Apparatus for tracking an object includes a plurality of field generators, which generate electromagnetic fields at different, respective frequencies in a vicinity of the object, and a radio frequency driver, which radiates a RF driving field toward the object. The thickness and mesh size of the expanded zinc mesh may vary. Mutually different unambiguity areas for the range andor mutually different unambiguity areas for the relative velocity are defined for at least two successive measurement cycles, and the range andor the relative velocity areis determined on the basis of, in each case, at least one measured value for the range andor for the relative velocity from each measurement cycle.