaamalla todettu sopivaksi kÀytettÀvÀksi Indisputable Key -projektissa ja metsÀkoneessa. RFID-lukijaa, johon sulautettu jÀrjestelmÀ toteutetaan, hyödynnetÀÀn Indisputable Key -projektin laajan mittakaavan testeissÀ, jotka on suunniteltu suoritettaviksi talvella 2009-2010.Traceability chains are used in multiple industrial fields to gather more knowledge about the manufacturing processes and, also, to link gathered data to the final product. Although, significant savings would be possible also in Forestry, no complete traceability chain yet exists. This thesis is written as a part of a large international Indisputable Key project that aims to improve the traceability in Forestry leading to economical and environmental improvements in the wood processing. In this thesis an embedded system for an RFID reader is designed and implemented. The RFID reader is designed at VTT to be used in a forest harvester head as a part of the wood material traceability chain. Using environment and purpose set requirements for the reader and the embedded software in terms of networking possibilities and used communication interface standards as well as electronics control. The designed embedded system handles the host communication to the rest of the traceability system via the forest harvester CAN network, but, also, additional serial line interface for host communication is implemented and used for testing and demonstration purposes. Embedded system of the reader handles both host and air interface communication through widely used EPCglobal RFID protocols. In addition to the networking and host and tag communication interfaces, the embedded system controls the inner operation of the RFID reader and RF electronics. Harvester head, where the RFID reader is utilized, limits the use of normal RF designs and sets requirements also for the RF electronics control. The result of the thesis is an embedded system that is tested and measured to be suitable for the use in the Indisputable Key and the forest harvester. RFID reader is utilized in the Indisputable Key final demonstrations and large-scale testing that are scheduled to be conducted in Winter 2009-2010

    Thin Flexible Radio Frequency Identification Tags And Subsystems Thereof

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    Embodiments according to the present invention comprised RFID tags comprised of components disposed on a flexible conformal substrate. The substrate may be substantially transparent or opaque and the components may be comprised of organic electronic components. Components and circuits may be manufactured using thin-film deposition processes or by deposition of metal-containing inks using inkjet technology. Exemplary use of an embodiment according to the present invention is as a component in an on-vehicle radio-frequency (RF) automated toll system.Georgia Tech Research Corporatio

    Study on Analog Front End of Passive UHF RFID Transponder

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    In this paper, an overview of passive Ultra High Frequency (UHF) Radio Frequency Identification (RFID) is presented. This literature review emphasis on the analog front end part of the RFID transponder based on several published papers conducted by previous researchers. A passive UHF RFID transponder chip design was proposed using 0.18 ÎŒm standard CMOS process. It is estimated to have power of 1ÎŒW and high efficiency that greater than 32%. This design will work in the range of frequency between 900MHz to 960MHz

    Analysis and design of UHF and millimetre wave radio frequency identification

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    Radio frequency identification (RFID) is an asymmetric radio protocol, where uplink communication (from transponder to reader) is implemented with backscattering modulation. The idea was first demonstrated in the 1940's. One of the first consumer applications of RFID was access control, and key cards based on an inductive near field coupling are widely used even today. The introduction of Schottky diodes to CMOS processes enabled passive RFID, i.e. transponders without a battery, at ultra high frequencies (UHF) with reasonable cost and read range in the end of 1990's. This has opened up new applications and inspired new research on RFID. This thesis studies the radio frequency (RF) components and general RF phenomena in RFID at UHF and millimetre waves. The theoretical analysis of the radio path reveals that the read range of a passive UHF system is ideally limited by the downlink, i.e. the power transfer from reader to the transponder. However, the architecture of the reader RF front end is critical, because the transmitted signal may couple a significant amount of noise to the receiver, overpowering the faint reflection from the transponder. In the thesis, two adaptive RF front ends are introduced to eliminate the noise coupling from the transmitter. One of the most critical problems with UHF RFID has been the detuning of transponder antennas on different mounting platforms. The detuning may significantly diminish the read range of the transponder, especially on metal surfaces. In this thesis, two backscattering-based measurement techniques for the transponder antennas are presented. The detuning effect has been studied using these measurement techniques, and a platform tolerant antenna is introduced. RFID at millimetre waves enables miniaturisation of the reader antenna, and widening the data bandwidth over short distances. This could be used to access wirelessly mass memories with wide data bandwidth. A semi-passive or active transponder could communicate, e.g., with automotive radars. The millimetre wave identification (MMID) has been theoretically studied and experimentally verified at 60 GHz
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