Common base amplifier voltage gain

[Physicist3]

Hi,

I have a common base amplifier circuit but I am not sure of the equation to use to calculate the voltage gain? Could someone help me please

 

[carlgrace]

Av = gmRl where gm is the transconductance of the transistor and Rl is the equivalent load resistance at the drain/emitter.

If it is a BJT then gm is Ic/vt where Ic is the collector current and vt is the thermal voltage kT/q.