VBE VBC IE =IEBs(e-1)-aglcas(e-1)IE =IF-aRIR VBE VBC Ic =ar!ms(e-D-lens(e-DIc arIg-In VBE VBC I8 Ig-Ic=(1-ap)IEBs(e-1)+(1-ag)Icas(e-D 年-R才 -c CBS I EBS 1 CBS B 图(a)= ( − 1 ) − ( T − 1 ) BC T BE VV R CBS VV E EBS I I e I e = ( − 1 ) − ( T − 1 ) BC T BE VV CBS VV C F EBS I I e I e = − =(1− ) ( −1)+(1− ) ( T −1) BC T BE VV R CBS VV B E C F EBS I I I I e I e E BIF IRIB CIC I E R R I F F I E B IF IR IB C I E I C R R I F F I 图( a ) E F R R I = I − I C F F R I = I − I EBS I CBS I EBS I CBS I