Simple VCO nonlinearity correction algorithm based on EMD in FMCW radar system

A simple software correction algorithm based on the empirical mode decomposition (EMD) algorithm to correct the nonlinearity of a VCO is proposed. The proposed algorithm divides a dechirp signal into mono-component signals using EMD so that the nonlinearity is extracted from the decomposed components in the form of phase distortion. The phase distortion due to nonlinearity is compensated by using the resampling method. As a result, the proposed algorithm corrects the phase distortion without assistance from any additional hardware, thus maintaining simplicity and cost effectiveness. The proposed algorithm is verified by a simulation and an experiment, and it yields well corrected range profiles.