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1. |
Record Nr. |
UNINA9910463924203321 |
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Titolo |
Ultrawideband antennas [[electronic resource] ] : design and applications / / Daniel Valderas ... [et al.] |
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Pubbl/distr/stampa |
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London, : Imperial College Press, 2011 |
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ISBN |
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1-283-14337-2 |
9786613143372 |
1-61344-081-2 |
1-84816-492-0 |
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Descrizione fisica |
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1 online resource (210 p.) |
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Altri autori (Persone) |
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Disciplina |
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621.382/4 |
621.3824 |
621.384135 |
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Soggetti |
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Ultra-wideband antennas |
Ultra-wideband antennas - Design |
Electronic books. |
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Lingua di pubblicazione |
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Formato |
Materiale a stampa |
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Livello bibliografico |
Monografia |
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Note generali |
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Description based upon print version of record. |
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Nota di bibliografia |
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Includes bibliographical references (p. 183-190) and index. |
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Nota di contenuto |
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Foreword; Acknowledgements; Authors; Contents; 1. Introduction to Ultrawideband Systems Cong Ling; 1.1 Overview; 1.2 UWB Schemes; 1.2.1 Impulse radio/time hopping; 1.2.2 Direct sequence; 1.2.3 Frequency hopping; 1.2.4 OFDM; 1.3 Industry Standards; 1.3.1 Single band versus multiband; 1.3.2 Standards; 1.4 Applications; 1.5 Challenges; 2. Figures of Merit for UWB Antennas David Puente and Daniel Valderas; 2.1 Requirements for a UWB Antenna; 2.1.1 Efficiency and matching; 2.1.2 Signal distortion and dispersion (ringing) |
2.1.3 Stability over frequency of the transmission-reception transfer function2.1.3.1. Constant transfer function: Pulses selected directly by the source; 2.1.3.2. Variable transfer function: Concept of the antenna as a filter; 2.2 UWB Antenna Parameters; 2.2.1 Variability in the frequency domain; 2.2.1.1. Magnitude of the transfer function; 2.2.1.1.1. Stability of the reflection coefficient; 2.2.1.1.2. Polarisation stability; 2.2.1.1.3. Gain stability and channel losses; 2.2.1.2. Transfer function phase: Group delay; 2.2.2 Variability in the time domain: Pulse |
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distortion parameters |
2.2.2.1. Fidelity factor2.2.2.2. Time spread; 2.2.3 Variability in the space domain; 2.2.3.1. Statistical values; 2.2.3.1.1. Uniformity; 2.2.3.1.2. Spatially averaged transfer function (SATF); 2.2.3.1.3. Spatially averaged group delay (SAGD); 2.2.3.2. Correlation-based averages: Angular range; 2.3 Simulation in the Time Domain; 3. Classification of UWB Antennas David Puente and Daniel Valderas; 3.1 Helical Antennas; 3.2 Frequency-independent Antennas; 3.2.1 Spiral antennas; 3.2.2 Biconical antennas; 3.2.2.1. 3D biconical antennas; 3.2.2.2. 2D biconical antennas; 3.3 Log-periodic Antennas |
3.4 Horn Antennas3.4.1 3D horn antennas; 3.4.2 2D horn antennas; 3.5 UWB Antennas Derived from Resonant Antennas; 3.5.1 3D monopoles; 3.5.1.1. Modifications to the geometry; 3.5.1.1.1. Euclidean shapes; 3.5.1.1.2. Computer optimisation; 3.5.1.1.3. Partial variation on a Euclidean shape; 3.5.1.2. Changes in current distribution; 3.5.1.2.1. Use of parasitic elements; 3.5.1.2.2. Use of a short-circuit pin; 3.5.1.2.3. Asymmetric feed; 3.5.1.2.4. Double feed; 3.5.2 2D resonant antennas; 3.5.2.1. Full 2D monopoles; 3.5.2.2. Slot antennas; 3.6 Conclusions |
4. UWB Monopole Antenna Analysis Daniel Valderas and Juan I. Sancho4.1 Introduction; 4.2 Current-conductive Parts on Planar Monopole Antennas; 4.2.1 Currents parallel and perpendicular to the ground plane: A working hypothesis; 4.2.2 Non-radiating currents in a PMA; 4.3 Transmission Line Model for UWB Monopole Antennas; 4.3.1 General description; 4.3.2 Description of the model; 4.3.2.1. Transmission line; 4.3.2.2. Radiating structure; 4.3.3 Purpose of the analogy; 4.3.4 Graphical approach: The Smith Chart; 4.4 Design Based on TLM; 4.4.1 Design of an UWB-PMA antenna with a given bandwidth |
4.4.2 Design of an UWB-PMA antenna having a maximised bandwidth |
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Sommario/riassunto |
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Ultrawideband (UWB) technology, positioned as the cutting edge of research and development, paves the way to meet the emerging demands set by broadband wireless applications, such as high-speed data transmission, medical imaging, short-range radars, electromagnetic testing, etc. This breathtaking resource builds upon the basics of UWB technology to provide a complete compilation of figures of merit along with a vital state-of-the-art of the different antenna alternatives that are to be employed according to the specific application. Without excessive recourse to mathematics, this volume emphas |
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2. |
Record Nr. |
UNINA9910781244403321 |
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Autore |
Dubbs Chris |
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Titolo |
Realizing tomorrow [[electronic resource] ] : the path to private spaceflight / / Chris Dubbs and Emeline Paat-Dahlstrom ; Foreword by Charles D. Walker |
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Pubbl/distr/stampa |
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Lincoln, : University of Nebraska Press, c2011 |
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ISBN |
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1-283-14637-1 |
9786613146373 |
0-8032-3527-5 |
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Descrizione fisica |
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1 online resource (343 p.) |
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Collana |
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Altri autori (Persone) |
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Disciplina |
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Soggetti |
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Space flights |
Space tourism |
Space industrialization |
Outer space Civilian use |
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Lingua di pubblicazione |
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Formato |
Materiale a stampa |
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Livello bibliografico |
Monografia |
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Note generali |
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Description based upon print version of record. |
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Nota di bibliografia |
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Includes bibliographical references and index. |
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Nota di contenuto |
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The entire population of the earth in orbit -- The birth of private rocket companies -- Private citizens get their chance in space -- Russia commercializes space -- Citizen explorers -- The quest for a reusable spaceship -- The ansari x prize launches an industry -- Private manned spaceflight makes history -- Space tourism goes mainstream -- It takes more than a spaceship to build an industry. |
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Sommario/riassunto |
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Engaging account of the people and events who have shaped the development of private spaceflight |
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3. |
Record Nr. |
UNINA9910970836903321 |
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Autore |
Zimmerman Joseph Francis <1928-2022.> |
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Titolo |
Interstate cooperation : compacts and administrative agreements / / Joseph F. Zimmerman |
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Pubbl/distr/stampa |
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Westport, Conn. : , : Praeger, , 2002 |
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New York : , : Bloomsbury Publishing (US), , 2024 |
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ISBN |
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9798400671821 |
9786610423002 |
9781280423000 |
1280423005 |
9780313012600 |
0313012601 |
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Edizione |
[1st ed.] |
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Descrizione fisica |
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1 online resource (273 p.) |
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Disciplina |
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Soggetti |
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Interstate agreements - United States |
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Lingua di pubblicazione |
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Formato |
Materiale a stampa |
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Livello bibliografico |
Monografia |
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Note generali |
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Description based upon print version of record. |
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Nota di bibliografia |
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Includes bibliographical references (p. [221]-247) and index. |
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Nota di contenuto |
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CONTENTS; Preface; Acknowledgments; 1. Interstate Comity; 2. The Constitution and Interstate Governance; 3. The Compacting Process; 4. Compact Commissions; 5. Interstate Compacts Sans Commissions; 6. Formal and Informal Administrative Agreements; 7. Interstate Cooperation: An Assessment; Bibliography; Index |
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Sommario/riassunto |
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This text places in perspective the important roles played by interstate compacts and interstate administrative agreements in the governance systems of the US. Compacts are identified and classified by type, and particular emphasis is placed on federal governmental promotion of compacts. |
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