Transfer function of nonloading cascaded elements X1(s) X2(s) X3(s) R2 G1(s) G2(s) isolating amplifier X3(s) (gain K) X1(s) G1(s)G2(s) R1 R2 Obtain the transfer function e, eo E。(s) E,(s)Transfer function of nonloading cascaded elements G1(s) G2(s) G1(s)G2(s) X1(s) X1(s) X3(s) X3(s) X2(s) R1 C1 i e isolating amplifier (gain K) o e R 2 C 2 R1 C1 i e o e R 2 C 2 Obtain the transfer function ( ) ( ) E s E s i o