Search for dissertations about: "coaxial waveguide"

Showing result 6 - 10 of 14 swedish dissertations containing the words coaxial waveguide.

  2. 6. EM Design for New Ultra Wide Band Technologies: Eleven Feed Baluns, Bowtie Antennas and Gap Waveguides

    Author : Syed Hasan Raza Zaidi; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ultra-wideband; Eleven feed; gap waveguide; baluns; Multiport feeding network; power divider; ring hybrid.; packaging;

    Abstract : UWB (ultra wideband), depending on the application requirement, is usually referred to more than 500 MHz bandwidth for radio/wireless applications. Here in this thesis it is also used to denote extremely wideband antennas and components of several octaves bandwidth, particularly for high frequency applications. READ MORE

  4. 7. Perturbation approach to reconstructions of boundary deformations in waveguide structures

    Author : Mariana Dalarsson; Martin Norgren; Sergei Tretyakov; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inverse problems; waveguides; microwaves; perturbation theory; Electrical Engineering; Elektro- och systemteknik;

    Abstract : In this thesis we develop inverse scattering algorithms towards the ultimate goal of online diagnostic methods. The aim is to detect structural changes inside power transformers and other major power grid components, like generators, shunt reactors etc. READ MORE

  5. 8. Millimeter-Wave High-Gain Antenna for 5G Backhauling with Auto-beam-tracking Function

    Author : Enlin Wang; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gap waveguide; auto-beam-tracking; 5G backhaul; Ultra-high-gain antenna; me- chanical movement;

    Abstract : As microwave links are increasingly deployed within the millimeter-wave frequency range, E-band (70/80 GHz) links have been installed on a global scale. One major technological challenge in this high-frequency spectrum is the significant increase in path loss between receivers and transmitters. READ MORE

  6. 9. On the Analysis of Horns, Reflectors, and Periodic Structures

    Author : Martin Johansson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : The design and manufacturing of a dual-frequency horn is presented. The dual-depth corrugated horn is fed by a circular and a coaxial waveguide, in the upper and lower frequency band, respectively. The reason for choosing a waveguide-only feeding network is discussed. READ MORE

  7. 10. Online power transformer diagnostics using multiple modes of microwave radiation

    Author : Mariana Dalarsson; Martin Norgren; Sven Nordebo; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inverse problem; multiple modes; power transformers;

    Abstract : In the present thesis, we propose and investigate a new approach to diagnose the effects of the various degradation mechanisms, including thermal degradation at hot spots, winding deformations due to the mechanical forces from short circuit currents, partial discharges due to local electric field surges, and increased moisture levels in the cellulose insulation due to decomposition, that affect electric power transformers during their normal operation in an electric power grid.Although the proposed diagnostics method can in principle be used to detect various degradation mechanisms mentioned above, we focus in the present thesis on mechanical deformations of transformer winding structures. READ MORE