Sökning: "even frequencies"

Visar resultat 21 - 25 av 148 uppsatser innehållade orden even frequencies.

  1. 21. Computation of Acoustic Wave Propagation Under Water

    Master-uppsats, KTH/Matematik (Avd.)

    Författare :Frida Thörn; [2022]
    Nyckelord :Wave equation; Helmholtz equation; Waveholtz iteration; finite difference method; summation by parts; energy method; point source; curvilinear coordinates; vågekvationen; helmholtz ekvation; waveholtz iteration; finita differens methoden; energimetoden; punktkälla; kurvlinjära koordinater; kroklinjiga koordinater; SBP;

    Sammanfattning : In this thesis we look at acoustic wave propagation under water. We look in particular at waves generated by a point source and what happens with the propagation when we model the bottom as flat or as curvilinear. We assume the source to be working at a certain frequency and therefore we model this problem by solving the Helmholtz equation. LÄS MER

  3. 22. Multi-spectral X-ray imaging with a laser-plasma accelerator

    Master-uppsats, Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Författare :Andrea Angella; [2022]
    Nyckelord :Multi-spectral imaging; single-photon counting; X-ray absorption spectroscopy; XAS; LWFA; laser-wakefield acceleration; K-edge; imaging; metal-detection algorithm; Physics and Astronomy;

    Sammanfattning : This master thesis focuses on the creation of an algorithm to perform multispectral imaging of a metallic target using X-rays. The generation of an ultrashort high-power low-divergent X-ray beam is performed by means of a Ti:Sapphire laser driven wake-field plasma accelerator. LÄS MER

  4. 23. Numerical study of a vibroacoustic wave trap for e-vehicles

    Master-uppsats, KTH/Teknisk akustik

    Författare :Antoine Curien; [2022]
    Nyckelord :wheel vibrations; passive vibration control; multiple tuned mass damper; bending mode; numerical optimisation; damping; resonance; robustness; reduction methods; Hjulvibrationer; passiv vibrationsreglering; multi tuned mass damper; böjningsläge; numerisk optimering; dämpning; resonans; robusthet; modale reduktionsmetoder;

    Sammanfattning : The transition from internal combustion engine to battery electric cars is accompanied by a shift on the NVH issues damaging the passenger comfort. The rolling noise generated by the wheels and tyres is in particular characterized by an increasing attention from OEMs and car manufacturers. LÄS MER

  5. 24. E-Band SPDT RF Switch for a Class F PA in III-V Nanowire MOSFET Technology

    Master-uppsats, Lunds universitet/Institutionen för elektro- och informationsteknik

    Författare :Rungeng Xu; [2022]
    Nyckelord :E-band; III-V Nanowire MOSFET; RF Switch; Class-F PA; Technology and Engineering;

    Sammanfattning : This project designs an RF switch operating in E-band to provide a transmit path from a Class-F power amplifier (PA). The basic RF switch is based on the single-pole double-throw (SPDT) topology using shunt transistor switches and two λ/4 transmission line. LÄS MER

  7. 25. Low-profile fully-metallic Luneburg lens antenna

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Justine Djounidi; [2022]
    Nyckelord :Beam Scanning; Luneburg Lens Antenna; Fully-metallic; Millimeter Wave; Vinkelskanning; Luneburg Linsantenn; Fullt Metalliskt; Millimetervåg;

    Sammanfattning : Modern communication systems face new technological challenges, such as the narrowness and overload of the conventional frequency bands employed for these applications. Nowadays, communication systems are expected to operate at higher frequencies, such as the mm-wave band. LÄS MER