Sökning: "high efficiency"

Visar resultat 1 - 5 av 2313 avhandlingar innehållade orden high efficiency.

  1. 1. High-Efficiency SiC Power Conversion : Base Drivers for Bipolar Junction Transistors and Performance Impacts on Series-Resonant Converters

    Författare :Georg Tolstoy; Hans-Peter Nee; Stig Munk-Nielsen; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Silicon Carbide; Bipolar Junction Transistor BJT ; Resonant converter; Series-resonant converter SLR ; Base drive circuits; High- Efficiency Converters; High-Frequency Converters; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : This thesis aims to bring an understanding to the silicon carbide (SiC) bipolar junction transistor (BJT). SiC power devices are superior to the silicon IGBT in several ways. They are for instance, able to operate with higher efficiency, at higher frequencies, and at higher junction temperatures. LÄS MER

  2. 2. Innovation and Efficiency : a Knowledge-Based Approach to Organizing Industrial Firms

    Författare :Mats Magnusson; []
    Nyckelord :innovation; efficiency; knowledge; organizing; knowledge creation; knowledge exploitation;

    Sammanfattning : This thesis deals with the organizing of industrial firms that face the challenge of achieving high levels of both innovation and efficiency, taking a knowledge-based approach to this classical trade-off. With a constructionist perspective as a point of departure, knowledge, which contains tacit and explicit components, is seen to exist at both the individual and the organizational level. LÄS MER

  3. 3. High efficiency power amplifiers for wireless communications

    Författare :Hossein Mashad Nemati; Chalmers University of Technology; []
    Nyckelord :load modulation; GaN; supply modulation; LDMOS; efficiency; Power amplifier; MMIC; mHEMT; transmitter architecture;

    Sammanfattning : This thesis presents state-of-the-art high efficiencyharmonically-tuned power amplifiers (PAs) and investigates thecharacteristics and potentials of such amplifiers in two of the mostpromising efficiency enhancement techniques, dynamic supply and load modulation.In this work, a 10 W LDMOS harmonically-tuned PA with 80% power-added-efficiency (PAE) isrealized at 1 GHz. LÄS MER

  4. 4. Linearization of High Efficiency Transmitters for Wireless Communications

    Författare :Haiying Cao; Chalmers University of Technology; []
    Nyckelord :dynamic load modulation; Behavioral model; digital predistortion; I Q imbalance; Volterra series; efficiency; power amplifier; transmitter;

    Sammanfattning : In recent years, reducing energy consumption in wirelesscommunication systems has gained prominence. In order to achieve this energy saving, high power efficiency is necessary for the wireless transmitters used. LÄS MER

  5. 5. High-efficiency Power Amplification Techniques for Wireless Transmitters

    Författare :Hossein Mashad Nemati; Chalmers University of Technology; []
    Nyckelord :load modulation; LDMOS; supply modulation; GaN HEMT; Power amplifier; wireless communications.; GaAs mHEMT; efficiency;

    Sammanfattning : The low efficiency of existing power amplifiers (PAs) is causing excessive energy consumption in wireless systems. Improving the PA efficiency is therefore of great environmental and economical importance. LÄS MER