Translations:Frequency response of a digital system/42/en

In Figure 10, we show the angle $\phi$ for various points on the unit circle. We trace out one period of the frequency function if we travel counterclockwise around the unit circle from point A to B, C, D, E, and back to A. Over this journey, we see that the angle $\phi$ increases monotonically from 0 to $2\pi$. Thus, the given factor of a dispersive all-pass system produces an increase in phase lag of $2\pi$ over one complete period $2\pi$ of frequency $\omega$ Therefore, a dispersive all-pass system of q such factors would have a phase-lag spectrum $\phi \left(\omega \right)$ that increases monotonically by an amount $2\pi q$ over one complete period; that is,