ABSTRACT
Chapter 11 is devoted to plotting the open-loop transfer function G( jω)H( jω). The two types of plots that are emphasized are the direct polar plot (Nyquist plot) and the log magnitude (Lm)–angle plot (Nichols plot). Also included in Chapter 11 is the determination of closed-loop stability in terms of the open-loop transfer function by use of the Nyquist stability criterion, which is illustrated in terms of both types of plot. The result of the stability study places bounds on the permitted range of values of gain.
