如题所述
在发射极电阻被电容旁路时,输入电阻:Ri = rbe;负载电阻:RL' = Rc//RL;
那么,电路放大倍数;Au = β*RL' / rbe;
当发射极电阻的旁路电容开路时,输入电阻:Ri = rbe +(1+β)*Re;
显然此时,Ri > rbe,所以 Au 会下降,输入电阻会增大;
而输出电阻不变 =Rc;
Ui = Ib*rbe + URe = Ib*rbe + Ib*(1+β)*Re;