a=10.T= 1无源超前网络 1+aTs 15 aG(s) 1+T 20 lg 10lg a T L(Om)=20lg va=10lg a 1+sin 1-sin q R I (a)频率特性 ctg arcsin CR2凵ve a+14 10-2 10-1 100 101 0 5 10 15 20 10-2 10-1 100 101 0 10 20 30 40 50 60 (a)频率特性 a = 10,T = 1 aT 1 T 1  m 20lg a 10lg a  m Ts aTs aG s c + + = 1 1 ( ) T a m 1  = 1 1 arcsin 2 1 + − = − = a a a a  m arctg m m a   1 sin 1 sin − + = Lc (m ) = 20lg a =10lg a r u c u R1 C R2 1.无源超前网络