Signals Spectral Analysis and Distortion Measurements Using an Oscilloscope, a Camera and a Pc

This work describes a relatively simple yet effective method for analyzing harmonic distortions and spectral analysis of electronic signals up to the MHz range. The method involves the use a suitable analog or digital oscilloscopes to present the signal, taking a digital picture of the oscilloscope screen, converting the oscilloscope trace to numerical data and performing fast Fourier transform on the data. All MATLAB based software needed for the procedure is given. The results involve the spectrum analysis plot, the overall distortion, and all frequencies up to the tenth harmonic together with their relative amplitudes with respect to that of the fundamental frequency. The program provides for any user’s selected frequency band analysis to be presented.