A model for bandpass nonlinearities based on harmonic measurements

This paper presents a model for a bandpass nonlinearity, which is based on measurements on several harmonics of the output. The model has a quadrature structure, with a memoryless nonlinearity and a filter in each branch. The structure can describe AM/AM as well as AM/PM conversions. The parameters of the nonlinearity and the filter are jointly optimized to fit the measurements. Analytic expressions for the parameters of the model are found by means of the MMSE optimization. The method is applied to find a model for a 60 GHz solid-state power amplifier based on a set of measurements of different harmonics of the output.