Sökning: "cryogenic temperature"

Visar resultat 6 - 10 av 64 avhandlingar innehållade orden cryogenic temperature.

  1. 6. Cryogenic Ultra-Low Noise InP High Electron Mobility Transistors

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

    Sammanfattning : 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. LÄS MER

  3. 7. Cryogenic InP High Electron Mobility Transistors in a Magnetic Field

    Författare :Isabel Harrysson Rodrigues; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; magnetic field; cryogenic; low noise amplifier; angular dependence; InP HEMT; geometrical magnetoresistance;

    Sammanfattning : The InGaAs-InAlAs-InP high electron mobility transistor (InP HEMT) is the preferred active device used in a cryogenic low noise amplifier (LNA) for sensitive detection of microwave signals. In this thesis it is demonstrated that the InP HEMT, when placed in a magnetic field, has a strong angular dependence in its output current. LÄS MER

  4. 8. Extreme Implementations of Wide-Bandgap Semiconductors in Power Electronics

    Författare :Juan Colmenares; Hans-Peter Nee; Leon M. Tolbert; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cryogenic; Gallium Nitride; Gate Driver; Harsh Environments; High Efficiency Converter; High Temperature; MOSFETs; Normally- ON JFETs; Reliability; Silicon Carbide; Wide-Band Gap Semiconductors; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Wide-bandgap (WBG) semiconductor materials such as silicon carbide (SiC) and gallium-nitride (GaN) allow higher voltage ratings, lower on-state voltage drops, higher switching frequencies, and higher maximum temperatures. All these advantages make them an attractive choice when high-power density and high-efficiency converters are targeted. LÄS MER

  5. 9. Ultra-Low Power InAs/AlSb HEMTs for Cryogenic Low-Noise Applications

    Författare :Giuseppe Moschetti; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; low noise; InAs AlSb; metamorphic; low power; high frequency; high electron mobility transistor HEMT ; cryogenic; ion implantation;

    Sammanfattning : The InAs/AlSb high electron mobility transistor (HEMT) is an emerging microwave device technology for ultra-low power and low noise applications. Due to the low bandgap (0. LÄS MER

  7. 10. The Oxygen Evolving cycle in Photosystem II studied with EPR Spectroscopy at different pH and Temperature

    Författare :Susan F Morvaridi; Biokemi och Strukturbiologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Kemi; Chemistry; Naturvetenskap; Temperature; Natural science; pH; EPR; S cycle; Photosystem II;

    Sammanfattning : PSII catalyses the light-induced water splitting process which leads to electron transfer through the thylakoid membrane and formation of energy rich molecules. Several redox components including a Mn4Ca, an amino acid residueYZ, two special Chl molecules P680, two Pheo and two quinone molecules participate in this process. LÄS MER