Littérature scientifique sur le sujet « Antenne intelligenti »
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Articles de revues sur le sujet "Antenne intelligenti"
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Palantei, Elyas, Arif Hidayat, Wardi Wardi, Intan Sari Areni, Sunarno Sunarno, Eko Setijadi, Dewiani Jamaluddin et al. « 6 Monopole Elements Array Intelligent Antennas for IoT Based Environmental Surveillance Network ». EPI International Journal of Engineering 3, no 2 (22 janvier 2021) : 126–31. http://dx.doi.org/10.25042/epi-ije.082020.06.
Texte intégralRésumé :
Three types of 6 monopoles array intelligent antennas was numerically and practically examined. The main purposes of the investigation is to guarantee that those designed antennas are feasible to implement and to install in a particular IoT based environmental surveillance network configuration. The basic differences of the three intelligent antennas lied on the frequency operations (i.e. 433 MHz, 875-915 MHz and 2.5 GHz) and the actual environment operations (whether for indoor or outdoor). The extreme differences of such frequency operations, of course, affecting the differences on the whole antenna physical dimension. The higher the frequency operation determined then the smaller the physical size of the designed antennas produced. However, the deep intelligent antenna evaluations presented in the paper is the one that operated on frequency band of 875 -915 MHz. The intelligent electronic part of six monopole wire elements arrayed on a circular ground plate was composed of LoRa chip module, Android Uno microcontroller, and the switching network part. The three parts determined whole antenna operation throughout the IoT network. The results of whole antenna examinations are thoroughly discussed in the paper.
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Bashar, Dr Abul. « Artificial Intelligence Based LTE MIMO Antenna for 5th Generation Mobile Networks ». September 2020 2, no 3 (13 juin 2020) : 155–62. http://dx.doi.org/10.36548/jaicn.2020.3.002.
Texte intégralRésumé :
Artificial intelligence based long term evolution multi in multi output antenna supporting the fifth generation mobile networks is put forth in the paper. The mechanism laid out in paper is devised using the monopole-antenna integrated with the switchable pattern. The long term evolution based multiple input and multiple output antenna is equipped with four antennas and capable of providing a four concurrent data streams quadrupling the theoretical maximum speed of data transfer allowing the base station to convey four diverse signals through four diverse transmit antennas for a single user equipment. The utilization of the long term evolution multiple input multiple output is capable of utilizing the multi-trial broadcasting to offer betterments in the signal performance as well as throughput and spectral efficiency when used along the fifth generation mobile networks. So the paper proposes the artificial intelligence based long term evolution multiple input multiple output four transmit antenna with four diverse signal transmission capacity that is operating in the frequency of 3.501 Gigahertz frequency. The laid out design is evaluated using the Multi-input Multi output signal analyzer to acquire the capacity of the passive conveyance of the various antennas with the diverse combination of patterns. The outcomes observed enables the artificial intelligence antenna to identify the choicest antenna to be integrated in the diverse environments for improving the throughput, signal performance and the data conveyance speed.
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Hlal Mutlaq, Ali, Mohammed Ayad Saad, Faris Hassan Tata et Ghanim Thiab Hasan. « Analysis the efficiency of multi-input-multi-output (MIMO) transmit receive systems ». Indonesian Journal of Electrical Engineering and Computer Science 29, no 1 (1 janvier 2022) : 190. http://dx.doi.org/10.11591/ijeecs.v29.i1.pp190-196.
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Transmit antennas are chosen in multi-input-multi-output (MIMO) systems. Effective in improving system capacity while lowering RF connection costs and simplifying the system. Complete method with greatest accuracy for joint transmits and receive antenna selection (JTRAS), capable of scanning all subsets of both transmitting and receiving antennas for the optimal solution. However, when as the number of antennas but also computational complexity increase grows too great, limiting its application. Antennas are coded fractionally channel capacity maximizing coding is used as a basic criterion in this paper, and an intelligent algorithm Particle swarm algorithm, generic algorithm are used to pick antennas. The simulation results show that both algorithms are capable of performing antenna selection.
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Lohn, Jason D., Gregory S. Hornby et Derek S. Linden. « Human-competitive evolved antennas ». Artificial Intelligence for Engineering Design, Analysis and Manufacturing 22, no 3 (12 juin 2008) : 235–47. http://dx.doi.org/10.1017/s0890060408000164.
Texte intégralRésumé :
AbstractWe present a case study showing a human-competitive design of an evolved antenna that was deployed on a NASA spacecraft in 2006. We were fortunate to develop our antennas in parallel with another group using traditional design methodologies. This allowed us to demonstrate that our techniques were human-competitive because our automatically designed antenna could be directly compared to a human-designed antenna. The antennas described below were evolved to meet a challenging set of mission requirements, most notably the combination of wide beamwidth for a circularly polarized wave and wide bandwidth. Two evolutionary algorithms were used in the development process: one used a genetic algorithm style representation that did not allow branching in the antenna arms; the second used a genetic programming style tree-structured representation that allowed branching in the antenna arms. The highest performance antennas from both algorithms were fabricated and tested, and both yielded very similar performance. Both antennas were comparable in performance to a hand-designed antenna produced by the antenna contractor for the mission, and so we consider them examples of human-competitive performance by evolutionary algorithms. Our design was approved for flight, and three copies of it were successfully flown on NASA's Space Technology 5 mission between March 22 and June 30, 2006. These evolved antennas represent the first evolved hardware in space and the first evolved antennas to be deployed.
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Krasnok, Alex. « Coherently Driven and Superdirective Antennas ». Electronics 8, no 8 (29 juillet 2019) : 845. http://dx.doi.org/10.3390/electronics8080845.
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Antennas are crucial elements for wireless technologies, communications and power transfer across the entire spectrum of electromagnetic waves, including radio, microwaves, THz and optics. In this paper, we review our recent achievements in two promising areas: coherently enhanced wireless power transfer (WPT) and superdirective dielectric antennas. We show that the concept of coherently enhanced WPT allows improvement of the antenna receiving efficiency by coherent excitation of the outcoupling waveguide with a backward propagating guided mode with a specific amplitude and phase. Antennas with the superdirectivity effect can increase the WPT system’s performance in another way, through tailoring of radiation diagram via engineering antenna multipoles excitation and interference of their radiation. We demonstrate a way to achieve the superdirectivity effect via higher-order multipoles excitation in a subwavelength high-index spherical dielectric resonator supporting electric and magnetic Mie multipoles. Thus, both types of antenna discussed here possess a coherent nature and can be used in modern intelligent antenna systems.
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Dou, Weiping, Yuandong Tian, Geng Ye et Jiang Zhu. « Antenna Artificial Intelligence : The Relentless Pursuit of Intelligent Antenna Design [Industry Activities] ». IEEE Antennas and Propagation Magazine 64, no 5 (octobre 2022) : 128–30. http://dx.doi.org/10.1109/map.2022.3196032.
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Chhabra, Rinkle, et Anuradha Saini. « Designing an Energy Efficient Scheme in MANET using Reconfigurable Directional (RDA) Algorithm ». International Journal of Advanced Research in Computer Science and Software Engineering 8, no 4 (4 avril 2018) : 92. http://dx.doi.org/10.23956/ijarcsse.v8i4.637.
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Mobile Ad Hoc Networks (MANET) are autonomous, infrastructure less and self-configuring networks. MANETs has gained lots of popularity due to on the fly deployment i.e. small network setup time and ability to provide communication in obstreperous terrains. Major challenges in MANETs include routing, energy efficiency, network topology control, security etc. Primary focus in this article is to provide method and algorithm to ensure significant energy savings using re-configurable directional antennas. Significant energy gains can be clinched using directional antenna. Key challenges while using directional antenna are to find destination location, antenna focusing, signal power and distance calculations. Re-configurable directional antenna can ensure significant energy gains if used intelligently. This article provides a brief insight into improved energy savings using re-configurable directional antennas and an associated algorithm
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Pryshchenko, Oleksandr A., Vadym Plakhtii, Oleksandr M. Dumin, Gennadiy P. Pochanin, Vadym P. Ruban, Lorenzo Capineri et Fronefield Crawford. « Implementation of an Artificial Intelligence Approach to GPR Systems for Landmine Detection ». Remote Sensing 14, no 17 (5 septembre 2022) : 4421. http://dx.doi.org/10.3390/rs14174421.
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Artificial Neural Network (ANN) approaches are applied to detect and determine the object class using a special set of the UltraWideBand (UWB) pulse Ground Penetrating Radar (GPR) sounding results. It used the results of GPR sounding with the antenna system, consisting of one radiator and four receiving antennas located around the transmitting antenna. The presence of four receiving antennas and, accordingly, the signals received from four spatially separated positions of the antennas provide a collection of signals received after reflection from an object at different angles and, due to this, to determine the location of the object in a coordinate system, connected to the antenna. We considered the sums and differences of signals received by two of the four antennas in six possible combinations: (1 and 2, 1 and 3, 2 and 3, 1 and 4, etc.). These combinations were then stacked sequentially one by one into one long signal. Synthetic signals constructed in such a way contain many more notable differences and specific information about the class to which the object belongs as well as the location of the searched object compared to the signals obtained by an antenna system with just one radiating and one receiving antenna. It therefore increases the accuracy in determining the object’s coordinates and its classification. The pulse radiation, propagation, and scattering are numerically simulated by the finite difference time domain (FDTD) method. Results from the experiment on mine detection are used to examine ANN too. The set of signals from different objects having different distances from the GPR was used as a training and testing dataset for ANN. The training aims to recognize and classify the detected object as a landmine or other object and to determine its location. The influence of Gaussian noise added to the signals on noise immunity of ANN was investigated. The recognition results obtained by using an ANN ensemble are presented. The ensemble consists of fully connected and recurrent neural networks, gated recurrent units, and a long-short term memory network. The results of the recognition by all ANNs are processed by a meta network to provide a better quality of underground object classification.
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Ameerudden, Mohammad Riyad, et Harry C. S. Rughooputh. « Hybridized Genetic Algorithms in the Optimization of a PIFA Antenna Using Fitness Characterization and Clustering ». Advanced Materials Research 622-623 (décembre 2012) : 40–44. http://dx.doi.org/10.4028/www.scientific.net/amr.622-623.40.
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With the exponential development of mobile communications and the miniaturization of radio frequency transceivers, the need for small and low profile antennas at mobile frequencies is constantly growing. Therefore, new antennas should be developed to provide both larger bandwidth and small dimensions. The aim of this project is to design and optimize the bandwidth of a Planar Inverted-F Antenna (PIFA) in order to achieve a larger bandwidth in the 2 GHz band. This paper presents an intelligent optimization technique using a hybridized Genetic Algorithms (GA) coupled with the intelligence of the Binary String Fitness Characterization (BSFC) technique. The optimization technique used is based on the Binary Coded GA (BCGA) and Real-Coded GA (RCGA). The process has been further enhanced by using a Clustering Algorithm to minimize the computational cost. Using the Hybridized GA with BSFC and Clustering, the bandwidth evaluation process has been observed to be more efficient combining both high performance and minimal computational cost. During the optimization process, the different PIFA models are evaluated using the finite-difference time domain (FDTD) method.
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Sagar, Md Samiul Islam, Hassna Ouassal, Asif I. Omi, Anna Wisniewska, Harikrishnan M. Jalajamony, Renny E. Fernandez et Praveen K. Sekhar. « Application of Machine Learning in Electromagnetics : Mini-Review ». Electronics 10, no 22 (11 novembre 2021) : 2752. http://dx.doi.org/10.3390/electronics10222752.
Texte intégralRésumé :
As an integral part of the electromagnetic system, antennas are becoming more advanced and versatile than ever before, thus making it necessary to adopt new techniques to enhance their performance. Machine Learning (ML), a branch of artificial intelligence, is a method of data analysis that automates analytical model building with minimal human intervention. The potential for ML to solve unpredictable and non-linear complex challenges is attracting researchers in the field of electromagnetics (EM), especially in antenna and antenna-based systems. Numerous antenna simulations, synthesis, and pattern recognition of radiations as well as non-linear inverse scattering-based object identifications are now leveraging ML techniques. Although the accuracy of ML algorithms depends on the availability of sufficient data and expert handling of the model and hyperparameters, it is gradually becoming the desired solution when researchers are aiming for a cost-effective solution without excessive time consumption. In this context, this paper aims to present an overview of machine learning, and its applications in Electromagnetics, including communication, radar, and sensing. It extensively discusses recent research progress in the development and use of intelligent algorithms for antenna design, synthesis and analysis, electromagnetic inverse scattering, synthetic aperture radar target recognition, and fault detection systems. It also provides limitations of this emerging field of study. The unique aspect of this work is that it surveys the state-of the art and recent advances in ML techniques as applied to EM.
Thèses sur le sujet "Antenne intelligenti"
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Comisso, Massimiliano. « Beamforming techniques for wireless communications in low-rank channels : analytical models and synthesis algorithms ». Doctoral thesis, Università degli studi di Trieste, 2008. http://hdl.handle.net/10077/2582.
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2006/2007The objective of this thesis is discussing the application of multiple antenna technology in some selected areas of wireless networks and fourth-generation telecommunication systems. The original contributions of this study involve, mainly, two research fields in the context of the emerging solutions for high-speed digital communications: the mathematical modeling of distributed wireless networks adopting advanced antenna techniques and the development of iterative algorithms for antenna array pattern synthesis. The material presented in this dissertation is the result of three-year studies performed within the Telecommunication Group of the Department of Electronic Engineering at the University of Trieste during the course of Doctorate in Information Engineering. In recent years, an enormous increase in traffic has been experienced by wireless communication systems, due to a significant growth in the number of users as well as to the development of new high bit rate applications. It is foreseen that in the near future this trend will be confirmed. This challenging scenario involves not only the well established market of cellular systems, but also the field of emerging wireless technologies, such as WiMAX (Worldwide interoperability for Microwave Access) for wireless metropolitan area networks, and Wi-Fi (Wireless Fidelity) for wireless local area networks, mobile ad-hoc networks and wireless mesh networks. The rapid diffusion of architectures adopting an ad-hoc paradigm, in which the network infrastructure is totally or partially absent and that can be deployed using low-cost self-configuring devices, has further enlarged the number of systems that have to coexist within a limited frequency spectrum. In such evolving environment, the development of interference mitigation methods to guarantee the communication reliability, the implementation of proper radio resource allocation schemes for managing the user mobility as well as for supporting multimedia and high speed applications, represent the most relevant topics. Classic approaches are focused on the use of the time-frequency resources of the propagation channel. However, to satisfy the increasing demand of network capacity, while guaranteeing at the same time the necessary levels in the quality of the offered services, operators and manufacturers must explore new solutions. In this scenario, the exploitation of the spatial domain of the communication channel by means of multiple antenna systems can be a key improvement for enhancing the spectral efficiency of the wireless systems. In a rich scattering environment, the use of multiple antennas enables the adoption of diversity and spatial multiplexing techniques for mitigating and, respectively, exploiting multipath fading effects. In propagation environments characterized by small angular spreads, the combination of antenna arrays and beamforming algorithms provides the possibility to suppress the undesired sources and to receive the signals incoming from the desired ones. This leads to an increase of the signal to interference plus noise ratio at the receiver that can be exploited to produce relevant benefits in terms of communication reliability and/or capacity. A proper design of the medium access control layer of the wireless network can enable the simultaneous exchange of packets between different node pairs as well as the simultaneous reception of packets from multiple transmitters at a single node. Switched-beam antennas, adaptive antennas (also referred to as smart antennas), and phased-antenna arrays represent some of the available beamforming techniques that can be applied to increase the overall system capacity and to mitigate the interference, in a scenario where several different technologies must share the same frequency spectrum. In the context of distributed wireless networks using multiple antenna systems, the core of this thesis is the development of a mathematical model to analyze the performance of the network in presence of multipath fading, with particular reference to a scenario in which the signal replicas incoming at the receiver are confined within a small angle and are characterized by small relative delays. This propagation environment, referred to as low-rank, is the typical operating scenario of smart antennas, which necessitate high spatial correlation channels to work properly. The novel aspects of this study are represented by the theoretical and numerical modeling of the sophisticated adaptive antennas in conjunction with a detailed description of the channel statistics and of the IEEE 802.11 medium access control scheme. A theoretical model providing a more realistic perspective may be desirable, considering that, at present, not only cost and competition issues, but also too optimistic expectations, as compared to the first measurements on the field, have induced the wireless operators to delay the adoption of smart antenna technology. The presented analysis includes the most relevant elements that can influence the network behavior: the spatial channel model, the fading statistic, the network topology, the access scheme, the beamforming algorithm and the antenna array geometry. This last aspect is numerically investigated considering that the size of the user terminal represents a strict constraint on the number of antennas that can be deployed on the device, and so the maximization of the performance becomes related to the geometrical distribution of the radiators. In ad-hoc and mesh networks, the typical communication devices, such as laptops, palmtops and personal digital assistants require compact and cheap antenna structures as well as beamforming algorithms easy to implement. In particular, the low-cost characteristics have guaranteed a wide popularity to wireless mesh technology, which have encouraged the birth of a new social phenomenon, known as wireless community networks, whose objective is the reduction of the Internet access cost. The adoption of multi-antenna systems is the purpose of the IEEE 802.11n amendment, which, however, not considering modifications of the medium access control layer, provides higher bit rates for the single link, but does not allow simultaneous communications between different couples of nodes. This aspect must be taken into account together with the fact that, nowadays, IEEE 802.11x represents the leading family of standards for wireless local communications, and enhancement proposals have to pay careful attention to the backward compatibility issues. The mathematical model presented in this thesis discusses the suitable parameter settings to exploit advanced antenna techniques in 802.11-based networks when the access scheme supports multiple communications at the same time, maintaining a realistic description for the antenna patterns and the channel behavior. The presentation of two new iterative algorithms for antenna array pattern synthesis represents the core of the last part of this dissertation. The proposed solutions are characterized by implementation simplicity, low computational burden and do not require the modification of the excitation amplitudes of the array elements. These advantages make the presented algorithms suitable for a wide range of communication systems, while matching also the inexpensiveness of mesh and ad-hoc devices. In particular, phase-only synthesis techniques allow the adoption of a cheaper hardware, including only phase shifters, which are available at a reasonable price, while avoiding the use of the more expensive power dividers. The first presented algorithm employs the spatial statistic of the channel for properly placing the pattern nulls, in order to suppress the undesired power incoming from a given angular interval. This solution exploits the improved knowledge of the spatial properties of the propagation environment for enhancing the interference suppression capabilities at the transmitter and receiver sides. The second algorithm is a phase-only technique that is able to generate multiple nulls towards the undesired directions and multiple main lobes towards the desired ones. This method provides the possibility to perform spatial multiplexing adopting low-cost electronic components. The thesis is organized in three parts. The first one provides the background material and represents the basics of the following arguments, while the other two parts are dedicated to the original results developed during the research activity. With reference to the first part, the fundamentals of antenna array theory are briefly summarized in the first chapter. The most relevant aspects of the wireless propagation environment are described in the second chapter, focusing on the characteristics of the spatial domain in a low-rank scenario. The third chapter presents a classification of the different multiple antenna techniques according to the channel properties and provides an overview of the most common beamforming algorithms. The fourth chapter introduces the most significant aspects of the distributed wireless networks, presenting the main open issues and the current proposals for the exploitation of the potential offered by antenna array systems. The second part describes the original results obtained in the mathematical modeling of ad-hoc and mesh networks adopting smart antennas in realistic propagation scenarios. In particular, the fifth chapter presents the theoretical analysis to evaluate the number of simultaneous communications that can be sustained by a distributed wireless network using adaptive antennas in presence of multipath. The sixth chapter extends this model to switched-beam antennas, while addressing the mobility aspects and discussing the cost-benefit tradeoff that is related to the use of multiple antenna techniques in today's wireless networks. A detailed throughput-delay analysis is performed in the seventh chapter, where the impact of advanced antenna systems on 802.11-based networks is investigated using a Markov chain model. The influence of the antenna array geometry is examined in the eighth chapter adopting a numerical approach based on a discrete-time simulator, which is able to take into account the details of the channel and of the antenna system behavior. The third part describes the original results obtained in the field of antenna array pattern synthesis. The ninth chapter presents the technique developed to modify the excitation phases of an antenna array in order to reject interferers spread over an angular region according to a given spatial statistic. The tenth chapter describes the iterative algorithm for phased arrays, which is able to produce low side-lobe level patterns with multiple prescribed main lobes and nulls. Finally, the eleventh chapter summarizes the thesis contributions and remarks the most important conclusions. The intent of the work presented hereafter is to examine the benefits that derive from the employment of smart antenna techniques from a realistic perspective, as well as to provide some useful solutions to improve the reliability of the communications and to increase the network capacity.
XX Ciclo
1973
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LONGHI, PATRICK ETTORE. « Circuiti e sottosistemi a microonde e onde millimetriche per ricevitori a basso rumore e antenne intelligenti ». Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/917.
Texte intégralRésumé :
Questo lavoro affronta gli aspetti riguardanti le metodologie e tecniche di analisi e progettazione per alcune funzionalità in front-end ricevitori a radiofrequenza ad elevata sensibilità e riconfigurabili. Tali funzionalità sono: l’amplificazione a basso rumore e il controllo dell’ampiezza di un segnale a RF. Infine, un’ulteriore investigazione ha focalizzato gli aspetti e le criticità in circuiti multi-funzione a elevata integrazione.
E’ stata mostrata una metodologia per progettazione di amplificatori a basso rumore a microonde che ha portato a definire le relazioni di adattamento simultaneamente ottenibile in ingresso e uscita in un LNA. Il principale risultato di tale investigazione è l’individuazione di un grafico che permette di valutare in modo sinottico il guadagno di trasduzione e gli adattamenti I/O di una rete 2-porte amplificatrice una volta fissata l’impedenza di sorgente, e quindi il fattore di rumore del LNA.
Sull’argomento degli amplificatori a basso rumore a onde millimetriche, è stato proposto un insieme di metodi analitici e sintetici che coprono le tematiche dalla scelta della tecnologia del dispositivo attivo al test del LNA realizzato. E’ stato ripreso il significato della Misura di Rumore nella progettazione a basso rumore a onde millimetriche investigando anche le tematiche della simulazione EM planare e 3D a onde millimetriche.
All’interno della tematica sul controllo dell’ampiezza di un segnale a RF è stato investigato in profondità lo sfasamento parassita connesso al cambio di stato in attenuatori digitali a commutazione. E’ stata suggerita una tecnica circuitale e sono state ricavate equazioni di progetto che permettono di compensare tale sfasamento indesiderato, fornendo una relazione che consente di dimensionare l’elemento reattivo che compensa tale effetto sgradito.
Infine, sulla materia della progettazione di circuiti-multi funzione a elevata integrazione è stata investigata la realizzabilità di un modulo contenente diverse funzionalità: controllo dell’ampiezza del segnale, amplificazione, scelta del modo T/R, controllo della fase del segnale e conversione seriale/parallelo dei dati di comando. Sono state presentate le procedure di progetto di alcuni sottosistemi nonché i criteri e i passi seguiti nella fase di integrazione.This work deals with aspects relating to analysis and design methodologies and techniques for some circuits in high sensitivity and reconfigurable front-end RF receivers. These circuits are: low noise amplifier and RF attenuators. Finally, further investigation has focused aspects and issues of multi-function high integration circuits. A methodology for designing microwave low noise amplifiers is reported. The latter has led to define the I/O matching relationships simultaneously achievable in an LNA. The main result of this investigation is the identification of a chart that allows to synoptically evaluating the achievable gain and I/O matching of a 2-port amplifier, once the source impedance is fixed and consequently the LNA noise factor. A set of analytical and synthetic methods on millimetre wave low noise amplifiers has been proposed, covering topics from the active device technology selection to test the realized LNA. The meaning of the noise measure parameter is reprised for designing millimetre wave low-noise. The issues of and 3D planar EM millimetre wave simulation is also investigated. The parasitic phase shift in digital attenuators has been investigated in depth. Such parasitic effect is related to the change of state in digital switched attenuators. A technique has been suggested and circuit equations were derived that allow to compensate such unwanted phase shift, providing design relations that allows to estimate the value of the reactive element that compensates for this undesirable effect. Finally, in the field of multi-function high-integration circuits design, the feasibility of a module containing several functionalities has been investigated. The latter are: control of the signal amplitude, amplification, selection of Tx/Rx mode, control the phase of the signal and serial to parallel control data conversion. The design procedures of some sub-modules, together with the criteria and the steps followed in the process of integration, have been reported.
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Jaeck, Vincent. « Développement d’antennes de communication reconfigurables en bande C pour munitions intelligentes ». Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S104/document.
Texte intégralRésumé :
De nos jours, les communications sans fil sont devenues un moyen incontournable et universel d'échange d'un large éventail d'informations entre différents systèmes, certains d'entre eux étant en mouvement comme des drones parmi tant d'autres. Dans le contexte de cette thèse nous considérons une liaison entre un projectile et une station de base. La géométrie de la structure ainsi que les contraintes aérodynamiques d'un tir balistique impliquent l'utilisation d'antennes patchs dans la partie conique à l'avant du projectile. Ce type d'antenne est facile à intégrer à une plate-forme en tant que réseau conformé tout en respectant les contraintes d'encombrement. Ces communications doivent être fiables et discrètes dans un environnement perturbé ou hostile. Les diagrammes de rayonnement du réseau d'antennes doivent présenter des caractéristiques spécifiques, notamment dans le cas particulier d'objets volants et possédant une rotation en roulis (rotation autour de son axe) qui impliquent l'utilisation d'un réseau phasé et commuté par rapport à sa position. Une antenne qui présenterait un rayonnement fixe assurerait une liaison avec un interlocuteur, mais rayonnerait également dans d'autres directions sensibles ce qui pourraient interférer avec la communication principale. La solution qui consiste à activer et désactiver des sous-réseaux verticaux afin d'orienter le lobe principal dans la plan orthogonal à la pointe semble être en accord avec les contraintes de la structure tournante. Un réseau conique a été étudié puis 2 prototypes ont été fabriqués, dont un à l'ISL. Les sous-réseaux sont répartis de manière égale autour de la pointe de façon à pouvoir rayonner dans toutes les directions. De plus, chaque sous-réseau est composé de trois éléments ce qui permet d'orienter également le lobe principal dans le plan longitudinal de la pointe (le long de l'axe du projectile) grâce à un dépointage électronique. Un système électronique de formation de faisceaux a été développé dans le but de contrôler 12 éléments rayonnants. Le réseau d'antennes ainsi que le circuit de répartition ont été caractérisés dans un premier temps de manière indépendante afin d'optimiser les lois de phase nécessaires à dépointer le lobe à partir des pondérations mesurées. Au final, le réseau de 12 éléments associé à son système d'alimentation dédié a été mesuré dans les chambres anéchoïques de DGA-MI et de l'ISL et les mesures sont en accord avec les simulationsNowadays wireless communications have become a useful and universal mean to exchange a wide range of information between different systems, some of them being moving, as UAVs among others. In this context we consider here the link between a projectile and a base station. The shape of the structure and the aerodynamic constraints involve the use of patch antennas in the conical front part. This class of antenna is easy to be integrated into the platform as a conformal array, while respecting space constraint. Communications have to be reliable and discrete in disturbed or hostile environment. Antennas array radiation patterns must have some specific characteristics, in particular in the case of flying objects with spin which involves the use of a switched phased array considering its roll position. A fixed-radiation pattern antenna may presents a relevant level or gain toward the interlocutor, but also toward sensitive directions, in which may be located others systems, interfering with the current communication. The solution to switch on and off vertical sub-arrays to steer the beam in the azimuthal plane seem convenient ant fitting the requirements of rotating platform. A conical phased array was studied and two prototypes were manufactured, one at ISL. Sub-arrays are distributed around the conical shape in order to be able to radiate in each direction. Moreover, each sub-array are composed of three radiating elements allowing to steer the main antenna beam in many direction (along the projectile fuze axes). A beam forming network was developed to control the 12 radiating elements conical array. The antenna array and the feeding network were characterized independently in order to optimized the phase of each radiating element. Finally, measurements were done on the whole system in the DGA-MI and ISL anechoic chambers and are in good agreement with simulation results
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Nguyen, Trong Duc. « Conception d'antenne intelligente reconfigurable pour la radio cognitive ». Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENT027/document.
Texte intégralRésumé :
Les antennes reconfigurables offrent de multiples fonctions en changeant dynamiquement leurs propriétés telles que la fréquence de fonctionnement, la polarisation, le diagramme de rayonnement ou toute combinaison de ces trois paramètres. Leur agilité et leur diversité créent de nouvelles possibilités d'applications pour les systèmes radio tels que les réseaux locaux, les liaisons par satellite et notamment la radio cognitive. Dans cette thèse, deux antennes reconfigurables en fréquence fonctionnant dans les bandes des standards sans fil actuels ont été proposées. Elles sont basées sur la modification de la géométrie du patch rayonnant. Leurs dimensions ont été optimisées par algorithmes génétiques embarqués et combinés à un logiciel de simulation électromagnétique. La commande de la reconfiguration de ces antennes est réalisée à l'aide d'un microcontrôleur qui pilote l'état des commutateurs (des diodes PIN). De ce fait, un système d'antenne reconfigurable intelligent dédié à la radio cognitive a été développéReconfigurable antennas offer multiple functions by dynamically changing their properties such as operating frequency, polarization, radiation pattern, and a combination of all these factors. Their agility and diversity create a wide range of different and new applications for radio systems such as local networks, satellites, and especially in cognitive radio. In this thesis, two new frequency reconfigurable antennas are proposed. The frequency reconfiguration is obtained by changing the geometry of radiating patch. Their dimensions have been optimized by genetic algorithm embedded in the electromagnetic simulation software. These antennas operate at the frequency band for IEEE 802.11b/g standard with satisfactory radiation characteristics. This thesis also presents a method of controlling the operation of the frequency reconfigurable antenna by a micro-controller. The operation of electronic switches (PIN diodes) are carried out through programs which allows an adaptive operating system like smart antennas and work well in cognitive radio environment
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Thévenard, Julian. « Contribution à la conception à bas coût d'antennes 3D reconfigurables : solutions originales d'intégration en technologie plastique pour les systèmes sans fil du futur ». Brest, 2008. http://www.theses.fr/2008BRES2011.
Texte intégralRésumé :
Cette thèse a été consacrée à la conception d'antennes volumiques reconfigurables pour les produits sans fils du futur. Ces recherches ont été motivées par la tendance actuelle conduisant à une centralisation des services au sein des réseaux locaux sans fil et une miniaturisation des dispositifs. Ceci se traduit par une contrainte d'encombrement pour les antennes qui se doivent également d'apporter des solutions aux problèmes d'affaiblissements dus aux trajets multiples et aux interférences tout en améliorant les capacités (portée, qualité, consommation) du dispositif. Nous présentons ainsi une solution d'antenne multi-secteurs associant plusieurs antennes Vivaldi en réponse aux problèmes de l'application visée à savoir un système embarqué de type caméra haute définition sans fil. Après une étude théorique de l'antenne Vivaldi, un nouveau concept d'antenne multi-secteurs a été introduit et validé. La nécessité d'une réalisation industrielle à grande échelle et à bas coût de formes complexes nous a conduit vers la technologie plastique métallisé pour fabriquer l'antenne. Un système original de report sans soudure a ainsi été développé pour intégrer l'antenne en plastique au reste du système. La caractérisation d'un prototype a permis de valider l'utilisation du plastique pour ce genre d'applications. Cette antenne a ensuite été intégrée à une caméra sans fil puis recouverte d'un radôme protecteur qui permet d'améliorer les performances. Cette intégration simplifiée associée au contrôle des performances et à la flexibilité de l'antenne permet d'envisager des utilisations dans des applications aussi diverses que les réseaux domestiques ou maillés, ou pour la technologie MIMOThis thesis is dedicated to the design of 3D smart antennas for forthcoming wireless devices. Our research work has been motivated by the actual wireless trends leading to service concentration within WLAN and device miniaturisation. Thus, antenna design is nowadays guided by size constraints and their capacity to deal with fading interference, wireless environments while improving the performances of devices in terms of communication quality, power consumption. This thesis presents a multi-sector antenna solution associating many Vivaldi-antennas to provide a solution for the targeted application which is an embedded system constituting of high definition wireless cameras. A theoretical analysis of the Vivaldi antenna is first performed and then a novel concept of multi-sector antenna has been introduced and validated. Then, in order to target consumer market and to reduce the manufacturing costs in high volume production, the metallized molded plastic technology which enables molding 3D complex structures has been retained. An original without-welding transfer system has been developed for integrating the antenna to the rest of the system. The characterization of a prototype has resulted in the validation of the use of plastics for such applications. This antenna has been integrated in a wireless camera ; a protective radome having as additional property to improve the overall performances of the device is finally designed. This simplified integration procedure associated to a monitoring of the performances and the flexibility of the system makes it a good candidate for various applications like domestic WLAN, mesh networks or for MIMO technology
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Nguyen, Trong duc. « Conception d'antenne intelligente reconfigurable pour la radio cognitive ». Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00859818.
Texte intégralRésumé :
Les antennes reconfigurables offrent de multiples fonctions en changeant dynamiquement leurs propriétés telles que la fréquence de fonctionnement, la polarisation, le diagramme de rayonnement ou toute combinaison de ces trois paramètres. Leur agilité et leur diversité créent de nouvelles possibilités d'applications pour les systèmes radio tels que les réseaux locaux, les liaisons par satellite et notamment la radio cognitive. Dans cette thèse, deux antennes reconfigurables en fréquence fonctionnant dans les bandes des standards sans fil actuels ont été proposées. Elles sont basées sur la modification de la géométrie du patch rayonnant. Leurs dimensions ont été optimisées par algorithmes génétiques embarqués et combinés à un logiciel de simulation électromagnétique. La commande de la reconfiguration de ces antennes est réalisée à l'aide d'un microcontrôleur qui pilote l'état des commutateurs (des diodes PIN). De ce fait, un système d'antenne reconfigurable intelligent dédié à la radio cognitive a été développé.
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Bletsas, Aggelos Anastasiou 1975. « Intelligent antenna sharing in cooperative diversity wireless networks ». Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33876.
Texte intégralRésumé :
Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2005.Includes bibliographical references (p. 143-152).
Cooperative diversity has been recently proposed as a way to form virtual antenna arrays that provide dramatic gains in slow fading wireless environments. However, most of the proposed solutions require simultaneous relay transmissions at the same frequency bands, using distributed space-time coding algorithms. Careful design of distributed space-time coding for the relay channel is usually based on global knowledge of some network parameters or is usually left for future investigation, if there is more than one cooperative relay. We propose a novel scheme that eliminates the need for space-time coding and provides diversity gains on the order of the number of relays in the network. Our scheme first selects the best relay from a set of M available relays and then uses this "best" relay for cooperation between the source and the destination. Information theoretic analysis of outage probability shows that our scheme achieves the same diversity-multiplexing gain tradeoff as achieved by more complex protocols, where coordination and distributed space-time coding for M relay nodes is required. Additionally, the proposed scheme increases the outage and ergodic capacity, compared to non-cooperative communication with increasing number of participating relays, at the low SNR regime and under a total transmission power constraint.
(cont.) Coordination among the participating relays is based on a novel timing protocol that exploits local measurements of the instantaneous channel conditions. The method is distributed and allows for fast selection of the best relay as compared to the channel coherence time. In addition, a methodology to evaluate relay selection performance for any kind of wireless channel statistics is provided. Other methods of network coordination, inspired by natural phenomena of decentralized time synchronization, are analyzed in theory and implemented in practice. It was possible to implement the proposed, virtual antenna formation technique in a custom network of single antenna, half-duplex radios.
by Aggelos Anastasiou Bletsas.
Ph.D.
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Somda, Flavien Hervé. « Développement de stratégies de commande et de perception pour une régulation de vitesse intelligente ». Rennes 1, 2009. https://tel.archives-ouvertes.fr/tel-00449772.
Texte intégralRésumé :
Les conditions actuelles de transport démontrent par elles-même l'urgence qu'il y'a à intervenir dans la sécurisation des routes par des moyens autres que purement répressifs. Le recours aux véhicules intelligents dotés de technologies de perception et de commande avancées, capables de prendre en charge, au moins en partie, certaines tâches de conduite, semble justier ce point de vue. Dans cette thèse, nous proposons une stratégie de commande basée sur un modèle d'accélération non linéaire de type exponentiel, sûre, robuste, confortable et compatible aussi bien avec les applications de régulation de vitesse intelligente (ACC) qu'avec les applications Stop&Go. Nous proposons également, une stratégie de détection par dépointage de faisceau d'antenne qui augmente sensiblement la distance de détection et permet l'identication de scénarios du trafic routier, toutes choses importantes pour la mise en oeuvre d'une stratégie de commande efficaceMonitoring and Perception Strategies Design for Intelligent Cruise Control Today's trac conditions call for the event of Intelligent Transportation Systems for road safety improvement. In Intelligent vehicles driven by such technologies, at least, part of the driving task is managed by embeded systems. In this thesis report, we oer a new longitudinal control strategy based on a nonlinear, second order, and exponential prole model. The approach is safe, robust, comfortable and consistent with Intelligent Cruise Control as well as Stop&Go applications. We also propose a detection approach based on an antenna beam scanning strategy that drastically improves distance of detection and enables identication of traffic scenarios. Such results are essential for an efficient longitudinal control strategy design
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Rodrigues, de Araujo Ricardo. « Traitement spatio-temporel basé sur l'utilisation de bases orthonormales généralisées : application aux réseaux de paquets ». Paris 11, 2003. http://www.theses.fr/2003PA112101.
Texte intégralRésumé :
La technique d'accès par paquet radio est une option intéressante pour les systèmes radio mobiles dédiés au trafic multimédia. Avec cette technique, les ressources radio sont allouées seulement lorsque les utilisateurs sont actifs, ce qui permet le partage du canal avec plusieurs usagers. L'accès est alors un point clé. Les protocoles S-Aloha et R-Aloha sont très populaires du à leur simplicité. Cependant, ces protocoles n'ont pas une bonne efficience spectrale. Une solution possible pour faire augmenter l'efficience de ces protocoles est l'utilisation d'antennes intelligentes. Dans ce contexte, plusieurs travaux ont été consacrés à l'analyse des performances des réseaux sous l'action des antennes. Toutefois, la plus part de ces études a privilégié les aspects systémiques en détriment des aspects du traitement des signaux. Dans cette thèse, nous évaluons les bénéfices apportés par l'utilisation d'antennes intelligentes aux réseaux de paquets sous les protocoles S-Aloha et R-Aloha. Nous abordons l'influence de la géométrie des antennes utilisée ainsi que l'influence des caractéristiques du canal sur les performances des réseaux. Dans les réseaux de paquets, la récupération de l'information envoyée doit, en général, être achevée durant la période de temps correspondant à l'envoi du paquet. De ce fait, la complexité des algorithmes ne doit pas être très élevée. Afin de réduire l'ordre et par conséquent la complexité des filtres utilisés pour le filtrage spatio-temporel, nous proposons une structure de filtrage basée sur l'utilisation de bases orthonormales généralisées. Ces bases s'avèrent très performantes si leurs paramètres, les pôles, sont judicieusement choisis. Dans ce travail, nous comparons les performances de la structure proposée avec celles des filtres RIF conventionnels. Nos simulations montrent que la structure proposée permet l'utilisation de filtres d'ordre réduite tout en gardant les mêmes performances des filtres RIF d'ordre beaucoup plus élevéeThe packet radio access is an interesting option for multimedia traffic in radio mobile networks. This technique allows a radio resource allocation based on the user's activity in such a way that the canal may be used in a multi-user mode. So, the MAC protocol plays a fundamental role in this context. The S-Aloha and R-Aloha protocols are the most popular schemes due to their simplicity. Nevertheless, they offer a poor spectral efficiency. The use of smart antennas is widely proposed as a way of increasing the spectral efficiency of these MAC protocols. Actually, several papers were dedicated to performance analysis of packet networks with smart antennas. However, most of then have focussed only on the systemic aspects in detriment of signal processing ones. In this work, we evaluate the advantage of using smart antennas in a packet network with S-Aloha and R-Aloha MAC. We focus on the channel and the array geometry influences over the network performances. In the packet networks, the signal processing must be accomplished within the packet transmission time slot. That is the why the algorithm complexity must be limited. In order to decrease the overall system complexity, we propose the use of generalized orthonormal basis for the space-time equalizers. This strategy allows an equalizer order reduction if the base poles are correctly chosen. In this thesis, we compare the proposed structure performance with the conventional FIR one. Our simulations show that the proposed strategy leads to an efficient equalizer order reduction
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Rafael, Marcos César. « Projeto e desenvolvimento de um sistema inteligente para alinhamento de uma antena parabólica receptora ». Universidade de Taubaté, 2011. http://www.bdtd.unitau.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=256.
Texte intégralRésumé :
O objetivo deste trabalho é projetar e desenvolver um sistema automatizado inteligente para o alinhamento de uma antena receptora com refletor parabólico aplicado a comunicação via satélite. Com base em procedimentos empíricos para o alinhamento manual de uma antena parabólica, foi concebida e desenvolvida uma solução tecnológica empregando hardware e software. O sistema concebido utiliza um GPS, para prover a localização espacial instantânea da antena receptora e um receptor digital, que fornece a relação portadora / ruído de recepção. A principal contribuição deste trabalho foi o projeto e desenvolvimento de um sistema computacional inteligente, denominado Sistema Inteligente de Alinhamento de Satélite que visa a automatizar o alinhamento de antena receptora. Para um determinado satélite, o sistema utiliza a informação sobre a qualidade do sinal recebido para acionar um servomecanismo responsável pelo alinhamento da antena. Verificou-se que quando a antena estiver na posição desejada, a relação portadora ruído deverá estar acima de 8 dB para uma boa qualidade de recepção. Foi desenvolvido um projeto de um sistema inteligente para uma varredura em torno do valor de referência de posição da antena, o qual se denominou ajuste fino da posição da antena. Nossa inédita abordagem para o ajuste fino projetou-se um controlador fuzzy do tipo Mandani, cujas regras foram geradas de acordo com o processo de posicionamento manual da antena parabólica. Nossa solução permitiu melhorar a relação portadora / ruído de recepção.The objective of this work is to design and develop an intelligent automated system for the alignment of a receiving antenna with parabolic reflector applied to satellite communication. Based on empirical procedures manual for the manual alignment of a parabolic antenna, we designed and developed a technological solution using hardware and software. The system uses a GPS to provide the initial spatial location of the receiving antenna and a digital receiver to provide the carrier-to-noise ratio. The main contribution of this work was the design and development of an intelligent computational system which aims at automating the receiving antenna alignment. For a given satellite, through the dynamic handling of relocate the receiving antenna, the system uses information about the quality of the received signal to drive the servo responsible for aligning the antenna. We found that, the antenna is in the desired position, the carrier-to-noise ratio should be above 8 dB for a good reception quality. We developed the project of an intelligent system to scan around the reference antenna position value, which was called the antenna position fine tuning. Our new approach consisted in a fuzzy controller type Mandani, generated according to the manual process of maneuvering the dish. Our solution has improved the carrier-to-noise ratio by repositioning the antenna in the desired position.
Livres sur le sujet "Antenne intelligenti"
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S©ırensen, Troels B. Intelligent Distributed Antenna Systems (IDAS) : Assessment by measurement and simulation. Aalborg : Dept. of Communication Technology, Institute of Electronic Systems, Aalborg University, 2003.
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Blogh, J. S. Third-generation systems and intelligent wireless networking : Smart antennas and adaptive modulation. Chichester, West Sussex, England : John Wiley & Sons, Ltd., 2002.
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United States. National Telecommunications and Information Administration., dir. Medium frequency propagation prediction techniques and antenna modeling for Intelligent Transportation Systems (ITS) broadcast applications. [Boulder, Colo.] : U.S. Dept. of Commerce, National Telecommunications and Information Administration, 1999.
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DeMinco, N. Medium frequency propagation prediction techniques and antenna modeling for Intelligent Transportation Systems (ITS) broadcast applications. [Boulder, Colo.] : U.S. Dept. of Commerce, National Telecommunications and Information Administration, 1999.
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United States. National Telecommunications and Information Administration, dir. Medium frequency propagation prediction techniques and antenna modeling for Intelligent Transportation Systems (ITS) broadcast applications. [Boulder, Colo.] : U.S. Dept. of Commerce, National Telecommunications and Information Administration, 1999.
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United States. National Aeronautics and Space Administration., dir. Wide-bandwidth high-resolution search for extraterrestrial intelligence : Semiannual status report 15 June 1993 - 15 Dec 1993. Cambridge, MA : Harvard University, 1993.
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7
United States. National Aeronautics and Space Administration., dir. Wide-bandwidth high-resolution search for extraterrestrial intelligence : Semiannual status report 15 June 1993 - 15 Dec 1993. Cambridge, MA : Harvard University, 1993.
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8
Paul, Horowitz. Wide-bandwidth high-resolution search for extraterrestrial intelligence : Semiannual status report 15 June 1993 - 15 Dec 1993. Cambridge, MA : Harvard University, 1993.
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Paul, Horowitz. Wide-bandwidth high-resolution search for extraterrestrial intelligence : Semiannual status report 15 June 1993 - 15 Dec 1993. Cambridge, MA : Harvard University, 1993.
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10
United States. National Aeronautics and Space Administration., dir. Wide-bandwidth high-resolution search for extraterrestrial intelligence : Semiannual status report 15 June 1993 - 15 Dec 1993. Cambridge, MA : Harvard University, 1993.
Trouver le texte intégralChapitres de livres sur le sujet "Antenne intelligenti"
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Sharma, Ragini, Vandana Niranjan, Vibhav Kumar Sachan et R. N. Baral. « Dual-Cavity SIW MIMO Antenna ». Dans Algorithms for Intelligent Systems, 623–28. Singapore : Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6307-6_63.
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Agarwal, Anshul, P. K. Singhal et V. V. Thakare. « Wideband Crossed Dipole Antenna for Base Station Antenna ». Dans Intelligent Computing Applications for Sustainable Real-World Systems, 261–70. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-44758-8_23.
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Tripathi, Subodh Kumar, et Ajay Kumar. « Performance Comparison of Graphene Terahertz Antenna and Copper Terahertz Antenna ». Dans Advances in Intelligent Systems and Computing, 489–97. Singapore : Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-1275-9_40.
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Mersani, A., W. Bouamra, J. M. Ribero et L. Osman. « UWB textile antenna for medical applications ». Dans Innovative and Intelligent Technology-Based Services for Smart Environments – Smart Sensing and Artificial Intelligence, 56–60. London : CRC Press, 2021. http://dx.doi.org/10.1201/9781003181545-10.
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Sanchez, Ernesto, Giovanni Squillero et Alberto Tonda. « Antenna Array Synthesis with Evolutionary Algorithms ». Dans Intelligent Systems Reference Library, 47–54. Berlin, Heidelberg : Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-27467-1_5.
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Keshri, Pankaj Kumar, et Richa Chandel. « Wideband MIMO antenna with improved isolation ». Dans Intelligent Circuits and Systems, 278–83. London : CRC Press, 2021. http://dx.doi.org/10.1201/9781003129103-44.
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Arya, Vivek, et Tanuj Garg. « Leaky Wave Antenna : Past and Present ». Dans Algorithms for Intelligent Systems, 229–37. Singapore : Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6307-6_24.
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Chouhan, Sonali, et Tinamoni Taye. « Low Complexity Antenna Selection Scheme for Spatially Correlated Multiple Antenna Cognitive Radios ». Dans Advances in Intelligent Systems and Computing, 275–83. Singapore : Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-15-0132-6_19.
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Singh, P., R. Doti, J. E. Lugo, J. Faubert, S. Rawat, S. Ghosh, K. Ray et A. Bandyopadhyay. « Biological Infrared Antenna and Radar ». Dans Advances in Intelligent Systems and Computing, 323–32. Singapore : Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-5699-4_31.
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Kumar, Sanjeev, A. Veekshita Sai Choudhary, Aditya Andotra, Himshweta Chauhan et Anshika Mathur. « Circularly Polarized Microstrip Patch Antenna for 5G Applications ». Dans Intelligent Sustainable Systems, 273–82. Singapore : Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-6369-7_24.
Texte intégralActes de conférences sur le sujet "Antenne intelligenti"
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Sulic, E., B. Pell, S. John, Rahul K. Gupta, W. Rowe, K. Ghorbani et K. Zhang. « Performance of Embedded Multi-Frequency Communication Devices in Smart Composite Structures ». Dans ASME 2008 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2008. http://dx.doi.org/10.1115/smasis2008-402.
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Lately, there has been an increased demand for vehicle manufacturers to incorporate a large number of communication, security, guidance and entertainment devices in their new vehicle models. In recent decades, the list has expanded from the AM and FM radio antennas to include GPS, mobile phone, collision avoidance radar, Digital Radio and Digital TV antennas. In addition, new technologies such as vehicle to vehicle and vehicle to road side communication are being implemented at 5.9 GHz in the next generation of vehicles. In the past the AM/FM antenna was typically a mast antenna protruding from the vehicle’s exterior, recently however, the trend has been to limit the visibility of vehicular antennas as much as possible to improve vehicle design and aerodynamics. This has lead to integration of antennae so that they become a seamless part of the vehicle structure. This paper reports on a parametric study of embedding an antenna in a polymeric composite substrate in relation to several material processing and coating parameters.
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Das, Hangsa Raj, Rajesh Dey et Sumanta Bhattacharya. « A REVIEW PAPER ON DESIGN FOR MICROSTRIP PATCH ANTENNA ». Dans Topics in Intelligent Computing and Industry Design. Volkson Press, 2021. http://dx.doi.org/10.26480/etit.02.2020.166.168.
Texte intégralRésumé :
Microstrip patch antenna is mostly used in modern communication devices over conventional antennas mainly because of their size. In this review paper a survey is conducted on commonly used techniques and design used in microstrip antenna papers which has been used by authors for designing of an efficient, low profile, small, compatible, affordable microstrip antenna, mainly used to designed reconfigurable, multiband and wideband antennas, after that a initiator patch design is given with dimensions on which technique will be applied for the analysis of different parameter of antenna.
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Daliri, Ali, Chun H. Wang, Sabu John, Amir Galehdar, Wayne S. T. Rowe, Kamran Ghorbani et Paul J. Callus. « FEA Evaluation of the Mechanical and Electromagnetic Performance of Slot Log-Spiral Antennas in Conformal Load-Bearing Antenna Structure (CLAS) ». Dans ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-5137.
Texte intégralRésumé :
Conformal load-bearing antenna structures (CLAS) have been attracting the attention of aerospace industries in recent years. This type of multifunctional structures combines the features of conventional antennas with load-bearing capacity and has important applications in military and commercial airplanes especially for Unmanned Aerial Vehicles (UAVs). Equiangular slot spiral antennas are an alternative to traditional rectangular slots because of its wideband radiation characteristics. However, the mechanical characteristics of such a spiral antenna integrated into a structure are so far largely unexplored. In this paper, the electromagnetic (scattering parameter, radiation pattern and gain) and mechanical properties (stress concentration factor (SCF)) of spiral antennas is investigated using finite element analysis (FEA). The results lead to a recommendation for using this type of antenna for future CLAS concepts.
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Wang, C. S., H. Bao et W. Wang. « Coupled Structural-Electromagnetic Optimization and Analysis of Space Intelligent Antenna Structural Systems ». Dans ASME 2008 9th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2008. http://dx.doi.org/10.1115/esda2008-59306.
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For high electromagnetic performances, large space truss antennas should have reflector surface with an extremely high precision. Due to the varied load and some random disturbances, active control strategy is always used in the kind of structure for the precise surface. For the improvement of the electromagnetic performances, an electromechanical synthesis optimization model of space antenna structure systems is developed based on the antenna’s characteristics, which adopts the axial gain of antenna and power consumption of actuators as the objective functions, and structural material strength and actuator’s capability as constraint conditions. The application of model to an 8-m antenna structure demonstrates the potential for significant improvement. The analysis results indicate the benefit of including electrical performance in model for necessary effort for shape control of large space antenna reflectors.
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Daliri, Ali, Sabu John, Chun H. Wang, Amir Galehdar, Wayne S. T. Rowe, Kamran Ghorbani et Paul J. Callus. « Effect of Filler Materials on the Performance of Conformal Load-Bearing Spiral Antennas ». Dans ASME 2012 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/smasis2012-7955.
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The slots in spiral antennas induce stress concentrations and hence may adversely affect the load-carrying capacity of the structural antenna. To minimise the detrimental effect of the slots, appropriate fillers are required to provide structural reinforcement without compromising the radar performance of the antenna. This paper presents an investigation of the effects of electrical and mechanical properties of potential filler materials on the performance of slot spiral antennas. Finite element analysis is carried out for a slot spiral that is designed to work in the C-Band range of frequencies (4–8 GHz). Computational simulations performed using commercial software packages ANSYS® and HFSS® show that by using commercially available filler materials the stress concentration factor of the spiral slot can be reduced by 20%. The results from this research enhance the previously introduced advantages of this type of conformal load-bearing antenna structure (CLAS). This CLAS concept provides a promising solution of replacing conventional externally mounted antennas, thus reducing aircraft weight and aerodynamic drag.
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Yi, Xiaohua, Chunhee Cho, Yang Wang, Benjamin S. Cook, James Cooper, Rushi Vyas, Manos M. Tentzeris et Roberto T. Leon. « Passive Frequency Doubling Antenna Sensor for Wireless Strain Sensing ». Dans ASME 2012 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/smasis2012-7923.
Texte intégralRésumé :
This paper presents the design, simulation, and preliminary measurement of a passive (battery-free) frequency doubling antenna sensor for strain sensing. Illuminated by a wireless reader, the sensor consists of three components, i.e. a receiving antenna with resonance frequency f0, a transmitting antenna with resonance frequency 2f0, and a matching network between the receiving and transmitting antennas. A Schottky diode is integrated in the matching network. Exploiting nonlinear circuit behavior of the diode, the matching network is able to generate output signal at doubled frequency of the reader interrogation signal. The output signal is then backscattered to the reader through the sensor-side transmitting antenna. Because the backscattered signal has a doubled frequency, it is easily distinguished by the reader from environmental reflections of original interrogation signal. When one of the sensor-side antennas, say receiving antenna, is bonded to a structure that experiences strain/deformation, resonance frequency of the antenna shifts accordingly. Through wireless interrogation, this resonance frequency shift can be measured by the reader and used to derive strain in the structure. Since operation power of the diode is harvested from the reader interrogation signal, no other power source is needed by the sensor. This means the frequency doubling antenna sensor is wireless and passive. Based on simulation results, strain sensitivity of this novel frequency doubling antenna sensor is around −3.84 kHz/με.
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Daliri, Ali, Chun H. Wang, Sabu John, Amir Galehdar, Wayne S. T. Rowe et Kamran Ghorbani. « Multidirectional Circular Microstrip Patch Antenna Strain Sensor ». Dans ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-5065.
Texte intégralRésumé :
In this paper, a new design for microstrip patch antenna strain sensors is proposed. The new antenna sensor works based on the meandered microstrip patch antennas. It is threefold more sensitive than previously proposed circular microstrip patch antenna strain sensors. Also, the overall physical dimension of the new antenna sensor is reduced by the factor of five. The current sensor is able to detect strain in all directions. In order to design the antenna sensor, two available commercial FEM software packages ANSYS™ and HFSS™ are used. Both experimental and FEM results corroborate the multidirectional feature of the new antenna sensor. Also, the effect of the hole size in the structure (for coaxial connection to the antenna) on the antenna performance has been studied. Based on the results obtained, the antenna sensor can be recommended for use in structural health monitoring for strain-based damage detection in aerospace structures.
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Daliri, Ali, Sabu John, Amir Galehdar, Wayne S. T. Rowe et Kamran Ghorbani. « Strain Measurement in Composite Materials Using Microstrip Patch Antennas ». Dans ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2010. http://dx.doi.org/10.1115/smasis2010-3703.
Texte intégralRésumé :
In this paper the feasibility of using a circular microstrip patch antenna to detect strain in composite plates and the effects of different materials on sensitivity of the patch antenna are investigated. Also the effect of strain direction on the frequency shift is studied. The theoretical model shows a linear relationship between strain and the shift in the resonant frequency of the antenna in any material. A circular microstrip patch antenna is designed and fabricated to work at 1.5GHz and attached to three different materials for testing. Both Finite Element Analysis (FEA) and experimental tests have been undertaken to corroborate the relationship between strain and frequency shift. The ultimate intention of this work is to configure antennas for the detection of relatively small damage zones in structures and to do so wirelessly.
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Daliri, Ali, Sabu John, Chun H. Wang, Amir Galehdar, Wayne S. T. Rowe et Kamran Ghorbani. « Wireless Strain Sensors Using Electromagnetic Resonators ». Dans ASME 2012 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/smasis2012-7954.
Texte intégralRésumé :
The concept of wireless passive strain sensors has been introduced in the last few years for applications such as structural health monitoring. This study investigates the use of circular microstrip patch antenna (CMPA) sensors for wireless passive measurement of strain. The strain induced in an aluminium plate was measured wirelessly up to 5 cm away from the sensor using a CMPA made from commercial FR4 substrate, and at a distance up to 20 cm using a CMPA made from Rogers® RT/duroid 6010™. These results show the substrate of antennas is one of the factors affecting the interrogation distance. The interrogation distance between the sensor and the patch antenna was improved significantly using the Rogers® substrate.
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Davies, Rose, et Lindsay Brazendale. « Intelligent Laundry Sorting System for Rest Homes ». Dans ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-63212.
Texte intégralRésumé :
Radio-frequency identification (RFID) and mechatronic technology has been applied to a laundry sorting system which can potentially be used by rest homes in the future to reduce the labour intensity of care givers, to increase the efficiency of laundry sorting, and to reduce the chance of garments being lost. A laboratory laundry identifying and sorting conveyor belt has been built. Several different types of RFID labels/tags have been considered and tested. A type of small RFID laundry tag, suitable for the laundry sorting conditions of a rest home, has been selected. The laundry tags have undergone endurance testing under actual washing and drying conditions with typical commercial laundry chemical products used in rest homes. There was a major challenge using commercial RFID tags in the proposed intelligent laundry sorting system due limitations in their antenna and signal receiving systems. A strategy to coordinate the orientations of the tags, range of the antenna, and the amplification of signal receiving units has been investigated. Several antenna designs to improve the identification rate have been tested and analysed for the selected small laundry tags, since the tag-receiver system has to work beyond the recommended range. A programme for signal detection and processing has been produced. The programme has taken into consideration the speed of the conveyor belt, antenna receiving range and the time required to process signals. It works with satisfactory precision at a satisfactory speed. A sorting strategy for implementation after laundry garment identification has been investigated. This strategy considers aspects of simplicity, multifunction and compactness of mechanical structure. A virtual sorting system has been produced to test the principles of the sorting strategy and the antenna design. The results of these tests will help us to move to the next stage, the design of a prototype laundry sorting system.