Research Article A low-order nonlinear amplier model with distributed delay terms

Abstract: In this paper, a novel behavioral modeling technique for the characterization of memory eects of ampliers is proposed. This characterization utilizes asymmetric intermodulation distortion (IMD) components, which are the result of a 2-tone excitation of a nonlinear amplier. These asymmetric IMD components are represented basically by a power series, where each term in the series has its own time delay term. These time delay terms successfully justify the presence of asymmetry in the intermodulation components, which leads to the prediction of amplitude-to-amplitude and amplitude-to-phase distortions. The parameters of the model are extracted using 2-tone measurements. A 100-W peak power amplier is examined. Model predictions are veried by the measurement results of a 4-tone stimulus. The proposed model can also be used in time domain analysis with arbitrary excitation. Key words: Behavioral model, asymmetric IMD, AM/PM conversion, nonlinear characterization 1