Search for dissertations about: "high frequency heating"

Showing result 1 - 5 of 72 swedish dissertations containing the words high frequency heating.

  2. 1. Impact of adjacent dielectrics on the high-frequency performance of graphene field-effect transistors

    Author : Muhammad Asad; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-frequency electronics; Graphene; transit frequency; contact resistance; MOGFETs; drift velocity; field-effect transistors; saturation velocity; maximum frequency of oscillation; diamond;

    Abstract : Transistors operating at high frequencies are the basic building blocks of millimeter wave communication and sensor systems. The high velocity and mobility of carriers in graphene can open ways for development of ultra-fast group IV transistors with similar or even better performance than that achieved with III-V based semiconductors. READ MORE

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

    Author : Georg Tolstoy; Hans-Peter Nee; Stig Munk-Nielsen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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;

    Abstract : 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. READ MORE

  5. 3. Low frequency noise during work. Effects on performance and annoyance

    Author : Johanna Bengtsson; Göteborgs universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Low frequency noise; performance; workload; annoyance; cortisol; subjective stress; subjective sensitivity to noise; sound characteristics; frequency balance; modulation frequency;

    Abstract : Aims. Low frequency noise (LFN) is defined as "a noise with a dominant frequency content of 20 to 200 Hz". Common sources of LFN in occupational environments are ventilation, heating and air-conditioning systems, computer network installations and compressors. READ MORE

  6. 4. Bi2212 intrinsic Josephson junctions, fabrication and high frequency properties

    Author : Mattias Torstensson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; intrinsic Joule heating; Shapiro steps; in plane critical current; Bi2212; high temperature superconductors; intrinsic Josephson junctions;

    Abstract : The objective for this work was to investigate the high-frequency properties of Bi2212 intrinsic Josephson junctions (IJJ’s). Particularly, the possibility to reach the THz range with a SIS mixer is theoretically promising due to the high energy gap of Bi2212. READ MORE

  7. 5. Heterostructure Barrier Varactors for High Efficiency Frequency Multipliers

    Author : Lars Dillner; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; frequency multiplier; Heterostructure Barrier Varactor HBV ; millimeter wave; submillimeter wave; power source;

    Abstract : This thesis describes the Heterostructure Barrier Varactor (HBV) and its application in frequency multipliers. Different HBV materials, fabrication processes, and device models are presented. The aim of this work is to improve the efficiency of HBV frequency multipliers. READ MORE