The invention features a theft resistant security system for motor vehicles. The system has receptacle with a coupling coil. A SAW (surface acoustical wave) device associated with the receptacle for relative movement thereto is also provided. The SAW device has a code and its own coupling coil for interaction...http://www.google.fr/patents/US5023605?utm_source=gb-gplus-shareBrevet US5023605 - Patterned transducer apparatus for correcting spurious signals in said devices
Patterned transducer apparatus for correcting spurious signals in said devices
