Search for dissertations about: "noise temperature"

Showing result 21 - 25 of 240 swedish dissertations containing the words noise temperature.

  2. 21. Silicon Carbide BipolarTechnology for High Temperature Integrated Circuits

    Author : Luigia Lanni; Zetterling Carl-Mikael; Sei-Hyung Ryu; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; silicon carbide SiC ; bipolar junction transistor BJT ; current gain; surface passivation; SiC etching; complementary bipolar; lateral PNP; Darlington transistors; SPICE modeling; high-temperature; integrated circuits; emitter coupled logic ECL ;

    Abstract : The availability of integrated circuits (ICs) capable of 500 or 600° C operation can be extremely beneficial for many important applications, such as transportation and energy sector industry. It can in fact enable the realization of improved sensing and control of turbine engine combustion leading to better fuel efficiency and reduced pollution. READ MORE

  4. 22. 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

  5. 23. Numerical investigation of tonal noise sources from centrifugal fan

    Author : Martin Ottersten; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Computational Aeroacoustics; Tonal Noise; Centrifugal Fan; Blade Passing Frequency;

    Abstract : Heating, ventilating, and air conditioning systems (HVAC) are today an important part of many people's life. They provide a sufficient amount of airflow with the correct temperature, quality, and humidity. The negative side is the noise it produces. Many improvements have been made in building development to reduce noise from the environment. READ MORE

  6. 24. Study of MgB2 HEB mixers at THz frequencies

    Author : Evgenii Novoselov; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; noise temperature; mixers; bandwidth; THz detectors; superconductors; bolometers; conversion gain; MgB2;

    Abstract : The terahertz (THz) range is very attractive for astronomical observations. Spectroscopy and photometry of remote space objects in the THz range allows for a study of their chemical composition, because this range covers rotational lines from simple molecules and electron transition lines from atoms and ions. READ MORE

  7. 25. Study of MgB2 and YBa2Cu3O7-x Microbolometers for THz Sensing Applications

    Author : Stella Bevilacqua; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; THz Detectors; bolometers; IF bandwidth; YBa2< sub>Cu3< sub>O7-x< sub>; Terahertz frequency; HEB; MgB2< sub>; noise; superconductors;

    Abstract : In this thesis, two novel THz detectors based on magnesium diboride (MgB2)and yttrium barium copper oxide (YBa2Cu3O7-x) are presented. In particular,MgB2 superconductor is used for the investigation of hot-electron bolometer(HEB) mixers, while YBa2Cu3O7-x is explored in microbolometers for room-temperaturecoherent and incoherent detection. READ MORE