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Visar resultat 1 - 5 av 17 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. SiC Varactors for Dynamic Load Modulation of Microwave Power Amplifiers

    Författare :Christer Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear characterization; varactors; active load-pull; power; microwave; amplifier; dynamic load modulation; SiC; energy efficiency;

    Sammanfattning : The rapid consumer adoption of mobile services is leading to an exponential growth in wireless data traffic. In order to accommodate more concurrent high data-rate users, the required complexity of transmitting radio base station (RBS) power amplifiers (PAs) is increasing. LÄS MER

  3. 2. High Efficiency Microwave Amplifiers and SiC Varactors Optimized for Dynamic Load Modulation

    Författare :Christer Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear measurements; power amplifiers; load modulation; GaN; SiC; varactors; HEMT; wide bandgap technology; energy efficiency;

    Sammanfattning : The increasing use of mobile networks as the main source of internet connectivity is creating challenges in the infrastructure. Customer demand is a moving target and continuous hardware developments are necessary to supply higher data rates in an environmentally sustainable and cost effective way. LÄS MER

  4. 3. High efficiency power amplifiers for wireless communications

    Författare :Hossein Mashad Nemati; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

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

    Författare :Hossein Mashad Nemati; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

  7. 5. 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