Closed-form spectral analysis of pulse-width modulation

This paper analyzes a pulse modulation system termed click modulation (CM) and shows that it is equivalent to single-sided pulse-width modulation (PWM) with a modified input signal. This paper then develops a spectral series for PWM with an arbitrary input duty ratio signal. Finally, a distortion equation for uniform-sampled PWM is given as a special case of natural-sampled PWM. The resulting analyses are confirmed through simulation.