Linearization of Intermodulation Distortion Using a Derivative Extended Model and Three-Tone Signal Identification

This article deals with the linearization of a radio frequency (RF) receiver chain through digital processing. An extension of a state-of-the-art distortion model is proposed, based on functions of the derivative of the signal. These are shown to translate to dependencies of the instantaneous frequency and instantaneous power of the processed signal. In addition, a three-tone signal identification method is presented, adapted to the estimation of the parameters of the proposed model. Finally, the construction of a measurement bench suitable for the validation of the identification and linearization method is described. Identification and linearization are done iteratively, based on the output signal of the system of interest. Results comparing the linearization using state-of-the-art model and our extended version show an improvement of the instantaneous dynamic range of up to 10 dB.