Control theory applied to the design of AGC circuits

Abstract

Applications of control theory in the design of automatic gain control (AGC) circuits are presented. A general model for AGC circuits is presented, and an equivalent linear system is proposed. Its behavior is compared with the dynamical response of two implemented AGC circuits. The results of classic and state variable correctors based on the model are presented. These results show the usefulness of this linear model in the design of the AGC dynamic response. By using a linear and t-variant system the dynamical behavior is improved. This approach is used to design hyperstability and Lyapunov-based correctors.