Sökning: "signal amplification"

Visar resultat 1 - 5 av 103 avhandlingar innehållade orden signal amplification.

  1. 1. Combining analytical and iterative reconstruction in helical cone-beam CT

    Författare :Johan Sunnegårdh; Gösta Granlund; Per-Erik Danielsson; Michel Defrise; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cone-beam tomography; forward projection; image reconstruction; iterative reconstruction; ordered subsets; regularization; WFBP; Signal processing; Signalbehandling;

    Sammanfattning : Contemporary algorithms employed for reconstruction of 3D volumes from helical cone beam projections are so called non-exact algorithms. This means that the reconstructed volumes contain artifacts irrespective of the detector resolution and number of projection angles employed in the process. LÄS MER

  3. 2. Nonlinearity mitigation in phase-sensitively amplified optical transmission links

    Författare :Kovendhan Vijayan; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; copier-PSA; nonlinearity mitigation; phase-sensitive amplifier; self-phase modulation mitigation; low-noise amplification; optical transmission; crossphase modulation mitigation;

    Sammanfattning : The fundamental limitations in fiber-optic communication are caused by optical amplifier noise and the nonlinear response of the optical fibers. The quantum-limited noise figure of erbium-doped fiber amplifier (EDFA) or any phase-insensitive amplifier is 3 dB. LÄS MER

  4. 3. Power Consumption and Joint Signal Processing in Fiber-Optical Communication

    Författare :Lars Lundberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; coherent detection; erbium-doped fiber amplifier; phase-tracking; optical amplifier; optical frequency comb; digital signal processing; carrier-recovery; spatial division multiplexing; power consumption; Fiber-optical communication; multicore fiber; Raman amplification; energy-efficiency;

    Sammanfattning : The power consumption of coherent fiber-optical communication systems is becoming increasingly important, for both environmental and economic reasons. The data traffic on the Internet is increasing at a faster pace than that at which optical network equipment is becoming more energy efficient, which means that the overall power consumption of the Internet is increasing. LÄS MER

  5. 4. Intermodulation in microresonators : for microwave amplification and nanoscale surface analysis

    Författare :Erik Tholén; David Haviland; Eyal Buks; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Superconductivity; Atomic Force Microscopy; Nonlinear oscillators; Parametric amplification; Mesoscopic physics; Mesoskopisk fysik;

    Sammanfattning : This work explores the effects of weak nonlinearity on harmonic oscillators.Two particular systems are studied experimentally: A superconductingresonator formed from a coplanar waveguide that oscillates at microwave frequencies,and the cantilever of an atomic force microscope (AFM) vibratingat ultrasonic frequencies. LÄS MER

  7. 5. All-optical nonlinearity mitigation in fiber-optic communications

    Författare :Henrik Eliasson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fiber-optic communications; phase-sensitive amplifiers; optical phase conjugation; nonlinear optics;

    Sammanfattning : The two main factors limiting the data throughput in modern fiber-optic communication links are the noise added by amplifiers and the nonlinear response of the optical fiber due to the Kerr effect. Today there are communication systems operating remarkably close to the limits set by these two factors. LÄS MER