Nonlinearity correction algorithm for wideband FMCW radars

This paper presents a novel nonlinearity correction algorithm for wideband frequency modulated continuous wave (FMCW) radars based on high-order ambiguity functions (HAF) and time resampling. By emphasizing the polynomial-phase nature of the FMCW signal, it is shown that the HAF is an excellent tool for estimating the sweep nonlinearity polynomial coefficients. The estimated coefficients are used to build a correction function which is applied to the beat signal by time resampling. The nonlinearity correction algorithm is tested by simulation and validated on real data sets acquired with an X-band FMCW radar.