WorldCat Identities

Le Thuc, Philippe (1975-....).

Works: 12 works in 12 publications in 1 language and 13 library holdings
Roles: Opponent, Other, Thesis advisor, Author
Publication Timeline
Most widely held works by Philippe Le Thuc
Optimisation des matériaux cellulosiques pour des applications en radiofréquences et térahertz by Cyril Guers( )

1 edition published in 2019 in French and held by 2 WorldCat member libraries worldwide

This thesis work deals with the optimization of cellulosic materials (papers, cardboard and cellulosic based materials). We seek to upgrade those materials for high frequencies applications: radiofrequency and terahertz. Actually the dielectric properties of cellulosic materials, and specifically their dielectric losses, are very high. It means that the efficiency and the yield of those applications are limited. In this work, we first study individually the properties and the dielectric parameters of the different component of cellulosic materials. Using radiofrequencies measuring techniques like the resonant cavity and terahertz measuring techniques like spectroscopy THz-TDS, we point our interest on the impact of those constituents upon the dielectric losses of papers. Thanks to the results, we then present method and techniques allowing to optimize paper reducing its losses. Eventually, we discuss of the transposition effects of those techniques on a paper industrial production line and propose transversal solutions to the exploitation of paper properties in its actual state. During this work, we show specifically the crucial effect of density on the paper losses and present studies upon crystallinity, length and orientation, of cellulose fibers. Two deeper studies present the impact of fillers and moisture on paper dielectric properties. We show moreover that the fillers are very interesting to reduce the losses of cellulosic materials and we highlight the impact of moisture on measured losses. In those studies, we present two effective medium models of filled papers and moist papers. Those predictive models allow the prediction of the evolution of paper properties in function of fillers and moist content. Thanks to those results we determine, in terahertz, the parameters of bound water to cellulose, unknown yet
Méthode de conception et d'optimisation d'éléments rayonnants de cartes à puce pour applications en RFID HF by Oumar Mourad( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

The HF frequency band is internationally allocated for worldwide and fastest growing band used in RFID (Radio Frequency IDentification) applications. The need for automation and advanced technologies in applications like tracking, packaging, transportation, and sensing has attracted the interest of the near-field contactless RFID at 13.56 MHz based on ISO/IEC 14443 communication standard. For low-cost RFID HF systems, communication interfaces use inductive loop antennas made up of the winding of conductive wires or strips. In this thesis, we are particularly interested in the antenna design and optimization of tags dedicated for transport to provide a maximum power to the integrated circuit. The influence of the geometric parameters and materials used for the realization of the radiating element has been particularly studied to reach to propose a methodology of inductive antennas design. To do this, a circuit model of HF RFID system has been proposed to analyze the reader / tag coupling and the different critical operating points. Several antenna prototypes were made with different materials to validate the different studies
Étude et conception d'un nouveau système intégré à une plateforme de monitoring pour la détection des décharges partielles en UHF pour les équipements électriques by Alexandre Marchal( )

1 edition published in 2019 in French and held by 1 WorldCat member library worldwide

SENSeOR has developed a system dedicated to the temperature monitoring for medium and high voltage equipments in order to avoid certain failures that could have major consequences on the electrical grid. However, phenomena other than the increase of the temperature are also present in these equipments like partial discharges (PD) whose detection would make it possible to establish a reliable and effective diagnosis of the apparatus state of health. This is what the presented research work suggests. For this, we will present the characteristics defining the insulation of an electrical equipment and the different properties of the partial discharge phenomenon. We also expose the problems and objectives as well as the interest to focus on the UHF method as a detection method and why targeting on Ultra-Wide Band (UWB) antenna topologies as PD sensors, and why this type of antenna, is a strong ally in the PD detection. The design of a new printed and miniature UWB antenna usable in a harsh and restricted environment, typically a metallic cavity of a medium-voltage cell, is then presented along with the technique used to widen its bandwidth. The last part of this work is dedicated to the development of the complete UHF PD detector with the description of hardware and firmware developments. Finally, various tests set up in laboratory and in situ in order to validate and characterize the designed system are presented
Conception d'un système antennaire multi-standard multi-applications dédié au module TRAXBOX pour le suivi de conteneurs by Tarik Faradi( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

This thesis presents the design of different small antenna systems, operating in harsh environmental and climatic conditions, but also be able to operate in several ISM frequency bands and several mobile communication standards. This antenna system designed to be integrated in the TRAXBOX modules developed by TRAXENS, must meet various technical, industrial and economic criteria, defined by their final application which is the monitoring of multimodal metallic containers. To this end, the system must provide a multiband and wideband operations, an omnidirectional radiation pattern, a good efficiency, a reduced size allowing an easy and efficient integration into its housing, mechanical rigidity allowing the system to be protected against vibrations and shocks, a wide operating temperature range and low manufacturing cost. These technical and manufacturing requirements are often difficult to simultaneously satisfy. To do this, several design techniques of multiband multi-antenna systems have been employed. The use of slots and parasitic elements has first allowed widening the antennas bands. Regarding the mutual isolation of the antennas, the insertion of slots on the ground plane is one of the techniques that improve the antennas isolation. However, in this manuscript, we have mainly focused on the optimal layout of the parasitic resonators to simultaneously increase the bandwidth but also optimize the system efficiency and the isolation between antennas after interpretation of the various physical phenomena observed
Étude et conception d'antennes miniatures et directives à polarisation circulaire pour lecteurs RFID UHF by Sylvain Pflaum( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

RFID technology is now a part of our daily lives. The corresponding applications are more and more numerous and widespread. This work having been done in the framework of the PACID textile project, this thesis has the ambition to research innovative solutions for RFID readers in order to enhance the management, the traceability and the security of the industrial and commercial textiles.Towards this end, the antenna reader has to be miniature while being low-cost, directive and in circular polarization in the RFID UHF band (0.865-0.868 GHz). The two main technological challenges that we have faced for the reader antenna is managing its main direction of propagation to restrict and control the reading zone as well as the miniaturization of its size in order to easily integrate it into any environment. To respond to this problem, the research areas discussed in this manuscript were: The obtaining of the circular polarization using short-circuited resonators. The study and design of microstrip antennas based on EBG (Electromagnetic Band Gap). Type metamaterials to improve their directivity by using the original properties of these structures. The research of new miniaturization techniques for printed antennas by introducing a new EBG ground plane
Système antennaire directif et reconfigurable pour réseaux de capteurs sans fil by Akimu Ayan Niyi Dihissou( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Studies have shown that the communication subsystem is one of the greatest sources of energy consumption in wireless sensor networks. This subsystem is directly bounded to the type of antenna used on the radio module. Several sensor nodes are equipped with omnidirectional antennas leading to a waste of energy due to the shape of their beam. Instead of using omnidirectional antennas, directive and reconfigurable antennas system dedicated to wireless sensor networks are presented in this work so as to alleviate the waste of energy. On one hand, such dedicated antennae should be small in size and particularly designed by taking into consideration the frequency bandwidth of the node. On the other hand, their radiation pattern should also be reconfigurable by using powerless active components with a simple active control. To reach these objectives, we have in a first time proposed a directive solution inspired of a Printed-Yagi antenna in the ISM band (2.4-2.485) GHz. It provides high gain with a value of 7.3dB and a half power beam width BW-3dB of 57° in the azimuth plane. Secondly, we have proposed a multiple directional antenna in the ISM band. This antenna consists of six identical monopole antennas arranged in the same structure, having each one feeding port. Due to the selection of each feeding port, the proposed antenna covers the whole azimuthal plane with a simulated beam of 4.6 dB along with a half power beam width BW-3dB of 55°. Moreover, an electronic card equipped with an SP6T switch dedicated to that antenna has been developed to control the radiation pattern of the six identical antennas automatically. Willing to reduce the number of radiating elements while enhancing the radio performance, a third antenna has been proposed. It consists of a fed monopole and a loaded parasitic one having an inductance component of 9.6nH. The nature and the value of this inductance are obtained using the Uzkov equations that calculate the current weighting coefficients in the case of two separately fed antennas to maximize the gain and the directivity in the desired direction. Contrary to the use of electronic card in the control of radiation pattern prior to the conception of the third antenna, the reconfigurable aspect is obtained by using reflectors and director's elements activated by PIN diodes. It offers a maximum gain of 5.2 dB in simulation at 2.4GHz along with a half power beam width BW-3dB of 52°, in both the 270° and +90° azimuthal directions depending on the selection of the set of PIN diodes. Finally, a straight application of this structure has been proposed in order to cover more than two directions in the azimuth plane. It is an array of four monopole antennas in which two of them are fed and the two others are loaded. Such antenna is capable to steer its radiation pattern in the azimuth plane covering 360° directions (0°, 90°, 180° and 270°). The achieved simulated realized total gain is 4 dB for each radiation pattern in the azimuth plane along with a half power beam width of about 60°. Measurement campaign test has been carried out for each proposed antenna in this work. During these measurements, the received signal strength indicator (RSSI) has been the paramount value to estimate the antenna performance in connection with the sensor node. Following this measurement campaign, we have been able to notice that the use of only directive antennas is not sufficient in a random deployment of sensor nodes. Hence, the reconfigurable aspect of the beam pattern by use of powerless active components should be taken into consideration. Such kind of antennas provide an improvement of the RSSI, which is a key factor in the reduction of collisions drastically on one hand, and on the other hand related to a reduction of power consumption
Antennes miniatures basses fréquences, reconfigurables pour le LTE by Kadidiatou Diallo( )

1 edition published in 2021 in French and held by 1 WorldCat member library worldwide

This thesis focuses on the study, design and optimization of miniature multiband and frequency reconfigurable antennas for IoT and mobile applications in LTE and 5G frequency bands. Ground planes of dimensions 120*60 mm² were used. First the design of a dual-band PIFA antenna operating in the ISM 868 MHz and 915 MHz bands is carried out. Then, we proposed the design and optimization of a two-port multi-antenna system, operating on the low frequency LTE band (from 700 MHz to 900 MHz) and covering at the same time the LTE 2600 band and part of the 5G middle band. This antenna system consists of two PIFAs antennas associated with parasitic elements that used to expand their bandwidths in certain frequency bands. One of the antennas operates on three frequency bands and it is frequency tunable on the low band. The other antenna operates only on two frequency bands, the LTE 2600 band (from 2500 MHz to 2700 MHZ) and 5G middle band (from 3.4 GHz to 3.8 GHz). The frequency agility of the reconfigurable antenna is achieved by using a varactor diode which is directly biased on antenna feeding port. Finally, thanks to the study of the characteristic modes of the ground plane, the positions of the MIMO system antennas are chosen so that they are naturally isolated without the use of conventional decoupling methods. The final system covers the LTE [700 - 900 MHz] band, reconfigurable in frequency, the LTE 2600 band and part of the 5G middle band. The measurements showed good port isolation (|S21| -20 dB) in the two bands where the system operates in MIMO mode. The efficiencies measured in the reconfigurable band are not very high, however, they remain correct for the intended application
Antennes quasi-auto-complémentaires pour terminaux mobiles multi-standards by Cédric Requin( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

Une antenne auto-complémentaire possède des caractéristiques radioélectriques très intéressantes en ce qui concerne l'élargissement de sa bande passante. Basée sur le principe de Babinet, l'auto-complémentarité permet en effet de maximiser la largeur de bande de par la complémentarité air-métal dans la structure de l'antenne. L'objectif de cette thèse est d'étudier quels pouvaient être les apports de l'auto-complémentarité dans le cas d'antennes à fortes contraintes d'intégration telles que celles utilisées pour les terminaux mobiles. Pour tester les limites de notre étude, nous avons choisi d'appliquer nos résultats à l'intégration d'antennes auto-complémentaires dans un objet communicant de type Smartphone multi-standards. Les antennes dites AC doivent par conséquent satisfaire de nombreux critères de performances tout en montrant leur capacité d'intégration. Celle-ci est rendue d'autant plus délicate, que la miniaturisation implique à son tour des phénomènes physiques limitant certaines performances, notamment en basse fréquence avec la nouvelle bande LTE. Dans une première étude, nous avons considéré différentes antennes et opté pour les antennes IFA-AC sur un plan de masse fini afin de couvrir initialement les bandes hautes DCS/PCS/UMTS et WLAN/LTE2600. Dans une seconde étude, nous avons amélioré leurs performances à l'aide d'éléments structurels nouveaux et interdépendants (éléments rayonnants de type double IFA), qui nous ont permis d'obtenir des résultats probants relatifs notamment à la couverture des bandes LTE800 et GSM. Enfin, nous avons complété notre projet en optimisant le lien radio par l'intégration de plusieurs éléments rayonnants AC sur un même PCB
Antennes imprimées miniatures pour systèmes de télécommunications : applications aux communications mobiles by Philippe Le Thuc( Book )

1 edition published in 2003 in French and held by 1 WorldCat member library worldwide

These works are a part of the MUSIC's (Monolithic mUlti-Standard Integrated Components) project supported by the RNRT. The aim is the integration of small multiband antennas into a mobile handset to receive several communications systems. In the first part of this thesis, the study of a broadband circularly polarised antenna is described. The second part deals with the study ant the realisation of linearly polarisation antennas for the third generation of mobile phone. These elements must satisfy different criterions (broad and multiple bands, omnidirectional radiated field, small size) difficult to obtain simultaneously. Several techniques are used to achieve these characteristics like, stacked resonators, addition of short-circuit, shorting posts and slots. The simultaneous applying of some of these techniques has led to the elaboration of broadband antennas for DCS/PCSUMTS telecommunications standards, of prototypes associating two antennas laid on a small ground plane for GSM/DCS/PCS/UMTS standards, of dual and wide-band structures, especially one realised on a reduced ground plane for GSM/DCS/PCS/UMTS. Parametric studies have allowed the interpretation of physical phenomenon and the estimate of the influence of the different parameters. Several realisations have validated the structures steamed from simulations tools
Conception d'antennes pour biocapteurs implantables by Philippe Perrissol( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

De tous temps, l'amélioration des moyens de guérison et de prévention des maladies a constitué un enjeu majeur de nos sociétés. Les possibilités offertes désormais par les technologies modernes ont permis de multiplier le nombre d'applications médicales mais toutes ces pratiques nouvelles ont un impact dans le domaine de l'expérimentation animale et impliquent aussi un suivi sanitaire à grande échelle. Le travail présenté dans cette thèse a pour but de moderniser la surveillance de l'état de santé des souris de laboratoire, et s'inscrit dans un projet collaboratif entre le LEAT et TIRO-MATOs. L'objectif est la conception d'un système capable de faciliter ce suivi au quotidien. Pour cela, la conception d'une antenne à 433MHz, connectée à un capteur de température, implantable dans une souris et intégrant notamment l'impact de l'environnement biologique a tout d'abord été étudiée. Après caractérisation des éléments obtenus, la faisabilité d'un système de géolocalisation est présentée. Afin de disposer également de la capacité d'identification des sujets, cette étude s'est poursuivie à 868 MHz (standard RFID). Dans cette partie, l'antenne interrogatrice placée sous la cage, a été plus particulièrement étudiée. Afin de comparer les différentes antennes obtenues, des mesures de puissance récupérées par le lecteur (RSSI) sont réalisées, utilisant pour cela des phantoms de souris spécialement mis au point pour cette étude. Les conclusions tirées par comparaison notamment avec les résultats de phantoms numériques ont permis de concevoir un dispositif de diversité à 4 antennes et de le tester en présence de un à quatre phantoms dans quatre différentes zone de la cage
Antennes implantées et système de localisation pour petits animaux utilisant la technologie RFID by Van Hieu Nguyen( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

The monitoring of small animals in laboratory tests and the remote analysis of their behavior, with low cost and in real time interest researchers for a long time. This can be done by implanting miniature wireless sensors requiring vital components among which the most challenging is the antenna. Indeed, the main difficulty in designing antennas for bio-implantable communication devices is to provide an effective radiating structure, despite the volume constraints and the high impact of the surrounding biological tissues. Although many studies have focused on the use of implanted antennas dedicated to the MICS band (402405 MHz), it should be noted that at these frequencies, the size of the antennas can be a real disadvantage in the case of small animals, requiring miniaturization structures. Another solution consists in the using RFID (Radio-Frequency Identification) technology in the UHF band at 868 MHz. Indeed, it has two major advantages: it facilitates the implementation of the tag and does not require the addition of a battery to power the implanted device. This thesis funded by the ANR (French National Research Agency) within the framework of the Labex UCN@Sophia aims at designing a wireless system, including implantable RFID tags, reader's antennas and the reader connected to a computer that is responsible for the centralized management of information on a server for monitoring and collecting the data of laboratory mice. This thesis presents the design of implanted antennas for RFID tags in a homogeneous model representing the body of a mouse. After an analysis of a link budget allowing to determine the minimum performance of the implanted antenna to be designed for a reliable and an efficient communication, two RFID passive tag antenna designs have been optimized to obtain final structures able to be implanted or injected in the back of a mouse. A characterization of the proposed solutions in terms of impedance, E and H fields and SAR (Specific Absorption Rate) was then performed in a homogeneous phantom. Finally, an interrogation system capable to estimate the position of several animals placed in a cage thanks to the RSSI (Received Signal Strength Indicator) levels is presented
Conception d'antennes miniatures intégrées à leur support pour applications en télémédecine mobile by Hafedh Hamouda( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

La télémédecine et plus particulièrement la télémédecine mobile semble représenter l'avenir en termes de soins médicaux. Ce concept nécessite cependant pour sa viabilité, de disposer d'éléments rayonnants miniatures, fortement efficaces, et capables de communiquer sur plusieurs bandes. Ce mémoire présente la méthodologie de conception et l'optimisation d'antennes miniatures intégrées, dédiées à un dispositif spécifique permettant de réaliser une liaison radiofréquence entre un implant médical et le téléphone portable d'un patient. Cependant, la miniaturisation des antennes, éléments clés de ce concept, s'accompagne généralement d'une dégradation de son efficacité et de sa bande passante, ce qui rend délicat leur mise en œuvre sur au moins deux des points essentiels recherchés. La conception de ce type d'antennes nécessite donc une analyse très fine des phénomènes physiques mis en jeu dont notamment la limite théorique en termes de performances que l'on peut atteindre pour une antenne circonscrite à un volume donné. De plus, ces performances radioélectriques sont fortement dépendantes de l'environnement dans lequel est placée l'antenne. Par conséquent, l'influence de chaque partie constituant cet environnement doit être prise en compte lors de l'intégration, ce que nous décrivons également dans ce manuscrit à travers différentes solutions d'éléments rayonnants
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Alternative Names
Le Thuc, P.

French (12)