H(s)= k(S2+1) (S+1)(S+1+j)(S+1-j H(0)=1,∴k=2 H(s) 2(S2+1) (S+1)(S2+2s+2)( 1)( 2 2) 2( 1) ( ) ( 0) 1, 2 ( 1)( 1 )( 1 ) ( 1) ( ) 2 2 2 + + + +  = =  = + + + + − + = s s s s H s H j k s s j s j k s H s 