Sökning: "HEMT"

Visar resultat 1 - 5 av 67 avhandlingar innehållade ordet HEMT.

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

    Författare :Mattias Ferndahl; Chalmers University of Technology; []
    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

  3. 2. Development of Cryogenic Low Noise 4-8 GHz HEMT Amplifier and its Advanced Characterization

    Författare :Erik Sundin; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shot-noise; low noise amplifier; cryogenic amplifier; sis; noise measurement; HEMT;

    Sammanfattning : In most radio astronomy instrumentation, cryogenic low noise amplifiers (LNA) are used as intermediate frequency (IF) amplifiers. The system noise temperature is among the most important parameters of a receiver and requires state of the art components. LÄS MER

  4. 3. InP HEMT Technology and Applications

    Författare :Anders Mellberg; Chalmers University of Technology; []
    Nyckelord :Indium phosphide InP ; cryogenic LNA; high electron mobility transistor HEMT ; metal-insulator-metal capacitor; MODFET; thin film resistor; semiconductor device fabrication; MMIC;

    Sammanfattning : Indium phosphide high electron mobility transistors (InGaAs/InAlAs/InP HEMTs) exhibit the highest cut-off frequencies and the lowest microwave noise figures of all transistor technologies. Both InP HEMT technology and associated circuit demonstrators are therefore interesting to explore further. LÄS MER

  5. 4. Optimum GaN HEMT Oscillator Design Targeting Low Phase Noise

    Författare :Mikael Hörberg; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; low frequency noise; resonator coupling; cavity resonator; GaN HEMT; MMIC; reflection oscillator; phase noise;

    Sammanfattning : The thesis considers design of low phase noise oscillators, given the boundary condition of the used technology. Important conditions are the power handling of the active device, device noise floor, the quality factor of the resonator, bias settings, and low frequency noise. LÄS MER

  7. 5. Ohmic Contacts and Thin Film Resistors for GaN MMIC Technologies

    Författare :Anna Malmros; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ohmic contact; TFR; TiN; HEMT; GaN; TaN;

    Sammanfattning : Gallium nitride (GaN) based high electron mobility transistor (HEMT) technology has attracted much attention during the last decade which has resulted in a rapid development in material quality and device performance. GaN HEMT microwave electronics are currently finding its applications in wireless communication infrastructure and radar systems. LÄS MER