KMb=20gK-40g0-20gy(7o)2+1 EX2 GH(S) +1)=-180°-1g 201gGH(o 40dB/dec 60dB/dec (g @) ∠GH(j) (g o) 180 270°Ex. 2 ( 1) ( ) 2 + = s Ts K GH s 20lg 40lg 20lg ( ) 1 2 Md b = K −  − T +  tg T 1 180 − = − −  (lg)  GH( j) 0 −180 −270 T 1  (lg) 20lg GH( j) −40dB/ dec −60dB/ dec