Discussion in 'Homework Help' started by Cerkit, May 12, 2010.

  1. Cerkit

    Thread Starter Senior Member

    Jan 4, 2009
    Hi. Can someone explain why the regular sampling method as opposed to naturally sampling reduces the subharmonic content for a given sampling frequency?
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    There may not be a concise explanation. The Fourier analysis of the two methods - natural & uniform - is a difficult task. The two techniques originate from different approaches to PWM generation. The former from an analogue approach - the latter from a digital method. I guess you know that already.

    It probably transpired that harmonic measurements of practical implementations of the two methods revealed important differences [strengths / weaknesses?] which were then analysed from a detailed theoretical approach.

    Doing some reading on the topic a clue may be that there is an inherent switching timing uncertainty in the digital sample & hold approach of uniform digital PWM generation. Refer for instance, to Geoffrey Walker's (BE) honours thesis on modulation & control of converters - The University of Queensland.