A Study of Nonlinearity Including Feedback Memory With Application to RF Amplifiers

A large number of systems may be modeled by placing feedback around a mildly nonlinear device. A technique for generically calculating the third-order intercept point (IP3) of these systems is developed. Common circuit configurations relevant to RF amplifiers are studied and analytical closed form equations for their IP3 are presented. The theoretical results are compared to simulated results obtained using commercial foundry models. The method may be applied to other circuit configurations.