Keyless access, e.g. RFID, system, especially for motor vehicles has a frequency and of phase displacement method for measuring the range of the key from the vehicle and thus blocking access above a certain range

摘要

Keyless access system, e.g. a radio frequency identity system (RFID), comprises a transmitter or transponder and a receiver or reader station. The receiver or reader station has frequency and or phase displacement means for measurement of the range of the key or transponder from the reader station and thus blocking releasing or undoing of an access or lock system beyond a certain range. The inventive also relates to a wireless access method.