so that the ratio of high-to - low frequency gain is D1a(0)二0 The lead compensator is still a high-pass filter but the high frequency gain is limited by the pole at s=-Po. Typically, the ratio of po to zo is kept to below 10 2022-2-3 52022-2-3 5 so that the ratio of high-to-low frequency gain is 0 ( 0) ( ) 0 0 lead lead    z p D j D j (6.6) The lead compensator is still a high-pass filter but the high frequency gain is limited by the pole at . Typically, the ratio of p0 to z0 is kept to below 10. p0 s  