An oscillator can be viewed as a positive feedback system, with a forward gain stage A and a feedback network B. If the forward gain stage has a gain of 10 with a phase shift of pericular angle, specify the S parameters for the feedback stage B to ensure oscillation. Assume that the amplifier output is connected to the feedback port 1 and the feedback port 2 is connected to the amplifier input. Express the S parameters as a matrix. Assume the feedback element is ideal. Solution output = AB/(1+AB) if magniitude(AB)= 1 angle1 + angle2 = 180.