Search for dissertations about: "trapping effects"

Showing result 1 - 5 of 86 swedish dissertations containing the words trapping effects.

  2. 1. Buffer Related Dispersive Effects in Microwave GaN HEMTs

    Author : Johan Bergsten; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; trapping effects; C-doping; AlGaN GaN interface quality; recessed ohmic contacts; GaN HEMT; buffer design;

    Abstract : In applications such as mobile communication and radar, microwave power generation at high frequency is of utmost importance. The GaN HEMT offers a unique set of properties that makes it suitable for high power amplification at high frequencies. READ MORE

  4. 2. Nonlinear Characterization of Wideband Microwave Devices and Dispersive Effects in GaN HEMTs

    Author : Sebastian Gustafsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; large-signal; dispersive effects; electron trapping; thermal coupling; HEMT; GaN; microwave; wideband;

    Abstract : Measurements play a key role in the development of microwave hardware as they allow engineers to test and verify the RF performance on a system, circuit, and component level. Since modern cellular standards employ complex modulation formats with wider signal bandwidths to cope with the growing demand of higher datarates, nonlinear characterization using wideband stimuli is becoming increasingly important. READ MORE

  5. 3. Residual and Solubility trapping during Geological CO2 storage : Numerical and Experimental studies

    Author : Maria Rasmusson; Fritjof Fagerlund; Auli Niemi; Jonathan Ennis-King; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; capillary trapping; CCS; convective flow; CO2; light transmission; SO2; well test; Hydrology; Hydrologi;

    Abstract : Geological storage of carbon dioxide (CO2) in deep saline aquifers mitigates atmospheric release of greenhouse gases. To estimate storage capacity and evaluate storage safety, knowledge of the trapping mechanisms that retain CO2 within geological formations, and the factors affecting these is fundamental. READ MORE

  6. 4. Influence of Self-trapping, Clamping and Confinement on Hydrogen Absorption

    Author : Gunnar Karl Pálsson; Björgvin Hjörvarsson; Keith Ross; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; hydrogen diffusion; thin films; superlattices; phase transitions; confinement; clamping; self-trapping; finite-size effect; Surfaces and interfaces; Ytor och mellanytor; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : The dissociation of hydrogen molecules at surfaces is the first step in the absorption process. If the absorbing material is covered by an oxide, this layer will determine the effective uptake rate of an underlying absorbing material. READ MORE

  7. 5. Characterization and Compensation of Thermal Effects in GaN HEMT Technologies

    Author : Johan Bremer; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermal coupling; thermal effects; thermal resistance; AlGaN GaN; temperature compensation.; electrothermal; characterization;

    Abstract : Further advancements with GaN based technologies relies on the ability to handle the heat flux, which consequently arises from the high power density. Advanced cooling techniques and thermal optimization of the technology are therefore prioritized research areas. READ MORE