Sökning: "gallium nitride GaN"

Visar resultat 16 - 20 av 43 avhandlingar innehållade orden gallium nitride GaN.

  1. 16. 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

  3. 17. Theory and Design of Efficient Active Load Modulation Power Amplifiers

    Författare :Han Zhou; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GaN; circulator; non-reciprocity; Doherty power amplifier; Combiner synthesis; CLMA; deep power back-off; energy efficiency;

    Sammanfattning : The increasing demand for mobile data traffic has put new challenges and requirements for the development of the wireless communication infrastructure. The performance of the RF power amplifier (PA) is, in particular, of great importance, since it is the key building block for microwave transmitters in base stations and radio link equipment. LÄS MER

  4. 18. Microwave power device characterization

    Författare :Kristoffer Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; statistical estimation; self-heating; Silicon Carbide; Gallium Nitride; mixer; thermal resistance; wide bandgap; microwave; error-correction; small-signalmodel;

    Sammanfattning : The first part of the thesis covers work done on device characterizationmethods. A statistical method for estimating small-signal model parametersin FET-models was proposed. A maximum likelihood estimator wasderived and the new method was compared to a standard direct extractiontechnique. LÄS MER

  5. 19. 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. 20. Design, Fabrication and Characterization of GaN HEMTs for Power Switching Applications

    Författare :Björn Hult; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DCIT; SCE; high voltage; isolation; ‘buffer-free’; gate dielectric; GaN HEMT; passivation; DIBL;

    Sammanfattning : The unique properties of the III-nitride heterostructure, consisting of gallium nitride (GaN), aluminium nitride (AlN) and their ternary compounds (e.g. AlGaN, InAlN), allow for the fabrication of high electron mobility transistors (HEMTs). LÄS MER