Sökning: "frequency conversion"

Visar resultat 1 - 5 av 170 avhandlingar innehållade orden frequency conversion.

  1. 1. Symmetric varactor frequency multipliers

    Författare :Mattias Ingvarson; Chalmers University of Technology; []
    Nyckelord :sub-millimetre wave; heterostructure barrier varactor HBV ; symmetric varactor; frequency multiplier; millimetre wave; semiconductor diode;

    Sammanfattning : This thesis describes heterostructure barrier varactor (HBV) frequency multipliers for millimetre and sub-millimetre wave applications.The basic principles of HBVs are explained. Starting from basic varactor theory, an equivalent circuit model for HBVs is presented. LÄS MER

  2. 2. Diode laser spectroscopy in extended wavelength ranges

    Författare :Ulf Gustafsson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; diode-laser spectroscopy; frequency-modulation spectroscopy; frequency conversion; fluorescence spectroscopy; scattering; diffraction; Fysicumarkivet A:2000:Gustafsson; Atomic and molecular physics; Atom- och molekylärfysik; absorption spectroscopy;

    Sammanfattning : Diode laser spectroscopy performed in the ultraviolet, visible and infrared spectral regions is presented. The accessible wavelength range for visible and near-infrared diode lasers is extended by the use of sum- and difference-frequency generation. LÄS MER

  3. 3. Environmental Monitoring - using diode-laser-based spectroscopic techniques

    Författare :Gabriel Somesfalean; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Diode-laser spectroscopy; frequency-modulation spectroscopy; frequency conversion; diffraction; scattering; Electromagnetism; acoustics; akustik; optik; absorption spectroscopy; Elektromagnetism; optics; Fysicumarkivet A:2004:Somesfalean;

    Sammanfattning : Monitoring of environmental gases is necessary to understand the complex processes governing global warming and the impact of pollutant emissions related to human activity. Diode-laser-based spectroscopic techniques, being robust and affordable, have a great potential to become an industrially well-established technology for environmental sensing. LÄS MER

  4. 4. High-Efficiency SiC Power Conversion : Base Drivers for Bipolar Junction Transistors and Performance Impacts on Series-Resonant Converters

    Författare :Georg Tolstoy; Hans-Peter Nee; Stig Munk-Nielsen; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Silicon Carbide; Bipolar Junction Transistor BJT ; Resonant converter; Series-resonant converter SLR ; Base drive circuits; High- Efficiency Converters; High-Frequency Converters; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : This thesis aims to bring an understanding to the silicon carbide (SiC) bipolar junction transistor (BJT). SiC power devices are superior to the silicon IGBT in several ways. They are for instance, able to operate with higher efficiency, at higher frequencies, and at higher junction temperatures. LÄS MER

  5. 5. HBV frequency multiplier 2D arrays and application

    Författare :Robin Dahlbäck; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; terahertz sources; 2D array frequency multipliers; Heterostructure Barrier Varactors HBVs ; THz; sub-millimetre waves; THz imaging; varactor frequency multipliers;

    Sammanfattning : The utilisation of the THz spectrum ( 0.3-3 THz ) is hampered by technological difficulties to generate power at these frequencies. LÄS MER