Common emitter amplifier with RE

AC Analysis:

All capacitors are short circuited and DC source are deactivated.

Voltage gain: 

                       Av = Vo/Vin

                             = -g_mx r_𝝿(Rc||R_L||r_o)/[r_𝝿+(1+g_mr_𝝿)R_E]

Current gain 

                    Av = -g_mr_𝝿  = -𝜷
Input resistance 

R_iB =  r_𝝿+(1+g_mr_𝝿)R_E

Ri =R_TH||Ri_B

RiB  is input resistance looking into base of BJT

Ri is input resistance  of amplifier 

Ris is input resistance looking from source 

Output resistance:

Ro   =    Rc||Ri_B