(a) For the CG amplifier in Fig. 8.18(a), show that the current gain io/isig is given by
(b) For the case gm = 2 mA/V, ro = 20 kΩ, and Rs = 20 kΩ, find the current gain obtained with RL = 20 kΩ.
(c) If RL is doubled (that is, increased by 100%), find the corresponding percentage change in current gain.
(d) If RL is increased from 20 kΩ to 200 kΩ (that is, increased by 900%), what is the corresponding change in current gain?
(e) Using the results of (c) and (d), comment on the performance of the CG circuit as a current buffer.