re model of BJT-page-1
Common Base (CB) configuration
So, we see that of the input port of the transistor is forward biased, so it can be replaced by forward biased p-n junction diode.
From the output characteristics
So the output port of the transistor can be replaced by current controlled control source where controlling current is Ie.
re quivalent circuit (ckt)
Or re model of BJT in CB configuration.
When IE =d.c component of emitter current
Final equivalentre model of transistor in CB configuration (config)