将rhe,Rl的阻值代入上式,得 80× 80 R=RB1|RB2m2=75151≈ R=R=2kQ (-80)=-50 R、+R20.6+1将rbe, R′ L的阻值代入上式，得 ( 80) 50 0.6 1 1 2 75 15 1 1 80 1 80 1 1 2  − = − + = + = = = =  = =   = −  = − u s i i s o u s o C i B B b e u A R R R U U A R R k R R R r k A