Security system, in particular in a motor vehicle
AssigneeNXP B.V.
InventorMichael Harald Kuhn
Life of this patent
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Abstract
In order to provide a security system, in particular in a motor vehicle (10), comprising a transmitter which transmits a signal in the form of an electromagnetic field (11, 14) and a transportable receiver (12) which receives the signal and sends back a corresponding response signal to a further receiver, in which it is more difficult to imitate the signal transmitted by the transmitter, it is proposed that a gradient of the electromagnetic field (11, 14) can be detected by the receiver (12).
Claims19
A security system, in particular in a motor vehicle comprising:
- a transmitter which transmits a signal in the form of an electromagnetic field:
- and
- a transportable receiver which receives the signal and sends back a corresponding response signal to a further receiver, characterized in that a spatial gradient of the electromagnetic field is measured by the transportable receiver.
A security system, in particular in a motor vehicle comprising:
- two transmitters within the motor vehicle, wherein each of the two transmitters transmits a signal in the form of an electromagnetic field;
- and
- a transportable receiver that is carried by a user of the motor vehicle, wherein the transportable receiver receives the signals from the two transmitters and sends back a corresponding response signal to a further receiver, characterized in that a spatial gradient of the electromagnetic field is measured by the transportable receiver, and wherein the transportable receiver is configured to determine the locations of the two transmitters in response to the measured spatial gradient and to emit the response signal only if the transportable receiver determines that the two transmitters are at a previously defined distance from one another.
A security system, in particular in a motor vehicle comprising:
- a transmitter which transmits a signal in the form of an electromagnetic field:
- and
- a transportable receiver which receives the signal and sends back a corresponding response signal to a further receiver, characterized in that a spatial change of the electromagnetic field is measured by the transportable receiver.
Dependencies are inferred from the claim text.