Sökning: "wave length bands"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden wave length bands.

  1. 1. Combined Electrical Power Generation using Solar and Wind

    Författare :Ingemar Mathiasson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wave length bands; atmospheric transmittance; energy storage; Wind turbine; wind speed; quantum dots; electrical load.; extinction coefficient; silicon solar cell; solar cell;

    Sammanfattning : The need for systems for renewable electrical power production is enormous worldwide.This applies to systems of varying size and capacity. From small systems for household purposes up to large systems for regional purposes. If possible, all systems should be linked in a common power grid. LÄS MER

  3. 2. InP High Electron Mobility Transistor Design for Cryogenic Low Noise Amplifiers

    Författare :Eunjung Cha; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cryogenic; stability; noise temperature; InP HEMT; LNA; MMIC;

    Sammanfattning : The InGaAs/InAlAs/InP high electron mobility transistor (InP HEMT) is the superior technology for the most demanding low-noise and high-speed microwave and millimeter-wave applications, in particular in radio astronomy and deep-space communication. InP HEMT has enabled cryogenic low noise amplifier (LNA) designs with noise temperatures about ten times the quantum noise limit from sub  GHz up to 120 GHz. LÄS MER

  4. 3. Wideband Active and Passive Antenna Solutions for Handheld Terminals

    Författare :Peter Lindberg; Anders Rydberg; Anders Pers; Nicholas Buris; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; active antennas; impedance matching; dipole antennas; baluns; slot antennas; microstrip antennas; mobile antennas; multifrequency antennas; antenna proximity factors; receiving antennas; ferrite devices; Teknisk fysik;

    Sammanfattning : This thesis presents solutions and studies related to the design of wideband antennas for wireless handheld terminal applications. A method of electrically shortening the terminal chassis length to obtain resonance at high frequencies has been proposed and evaluated, thereby increasing the antennas impedance bandwidth. LÄS MER

  5. 4. InP High Electron Mobility Transistors for Cryogenic Low-Noise and Low-Power Amplifiers

    Författare :Eunjung Cha; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; indium channel content; electrical stability.; dc power dissipation; noise temperature; scaling; low-noise amplifier LNA ; InP high-electron mobility transistor InP HEMT ; cryogenic;

    Sammanfattning : The InAlAs/InGaAs/InP high-electron mobility transistor (InP HEMT) is the preferred low-noise device in cryogenic low-noise amplifiers (LNAs) operating at 5-15 K. Such LNAs are utilized in microwave and millimeter-wave detection in radio astronomy. LÄS MER

  7. 5. Multicomponent superconductivity : Vortex matter and phase transitions

    Författare :Johan Carlström; Egor Babaev; Leo Radzihovsky; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Superconductivity; Ginzburg Landau; field theory; Iron pnictide;

    Sammanfattning : The topic of this thesis is vortex-physics in multi component Ginzburg- Landau models. These models describe a newly discovered class of super- conductors with multiple superconducting gaps, and possess many properties that set them apart from single component models. LÄS MER