Sökning: "GaN HEMT"

Visar resultat 31 - 35 av 40 avhandlingar innehållade orden GaN HEMT.

  1. 31. Characterization of Microwave Transistors for Robust Receivers and High Efficiency Transmitters

    Författare :Mattias Thorsell; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; noise modeling; access resistance; self-heating; AlGaN GaN HEMT; thermal characterization; active load-pull; load modulation;

    Sammanfattning : The next generation of integrated transceiver front-ends needs both robustlow noise amplifiers and high power amplifiers on a single-chip. The AluminiumGallium Nitride / Gallium Nitride (AlGaN/GaN) High Electron MobilityTransistors (HEMT) is a suitable semiconductor technology for this purposedue to its high breakdown voltage and high electron mobility. LÄS MER

  3. 32. Nonlinear Characterisation and Modelling of Microwave Semiconductor Devices

    Författare :Mattias Thorsell; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; noise modelling; nonlinear measurement; active load-pull; noise measurement; thermal characterisation; AlGaN GaN HEMT; nonlinear modelling;

    Sammanfattning : There is an increasing need for more accurate models taking into account the nonlinearities and memory effects of microwave transistors. The memory effects are especially important for transistor technologies suffering from relatively large low frequency dispersion, such as GaN baed HEMTs. LÄS MER

  4. 33. MOCVD growth of GaN-based high electron mobility transistor structures

    Författare :Jr-Tai Chen; Erik Janzén; Urban Forsberg; James S. Speck; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The present work was to improve the overall quality of GaN-based high electron mobility transistor (HEMT) epitaxial structures grown on semi-insulating (SI) SiC and native GaN substrates, using an approach called bottom-to-top optimization. The bottom-to-top optimization means an entire growth process optimization, from in-situ substrate pretreatment to the epitaxial growth and then the cooling process. LÄS MER

  5. 34. P-type and polarization doping of GaN in hot-wall MOCVD

    Författare :Alexis Papamichail; Vanya Darakchieva; Anelia Kakanakova-Gueorguieva; Jr-Tai Chen; Zhaoxia Bi; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The devolopment of group-III nitride semiconductor technology continues to expand rapidly over the last two decades. The indium nitride (InN), gallium nitride (GaN) and aluminum nitride (AlN) compounds and their alloys are direct bandgap semiconductors with a wide bandgap range, spanning from infrared(IR) to deep-ultraviolet (UV), enabling their utilization in optoelectronic industry. LÄS MER

  7. 35. 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