C ase 2 GH(S) → 90 S s=jo MdB=20log,o M=-20n log a de n×20dB/ decade log o logo n×90
Case 3: GH(s)=K db (dB) 201g K Muh=201g K 100 o(g o) p=0° ● 100 o(g o) 90° 180
(lg) (lg) Mdb (dB) 0.1 1 10 100 0.1 1 10 100 −90 −180 20lg K Case 3: GH(s) = K = = 0 20lg Mdb K
C ase GH()=1+3=1+107→M=+o72;g=n(mr) MaB=20logo M=20-logl1+@ T2 2 0<< @=-(break point) Ma=202g(7) 2 g=tan(0)=0 o=tan (1 )=45 =+20 logT+20l0g o g=tan(∞) 20dB/decade 3dB 107
Case 5: GH(S 1+s+ 02)442 s=j0 Mur=20 log p=-tan-1a 2 <<a台<<1 0>>0台>>1 =20l og 0+0 M≈20log =20(-) +43 q=-tan(0)=0 M=20 lo =-20log25=20(-)og =20(-+k4 (log @-log a, )=-40(log a-log a 1)+45 g=-tan(∞)=-90 q=-tan(-0)=-180