Fusion of FMCW secondary radar signal beat frequency and phase estimations for high precision distance measurement

The accuracy of a radar operating in a multipath environment or in presence of strong clutter noise is mainly limited by the radar signal bandwidth. In the actual paper a phase evaluation concept is introduced that allows for the estimation of the distance of a moving target with mm accuracy even under the above mentioned conditions. The concept is based on an algorithm that combines beat frequency and phase acceleration estimations. The paper will discuss the theoretical background of the approach and the performance of the concept will be illustrated by measurement results of a 5.8 GHz secondary radar system.