Search for dissertations about: "Bipolar transport"

Showing result 16 - 20 of 20 swedish dissertations containing the words Bipolar transport.

  2. 16. Cryogenic Ultra-Low Noise InP High Electron Mobility Transistors

    Author : Joel Schleeh; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MMIC; LNA; cryogenic; low noise; DC power dissipation; ALD; GaAs MHEMT; gain fluctuations; InP HEMT;

    Abstract : Indium phosphide high electron mobility transistors (InP HEMTs), are today the best transistors for cryogenic low noise amplifiers at microwave frequencies. Record noise temperatures below 2 K using InP HEMT equipped cryogenic low noise amplifiers (LNAs) were demonstrated already a decade ago. READ MORE

  4. 17. Ohmic Contacts for High Temperature Integrated Circuits in Silicon Carbide

    Author : Katarina Smedfors; Carl-Mikael Zetterling; Niklas Rorsman; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Informations- och kommunikationsteknik; Information and Communication Technology;

    Abstract : In electrical devices and integrated circuits, ohmic contacts are necessary and a prerequisite for the current transport over the metal-semiconductor junctions. At the same time, a desired property of the ohmic contacts is to not add resistance or in other way disturb the performance. READ MORE

  5. 18. Features and Origin of Electromagnetic Fields Generated by Lightning Flashes

    Author : Mohd Muzafar Ismail; Vernon Cooray; Farhad Rachidi; Uppsala universitet; []
    Keywords : negative cloud-to-ground lightning flashes; HF and VHF radiation; chaotic pulse trains; lightning initiation; zero-crossing time; electromagnetic fields; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

    Abstract : Negative cloud-to-ground (CG) lightning flashes transport negative charge from cloud to ground. Negative ground flashes typically involve various processes identified as preliminary breakdown, stepped leader, return stroke, dart leader, dart-stepped leader, subsequent return stroke, and cloud activity between strokes, such as regular pulse trains and chaotic pulse trains. READ MORE

  6. 19. Near-infrared photodetectors based on Si/SiGe nanostructures

    Author : Anders Elfving; Wei-Xin Ni; Thomas P. Pearsall; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; SiGe; Ge dots; nanostructures; molecular beam epitaxy; photodetector; Semiconductor physics; Halvledarfysik;

    Abstract : Two types of photodetectors containing Ge/Si quantum dots have been fabricated based on materials grown by molecular beam epitaxy and characterized with several experimental techniques. The aim was to study new device architectures with the implementation of Ge nanostructures, in order to obtain high detection efficiency in the near infrared range at room temperature. READ MORE

  7. 20. Retinal tumorigenesis and neurodegeneration : strategies to promote tumor cell death and support retinal cell survival to preserve vision

    Author : Tanzina Mollick; Karolinska Institutet; Karolinska Institutet; []
    Keywords : ;

    Abstract : Our vision is central to our quality of life enabling us to interact with our environment and lead productive lives. The ability to see begins in the retina, one of the paramount features of the eye, as it takes on the task of converting light signals to nerve impulses that are relayed to the visual centers of the brain. READ MORE