Studies of Front-End Distortion Characterization via Mutual Coupling Measurements in Phased Array Systems

In pursuit of digital-at-every-element phased array radars, research is ongoing investigating the application of memory-polynomial predistortion for correcting nonlinear distortion effects observed in high-power amplifiers operating in saturation. This paper describes the motivation behind and several experiments from a project exploring whether distortion models may be trained using data captured from an active array via mutual coupling between elements, a method which could theoretically provide a complete description of the distortion affecting each element from the digital-to-analog converter to antenna. For the first time, this paper addresses the concept of combining mutual coupling with digital predistortion.