Nyquist Criterion

The Nyquist Criterion is a way to determine if a control system will remain stable when amplifying signals. It involves analyzing how the system’s frequency response behaves around a key point called the "gain margin." If the system’s response encircles a certain critical point in the complex plane too many times or in the wrong way, it can become unstable, leading to oscillations or uncontrolled behavior. Essentially, the criterion helps engineers design systems that respond accurately without becoming unstable, ensuring reliable operation by checking how the system reacts to different frequencies.