The open-loop amplifier of a feedback system has its first two poles at \(f_{P 1}=1\) \(\mathrm{MHz}\) and \(f_{P 2}=10 \mathrm{MHz}\), and has a low-frequency open-loop gain of \(\left|A_{o}\right|=100 \mathrm{~dB}\).

(a) A dominant pole is to be added such that the closed-loop amplifier with a low-frequency gain of 20 has a phase margin of 45 degrees. What is the dominant pole frequency?

(b) If the feedback transfer function from part (a) is increased such that the closed-loop low-frequency gain is 5 , determine the phase margin of the amplifier.