The Experts below are selected from a list of 2289 Experts worldwide ranked by ideXlab platform

Diego R. Yankelevich - One of the best experts on this subject based on the ideXlab platform.

  • Measurement of the modulation efficiency of an optical phase modulator using a self-homodyne receiver
    IEEE Photonics Technology Letters, 2002
    Co-Authors: Jack H. Campbell, Andre Knoesen, Diego R. Yankelevich
    Abstract:

    The authors describe a self-homodyne technique to measure the modulation efficiency of an optical phase modulator. The phase modulator is driven by a sine wave and the Baseband Spectrum is measured and analyzed. Combinations of the ratio of harmonics are used to estimate V/sub /spl pi// of a commercially available modulator with a resolution of 0.8%. The method offers simplicity because it uses a single laser, does not require sensitive optical adjustments, and lends itself to the measurement of V/sub /spl pi// as a function of modulation frequency and optical carrier wavelength.

Jack H. Campbell - One of the best experts on this subject based on the ideXlab platform.

  • Measurement of the modulation efficiency of an optical phase modulator using a self-homodyne receiver
    IEEE Photonics Technology Letters, 2002
    Co-Authors: Jack H. Campbell, Andre Knoesen, Diego R. Yankelevich
    Abstract:

    The authors describe a self-homodyne technique to measure the modulation efficiency of an optical phase modulator. The phase modulator is driven by a sine wave and the Baseband Spectrum is measured and analyzed. Combinations of the ratio of harmonics are used to estimate V/sub /spl pi// of a commercially available modulator with a resolution of 0.8%. The method offers simplicity because it uses a single laser, does not require sensitive optical adjustments, and lends itself to the measurement of V/sub /spl pi// as a function of modulation frequency and optical carrier wavelength.

Jenshan Lin - One of the best experts on this subject based on the ideXlab platform.

  • Adaptive harmonics comb notch digital filter for measuring heart rate of laboratory rat using a 60-GHz radar
    2016 IEEE MTT-S International Microwave Symposium (IMS), 2016
    Co-Authors: Tien-yu Huang, Linda F. Hayward, Jenshan Lin
    Abstract:

    Harmonics of respiration frequency due to nonlinear Doppler phase demodulation may interfere the identification of heartbeat frequency in vital sign radar's Baseband Spectrum. The proposed adaptive harmonics comb notch digital filter is a type of Spectrum-based filtering function with no degradation on the heartbeat signal, and no calibration is needed when the detection distance changes. Experimental results show that the proposed filter for removing respiration harmonics can help measuring laboratory rat's heart rate more accurately when the heartbeat movement is weak or overwhelmed by the respiratory movement in the detected Spectrum. Furthermore, even when the heart rate is totally overlapped by the respiration rate harmonics, the heart rate can still be extracted.

  • Analysis of Detection Methods of RF Vibrometer for Complex Motion Measurement
    IEEE Transactions on Microwave Theory and Techniques, 2011
    Co-Authors: Yan Yan, Louis N. Cattafesta, Jenshan Lin
    Abstract:

    In this paper, the detection technique of the previously reported wavelength-division-sensing RF vibrometer is thoroughly analyzed by investigating the Bessel function coefficient of harmonics in the Baseband Spectrum. The analysis provides guidelines on the selection of harmonic pairs to help improve detection accuracy and reliability. A new detection method that utilizes multiple harmonic pairs under a fixed carrier frequency proves to be a more reliable approach for RF vibrometers. The sensitivity of harmonic amplitude ratio to the excess phase angle is explored as well. The results show that by using insensitive harmonic pairs, information about the characteristics of the vibration system and the external driving force are still attainable even when the phase angles are unknown. Real-time monitoring of various harmonic vibrations has been realized through a LabVIEW program with a user interface that provides visualization of the vibration patterns. The function of through-wall detection of the RF vibrometer has also been verified by conducting all measurements behind a wall with a detection distance of 1.5 m.

Andre Knoesen - One of the best experts on this subject based on the ideXlab platform.

  • Measurement of the modulation efficiency of an optical phase modulator using a self-homodyne receiver
    IEEE Photonics Technology Letters, 2002
    Co-Authors: Jack H. Campbell, Andre Knoesen, Diego R. Yankelevich
    Abstract:

    The authors describe a self-homodyne technique to measure the modulation efficiency of an optical phase modulator. The phase modulator is driven by a sine wave and the Baseband Spectrum is measured and analyzed. Combinations of the ratio of harmonics are used to estimate V/sub /spl pi// of a commercially available modulator with a resolution of 0.8%. The method offers simplicity because it uses a single laser, does not require sensitive optical adjustments, and lends itself to the measurement of V/sub /spl pi// as a function of modulation frequency and optical carrier wavelength.

Bernard Lacaze - One of the best experts on this subject based on the ideXlab platform.

  • From periodic sampling to irregular sampling through PNS (Periodic Nonuniform Sampling)
    arXiv: Data Analysis Statistics and Probability, 2019
    Co-Authors: Bernard Lacaze
    Abstract:

    Resampling is an operation costly in calculation time and accuracy. It regularizes irregular sampling, replacing N data by N periodic estimations. This stage can be suppressed, using formulas built with incoming data and completed by sequences of elements which influence decreases when the number of data increases. Obviously, some spectral properties (for processes) and some asymptotic properties (for the sampling sequence) have to be fulfilled. In this paper, we explain that it is possible to elaborate a logical theory, starting from the ordinary periodic sampling, and generalized by the PNS (Periodic Nonuniform Sampling), to treat more general irregular samplings. The "Baseband Spectrum" hypothesis linked to the "Nyquist bound" (or Shannon bound) is generalized to spectra in a finite number of intervals, suited to the "Landau condition".