Ultrawideband antennas [[electronic resource] ] : design and applications / / Daniel Valderas ... [et al.]

• Pubblicazione: London, : Imperial College Press, 2011
• Descrizione fisica: 1 online resource (210 p.)
• Disciplina: 621.382/4; 621.3824; 621.384135
• Soggetto topico: Ultra-wideband antennas; Ultra-wideband antennas - Design
• Soggetto genere / forma: Electronic books.
• Altri autori: ValderasDaniel
• Note generali: Description based upon print version of record.
• Nota di bibliografia: Includes bibliographical references (p. 183-190) and index.
• Nota di contenuto: 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 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
• Sommario/riassunto: 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
• Titolo autorizzato: Ultrawideband antennas
• ISBN: 1-283-14337-2; 9786613143372; 1-61344-081-2; 1-84816-492-0
• Formato: Materiale a stampa
• Livello bibliografico: Monografia
• Lingua di pubblicazione: Inglese
• Record Nr.: 9910463924203321
• Lo trovi qui: Univ. Federico II