g rbe 47M 20ksk 10k16(ks 200k 1009 3k2 gmU gs 200k2 电压增益 R R2=602∥20k2Mm2+(1+)0 U/as10k2∥R B(3k∥3k2) 2+(1+/)0D TS A1=A21×A2=369( )   ( ) ( ) 36.9 1 100 3 // 3 ; 10 // 60 // 20 //[ 1 100 ] 1 2 2 2 1 2 =  = + +    = −  = − =   + +  • • u u u b e u g s i m g s u i b e A A A r k k A U g U k R A R k k r    g + _ s d b e c + _ 47M 200k 200k gmU gs • 10k 60k 20k rbe I b • 100 I b •  3k U o •     • Ui 电压增益： Ri2