Search for dissertations about: "GaN"

Showing result 16 - 20 of 153 swedish dissertations containing the word GaN.

  2. 16. 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. 17. Silicon δ-doping and Isoelectronic Doping in GaAs ans GaN Layers Grown by MBE

    Author : Jan Thordson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; MBE; doping; GaN; III-V; delta-doping; heterostructures; GaAs;

    Abstract : This work concerns MBE-grown material, particularly physical effects due to controlled impurities of Si and N in arsenides, and the growth of nitrides and studies of Al- and As-impurities in them. Apart from interesting physical phenomena there are important device applications. The first part is devoted to studies of Si .delta. READ MORE

  5. 18. Optimum GaN HEMT Oscillator Design Targeting Low Phase Noise

    Author : Mikael Hörberg; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; low frequency noise; resonator coupling; cavity resonator; GaN HEMT; MMIC; reflection oscillator; phase noise;

    Abstract : The thesis considers design of low phase noise oscillators, given the boundary condition of the used technology. Important conditions are the power handling of the active device, device noise floor, the quality factor of the resonator, bias settings, and low frequency noise. READ MORE

  6. 19. 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

  7. 20. Magnetron Sputter Epitaxy of GaN

    Author : Muhammad Junaid; Jens Birch; Lars Hultman; Vanya Darakchieva; Linköpings universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : Electronic-grade GaN (0001) epilayers have been grown directly on Al2O3 (0001) substrates by reactive DC-magnetron sputter epitaxy (MSE) from a liquid Ga sputtering target in an Ar/N2 atmosphere. The as-grown GaN epitaxial film exhibit low threading dislocation density on the order of ≤ 1010 cm-2 obtained by transmission electron microscopy and modified Williamson-Hall plot. READ MORE