↑ Ordinarily, as frequency increases the magnitude of the gain drops and the phase becomes more negative, although these are only trends and may be reversed in particular frequency ranges.
↑ The critical amount of feedback where the peak in the gain just disappears altogether is the maximally flat or Butterworth design.
↑ The frequency where the open-loop gain flips sign f180 does not change with a change in feedback factor; it is a property of the open-loop gain.
