Siemens Aktiengesellschaft

Peter Gold

Ulrich Emmerling

Michael Stippler

Thomas R&ouml;hrl

A device is provided for generating electromagnetic waves, in particular for data transfer between a vehicle and a data storage medium, whereby a choke coil () is provided between at least one part of an energy supply device () and an oscillating circuit (). The device provides short build-up and decay times for the resonant oscillation of the oscillating circuit (). Furthermore, a method is provided for operation of the device, whereby the choke coil () is operated in the saturation state at times during the transient condition of the oscillating circuit (). The device can be used for modulating electromagnetic waves to be generated in accordance with data to be transmitted.

Device for generating electromagnetic waves, method for operating a device of this type and method for modulating the electromagnetic waves to be generated using a device of this type in accordance with data to be transmitted

The transmitting and receiving station generates a interrogation code signal which is identical for all of the transponders. All of the transponders that receive the signal answer simultaneously at the same carrier frequency. In order to avoid signal collisions, the transponders are synchronized before and/or during the transmission of the response signals. As an alternative, each transponder is assigned a dedicated subcarrier frequency in addition to the main carrier frequency, which is the same for all of the transponders.

Functional monitoring system, in particular access control system, and method for functional control

An antenna system, especially for an anti-theft system of a motor vehicle. A primary magnetic field is produced by a primary coil ( ). In the vicinity of the primary coil ( ), a coupling coil ( ) is disposed which is connected by a flexible conductor ( ) with a secondary coil ( ). By the magnetic connection of the primary field a secondary field can be produced through the secondary coil ( ), which due to the distributed installation of the secondary coils ( ) can act specifically in areas in which the primary field is not acting.

Antenna system especially for an anti-theft system of a motor vehicle

A transmission unit includes a sine-wave generator that generates a carrier oscillation. A binary information item is modulated onto the carrier oscillation in a modulator. The modulated oscillation is fed to a transformer that forwards the modulated oscillation to a plurality of antennas connected in parallel. A method for transmitting an information item includes providing a generator having a primary side and a secondary side, a modulator, a transformer, and a plurality of antennas. The plurality of antennas is connected to the secondary side of the transformer. An information item to be transmitted is created. A sinusoidal carrier oscillation is generated. The information item is modulated onto the carrier oscillation and forms a modulated oscillation. The modulated oscillation is transformed from the primary side to the secondary side and an electromagnetic field is generated by the plurality of antennas to aid transmission of the information item. The transmission unit and the method for transmitting provide little interference radiation. The transmission unit and the method for transmitting may be used for an anti-theft protection system of a motor vehicle.

Transmission unit and method for transmitting an information item, in particular for an anti-theft protection system of a motor vehicle

A control system for controlling an object function includes a base station and a portable code transmitter. The base station is at the object and has a transceiver unit for transmitting an interrogation signal. The code transmitter emits a response signal with a code information item in response thereto. The base station checks an authorization of the code information item contained in the response signal. The base station and/or the code transmitter determines a time period between a transmission of a part of the interrogation signal and a reception of a part thereof obtained in reaction thereto, and compares the time period with a predefined reference time period. The base station enables the object-specific function only if the measured time period is shorter than the reference time period even if the code information item of the response signal is correct. There is also provided an access control and driver authorization device for a motor vehicle where the base station transmits the interrogation signal to the code transmitter from which checkbits are transmitted back directly to the motor vehicle, bypassing an evaluation unit. The base station measures the time period between the checkbits being emitted and received back and only accepts a response signal of the code transmitter if the measured time period is shorter than a reference time period. There is also provided a method for controlling at least one function of the object.

Control system and method for controlling at least one function of an object and access control and driving authorization device for a motor vehicle

Antennas of an anti-theft system are controlled with a pulse width modulated square-wave signal by a power control unit and a phase control unit. The control is such that a change in power causes no change in phase, and vice versa. This is accomplished by varying the pulse width of the square-wave signal if a change in power occurs and at the same time shifting the pulse rise time such that the phase remains constant.

Growing community of inventors

Sinzing, Germany

Peter Gold