Sökning: "frequency selective structures"

Visar resultat 16 - 20 av 23 avhandlingar innehållade orden frequency selective structures.

  1. 16. Device design and process integration for SiGeC and Si/SOI bipolar transistors

    Författare :Erik Haralson; KTH; []
    Nyckelord :Silicon-Germanium SiGe ; SiGeC; heterojunction bipolar transistor HBT ; nickel silicide; selectively implanted collector SIC ; device simulation; SiGeC layer staiblity; high resolution x-ray diffraction HRXRD ; silicon-on.insulator SOI ; self-heating;

    Sammanfattning : SiGe is a significant enabling technology for therealization of integrated circuits used in high performanceoptical networks and radio frequency applications. In order tocontinue to fulfill the demands for these applications, newmaterials and device structures are needed. LÄS MER

  3. 17. Leveraging HVPE for III-V/Si Integration and Mid-Infrared Photonic Device Fabrication

    Författare :Axel Strömberg; Yan-Ting Sun; Sebastian Lourdudoss; Mattias Hammar; Charles Cornet; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; HVPE; III-V Si; Photovoltaics; PEC; MIR; non-linear optics; QPM; QCL; Energiteknik; Energy Technology;

    Sammanfattning : This work covers the implementation of highly specialized epitaxial techniques enabled by the near-equilibrium hydride vapor-phase epitaxy growth process in III-V/Si integration for Si-based tandem solar cells and photoelectrochemical reactions, quasi phase matching GaP structures on GaAs substrates, and regrowth of InP:Fe on quantum cascade lasing structures.III-V/Si integration is an important topic in several fields of research with a significant one being solar energy harvesting. LÄS MER

  4. 18. Optical Studies of Periodic Microstructures in Polar Materials

    Författare :Herman Högström; Carl Gustaf Ribbing; Clivia M. Sotomayor Torres; Uppsala universitet; []
    Nyckelord :Engineering physics; polaritonic; polar; photonic crystal; surface phonon polariton; multilayer; Reststrahlen; SiC; SiO2; Teknisk fysik;

    Sammanfattning : The optical properties of matter are determined by the coupling of the incident electromagnetic radiation to oscillators within the material. The oscillators can be electrons, ions or molecules. Close to a resonance the dielectric function exhibits strong dispersion and may be negative. LÄS MER

  5. 19. Coated Surfaces for Inkjet-Printed Conductors

    Författare :Thomas Öhlund; Hans-Erik Nilsson; Jonas Örtegren; Jouko Peltonen; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Inkjet; Nanoparticles; Paper; Flexible substrates; Sintering; Printed Electronics; Functional Printing;

    Sammanfattning : In this thesis, a number of commercially available paper substrates of various types are characterized and their characteristics related to the performance of inkjet-printed conductors using silver nanoparticle ink. The evaluated performance variables are electrical conductivity as well as the minimum achievable conductor width and the edge raggedness. LÄS MER

  7. 20. Function and dynamics of woody debris in boreal forest streams

    Författare :Niklas Dahlström; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Boreal forest; CPOM; CWD; forest management; geomorphology; LWD; riparian forest; retention; residence time; streams; Sweden; woody debris; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : The work in this thesis deals with (1) the effects of woody debris on stream channel morphology and retention of organic material, and (2) the dynamics of woody debris and its relation to riparian forest history and composition. The studied stream reaches are situated in mature, productive forests in the boreal zone of Sweden. LÄS MER