I have found in the examples the way to simulate phase locked loop systems in terms of stability. These examples make open loop, closed loop and filter AC simulations, and get the Bode plots and from them the gain and phase margin are obtained, being the best way to analyze the loop stability.

I tried to get a similar example but for a RF AGC loop, with no success. A variable gain amplifier, power detector, low pass filter are the usual components on this system, but is there any linear block that makes its function? How to implement the simulation? Where the loop has got to be opened to get the Open Loop frequency response?.

Thanks in advance.

I tried to get a similar example but for a RF AGC loop, with no success. A variable gain amplifier, power detector, low pass filter are the usual components on this system, but is there any linear block that makes its function? How to implement the simulation? Where the loop has got to be opened to get the Open Loop frequency response?.

Thanks in advance.