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

• US 6,374,081 B1
• Filed: 08/09/1999
• Issued: 04/16/2002
• Est. Priority Date: 12/09/1997
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Gold, Peter
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): Vuong, Quochien B.
• Application Number:
  US09/370,231
• Time in Patent Office: 981 Days
• Field of Search: 455/41, 455/42, 455/45, 455/48, 455/91, 455/95, 455/99, 340/425.5, 340/426, 340/427, 340/539, 340/540, 340/541, 340/571, 340/542
• US Class Current: 455/41.2
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user
• CPC Class Codes: G08C 17/04 using magnetically coupled devices
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils

Abstract

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.

Claims

1. A transmission unit, comprising:

a generator for generating a sinusoidal carrier oscillation;

a modulator connected to said generator for modulating an information item to be transmitted onto said carrier oscillation into a modulated oscillation;

a transformer connected to said modulator, said transformer having a primary side and a secondary side for transforming said modulated oscillation from said primary side to said secondary side; and

a plurality of antennas connected to said secondary side for generating respective electromagnetic fields and aiding a transmission of the information item.

2. The transmission unit according to claim 1, wherein said plurality of antennas are connected in parallel to said secondary side.

3. The transmission unit according to claim 1, wherein said generator is a sine-wave oscillator.

4. The transmission unit according to claim 1, wherein said transformer is a step-up transformer stepping up the modulated oscillation with regard to voltage and current.

5. The transmission unit according to claim 1, wherein said plurality of antennas are coils connected in parallel with said secondary side and electrically connected to said secondary side.

6. The transmission unit according to claim 1, including twisted two-wire lines electrically connecting said plurality of antennas to said secondary side.

7. The transmission unit according to claim 1, including a two-pole, shielded line electrically connecting said plurality of antennas to said secondary side.

14. The method for transmitting an information item according to claim 1, including the step of providing twisted two-wire lines, and electrically connecting the plurality of antennas to the secondary side through the twisted two-wire lines.

15. The method for transmitting an information item according to claim 1, including the step of providing a two-pole, shielded line, and electrically connecting the plurality of antennas to the secondary side through the two-pole, shielded line.

8. A transmission unit of an anti-theft protection system of a motor vehicle, comprising:

a generator for generating a sinusoidal carrier oscillation;

a modulator connected to said generator for modulating an information item to be transmitted onto said carrier oscillation into a modulated oscillation;

a transformer connected to said modulator and having a primary side and a secondary side for transforming said modulated oscillation from said primary side to said secondary side; and

a plurality of antennas connected to said secondary side for generating respective electromagnetic fields and aiding a transmission of the information item.

9. A method for transmitting an information item, comprising:

providing a generator having a primary side and a secondary side, a modulator, a transformer, and a plurality of antennas;

connecting the plurality of antennas to the secondary side of the transformer;

creating an information item to be transmitted;

generating a sinusoidal carrier oscillation;

modulating the information item onto the carrier oscillation and forming a modulated oscillation;

transforming the modulated oscillation from the primary side to the secondary side; and

generating respective electromagnetic fields with the plurality of antennas to aid transmission of the information item.

10. The method for transmitting an information item according to claim 9, including the step of connecting the plurality of antennas in parallel to the secondary side.

11. The method for transmitting an information item according to claim 9, wherein the step of providing the generator includes providing a sine-wave oscillator as the generator.

12. The method for transmitting an information item according to claim 9, wherein the step of providing the transformer includes providing a step-up transformer, and stepping up the modulated oscillation with regard to voltage and current with the step-up transformer.

13. The method for transmitting an information item according to claim 9, wherein the step of providing the plurality of antennas includes providing coils, and electrically connecting the coils in parallel with the secondary side.

16. A method for transmitting an information item in an anti-theft protection system of a motor vehicle, comprising:

providing a generator having a primary side and a secondary side, a modulator, a transformer, and a plurality of antennas;

connecting the plurality of antennas to the secondary side of the transformer;

creating an information item to be transmitted;

generating a sinusoidal carrier oscillation;

modulating the information item onto the carrier oscillation and forming a modulated oscillation;

transforming the modulated oscillation from the primary side to the secondary side; and

generating respective electromagnetic fields with the plurality of antennas to aid transmission of the information item.