A CS amplifier that can be represented by the equivalent circuit of Fig. 10.24 has Cgs =2 pF, Cgd =0.1 pF, CL = 2 pF, gm = 4 mA/V, and R1sig = R1L = 20 kΩ. Find the midband gain AM, the input capacitance Cin using the Miller approximation, and hence an estimate of the 3-dB frequency fH. Also, obtain another estimate of fH using open-circuit time constants. Which of the two estimates is more appropriate and why?
