24GHz RFID for Orientation Detection and Tracking Applications in Human Activity Recognition and Motion Capture

Utilizing technology derived from a combination of modulated backscatter and FMCW radar, a simple low cost and highly accurate means to report and track the orientation of a tagged structure is reported. The system is comprised of a pair of closely spaced 24 GHz RFID tags interrogated by an FMCW radar and uses a method of phase difference to infer the orientation of the tagged structure. The result is an ultra sensitive, low cost orientation detection system suitable for use in human activity recognition and motion capture applications.