Sökning: "frequency conversion"
Visar resultat 1 - 5 av 170 avhandlingar innehållade orden frequency conversion.
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
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
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. High-Efficiency SiC Power Conversion : Base Drivers for Bipolar Junction Transistors and Performance Impacts on Series-Resonant Converters
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
Sammanfattning : The utilisation of the THz spectrum ( 0.3-3 THz ) is hampered by technological difficulties to generate power at these frequencies. LÄS MER