4.动态分析 U。BR1 BiLl Re Rill U R=R1∥RB2∥e R=R 无旁路电容C时: Blb(R2∥R1) i, Rbd Rb2 R R Re BRI R=Rn1∥R2[me+(1+B)R The +(+B)R R 利?弊? 若(1+B)R>>,则A1≈ R4. 动态分析 be ' L i o r R U U Au  = = −    i b1 b2 be R = R ∥R ∥r Ro = Rc e e (1 ) ( ) be ' L b be e b c L i o r R R I r I R I R R U U Au    + + = − + − = =       ∥ [ (1 ) ] i b1 b2 be Re R = R ∥R ∥ r + +  利?弊? e ' L e be (1 ) R R 若 +  R  r ，则Au  − 无旁路电容Ce时：