L'identification par radiofréquence constitue une technologie émergente et très prometteuse pour l'identification des biens et des personnes : automatisation des opérations manuelles, rapidité, informations précises...<br />Il existe plusieurs technologies RFID. Dans cette thèse, nous nous intéressons à la technologie UHF passive et plus particulièrement à la conception, caractérisation et fabrication des antennes de tags RFID. En 2007, il s'est vendu plus de 1,7 milliard de tags RFID. En vue de réduire le coût de ces derniers, nous abordons leur fabrication par une technique très prometteuse qui pourrait révolutionner l'électronique, le jet d'encre. Ces travaux s'appuient sur des simulations électromagnétiques et des mesures, et considèrent différents types d'antennes RFID.

Ultra high frequency (UHF) radio frequency identification (RFID) systems suffer from issues that limit their widespread deployment and limit the number of applications where they can be used. These limitations are: lack of a well defined read zone, interference, and environment sensitivity. To overcome these limitations a novel receiver device is introduced into the system. The use of such device or devices mitigates the issues by enabling more "anchor points" in the system. Two such devices exist in industry and academia: the Astraion Sensatag and the Gen2 Listener. The drawbacks of the Sensatag is that it offers poor performance in capturing tag signals. The Gen2 Listener is based on the expensive software defined radio hardware. The purpose of the thesis was to develop a receiver that will enable several new RFID applications that are not available with current RFID systems. The receiver, named ARR (Augmented RFID Receiver), receives tag and reader signals, which are decoded by an FPGA and the results are reported through Ethernet. This device is central to the augmented RFID system. To show the suitability of such an approach, the performance of the implementation was compared to the other two outlined solutions. A comparison of the read rate and range of the implementations were the defining factors. The analysis showed that the ARR is capable of receiving tag signals with a read rate of 50% for passive and 66% for semi-passive tags at a one meter distance and is capable of receiving tag signals at a maximum of 3.25 meters for passive and 5.5 meters for semi- passive tags, with the reader being within 8 meters of the ARR. Two applications were implemented to showcase the ARR: an RFID portal and protocol analyzer.

Doctor of Philosophy / Department of Electrical and Computer Engineering / William B. Kuhn / Design challenges and solution methods for Watt-level UHF CMOS power amplifiers are presented. Using the methods, a fully-integrated UHF (400MHz) CMOS power amplifier (PA) with more than 1-Watt output is demonstrated for the first time in Silicon on Sapphire (SOS) process. The design techniques are extended for a two-stage five-chip 5-Watt CMOS PA. In the 1-Watt PA, a differential stacked PMOS structure with floating-bias and a 1:3 turns-ratio output transformer are chosen to overcome low breakdown voltage (Vbk) of CMOS and chip area consumption issues at UHF frequencies. The high Q on-chip transformer on sapphire substrate enables the differential PA to drive a single-ended antenna effectively at 400 MHz. The PA is designed for a surface-to-orbit proximity link microtransceiver, used on Mars exploration rovers, aerobots and small networked landers. In a standard package the PA delivers 30 dBm output with 27 % PAE. No performance degradation was observed in continuous wave (CW) operation with various output terminations and the PA was tested to 136 % of its nominal 3.3 V supply without failure. Stability analysis and measurements show that the PA is stable in normal operation. It is also shown that the PA is thermally reliable. In the microtransceiver circuits, the PA works in conjunction with transmit/receive (TR) switch to allow nearly the full 1-Watt to reach the antenna. The 1-Watt PA design is also leveraged to demonstrate a power-combined two-stage five-chip PA. The 1-Watt PA’s output balun is modified for the four-transformer combining. Four identical chips are wire-bonded in the output stage and the fifth identical chip is added as a drive-amplifier. Despite low efficiency due to damaged bias circuits, the PA provides 5-Watt output power (37 dBm) at 480 MHz with 17 % PAE with 17 dB gain. The PA layout is carried out considering full integration on a 7×10mm2 die. It will be the highest output CMOS PA ever reported once the full integration is implemented. The research contributes to state of the art by developing design-techniques for a TR switch and PAs on SOS process. The resonant TR switch technique is applied to a full transceiver and the multi turns-ratio on-chip transformer is used in PA’s output matching network for the first time. The PA design is also extended to the 5-Watt PA, demonstrating the highest output power in CMOS process.

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Ultra high frequency (UHF) radio frequency identification (RFID) systems suffer from issues that limit their widespread deployment and limit the number of applications where they can be used. These limitations are: lack of a well defined read zone, interference, and environment sensitivity. To overcome these limitations a novel receiver device is introduced into the system. The use of such device or devices mitigates the issues by enabling more "anchor points" in the system. Two such devices exist in industry and academia: the Astraion Sensatag and the Gen2 Listener. The drawbacks of the Sensatag is that it offers poor performance in capturing tag signals. The Gen2 Listener is based on the expensive software defined radio hardware. The purpose of the thesis was to develop a receiver that will enable several new RFID applications that are not available with current RFID systems. The receiver, named ARR (Augmented RFID Receiver), receives tag and reader signals, which are decoded by an FPGA and the results are reported through Ethernet. This device is central to the augmented RFID system. To show the suitability of such an approach, the performance of the implementation was compared to the other two outlined solutions. A comparison of the read rate and range of the implementations were the defining factors. The analysis showed that the ARR is capable of receiving tag signals with a read rate of 50% for passive and 66% for semi-passive tags at a one meter distance and is capable of receiving tag signals at a maximum of 3.25 meters for passive and 5.5 meters for semi- passive tags, with the reader being within 8 meters of the ARR. Two applications were implemented to showcase the ARR: an RFID portal and protocol analyzer.

La technologie RFID fait dorénavant partie intégrante de notre quotidien. Les applications correspondantes à cette technologie sont des plus en plus nombreuses et répandues. Ce manuscrit a pour ambition la recherche de solutions innovantes pour lecteurs RFID UHF. Ce travail ayant été accompli dans le cadre du projet PACID Textile, les champs d'application de nos recherches ont été l'amélioration de la gestion, de la traçabilité et de la sécurité des textiles industriels et commerciaux de par des performances accrues des structures antennaires. Pour cela, l'antenne lecteur, entre autre, doit être miniature tout en étant faible coût, directive et à polarisation circulaire dans la bande RFID UHF (0,865-0,868 GHz). Les deux verrous technologiques principaux auxquels nous avons été confrontés pour l'antenne lecteur sont la gestion de sa direction de propagation privilégiée permettant de restreindre et maîtriser la zone de lecture ainsi que son encombrement afin de l'intégrer facilement dans n'importe quel environnement. Pour répondre à cette problématique, les axes de recherche abordés dans ce manuscrit ont été : L'obtention de la polarisation circulaire à l'aide de résonateurs à courts-circuits. L'étude et la conception d'antennes à base de métamatériaux de type BIE (Bande Interdite Electromagnétique) afin d'améliorer la directivité des antennes imprimées de par les propriétés originales de ces structures. La recherche de nouvelles techniques de miniaturisation des antennes imprimées par introduction d'un nouveau plan de masse de type BIE.

Passive radio frequency identification (RFID) tag has been shown efficient in item tracking and management in the supply chain. Attracted to low weight and small size of wireless nodes, some research work was conducted to extend the RFID advantage into environmental sensing applications. The concept is to using tag frequencies as sensing parameters. When variation occurs in the surrounding environment, such as temperature and humidity level, the operation frequencies of tags would be shifted, and such shift can be used to identify the degree of variation in the environment. One challenge of RFID tag is the distortion from other surrounding objects, the existence of obstacles and metals can have greatly impact on the sensing performance in both accuracy and sensing range. This thesis work conducts an investigation of the performance of a passive radio-frequency identification (RFID) based system. The investigation systematically probed the effects of passive RFID tag orientation and obstacles (blocking line-of-sight between a reader and a tag) as well as reading period (the time required for successful detection) on the range of detection. In the absence of obstacles, optimized tag orientation improved the system reliability and range of detection. At a reading distance where tag readability became unstable, increasing the reading period led to a higher reliability. A theoretical model was also established and was in good agreement with measurement results, providing a simple guideline to the further experiments. This work would also advance the knowledge understanding on wireless sensing on metal effect, humidity and temperature.

Στόχος της παρούσας διπλωματικής εργασίας είναι η ηλεκτρομαγνητική μοντελοποίηση υπό βρoχόπτωση στις VHF και UHF περιοχές συχνοτήτων. Προκειμένου να εξαχθούν συμπεράσματα για την ποιότητα των παρεχόμενων υπηρεσιών (κυτταρική και δορυφορική τηλεφωνία, μετάδοση τηλεοπτικών σημάτων) προσδιορίζονται η ισχύς λήψης και μία σειρά από παραμέτρους. / The aim of this master thesis is the RF modeling during rainfall for the VHF and UHF ranges. In order to infer conclusions for the quality of the supplied services (cellular and satellite telephony, transmission of television signals) the received power and a series of parameters are defined.

<p>This thesis re-examines the physical layer of a communication link in order to increase the energy efficiency of a remote device or sensor. Backscatter modulation allows a remote device to wirelessly telemeter information without operating a traditional transceiver. Instead, a backscatter device leverages a carrier transmitted by an access point or base station.</p><p>A low-power multi-state vector backscatter modulation technique is presented where quadrature amplitude modulation (QAM) signalling is generated without running a traditional transceiver. Backscatter QAM allows for significant power savings compared to traditional wireless communication schemes. For example, a device presented in this thesis that implements 16-QAM backscatter modulation is capable of streaming data at 96 Mbps with a radio communication efficiency of 15.5 pJ/bit. This is over 100x lower energy per bit than WiFi (IEEE 802.11).</p><p>This work could lead to a new class of high-bandwidth sensors or implantables with power consumption far lower than traditional radios.</p> / Dissertation

Passive radio frequency identification (RFID) tag has been shown efficient in item tracking and management in the supply chain. Attracted to low weight and small size of wireless nodes, some research work was conducted to extend the RFID advantage into environmental sensing applications. The concept is to using tag frequencies as sensing parameters. When variation occurs in the surrounding environment, such as temperature and humidity level, the operation frequencies of tags would be shifted, and such shift can be used to identify the degree of variation in the environment. One challenge of RFID tag is the distortion from other surrounding objects, the existence of obstacles and metals can have greatly impact on the sensing performance in both accuracy and sensing range. This thesis work conducts an investigation of the performance of a passive radio-frequency identification (RFID) based system. The investigation systematically probed the effects of passive RFID tag orientation and obstacles (blocking line-of-sight between a reader and a tag) as well as reading period (the time required for successful detection) on the range of detection. In the absence of obstacles, optimized tag orientation improved the system reliability and range of detection. At a reading distance where tag readability became unstable, increasing the reading period led to a higher reliability. A theoretical model was also established and was in good agreement with measurement results, providing a simple guideline to the further experiments. This work would also advance the knowledge understanding on wireless sensing on metal effect, humidity and temperature.