Sökning: "Characteristic Modes"

Visar resultat 1 - 5 av 59 avhandlingar innehållade orden Characteristic Modes.

  1. 1. Systematic Antenna Design Using the Theory of Characteristic Modes

    Detta är en avhandling från Lund University

    Författare :Zachary Miers; Lunds universitet.; Lund University.; [2016-11-02]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Theory of Characteristic Modes; Antenna Design; Antenna; Characteristic Modes; Computational Electromagnetics; MIMO Systems; MIMO Antenna; MIMO; Mutual Coupling; Mobile Antenna;

    Sammanfattning : The day Faraday moved a magnet in and out of a wire loop and detected the time-varying magnetic field, the first wireless transmitter / receiver system was created and the world was changed forever. However, it took almost fifty years for Heinrich Hertz to use Maxwell's equations and Faraday's insights in his professorship at Karlsruhe to create the first electromagnetic wireless communication system using a spark gap dipole transmitter and a loop antenna-based receiver. LÄS MER

  2. 2. Computational Tools for Antenna Analysis and Design

    Detta är en avhandling från Electromagnetic Theory Department of Electrical and Information Technology Lund University Sweden

    Författare :Doruk Tayli; Lunds universitet.; Lund University.; [2018-01-31]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Antenna theory; Fundamental bounds; method of moments MoM ; Characteristic modes; macro basis functions MBFs ; adaptive cross approximation ACA ; endfire arrays;

    Sammanfattning : Many engineers and scientists prevalently use computational tools in electromagnetics, which is also the predominant case for antennas. The ever-increasing number of applications and technologies that employ antennas create a constant demand to improve and extend existing tools and develop new ones. LÄS MER

  3. 3. Dilute Nitride Lasers and Spectrally Engineered Semiconductor Laser Resonators

    Detta är en avhandling från Electromagnetic Theory Department of Electrical and Information Technology Lund University Sweden

    Författare :Göran Adolfsson; [2011]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; single mode laser; transfer matrix method; threshold current; InGaAs; GaAs; multiple quantum wells; dilute nitrides; two-color laser; GaInNAs; Semiconductor lasers; molecular beam epitaxy; characteristic temperature; temperature dependence; ambipolar diusion; Fabry-Perot resonator; spectral engineering;

    Sammanfattning : The first part of this thesis deals with long wavelength (1.2-1.3 um) InGaAs(N)multiple quantum-well (QW) lasers grown on GaAs, with the aim of understandingand improving their threshold and temperature characteristics. The epitaxialmaterial is grown by molecular beam epitaxy (MBE). LÄS MER

  4. 4. Acoustical Measurements of Material Nonlinearity and Nonequilibrium Recovery

    Detta är en avhandling från Karlskrona : Blekinge Institute of Technology

    Författare :Kristian Haller; Blekinge Tekniska Högskola.; [2008]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear acoustics; nondestructive testing; activation density; slow dynamics; nonequilibrium recovery; resonance frequency; nonlinear wave modulation spectroscopy; harmonic generation; trapped modes; open resonator; sweep rate; constant strain sweep;

    Sammanfattning : A damaged material or a material with non perfect atomic geometry, dislocations or cracks, exhibits two types of characteristic responses to acoustic excitations. First is the fast nonlinear dynamics response that is present as long as the material is excited. As soon as the excitation stops the response disappear. LÄS MER

  5. 5. Och nu börjar historien : Hjalmar Söderbergs novellkonst

    Detta är en avhandling från Bokförlaget Atlantis

    Författare :Miranda Landen; Lunds universitet.; Lund University.; [2013]
    Nyckelord :HUMANIORA; HUMANITIES; illustrations; short stories in periodicals; modern collection; echoes; short-story collection; twist; narrative modes; closure; external narrator; debate-driven story; travel story; hunter’s-fire story; early 20th century writing; late 19th century writing; classic short story; short format; short story; genre history and genre theory of the short story; story type; narration; Hjalmar Söderberg;

    Sammanfattning : Hjalmar Söderberg (1869–1941) published some seventy short stories in five collections, Historietter (1898), Främlingarna (1903), Det mörknar öfver vägen (1907), Den talangfulla draken (1913) and Resan till Rom (1929). The present study explores Söderberg’s short fiction from a genre-historical and genre-theoretical perspective. LÄS MER