Anti theft protector for vehicle has radar distance sensor and transponder for user identification, where signals from transponder and distance sensor are used to determine distance to transponder

摘要

The protector (10) has at least one radar distance sensor (14) and a transponder (16) for user identification. Radar signals (18) output from the distance sensor are detected, amplified, and if necessary re-transmitted at a different frequency. The distance (d) between the distance sensor and the transponder is determined from radar signals (20) re-transmitted by the transponder and re-received by the distance sensor. The transponder is preferably formed as a chip card. An Independent claim is included for an anti theft protection system for a vehicle.