An amplifier has a low-frequency forward gain of 5000 and its transfer function has three negative real poles with magnitudes 300 kHz, 2 MHz, and 25 MHz.

(a) Calculate the dominant-pole magnitude required to give unity-gain compensation of this amplifier with a 45° phase margin if the original amplifier poles remain fixed. What is the resulting bandwidth of the circuit with the feedback applied?

(b) Repeat (a) for compensation in a feedback loop with a closed-loop gain of 20 dB and 45◦ phase margin.