输入电阻、输出电阻 L R1=150k2 R,=50kQ G R D L Ro=IMQ 2 Rp=10ko R Rs=1OkQ S R31=10kg -RG+R//r2 r=R D gm=3mA/V 1+0.15/0.05 =10KQ Unn=20V DD 1.0375Mgro =RD =10K  S G R2 R1 RG RL  D R RL D 输入电阻、输出电阻 =1+0.15//0.05 =1.0375M  R1=150k R2=50k RG=1M RD=10k RS=10k RL=10k gm =3mA/V UDD=20V ri ro ri=RG+R1 //R2