When to use cos(omega*t) vs exp(j*omega*t)
  • Edward Ackerman
    0
    When is it accurate to represent a signal voltage (in the example to follow, but the same question could be asked for current or electric field intensity or...) as V*cos(omega*t + phi) vs when the signal voltage must be represented as V*exp(j*[omega*t + phi])?
    Edward Ackerman Options
  • madengr
    1
    It's not an issue of accuracy, rather application. The cos(wt+phi) is a real function while the e^j*(wt+phi) is an analytic function, or phasor (typically used in RF texts with the wt (time varying term) dropped.

    https://en.wikipedia.org/wiki/Phasor

    In general, I'd read up on analytic signals and get used to thinking in those terms, as they have practical uses in I/Q conversion, SDR (e.g. GNU Radio), and RF system simulation (e.g.) AWR VSS. It's really a method of representing signals by separating out the carrier and envelope (i.e. the baseband, modulation, information).
    madengr Options
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