1.电量放大倍数 Ri=R ∥R L E U。=lR (1+B)IR rI RIIU U=n +l R I, rhe +(1+ B)IR = (1+B)IBR (1+B)R b+(1+/)bRrh2+(1+/)R 55 o e RL U = I    RL RE RL  = // b RL = + I  （ ）  1  i b b e e RL U = I r + I     b be b RL = I r + + I    (1 ) b b e b L b L u I r I R I R A + +  +  =    (1 ) (1 )   be L L r R R + +  +  = (1 ) 1  （ ） 1. 电压放大倍数 rbe Ui  b I  RE RL RB Uo  c I  b I   i I 