Patent ID: 8149087

Claim:
A device ( 4 ) to be provided onboard a vehicle ( 1 ) for locking/unlocking doors/windows of the vehicle ( 1 ) in response to a communication with a mobile remote identifier, said device comprising: a first antenna ( 14 a ) coupled to a first amplifier ( 12 a ) that is active in a tracking mode P; and a second antenna ( 14 b ) coupled to at least a second amplifier ( 12 b ) that is active in said mode P; and a third amplifier ( 12 c ) different from the first and second amplifiers ( 12 a , 12 b ), said third amplifier ( 12 c ) being active and coupled to both the first antenna ( 14 a ) and to the second antenna ( 14 b ) in an approach-detection mode D, said third amplifier ( 12 c ) being inactive and decoupled from said first antenna and from said second antenna in said mode P, and the first and second amplifiers ( 12 a , 12 b ) being inactive and decoupled from the first and second antennae ( 14 a , 14 b ) in said mode D, wherein, in said mode D, the remote identifier has not been detected by the onboard system and the device is configured to detect whether the remote identifier has come into a proximity perimeter of the vehicle, and wherein, in said mode P, the remote identifier has been detected inside the proximity perimeter of the vehicle by the device.