1.

Record Nr.

UNINA9910371160203321

Autore

Applebaum, Anne

Titolo

La grande carestia : la guerra di Stalin all'Ucraina / Anne Applebaum

Pubbl/distr/stampa

Milano : Mondadori, 2019

ISBN

9788804711032

Descrizione fisica

539 p. ; 22 cm

Collana

Le scie

Disciplina

947.70842

Locazione

bfs

Collocazione

947.70842 APP 1

Lingua di pubblicazione

Italiano

Formato

Materiale a stampa

Livello bibliografico

Monografia

2.

Record Nr.

UNINA9910463924203321

Titolo

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

Pubbl/distr/stampa

London, : Imperial College Press, 2011

ISBN

1-283-14337-2

9786613143372

1-61344-081-2

1-84816-492-0

Descrizione fisica

1 online resource (210 p.)

Altri autori (Persone)

ValderasDaniel

Disciplina

621.382/4

621.3824

621.384135

Soggetti

Ultra-wideband antennas

Ultra-wideband antennas - Design

Electronic books.

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa



Livello bibliografico

Monografia

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

3.

Record Nr.

UNISALENTO991004046819707536

Titolo

Antologia de la narrativa hispano-americana : 1940-1970 / Paul Verdevoye

Pubbl/distr/stampa

Madrid : Gredos, 1979

ISBN

8424915895 (v. 2)

Descrizione fisica

2 v. ; 19 cm

Collana

Biblioteca románica hispánica. 6, Antología hispánica ; 34

Altri autori (Persone)

Verdevoye, Paulauthor

Disciplina

860

Soggetti

Narrativa ispano-americana

Lingua di pubblicazione

Spagnolo

Formato

Materiale a stampa

Livello bibliografico

Monografia



4.

Record Nr.

UNINA9910711325403321

Titolo

Asia's diplomatic and security structure : planning U.S. engagement : hearing before the Subcommittee on Asia and the Pacific of the Committee on Foreign Affairs, House of Representatives, One Hundred Fifteenth Congress, second session, May 23, 2018

Pubbl/distr/stampa

Washington : , : U.S. Government Publishing Office, , 2018

Descrizione fisica

1 online resource (iii, 58 pages)

Soggetti

National security - Southeast Asia

Legislative hearings.

Southeast Asia Foreign relations United States

United States Foreign relations Southeast Asia

United States Foreign economic relations Southeast Asia

Southeast Asia Foreign economic relations United States

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Note generali

"Serial No. 115-152."

Nota di bibliografia

Includes bibliographical references.