Outdoor Activity Monitoring System Based on FMCW Radar with Multiple Active Transponders

This work presents a frequency-modulated continuous-wave (FMCW) radar system incorporating multiple active transponders for applications in sports science. The transponders with distinct modulation frequencies can be attached to the athletes’ bodies to monitor the movement of different body parts. To enhance the reading range for application in outdoor scenarios, the transponders are realized in active form, thereby providing a gain of 16.5 dB. Due to the separation of the modulation frequency, the radar system can identify the transponders and simultaneously measure the distance of the multiple targets for obtaining more information on different body parts.