A data processing device and method for detecting interference in FMCW radar signals, configured to use an adaptive thresholding technique to identify interference in a plurality of samples forming a beat signal, the adaptive thresholding including grouping the plurality of samples into a plurality of subsets, determining a maximum magnitude of each subset and extracting an nth lowest maximum magnitude of the plurality of subsets to determine an adaptive threshold, and applying the adaptive threshold to each sample to generate a mask.