Method and system for determining the distance, velocity and / or the movement direction of an RFID transponder

The invention relates to a method and a system for determining the distance, velocity and / or the movement direction of an RFID transponder. The transponder is interrogated in known manner by a RFID reader, to which the reader sends out a phased modulated supply carrier signal. A radar module simultaneously sends out a radar signal that is received at the transponder and reflected therefrom. The reflected radar signal is finally received again by the radar module. the position of the RFID transponder can be determined from the reflected, received radar signal. The radar signal is especially emitted when no query data is modulated onto the supply carrier signal. Further, the supply carrier signal and the radar signal have different frequencies.