Dynamic nonlinear behavior characterization for wideband RF transmitters using augmented Hammerstein models

This paper presents an augmented Hammerstein nonlinear model intended for characterization of the dynamic nonlinear behaviors of the wideband RF transmitter. With the substitution of the linear filter used in the conventional Hammerstein model by a weakly nonlinear filter, the augmented Hammerstein model shows a better capability to account for all of the sources of the memory effects. A transmitter prototype, which consists of a Vector Signal Generator (VSG: Agilent ESG E4438C) and an L- band 60-Watt GaAs FET push-pull amplifier, utilized in this paper for model validation. By comparing the accuracy of the augmented Hammerstein model with that of the traditional one under a two carrier WCDMA excitation condition, the validation results demonstrate the superiority of this new dynamic nonlinear model to the conventional one.