Help with this problem would be greatly appreciated Based on

Help with this problem would be greatly appreciated!

Based on the Bode plot shown below, calculate: a. Gain Margin b. Phase Margin (b) Based on the Bode plot shown below, calculate: a. Gain Margin b. Phase Margin

Solution

a) In the problem as the magnitude is always less than 0db, the system has infinite phase margin

the phase crossover frequency is point where the plot cuts the negative 180 degrees ie, from the graph it is 15 rad/s

but the gain crossover frequency doesnot exist as the plot doesnot cut the 0 db line, So the gain margin is indeterministic.

b)in the problem b, the phase desnot touch the -180 degree line . So the system has infinite gain margin.

the gain crossover frequency is point where the plot cuts the 0 db line ie, from the graph it is 50 rad/s

but the phase crossover frequency doesnot exist as the plot doesnot cut the -180 degree line, So the phase margin is indeterministic.