Sökning: "parallel plate mode"
Visar resultat 1 - 5 av 8 avhandlingar innehållade orden parallel plate mode.
1. Gap Waveguide for High Frequency Microwave Application- Validation of Concept, Filter Design & Packaging Aspects
Sammanfattning : The overall goal of this thesis is to validate the low loss performance of recently evolved gap waveguide technology and to use this low loss technology for designing critical passive microwave component such as narrow band filter. Also, the exploitation of gap waveguide concept as a packaging solution for densely packed RF circuitry has been presented in this thesis. LÄS MER
2. Gap waveguide for packaging microstrip filters & investigation of transitions from planar technologies to ridge gap waveguide
Sammanfattning : Gap waveguide technology has proved to constitute an effective alternative for the design of microwave passive components, due to its advantages with respect to traditional planar technologies and standard waveguides. There is no requirement for conductive contact between the two different metal pieces making up a gap waveguide prototype, since one of these pieces makes use of a textured surface that eliminates any possible leakage of the field through the gap to the surface of the other metal piece above it. LÄS MER
3. Tunable Filters based on Ferroelectrics and Semiconductor Varactors
Sammanfattning : Experimental investigation and development of tunable microwave filters, based on single crystals of SrTiO3 (STO) and KTaO3 (KTO), form the main work of this thesis. The dielectric properties of STO and KTO crystals are evaluated experimentally for a wide temperature range, with a DC bias, using parallel-plate resonators with High Temperature Superconductor (HTS) and normal metal (Cu) electrodes. LÄS MER
4. Online power transformer diagnostics using multiple modes of microwave radiation
Sammanfattning : 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. LÄS MER
5. The Multimodal Transfer Matrix Method : And its application to higher-symmetric periodic structures
Sammanfattning : This thesis focuses on the understanding and computation of the dispersion properties of periodic structures possessing higher symmetries with the multimodal transfer matrix method (MMTMM). Periodic structures with higher symmetries are invariant after additional symmetry operations over the translation operation. LÄS MER
