Response to the following problem:
Derive an expression for the small-signal voltage gain vo/vi of the circuit shown in Fig. in two different ways:
(a) As a differential amplifier
(b) As a cascade of a common-collector stage Q1: and a common-base stage Q2: Assume that the BJTs are matched and have a current gain α, and neglect the Early effect. Verify that both approaches lead to the same result.
