Coupon Accepted Successfully!


Nyquist Criterion

The Nyquist criterion states that the amplifier is unstable if the Nyquist plot encloses the point (–1+j0), and the amplifier is stable if the curve does not enclose the point (–1+j0). The Nyquist criterion for positive and negative feedback is represented in the complex plane as depicted in Fig.



Locus of |1 + ßA|


Locus of βA in the complex plane for a feedback circuit which acts as negative feedback from f = 0 to f = f1 and acts as positive feedback form f = f1 to f = 

Nyquist plot of feedback amplifier:(a) Unstable (b) Stable


Test Your Skills Now!
Take a Quiz now
Reviewer Name