Analysis and applications of techniques for envelope and phase extraction

Five digital techniques for envelope and phase extraction are analyzed in this thesis. These techniques are: Complex Demodulation, Hilbert Transformation, In-Phase and In-Quadrature Filtering, Phase-Locked Loop Demodulation and a zero-crossing and peak amplitude detection method. The relationship between these techniques is examined with attention to the mathematic and implementation aspects. The model of the signal, on which envelope and phase extraction techniques operate, is discussed. The differences between the above techniques and Fourier spectral analysis are elucidated. Computer programs for Complex Demodulation and a zero-crossing and peak amplitude detection method are presented. Finally applications to real and simulated data are described.