A technique that allows the return ratio to be simulated using SPICE without disrupting the dc operating point is shown in Fig. 8.60 and explained in Problem 8.33.

(a) Use that technique to simulate the return ratio for the op amp from Problem 9.21 connected in a non-inverting unity-gain configuration for f = 1 kHz, 100 kHz, 10 MHz, and 1 GHz.

(b) Use that technique to plot the magnitude and phase of the return ratio. Determine the unity-gain frequency for the return ratio and the phase and gain margins.

R2 R1 (a) R2 V yt R4 (b)