7.3. Effect of Process Parameters on Bode and Nyquist Plots
In this section we stress the effect of process parameters and the concepts of “all-pass” and “nonminimum phase.”
Effect of Process Order
Consider the following first-, second-, and third-order transfer functions.
The Bode plot is shown below in Figure 7-6. The higher order transfer functions have amplitude ratios that decrease more rapidly with frequency, and the phase angles asymptotically approach larger (more negative) values (−180° and −270° for the second- and third-order processes).