A common-emitter (CE) bipolar junction transistor amplifier is shown in FIGURE 1. Voc i. Vs R$ CCI ww HH Ri R www W FIGURE 1 Rc CC2 -VEE HH RE CE ww RL Vo If the amplifier is to operate for mid-band operation, perform AC analysis of the amplifier by choosing the appropriate AC model. This including drawing the complete AC equivalent circuit of the amplifier and deriving its input resistance, output resistance, voltage gain, and the overall voltage gain. [15 marks] ii. If the amplifier in FIGURE 1 is now to operate at low frequency of operation, by only considering the effect of Cc, draw its new AC equivalent circuit using the appropriate model and derive the voltage gain, Av. From the knowledge of Av, extract the cut-off frequency formula of the amplifier.