Étude de la transmission de signaux analogiques haute fréquence à large bande passante au moyen de liaisons à fibres optiques PDF Download

Author: Sophie Borderieux
Publisher:
ISBN:
Category :
Languages : fr
Pages : 248

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Book Description
Nous analysons le comportement de liaisons à fibres optiques pour la transmission de signaux analogiques haute fréquence à large bande passante. Le domaine d'application de cette étude est celui de la radioastronomie, où les liaisons à fibres optiques sont utilisées pour la transmission de signaux radiofréquence entre des antennes de radioastronomie et un récepteur central. Nos essais ont porté sur la mise en oeuvre d'une liaison de transmission analogique constituée d'un émetteur à laser semiconducteur, d'une fibre monomode et d'un photorécepteur à diode de type PIN ou à avalanche. Nous avons discuté des paramètres principaux qui caractérisent les performances d'une liaison analogique à fibre optique gain de la liaison, réponse en fréquence , paramètre RIN du laser, bruit de la liaison, dynamique et linéarité, rapport Signal sur Bruit. Des liaisons à fibres optiques ont pu être testées sur des instruments exploités à l'Observatoire de NANCAY : (1) au Radiotélescope Décimétrique, pour la transmission du signal radioélectrique contenu dans une bande spectrale de 60MHz centrée sur la moyenne fréquence de 545 MH ; proven.mt de l'antenne ; la liaison comprenant un câble à fibre optique de 200 mètres de long relie l'antenne mob ile au récepteur. (2) à l'interféromètre solaire, pour la transmission vers deux antennes du réseau d'un signal référence de fréquence entre 250 et 560 MHz; deux liaisons comprenant chacune 1 kilomètre de câble optique ont été utilisées.

Author: International Conference on Large High Voltage Electric Systems
Publisher:
ISBN:
Category : Electric industries
Languages : en
Pages : 1098

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Author: Rob Flickenger
Publisher: "O'Reilly Media, Inc."
ISBN: 9780596005023
Category : Computers
Languages : en
Pages : 190

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Book Description
Building Wireless Community Networks is about getting people online using wireless network technology. The 802.11b standard (also known as WiFi) makes it possible to network towns, schools, neighborhoods, small business, and almost any kind of organization. All that's required is a willingness to cooperate and share resources. The first edition of this book helped thousands of people engage in community networking activities. At the time, it was impossible to predict how quickly and thoroughly WiFi would penetrate the marketplace. Today, with WiFi-enabled computers almost as common as Ethernet, it makes even more sense to take the next step and network your community using nothing but freely available radio spectrum. This book has showed many people how to make their network available, even from the park bench, how to extend high-speed Internet access into the many areas not served by DSL and cable providers, and how to build working communities and a shared though intangible network. All that's required to create an access point for high-speed Internet connection is a gateway or base station. Once that is set up, any computer with a wireless card can log onto the network and share its resources. Rob Flickenger built such a network in northern California, and continues to participate in network-building efforts. His nuts-and-bolts guide covers: Selecting the appropriate equipment Finding antenna sites, and building and installing antennas Protecting your network from inappropriate access New network monitoring tools and techniques (new) Regulations affecting wireless deployment (new) IP network administration, including DNS and IP Tunneling (new) His expertise, as well as his sense of humor and enthusiasm for the topic, makes Building Wireless Community Networks a very useful and readable book for anyone interested in wireless connectivity.

Author: Rob Flickenger
Publisher: "O'Reilly Media, Inc."
ISBN: 9780596005597
Category : Computers
Languages : en
Pages : 310

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Continuing with the successful Hack Series, this title provides real-world working examples of how to make useful things happen with wireless equipment.

Author: Paolo Prandoni
Publisher: Collection Savoir suisse
ISBN: 2940222207
Category : Signal processing
Languages : en
Pages : 392

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Book Description
With a novel, less classical approach to the subject, the authors have written a book with the conviction that signal processing should be taught to be fun. The treatment is therefore less focused on the mathematics and more on the conceptual aspects, the idea being to allow the readers to think about the subject at a higher conceptual level, thus building the foundations for more advanced topics. The book remains an engineering text, with the goal of helping students solve real-world problems. In this vein, the last chapter pulls together the individual topics as discussed throughout the book into an in-depth look at the development of an end-to-end communication system, namely, a modem for communicating digital information over an analog channel.

Author:
Publisher:
ISBN:
Category : High technology
Languages : en
Pages : 160

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Author: Michel Chion
Publisher: Columbia University Press
ISBN: 9780231108232
Category : Performing Arts
Languages : en
Pages : 204

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Book Description
Chion analyzes imaginative uses of the human voice by directors like Lang, Hitchcock, Ophuls, Duras, and de Palma.

Author: Matthias Gross
Publisher: Routledge
ISBN: 1317964675
Category : Business & Economics
Languages : en
Pages : 427

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Book Description
Once treated as the absence of knowledge, ignorance today has become a highly influential topic in its own right, commanding growing attention across the natural and social sciences where a wide range of scholars have begun to explore the social life and political issues involved in the distribution and strategic use of not knowing. The field is growing fast and this handbook reflects this interdisciplinary field of study by drawing contributions from economics, sociology, history, philosophy, cultural studies, anthropology, feminist studies, and related fields in order to serve as a seminal guide to the political, legal and social uses of ignorance in social and political life. Chapter 33 of this book is freely available as a downloadable Open Access PDF under a Creative Commons Attribution-Non Commercial-No Derivatives 4.0 license available here: https://tandfbis.s3-us-west-2.amazonaws.com/rt-files/docs/Open+Access+Chapters/9780415718967_oachapter33.pdf

Author: Neil Gershenfeld
Publisher: Cambridge University Press
ISBN: 9780521580441
Category : Computers
Languages : en
Pages : 390

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Book Description
The Physics of Information Technology explores the familiar devices that we use to collect, transform, transmit, and interact with electronic information. Many such devices operate surprisingly close to very many fundamental physical limits. Understanding how such devices work, and how they can (and cannot) be improved, requires deep insight into the character of physical law as well as engineering practice. The book starts with an introduction to units, forces, and the probabilistic foundations of noise and signalling, then progresses through the electromagnetics of wired and wireless communications, and the quantum mechanics of electronic, optical, and magnetic materials, to discussions of mechanisms for computation, storage, sensing, and display. This self-contained volume will help both physical scientists and computer scientists see beyond the conventional division between hardware and software to understand the implications of physical theory for information manipulation.

Author: Michel Le Bellac
Publisher: Cambridge University Press
ISBN: 1139457047
Category : Science
Languages : en
Pages : 179

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Book Description
Quantum information and computation is a rapidly expanding and cross-disciplinary subject. This book, first published in 2006, gives a self-contained introduction to the field for physicists, mathematicians and computer scientists who want to know more about this exciting subject. After a step-by-step introduction to the quantum bit (qubit) and its main properties, the author presents the necessary background in quantum mechanics. The core of the subject, quantum computation, is illustrated by a detailed treatment of three quantum algorithms: Deutsch, Grover and Shor. The final chapters are devoted to the physical implementation of quantum computers, including the most recent aspects, such as superconducting qubits and quantum dots, and to a short account of quantum information. Written at a level suitable for undergraduates in physical sciences, no previous knowledge of quantum mechanics is assumed, and only elementary notions of physics are required. The book includes many short exercises, with solutions available to instructors through [email protected].