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Visar resultat 1 - 5 av 8 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Nonlinear Microwave Measurement Architectures for Wideband Device Characterization

    Författare :Sebastian Gustafsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nonlinear characterization; wideband; GaN HEMT; oscilloscope; microwave; active load-pull;

    Sammanfattning : The global surge for ubiquitous mobile communication requiring high speed and high capacity cellular networks has resulted in a golden age for the development of wireless technology. Modern cellular standards employ complex modulation formats with wider signal bandwidths to cope with the growing demand. LÄS MER

  3. 2. 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

  4. 3. Time-resolved laser spectroscopic studies of atoms, ions and Molecules

    Författare :Zhongshan Li; Fysiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atomic and molecular physics; Atom- och molekylärfysik; Fysicumarkivet A:2000:Li;

    Sammanfattning : Time-resolved laser spectroscopy has been performed to study the radiative properties of various microscopic systems. Using Laser-Induced Fluorescence (LIF) techniques, natural radiative lifetimes have been studied not only in neutral B, S, Ge, Ce, Pb, and in singly ionized V, Fe, Zr, Mo, La, Ce, Eu, Gd and Yb, but also in doubly ionized La, Ce, Pr, Eu, Er, Gd, Tm, Lu, and W. LÄS MER

  5. 4. Fiber-based all-optical sampling for ultrafast waveform monitoring

    Författare :Mathias Westlund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polarization independent; waveform monitoring; software synchronization; four-wave mixing; all-optical sampling;

    Sammanfattning : Digital sampling is a technique to visualize a time-varying waveform by capturing quasi-instantaneous snapshots of a signal via a sampling gate. The gate is opened and closed by narrow pulses in a pulse train having a well defined repetitive behaviour such that all parts of the waveform are measured. LÄS MER

  7. 5. Using Inhomogeneous Neuronal–Synaptic Dynamics for Spatiotemporal Pattern Recognition in Neuromorphic Processors

    Författare :Mattias Nilsson; Fredrik Sandin; Foteini Liwicki; Jerker Delsing; Elisabetta Chicca; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cyber-Physical Systems; Cyberfysiska system;

    Sammanfattning : Mixed-signal neuromorphic processors emulate the electrochemical dynamics of neurons and synapses using conventional analog CMOS-transistor technology and have potential for ultra-low-power machine learning and inference. However, the energy-efficiency of such systems is dependent on sparse, time-based information encoding and processing, and they are, furthermore, subject to imprecision from “device mismatch” in the analog circuitry. LÄS MER