Behavioural Modelling for Adaptive Array Systems Incorporating High-Power Amplifier Nonlinearities

We develop a novel method for the behavioural modelling of adaptive array systems (AASs) incorporating high- power amplifier (HPA) nonlinearities. The model is motivated by the need to better define the spatial and spectral interference profile of AASs. We provide a simulated proof of concept as a precursor to experimental validation. In our demonstration, the model is identified using simulated near-field measurements made while the antenna’s input channels are simultaneously undergoing a representative excitation. These measurements are used to identify a large number of memory polynomials (MPs) which characterise the transfer function from the antenna inputs to the near-field. We then use the array of MPs and a near-field to far- field transformation to obtain the far-field pattern of the antenna for arbitrary input. We show the impact of antenna element HPA nonlinearities on the far-field pattern, and our ability to predict them via the developed model.