The feedback amplifier of Fig. P11.72 consists of a common-gate amplifier formed by Q1 and RD, and a feedback circuit formed by the capacitive divider (C1, C2) and the common-source transistor Qf . Note that the bias circuit for Q is not shown. It is required to derive expressions for Af ≡Vo/Is, Rin , and Rout . Assume that C1 and C2 are sufficiently small that their loading effect on the basic amplifier can be neglected. Also neglect ro. Find the values of Af , Rin , and Rout for the case in which gm1 = 5 mA/V, RD = 10 kΩ, C1 = 0.9 pF, C2 = 0.1 pF, and gmf = 2 mA/V.
