Search for dissertations about: "Antenna theory"

Showing result 1 - 5 of 79 swedish dissertations containing the words Antenna theory.

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

    Author : Zachary Miers; Institutionen för elektro- och informationsteknik; []
    Keywords : 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;

    Abstract : 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. READ MORE

  4. 2. Investigating and Enhancing Performance of Multiple Antenna Systems in Compact MIMO/Diversity Terminals

    Author : Shuai Zhang; Sailing He; Raj Mittra; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple antennas; planar inverted-F antenna; mutual coupling; slot antenna; compact antenna; mobile antenna; Q factors; antenna array; ultra-wideband UWB antenna; pattern diversity; polarization diversity; user effects; adaptive arrays; chassis mode;

    Abstract : Today, owners of small communicating device are interested in transmitting or receiving various multimedia data. By increasing the number of antennas at the transmitter and/or the receiver side of the wireless link, the diversity/Multiple-Input Multiple-Output (MIMO) techniques can increase wireless channel capacity without the need for additional power or spectrum in rich scattering environments. READ MORE

  5. 3. Integral Identities for Passive Systems and Spherical Waves in Scattering and Antenna Problems

    Author : Anders Bernland; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dispersion relations; sum rules; physical limitations; Herglotz functions; electromagnetic scattering; antenna theory; spherical wave expansions; antenna measurements; propagation channel measurements;

    Abstract : Sum rules and physical limitations within electromagnetic theory and antenna theory have received significant attention in the last few years. However, the derivations are often relying on application specific and sometimes unsupported assumptions, and therefore a mathematically rigorous and generally applicable approach seems timely. READ MORE

  6. 4. Computational Tools for Antenna Analysis and Design

    Author : Doruk Tayli; Teoretisk elektroteknik; []
    Keywords : Antenna theory; Fundamental bounds; method of moments MoM ; Characteristic modes; macro basis functions MBFs ; adaptive cross approximation ACA ; endfire arrays;

    Abstract : 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. READ MORE

  7. 5. Theory and Applications of Tri-Axial Electromagnetic Field Measurements

    Author : Roger Karlsson; Bo Thid'e; Tobia Carozzi; Gudmund Wannberg; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; polarisation; polarization; Stokes parameters; antenna; radio waves; whistler wave; SEE; direction-finding; statistics; Poynting theorem; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Abstract : Polarisation, which was first studied in optics, is a fundamental property of all electromagnetic fields. A convenient way to describe the polarisation of two dimensional electromagnetic fields is given by the Stokes parameters. This thesis deals with different aspects of wave polarisation and electromagnetic field measurements. READ MORE