The transfer function of a first-order controller is given as;
\({{G}_{C}}\left( s \right)=\frac{K\left( s+a \right)}{s+b}\)
Where K, a and b are positive real numbers. The condition for this controller to act as a phase lead compensator is1
a < b
2
a > b
3
K < ab
4
K > ab