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Showing result 1 - 5 of 12 swedish dissertations matching the above criteria.

  2. 1. Gap Waveguide for High Frequency Microwave Application- Validation of Concept, Filter Design & Packaging Aspects

    Author : Ashraf Uz Zaman; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; parallel plate stopband; PMC packaging; gap waveguide; fractional bandwidth; Quasi-TEM mode; PMC surface; narrowband filter; high Q resonators;

    Abstract : 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. READ MORE

  4. 2. Gap Waveguide: Low Loss Microwave Passive Components and MMIC Packaging Technique for High Frequency Applications

    Author : Ashraf Uz Zaman; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Quasi TEM; Slot Array; PMC; Gap waveguide; Narrow-band Filter;

    Abstract : The heavy congestion at the existing radio frequency spectrum allocated for the today’s wireless communications motivates and accelerates the research work at mmWave bands or even higher frequency range where more spectrum space is available for massive data rate delivery. The inclination of modern wireless system research and development is towards small size, reliable, high-performance and high-yield microwave multifunctional products. READ MORE

  5. 3. Gap waveguide for packaging microstrip filters & investigation of transitions from planar technologies to ridge gap waveguide

    Author : Astrid Algaba Brazalez; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; parallel plate mode; coupled line filter; microstrip circuit; packaging; Artificial magnetic conductor AMC ; perfect magnetic conductor PMC ; gap waveguide; transition.; coplanar waveguide CPW ;

    Abstract : 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. READ MORE

  6. 4. Influence of microstructure on debonding at the fiber/matrix interface in fiber-reinforced polymers under tensile loading

    Author : Luca Di Stasio; Janis Varna; Zoubir Ayadi; Alberto Barroso; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fiber matrix interface; Debonding; Polymer-Matrix Composites PMC ; Finite Element Method FEM ; Linear Elastic Fracture Mechanics LEFM ; Polymeric Composite Materials; Polymera kompositmaterial;

    Abstract : At the end of the second decade of the XXI century, the transportation industry at large faces several challenges that will shape its evolution in the next decade and beyond. The first such challenge is the increasing public awareness and governmental action on climate change, which are increasing the pressure on the industrial sectors responsible for the greatest share of emissions, the transportation industry being one of them, to reduce their environmental footprint. READ MORE

  7. 5. The transcription machinery in schizosaccharomyces pombe and its regulation

    Author : Henrik Spåhr; Karolinska Institutet; Karolinska Institutet; []
    Keywords : Gene expression; transcription regulation; in vitro; RNA polymerase II; holoenzyme; mediator; TBP; TFIIB; TFIIF; TFIIH; Srb8-11; Pmc;

    Abstract : The Mediator complex acts as a bridge, conveying regulatory information from enhancers and other control elements to the general transcription machinery. The Mediator was originally identified in Saccharomyces cerevisiae and is required for the basal and regulated expression of nearly all RNA polymerase II dependent genes. READ MORE