Dissertations / Theses on the topic 'Antennes planaires'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 40 dissertations / theses for your research on the topic 'Antennes planaires.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Lathière, Guillaume. "Alimentations orthogonales planaires appliquées aux Antennes à Résonateur Diélectrique (DRA)." Rennes, INSA, 2005. http://www.theses.fr/2005ISAR0011.
Full textIn this work, we present a new concept which aims at reducing the size of the elementary source in the active antenna network. The idea is to integrate active components on a planar substrate, which is orthogonally placed in respect to the radiating element. Then the horizontal plane is reserved for the radiating elements only , by placing on the vertical plane all the associated actives circuits. In this thesis, two planar orthogonal feed methods are proposed to excite a dielectric resonator. The two methods, which use a slotline waveguide and/or coplanar waveguide, are presented to realise structures with linear, circular or dual polarisations in the C-band. A technology feasibility study also proves that a transposition in Ka-band is possible
Dussopt, Laurent. "Technologies et concepts nouveaux d'antennes planaires pour systèmes de communication : structures passives et actives." Nice, 2000. http://www.theses.fr/2000NICE5425.
Full textElajmi, Mohammed. "Analyse tridimensionnelle des antennes planaires par la méthode de la résonance transverse." Toulouse, INPT, 1994. http://www.theses.fr/1994INPT034H.
Full textDuran, Venegas Juan Antonio. "Reconfigurable Metasurfaces for Beam Scanning Planar Antennas." Thesis, Toulouse, INPT, 2016. http://www.theses.fr/2016INPT0102.
Full textWe are studying the implementation of 'Scanning Antenna dedicated to the applications of satellite communications geostationary. The structures developed are suitable for to be on board an airplane or a train. The architecture of the antenna developed consists of a double linear network in two transverse dimmensions. The scan in each network is provided by the lines coplanar to metamaterials controlled by varactor. We porposons of new methods characterization of discontinuities coplanar online for the line design. In addition, a energy harvesting system has be designed to feed radiating elements and tested with patch different antennas. Finally, we are considering co-integration radiating structures and CRLH lines as well as control electronic by the diodes
Boutayeb, Halim. "Etude des structures périodiques planaires et conformes associées aux antennes. Application aux communications mobiles." Rennes 1, 2003. https://tel.archives-ouvertes.fr/tel-00133820.
Full textDauvignac, Jean-Yves. "Analyse rigoureuse de structures rayonnantes a 3 dimensions : applications aux antennes planaires." Nice, 1993. http://www.theses.fr/1993NICE4629.
Full textProust, Isabelle. "Contribution à l'étude des discontinuités en guides d'ondes coaxiaux : application aux antennes planaires." Toulouse, INPT, 1994. http://www.theses.fr/1994INPT090H.
Full textHan, Xiaoke. "Métamatériaux pour la réduction des couplages électromagnétiques dans les réseaux d’antennes planaires." Paris 10, 2013. http://www.theses.fr/2013PA100076.
Full textOne of the requirements, commercial in the first order, of mobile operators and modern electronic equipment is to increase the integration of systems with the aim to boost functionality while reducing space and the final cost “requirement of compactness!” This responds to the need to transmit information at very high speed to meet the demands of users: "Inserting more and more smaller antennas of a huge functionality with a high variety of innumerable frequency bands, into small volumes (miniaturized systems) still maintaining their performances. ” But in that containment, the levels of electromagnetic interference (EMI) and mutual coupling is the strongest. They can present a real threat to the functioning of the systems, by significantly reducing their performances and especially for some of these components that work with low level of threshold voltage, vulnerable to EM noise. Reducing the level of these disturbances becomes a critical issue faced by designers as well as electronic equipment (integrated circuits, printed circuits, interconnections. . . ) as antenna systems and antenna arrays. The problem that concerns us here is that of EM interference and mutual coupling "intentional" due to the fact that the radiating elements are placed close to each other and often share a ground plane (or reference) common. Several strategies and techniques can be implemented and/or developed to reduce electromagnetic interference (EMI coupling and EM). Among these techniques is the isolation of critical components for the shield, adaptation, filtering, adding of material absorber, and losses materials. . . However, note that all techniques are valid for a certain frequency band and they cannot protect the system for EMI that occur at different frequencies; outside these bands. This is a major limitation of these strategies. In the field of antennas (multiple-input and multiple-output, or MIMO mobile antenna system for transmitting/receiving for example), several processes (strategies or techniques) decoupling have been proposed to improve the isolation between two antennas. They are developed based on the level of insulation required for inter-element imposed by the current application remotely. For example, 10 to 15 dB of isolation are generally sufficient to obtain a low correlation in MIMO enabling them to ensure good performance, whereas isolation better than 60 dB is required for an application of radio altimeter antenna! We always take care to check the extent that the effectiveness, gain and radiation patterns of prototype antennas designed with these strategies insulation conform to specifications and that no alteration is made; rather they should achieve an improvement in some of these parameters. Among the techniques recently proposed, which uses a parasitic element (without any contact with the active antennas) of small dimensions relative to the wavelength which can provide the expected effect of decoupling? The parasitic element is inserted midway between the antennas. It can be designed as: - Defected Ground Structure; DGS. - A metamaterial as high surface impedance (SHI) of Sievenpiper (work of 1999). These structures can provide a very popular feature that suppress the propagation of surface waves in a given frequency band. The work presented in this thesis focused on the study of metamaterial structures (MTM) and their properties suppression of surface waves and their potential application to reduce the mutual coupling between microstrip antennas printed on a substrate. We specifically consider reducing mutual coupling associated with surface currents through the substrate. We propose the study of several metamaterial structures very different properties: - Periodic structures with a total bandgap for all modes of propagation; named EBG - Unit-planar structures that stop the propagation of surface waves (TE and/or TM) in a preferred direction. These are materials that have either a negative permittivity (ENG) or a negative permeability (MNG). And thus the propagation modes are evanescent modes
Pioch, Sébastien. "Etude d'antennes planaires à motifs périodiques par la théorie des matériaux à BIE." Nice, 2004. http://www.theses.fr/2004NICE4093.
Full textLes travaux présentés dans ce mémoire portent sur l'étude d'antennes planaires à motifs périodiques par la théorie des matériaux à BIE. Dans un premier temps, nous proposons une méthode de réduction de la taille d'antennes imprimées à partir de motifs périodiques (type UCPBG). Pour cela, nous modifions les dimensions de la cellule élémentaire afin de ralentir la vitesse de propagation de l'onde dans le réseau. Les diagrammes de bandes sont calculés analytiquement à l'aide de circuits équivalents. Les différentes structures ne fonctionnent pas dans leur première bande interdite car elles sont utilisées en tant qu'élément rayonnant. Puis, nous proposons un nouveau type d'antenne bibande basé sur l'empilement d'une antenne patch et d'une antenne à BIE. Dans la seconde partie, nous cherchons également à obtenir un effet de réduction à l'aide de métamatériaux basés sur des lignes coplanaires chargées périodiquement d'éléments réactifs. Des modèles équivalents sont introduits pour déterminer l'équation de dispersion en vue de localiser les bandes de fréquences interdites. Une étude paramétrique sur la période de la structure montre des fréquences situées à l'intérieur et à l'extérieur du cône de lumière. Pour ce type de structure, la réduction de la longueur résonnante n'a pas été obtenu car le matériau présente une atténuation importante. Dans la dernière partie, on s'intéresse à l'insertion de MEMS RF dans une antenne à fente blindée à l'arrière. Les résultats simulés montrent la possibilité d'avoir une antenne reconfigurable en fréquence sur une octave en modifiant le rapport capacitif de ces composants
Caillet, Nolwen. "Intégration d'extrémités radiofréquences millimétriques pour les réseaux de communication en environnement Indoor." Télécom Bretagne, 2010. http://www.theses.fr/2010TELB0121.
Full textThe demand for ultra-high data rate wireless communication systems is increasing daily with the emergence of a variety of multimedia applications. The availability of several unlicensed GHz bandwidths in the 60 GHz spectrum represents a great opportunity for ultra-high speed short range wireless communications. The first objective of this work was to characterize 60 GHz Indoor propagation channels. This information is crucial for deducing the appropriate usage models and for designing the front-end radio. More specifically, we examined the impact of the propagation channel's characteristics on the antenna’s needs. Studies were then carried out on different antenna’s topologies in order to find solutions which respond to the 60 GHz spécifications and which can be easily integrated with MMICs devices. We considered planar antennas, horn antennas integrated to a thin substrate and beam-steering antennas
Boutayeb, Halim. "ÉTUDE DES STRUCTURES PÉRIODIQUES PLANAIRES ET CONFORMES ASSOCIÉES AUX ANTENNES. APPLICATION AUX COMMUNICATIONS MOBILES." Phd thesis, Université Rennes 1, 2003. http://tel.archives-ouvertes.fr/tel-00133820.
Full textHattenberger, Véronique. "Contribution à l'étude de la formation de voies en numérique : application à la conception de récepteurs haut débit utilisant des antennes planaires à rayonnement direct." Nantes, 2005. http://www.theses.fr/2005NANT2069.
Full textThe demand of new multimedia services encourages the manufacturers to design receivers which use radio-software architecture and beamforming. A completely digital receiver is not yet feasible, or at great cost. A hybrid solution which associates in an optimal way analog and digital areas must be considered. A designing method was developed to specify the front-end of the system by taking into account the characteristics of the analog-to-digital converter, the beamforming and the desired signal to noise ratio at the output. A direct radiation planar antenna was developed so as to reduce the losses for the conversion of the broadband signal that requires a noise figure brought down to the input of the receiver the weakest possible, and to enable a distance inferior to /2 between the centers of phase of the element of the array so as to avoid the grating lobes in the case of important deviations of the beam
Perret, Étienne. "Application de l'approche par changements d'échelle aux circuits planaires hyperfréquences." Toulouse, INPT, 2005. http://ethesis.inp-toulouse.fr/archive/00000153/.
Full textAn electromagnetic modeling based on a Scale changing technique formulation has been developed and applied to various microwave planar circuits. This method aims at bypass traditional problems of simulation, related to the multiplicity of scales present in a structure. The multiscale nature of a structure is used to break up this one into sub-structures, still called building blocs of transition. These blocs seem true basic components of any multiscale structure. They characterize the transition of a scale towards another, and are associated with an N-port network. Taking into account the entire problem corresponds to the cascading of these different N-port. The study of MEMS, an active antenna and a phase-shifters cell was carried out. The results obtained, in particular in term of computing time, have confirmed the effectiveness of such an approach compared to the traditional methods
Zhao, Zhidong. "Optimisation d'antennes et de réseaux d'antennes planaires par gradient de forme et ensembles de niveaux (Level Sets)." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4097.
Full textThe objective of this thesis work is to find the optimal shape of planar antenna elements and arrays from imposed constraints (e.g. desired or imposed radiation patterns, gain or directivity) or to reconstruct the shape from experimental measurements. The optimization algorithm is based on the gradient-type method and an active contour reconstruction by means of the Level Set method. The forward problem is solved using an integral formulation of the EM problem with finite element discretization. The shape gradient is computed using two different methods: one is finite differential method based on nodal point mesh derivation with an infinitesimal modification of the triangular elements on the contour along the outward normal direction, another the topological shape gradient, which is computed based on a topological deformation on a contour. A narrow band level set method has been developed to evolve the contour of antennas and arrays using the deformation velocity computed from the shape gradient. Different configurations of antennas and antenna arrays are studied for investigating the performance of the optimization algorithm. Frequency hopping and multi-frequency techniques have been used for optimizing the shape within a frequency band. Shape optimization for planar antenna miniaturization has a large number of applications, particularly, for reflectarrays
Bensahla-Tani, Benoît. "Contribution à la conception et à la réalisation d’émetteurs/récepteurs monolithiques 140 GHz pour réseaux de capteurs sans fil." Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10174/document.
Full textThis thesis is a contribution to the development of transceivers for monolithic millimeter-wave wireless sensors networks. The deployment of short-range and autonomous wireless sensors networks tends towards ambient intelligence, changing the way we interact with our environment. The Internet of Things is democratizing rapidly with an unprecedented increase of connected objects. These nodes must and should become more discrete and independent, while still improving their features and performance. Moreover, the increase in nodes number constituting those networks amplifies well-known issues as interferences and indoor multipath problems. The development of sensors using millimeter-wave communications (D-band and G-band) should allow smaller nodes by reducing the antennas dimensions since the antenna is usually the technological lock in system integration. This integration will be accompanied by solutions for reducing node’s consumption. Thus, we have designed antennas, based on slot-line to reduce the usual constraints of antenna design. The antennas are well on substrates of high permittivity and small dimensions, with MMIC compatible technology. The experimental results are well consistent with the 3D electromagnetic simulation. We have also performed an experimental characterization of amplifiers and extensive study of amplifier’s stability in G-band. This study was performed using NDF method. This has allowed us to design a low noise amplifier that can be controlled by short pulses in order to realize a very low power tranceiver suitable for autonomous wireless networks-sensors
Marzolf, Eric. "Etude de technologies d'antennes pour les communications millimétriques." Rennes, INSA, 2002. http://www.theses.fr/2002ISAR0005.
Full textSalah, Toubeh Moustapha. "Etude d’antennes BIE planaires de hauteur très inférieure à la longueur d’onde dite : The ULP EBG Antennas." Limoges, 2011. https://aurore.unilim.fr/theses/nxfile/default/9ad79c31-e0cc-4074-a818-25d08af663a6/blobholder:0/2011LIMO4049.pdf.
Full textThis thesis is devoted to the study of EBG antenna with reduced resonator height, expected to reach dimensions less than tenth of the wavelength. The antenna is called Ultra low profile EBG antenna. Therefore the purpose of the thesis is understanding the limitations and exploring the potential of the antenna in terms of beam shaping, bandwidth and polarization. The works led to the development of three ULP EBG antenna prototypes. The first is a broadband device (71%), high gain (17 dB) developed as part of a high power application. The last two are EBG ULP prototypes designed to deliver left circular polarization for the first one and bi-circular polarization for the second
Gay-Balmaz, Philippe. "Structures 3-D planaires en milieux stratifiés : fonctions de Green et application à des antennes incluant des parois verticales /." [S.l.] : [s.n.], 1996. http://library.epfl.ch/theses/?nr=1569.
Full textClementi, Guillaume. "Conception et caractérisation fréquentielle et temporelle d'antennes réseaux planaires à très large bande passante." Phd thesis, Université Nice Sophia Antipolis, 2011. http://tel.archives-ouvertes.fr/tel-00926589.
Full textYousuf, Muhammad Amir. "Parametric Modeling of small terminals and Multiband or Ultra wideband Antennas." Palaiseau, Ecole polytechnique, 2011. https://pastel.hal.science/docs/00/63/48/66/PDF/Parametric_Modeling_of_UWB_antennas.pdf.
Full textSince the inception of short range Ultra Wideband (UWB) communication systems the factors like device miniaturization and high speed data rate create big challenges for antenna designers. One way to make the design job easy is to statistically model the variabilities of antenna radiation behavior as a function of its geometry. Such an effort is also useful for the better usage of the communication channel by combining the antenna model with it. This thesis is an attempt towards statistical modeling of UWB antennas. The subject faces two main challenges, the creation of sizeable statistical population of the class of antenna design(s) and modeling of antenna's radiation pattern which is composed of huge number of complex parameters. In this thesis we try to answer the former by proposing a generic design approach for UWB planar antennas and the latter by presenting the use of ultra-compressed parametric modeling technique. The generic design approach is based on trapezoidal shapes and offers great flexibility and versatility in designing various UWB antennas. This approach shows a significant ease in antenna optimization (also for population creation) as it reduces the no. Of parameters that controls the antenna geometry without compromising the degree of freedom. Ultra-compressed parametric modeling is based on two antenna synthesis methods, singularity expansion method (SEM) and Spherical mode expansion method (SMEM) that reduce the required no. Of complex parameters for the radiation pattern by 99. 9%, making the modeling effort possible. A statistical model of biconical antenna based on ultra-compressed modeling technique has been presented
Yousuf, Muhammad Amir. "Modélisation paramétrique des petits terminaux et antennes multi-bandes ou ultra large bande." Phd thesis, Télécom ParisTech, 2011. http://pastel.archives-ouvertes.fr/pastel-00634866.
Full textBenelli, Giacomo. "Développement de la méthode des sources fictives pour des milieux stratifiés et conception d'antennes à cavité résonante." Phd thesis, Université Paul Cézanne - Aix-Marseille III, 2007. http://tel.archives-ouvertes.fr/tel-00324206.
Full textAfin de concevoir et d'optimiser des antennes planes et compactes dans le cadre d'applications pour satellites, nous utilisons la méthode des éléments finis. Nous optimisons des structures métalliques constituées d'une cavité fermée par une grille périodique, pour obtenir des antennes compactes, ayant une efficacité de surface très élevée, et pouvant supporter de fortes puissances. Ce type d'antenne est destiné à servir d'élément de base pour les antennes réseau à rayonnement direct (DRA, Direct Radiating Array), ou comme source d'alimentation pour des réflecteurs.
Mohsen, Ibrahim. "Système coopératif radiofréquence de positionnement latéral d'un véhicule sur la chaussée." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066075/document.
Full textThe research carried out during this thesis aims to develop a lateral positioning system of a vehicle on its lane in order to alert the driver in case of an unintentional lane departure or to provide the lateral position of the vehicle for an autonomous driving system. The system developed is based on a hyperfrequency interaction between a transceiver module embedded in the vehicle and passive transponders integrated in the road. This system operates in the UHF band. Each passive transponder contains an antenna connected to two surface acoustic wave resonators that have a high quality coefficient at their resonant frequency. Each transponder receives the waves emitted by the hyperfrequency module and then retransmits it by adding a specific signature due to the resonators. The hyperfrequency module embedded in the vehicle contains transmitting and receiving antennas as well as a transmission and acquisition chain. It operates around the two center frequencies of the resonators. A received signal processing algorithm was devemoped to determine the lateral distance between the vehicle and the transponders by using the phase of the transponder signal after having extracted it from the received global signal. The system has been tested in an external environment and has an estimated lateral distance error of 4 cm
Adam, Aurèle. "Bolomètres à électrons chauds supraconducteurs pour la détection des ondes submillimétriques : modélisations et caractérisations." Paris 6, 2003. http://www.theses.fr/2003PA066347.
Full textMohsen, Ibrahim. "Système coopératif radiofréquence de positionnement latéral d'un véhicule sur la chaussée." Electronic Thesis or Diss., Paris 6, 2017. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2017PA066075.pdf.
Full textThe research carried out during this thesis aims to develop a lateral positioning system of a vehicle on its lane in order to alert the driver in case of an unintentional lane departure or to provide the lateral position of the vehicle for an autonomous driving system. The system developed is based on a hyperfrequency interaction between a transceiver module embedded in the vehicle and passive transponders integrated in the road. This system operates in the UHF band. Each passive transponder contains an antenna connected to two surface acoustic wave resonators that have a high quality coefficient at their resonant frequency. Each transponder receives the waves emitted by the hyperfrequency module and then retransmits it by adding a specific signature due to the resonators. The hyperfrequency module embedded in the vehicle contains transmitting and receiving antennas as well as a transmission and acquisition chain. It operates around the two center frequencies of the resonators. A received signal processing algorithm was devemoped to determine the lateral distance between the vehicle and the transponders by using the phase of the transponder signal after having extracted it from the received global signal. The system has been tested in an external environment and has an estimated lateral distance error of 4 cm
Almustafa, Mohamad. "Modélisation des micro-plasmas, conception des circuits micro-ondes, Coupleur Directionnel Hybride pour Mesures et des applications en Télécommunication." Phd thesis, Toulouse, INPT, 2013. http://oatao.univ-toulouse.fr/14170/1/almustafa.pdf.
Full textLeger, Ludovic. "Nouveaux développements autour des potentialités de l'antenne BIE planaire." Limoges, 2004. http://aurore.unilim.fr/theses/nxfile/default/ec7a7039-0521-498c-81e1-87c1eb678906/blobholder:0/2004LIMO0021.pdf.
Full textPlanar EBG antenna is realized from electromagnetic band gap materials. The spatial and frequency waves' filtering obtained with those materials allows controlling the radiation directions as well as the directivity of the antenna. The several potentialities which offers this radiating structure allowed numerous developments which are presented in this report. It proposes besides a reliable design technique, new improvements as multifrequency or multibeam functioning. Furthermore, an excitation with several sources combined with a simple calculation technique allowed a significant increase of the gain and the radiation bandwidth. This high gain and cumbersome antenna is convenient for a sample group of numerous applications. The presented realizations confirm successfully the various proposed functioning
Brand, Yan. "Antennes imprimées SSFIP : de l'élément isolé au réseau planaire /." [S.l.] : [s.n.], 1996. http://library.epfl.ch/theses/?nr=1568.
Full textKazemipour, Alireza. "Contribution à l'étude du couplage entre antennes, application à la compatibilité électromagnétique et à la conception d'antennes et de réseaux d'antennes." Paris, ENST, 2003. http://www.theses.fr/2002ENST0029.
Full textPresse, Anthony. "Conception d'antennes souples et de conducteurs magnétiques artificiels en bande UHF." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S087/document.
Full textThe invention of antennas was the base of wireless communications appearance at the dawn of the twentieth century. Originally metal objects for transmitting and receiving electromagnetic waves, antennas have steadily become more complex to meet the impressive development of wireless communications. It is in this context that the concept of wearable antennas was born less than two decades ago opening a new field of research namely flexible antennas. It is in this framework that this thesis is dedicated to the design of flexible antennas for UHF band.A first study enabled the design of a flexible antipodal Vivaldi antenna [150-900 MHz] for Technical Section of the Army. Six of these antennas are intended to be placed under a balloon inflated with helium for receiving RF signals.A second study was conducted in collaboration with the company Syrlinks and CNES. The objective of the project is to design flexible antennas for tracking people with ARGOS system (401 and 466 MHz). The selected solution is a planar PIFA which width is smaller than lambda/3. This antenna has the advantage of being thin and light. The flexible material used is a silicone rubber and it was selected among several others due to some dielectric characterizations. However, the drawback of this antenna is that it has a quasi-omnidirectional radiation pattern. Since it was not possible to use a reflector metal plane due to size constraints, it was decided to design a flexible artificial magnetic conductor (AMC). However, the design of AMCs in the lower UHF band is challenged with the miniaturization difficulties. Two concepts of small size (compared to the wavelength) AMCs unit cells were developed to work around this problem. The first solution uses interdigitated capacitors and the second a double layer structure. For these two concepts, a circuit model is proposed and validated by experimental measurements. The measurement of the AMC associated antenna demonstrates a bandwidth sufficient for ARGOS applications and a radiation pattern mostly directed in the direction opposite to that of the AMC
Rabobason, Yvon Georges. "Modélisation de système antennaire flexible à bas coût pour objets communicants non planaire." Rouen, 2016. http://www.theses.fr/2016ROUES060.
Full textFlexible electronics is currently considered as one of the technological solutions to face up to geometric constraints, lower cost and technological requirements. This emergence will ultimately drive the market for connected clothing, implanted electronics (in-body electronics). However, the flexible technology is not mature and has some issues that remain to lift as the choice of substrates both effective, environmentally friendly and at lower costs, modeling (analytic or digital) of a system or flexible subsystem, or the analysis of electromagnetic phenomena related to non-planar geometry. This manuscript presents the memory of my PhD thesis that focuses on the modeling of flexible antenna system for low-cost non-planar communicating objects. First, the different parameters such as the quality factor, antenna efficiencies, gain or bias, for evaluating the performance of an antenna are introduced. Subsequently, research work on flexible substrate based different antenna structures is presented. The main characteristics of flexible plastic substrates commonly used are addressed. The choice towards the substrates Kapton HN, as the best compromise cost-effectiveness robustness is justified. The influence of the antenna curvature constitutes the main object of the present PhD thesis. In this way, the study on the EM phenomena associated with the use of a flexible patch antenna structure is developed. Novel analytical formulas for assessing the antenna radiation efficiency in discrete curvatures scenarios are established. In addition, a methodology providing an analysis and modeling approach to passive and active 1×2 antenna arrays is presented and validated. Finally, two new structures of flexible high performance antennas in terms of bandwidth and radiation efficiencies are designed and implemented. The Kapton-based broadband structures are based on slots antenna topology with new matching adaptation technique by the use of lumped elements. The influence of the curvature on the slot antenna prototypes are analyzed and discussed
Andriamiharivolamena, Fanamperana Tsitoha. "Contribution au développement d'antennes intégrables aux vêtements : application aux gilets militaires." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT019/document.
Full textNowadays, the infantrymen of French army are equipped with a radio communication system when they are in field action. The antenna used to transmit and receive Radiofrequency (RF) signals is a monopole antenna called as whip antenna. It is placed parallel to the infantryman's body at the left clavicle. However, the whip antenna disrupts the field of view of infantrymen particularly when they turn their head to the left. Moreover, the position of the whip antenna bothers the left-handed infantrymen when they are in fire position. Finally, the whip antenna adds an additional weight to the infantrymen. Thus, it is obvious that the integration of the antenna into the military jackets allows to better meet the needs of infantrymen particularly in terms of ergonomy. However such an integration must also meet the needs in terms of radiation efficiency, spatial coverage and protection of the body against the antenna radiation. Moreover, the constraints of realization technology must be taken into account. The thesis is focused on the design and characterization of integrated antennas into military jackets. The research work is performed within the collaborative project GIANTE, supported by the DGA-RAPID frameproject, associating complementary partners: SAFRAN Sagem, laboratory LCIS, and ARDEJE. The work includes all the electromagnetic studies required by the environmental constraints by taking account the human body. It also includes the follow-up of the realizations made by ARDEJE that masters inkjet printing technologies. The RF characterization (impedance matching, bandwidth, radiation pattern) of antennas with a suitable bench test and the evaluation of global performances of antennas in functional environments (environment free from obstructions, urban areas, forest) are also part of the thesis work
Truong, Cong Tien. "Optimisation par approche physique des micro-antennes RMN fabriquées par Techniques Microélectroniques : Etude Théorique et Expérimentale." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0066.
Full textThe concept of NMR microsensors (named also microantennas or needle coils) could lead to reliable analysis tools able to ensure the reproducibility of high resolution spectroscopic measurements, making possible to consider their use for in vivo applications. To the best of our knowledge, no in vivo study has been done with such "high-tech micro coils". The main advantage of this device kind is the possibility to observe a well-defined micro region of interest in a large volume. On the opposite, the main drawback resides in the poor sensitivity of the device since the efficiency of presently designed microcoils suffers from several misadjustments (small inductance value of the useful wires compared to the inductance of connecting wires, strong coupling noise with sample ...etc.). Our initial approach carried out in vitro that presented in (http://www. spectroscopynow.com) and in thesis of N. Baxan (2008) and A. Kadjo (2011), cannot be realized in vivo without a very important complementary work. This is of crucial importance, because the source signals are so small as to be comparable to the thermal noise. The simplest approach to increase antennas efficiency is a careful design and accuracy of geometric parameters influencing the physical and electrical properties. The main part of the implantable "needle antenna" is the loop where the voltage is induced. It is schematically described by a resistance and inductance that modify directly and strongly the NMR performance criteria: signal to noise ratio (SNR) and the limits of detection (LOD). The design of such micro-antennas (500x1000µm2) is performed using microelectronic techniques that are very expensive. Thus modeling and numerical simulation are essential tools amply justified. The bulk of this work dedicates to the optimization of these microantennas, describes the results of the applied physical principles to improve their geometric parameters through the prediction of their electrical parameters: the self-inductance, mutual inductance and the additional losses caused by skin effect and proximity. The originality of this work is: (i) the conversion of technological point in question to fundamental issues, (ii) The development of a "homemade software" which, no pretend to compete with commercial software, can be extended to design of more complex configuration of NMR antennas or microantennas. It could also better target specific needs of designers of NMR antennas and users, providing them a time gain and a cost reduction
Di, Palma Luca. "Antennes réseaux transmetteur reconfigurables aux fréquences millimétriques." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S092/document.
Full textSeveral civil and military applications (hertzian beams, satellite communications, automotive radars, high resolution imaging systems) require antennas with reconfigurable beam capabilities (beam-scanning, beamshaping, multiple beam generation). Transmitarray antennas are good candidates and represent an alternative to classical phased arrays or reflect-arrays for these applications. The main objective of this thesis is to demonstrate the feasibility of reconfigurable transmitarrays fabricated with standard technologies in Ka-band (20-30 GHz). Different unit-cell designs based on p-i-n diodes have been developed to work in linear and circular polarization. Their optimization and experimental characterization have been performed. Waveguide measurements show insertion losses of 1.09 dB at 29.0 GHz with a 3-dB bandwidth of 14.7%. A hybrid simulation technique has been developed in order to analyze efficiently large transmitarrays in which the sequential rotation technique has been applied to optimize the polarization quality and the radiation patterns. A 400-elements transmitarray operating in circular polarization has been realized and tested in anechoic chamber. A beam-scanning angular coverage of ±60° and circular polarization selection (left/right) have been demonstrated
Chalumyan, Taguhi. "Contribution à la calibration des antennes actives pour applications radar." Electronic Thesis or Diss., Paris, ENST, 2017. http://www.theses.fr/2017ENST0032.
Full textThe main goal of this thesis is to develop a new active antennas calibration method for radar application. The calibration method takes into account the edge effects and the coupling between the antenna radiating elements. Moreover, this method allows avoiding the degradations of the antenna radiation pattern caused by mismatch produced during a scanning and/or a weighting process. HFSS software is used to provide near-field electromagnetic numerical simulations. Matlab is used for far-field calculation from the near-field data; and also for the calculation of the illumination on the antenna surface by back-propagation of far-field datas. The calibration process is performed by an optimization process by means of ADS software. An equivalent schematic is built in it, in order to obtain desired radiation pattern which corresponds to the illumination on the antenna surface. The presented approach allows full simulation of RF circuits and radiation of the antenna array together and to get the calibration coefficients automatically. The model can be applied to the real antennas in order to get the desired pattern. The antenna equivalent model can be improved by adding RF schematic in it
Kadjo, Aziz. "Micro-capteurs implantables : étude des critères de performance en vue de l'optimisation des acquisitions par spectroscopie RMN in vivo." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10179.
Full textThe objective of this thesis is to evaluate the micro-coil performance, in spectroscopy in vivo and provide any improvements, while respecting the constraints in terms of obstruction and biocompatibility imposed by applications on brain of animal models. Therefore, this work had also to assess the sensitivity understanding of these particular micro-sensors, a notion that has not yet been explored. This document is organized into five chapters: the first one is an "overview" of state of art techniques and a reminder of the work already done in terms of production and in relation to different metabolite "targets". Chapter II presents the instrumental developments undertaken to improve the detection: optimization of adaptation in power and noise matching at the spectrometer input, were also taken into account. The difficulty of maintaining the animal model in a reduced space is solved by providing different configurations of remote settings. The introduction of a low-noise preamplifier is also studied and implemented. The important question of the limit of detection is approached from a theoretical point of view in Chapter III. The interest of this analysis is to assess the performance of micro-coil, we will point out that this new concept enables to describe a spectroscopy facility (sensor associated with a spectrometer for a given experiment). A study of enhancement of the limit of detection by the apodization technique will be addressed and validated on spectroscopy acquisitions. Chapter IV is an implementation in the first part, through modelling, to discuss changes in the limit of detection for some structural changes (size and positioning of the micro-coil). In the second part, an implementation of the limit of detection through spectroscopic experiments will be presented in order to compare the performance of existing coils: a commercial coil and a micro-coil. The biocompatibility of implantable micro-coil treated in Chapter V. The completion of this study was carried out upstream of the theoretical and instrumental aspects in chapter III and IV and that helped their development with a more pragmatic approach
Visan, Silviu. "Simulation électromagnétique 3D basée sur la méthode des différences finies dans le domaine temporel : application à l'étude de structures planaires utilisées dans les circuits intégrés monolithiques microondes et millimétriques." Grenoble INPG, 1994. http://www.theses.fr/1994INPG0014.
Full textUlysse, Christian. "Bolomètres à électrons chauds à supraconducteurs haute température critique pour les ondes submillimétriques : élaboration et caractérisations." Paris 6, 2003. http://www.theses.fr/2003PA066327.
Full textSence, Johann. "Contribution au co-design et à la co-intégration de réseaux d’antennes actives multi-bandes pour systèmes de radionavigation par satellite." Thesis, Limoges, 2019. http://www.theses.fr/2019LIMO0087.
Full textThis work takesplace in the context of developingelectronic systems for communications equipment, localization or monitoringequipment with a high integration density. The deployment of these systems must also meet a growing demand for flexibility in terms of frequencies, power or coverage. The frequency flexibility can be simultaneous with multiband devices or selective by reconfiguring the frequency band. The power flexibility enables to minimize consumption of the system and the coverage flexibility to direct the beam to the target to optimize the budget link or otherwise protect a source of noise. The increase in efficiency and compactness passes through the combination of elementary functions (LNA / filter / antenna) that reduces interconnect floors and considering the interactions between the different elements. The primary objective of this project is to develop a co-design methodology of the antenna with the associated circuits (filters and LNA) to achieve optimal performances (radiation,efficiency, ...) with an integrated and compact device
Andriamiharivolamena, Fanamperana Tsitoha. "Contribution au développement d'antennes intégrales aux vêtements. Application aux gilets militaires." Thesis, 2015. http://www.theses.fr/2015GRENT019.
Full textNowadays, the infantrymen of French army are equipped with a radio communication system when they are in field action. The antenna used to transmit and receive Radiofrequency (RF) signals is a monopole antenna called as whip antenna. It is placed parallel to the infantryman's body at the left clavicle. However, the whip antenna disrupts the field of view of infantrymen particularly when they turn their head to the left. Moreover, the position of the whip antenna bothers the left-handed infantrymen when they are in fire position. Finally, the whip antenna adds an additional weight to the infantrymen. Thus, it is obvious that the integration of the antenna into the military jackets allows to better meet the needs of infantrymen particularly in terms of ergonomy. However such an integration must also meet the needs in terms of radiation efficiency, spatial coverage and protection of the body against the antenna radiation. Moreover, the constraints of realization technology must be taken into account. The thesis is focused on the design and characterization of integrated antennas into military jackets. The research work is performed within the collaborative project GIANTE, supported by the DGA-RAPID frameproject, associating complementary partners: SAFRAN Sagem, laboratory LCIS, and ARDEJE. The work includes all the electromagnetic studies required by the environmental constraints by taking account the human body. It also includes the follow-up of the realizations made by ARDEJE that masters inkjet printing technologies. The RF characterization (impedance matching, bandwidth, radiation pattern) of antennas with a suitable bench test and the evaluation of global performances of antennas in functional environments (environment free from obstructions, urban areas, forest) are also part of the thesis work