CW Radar Based System with Automated DC Offset Reduction for Heartbeat Detection

Radar systems can detect vital signs at a distance by sensing the chest movement, due to heartbeat and respiration. This paper presents an optimized implementation of a continuous wave (CW) radar-based system in order to detect the heartbeat of a person. A main limitation is that dc components added to the received signal, caused by reflections and circuit imperfections, are larger than the ac signal related to chest movement. A novel aspect of this work that mitigates this limitation is that these dc components that are detrimental to heartbeat detection, are automatically reduced to allow for better received signal quality.