3.高频电压放大倍数:定量分析 R=rbe∥(lb+Rb∥R3) Rb R R1 R h (gmR) r+r R+ Oc uSm 2兀RC2π[e∥(b+Rb∥R)Cn H( ) b'e bb Rb Rs R = r ∥ r + ∥ 3. 高频电压放大倍数：定量分析 2π [ ( )] 1 2π 1 1 j ' b 'e bb' b s π ' π H H s m s o s h RC r r R R C f f f A U U A u u ∥ + ∥ = = + = =     ( ) j 1 j 1 ' m L ' π ' π b e b 'e s i i C o ' s C s ' s s o s h ' π ' π g R C R C r r R R R U U U U U U U U Au  − +   + = =   =           