For a given open-loop gain A0 the conclusions above can be stated in terms of the feedback
factor β. That is, there exists a maximum value for β above which the feedback amplifier
becomes unstable. Alternatively, we can state that there exists a minimum value for the
closed-loop gain Af0 below which the amplifier becomes unstable. To obtain lower values of
closed-loop gain one needs therefore to alter the loop transfer function L(s). This is the process
known as frequency compensation. We shall study the theory and techniques of frequency
compensation in Section 10.13.