Sökning: "Varactor"

Visar resultat 1 - 5 av 37 avhandlingar innehållade ordet Varactor.

  1. 1. Symmetric varactor frequency multipliers

    Författare :Mattias Ingvarson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sub-millimetre wave; heterostructure barrier varactor HBV ; symmetric varactor; frequency multiplier; millimetre wave; semiconductor diode;

    Sammanfattning : This thesis describes heterostructure barrier varactor (HBV) frequency multipliers for millimetre and sub-millimetre wave applications.The basic principles of HBVs are explained. Starting from basic varactor theory, an equivalent circuit model for HBVs is presented. LÄS MER

  3. 2. Integrated VCOs in Gallium Arsenide HEMT technologies with a novel varactor structure

    Författare :Mattias Ferndahl; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; design; Oscillator; HEMT; pHEMT; MMIC; VCO; varactor; GaAs; mHEMT;

    Sammanfattning : This thesis presents results on metamorphic and pseudomorpic GaAs HEMT based Voltage Controlled Oscillators and a novel high-Q varactor structure, used in the VCOs, together with a straightforward extraction procedure for the varactors.Theory and fundamentals around LC-oscillators with oscillator criteria, phase noise and different topologies are given as background together with VCO phase noise measurement methods and an overview on device flicker noise; its physical origin and measurement. LÄS MER

  4. 3. Heterostructure Barrier Varactor Diodes for Frequency Multiplier Applications

    Författare :Jan Stake; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; III-V semiconductor; millimetre- and submillimetre wave power source; Heterostructure Barrier Varactor HBV ; frequency multiplier; varactor diode;

    Sammanfattning : This thesis deals with fabrication, characterisation and modelling of the Heterostructure Barrier Varactor (HBV) diode and its use in frequency multiplier circuits. Different aspects of material structures and frequency multipliers are described. LÄS MER

  5. 4. Frequency Reconfigurable and Linear Power Amplifiers Based on Doherty and Varactor Load Modulation Techniques

    Författare :William Hallberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gallium nitride GaN ; wideband; Class-J; linear; microwave; radio frequency RF ; Doherty; broadband; AM AM; silicon carbide SiC ; bandwidth; power amplifier PA ; AM PM; varactor; dynamic load modulation DLM ; fifth generation mobile networks 5G ; energy efficiency;

    Sammanfattning : In future mobile communication networks, there will be a shift towards higher carrier frequencies and highly integrated multiple antenna systems. The system performance will largely depend on the available RF hardware. As such, RF power amplifiers (PAs) with improved efficiency, linearity, and bandwidth are needed. LÄS MER

  7. 5. Planar Heterostructure Barrier Varactor Diodes for Millimetre Wave Applications

    Författare :Jan Stake; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; millimetre- and sub-millimetre wave power source; III-V semiconductor; varactor diode; frequency multiplier; Heterostructure Barrier Varactor HBV ;

    Sammanfattning : This thesis deals with fabrication, characterisation and modelling of the Heterostructure Barrier Varactor (HBV) diode and its use in frequency multiplier applications. Different aspects of material structures and frequency multipliers are described. LÄS MER