Use small-error PLLanalysis to show that a first-order loop [H (s) = 1] cannottrack an incoming signal whose instantaneous frequency is varying linearly with time (6;(1) = kr*). This signal can be tracked within a constant phase if H (s) = (s+ a)/s. It can be tracked with a zero phase error if H (s) = ( + as + b)/2. %3D