Sökning: "frequency"

Visar resultat 21 - 25 av 5210 avhandlingar innehållade ordet frequency.

  1. 21. Towards Ultimate Performance of THz Heterodyne Receivers: SIS Frequency Multiplier and Wideband Passive Components

    Författare :Hawal Marouf Rashid; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Wideband passive components; distributed SIS junction; Frequency multiplier; Frequency up-converter; Hybrids; distributed SIS frequency multiplier;

    Sammanfattning : This thesis focuses on the development of advanced components for the future wideband side band separating and / or multipixel receivers for radio-astronomy with ultimate sensitivity.In this thesis, a novel frequency multiplier based on distributed superconducting tunnel (SIS) junctions has been demonstrated for the first time, taking advantage of the extreme inherent nonlinearity of such device. LÄS MER

  3. 22. Frequency Optimization of Vibratory Rollers and Plates for Compaction of Granular Soil

    Författare :Carl Wersäll; Stefan Larsson; Michael Mooney; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; compaction; vibratory roller; frequency; resonance; vibration; sand; gravel; soil dynamics; Byggvetenskap; Civil and Architectural Engineering;

    Sammanfattning : Vibratory rollers are commonly used for compaction of embankments and landfills. This task is time consuming and constitutes a significant part of most large construction and infrastructure projects. By improving the compaction efficiency, the construction industry would reduce costs and environmental impact. LÄS MER

  4. 23. Low noise frequency combs and injection locking for broadly tunable laser sources and tomography

    Författare :Connor Skehan; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; relative intensity noise; frequency comb; frequency noise; phase noise; optical injection locking;

    Sammanfattning : Lasers have revolutionized the world of physics by providing a highly coherent source of photons which may be used for a large variety of purposes. Here, we study the noise properties of frequency combs - a special class of frequency stabilized and mutually coherent multi-mode lasers, as well as the optical injection locking of comb tones as a means for low noise amplification and tone selection. LÄS MER

  5. 24. High resolution time-frequency representations

    Författare :Isabella Reinhold; Statistical Signal Processing Group; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; time-frequency analysis; non-stationary signals; multi-component signals; IF estimation; reassignment;

    Sammanfattning : Non-stationary signals are very common in nature, e.g. sound waves such as human speech, bird song and music. It is usually meaningful to describe a signal in terms of time and frequency. LÄS MER

  7. 25. Microwave integrated circuits for frequency generation and power spectrum measurements / Lars Landén %C Göteborg

    Författare :Lars Landén; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gilbert mixer; frequency multiplier; frequency divider; autocorrelation; spectrometer; MMIC;

    Sammanfattning : .... LÄS MER