如图所示固定偏置共射放大电路中,已知三极管静态时的UBEQ=0.7V,电流放大倍数β=80

(1)
IBQ=(VCC-VBEQ)/RB=(12-0.7)/500k=0.0226mA
ICQ=β*IBQ=80*0.0226=1.808mA
VCEQ=VCC-ICQ*RC=12-1.808*5k=2.96V
(2)
RL'=RC//RL=RC*RL/(RC+RL)=2.5k
AV=-β*RL'/rbe=-80*5k/1.2k=333
Ri=RB//rbe=500k*1.2k/(500k+1.2k)=1.197k
Ro=RL'=2.5k