MULTIPLE-FREQUENCY SOLUTIONS FOR REMOTE ACCESS SYSTEMS

• US 20120062358A1
• Filed: 09/09/2010
• Published: 03/15/2012
• Est. Priority Date: 09/09/2010
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: NOWOTTNICK, Juergen
• Granted Patent: US 8,907,760 B2
• Time in Patent Office: Days
• US Class Current: 340/5.2
• CPC Class Codes: G06K 19/07767 the first and second communication means being two different antennas types, e.g. dipole and coil type, or two antennas of the same kind but operating at different frequencies
• CPC Class Codes: G06K 19/07792 the antenna adapted for extending in three dimensions
• CPC Class Codes: H01Q 1/3241 particular used in keyless entry systems
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 5/35 using two or more simultaneously fed points
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

Aspects of the present disclosure are directed toward a system in which a three-dimensional low-frequency (3D-LF) antenna and a high frequency (HF) antenna are used. The 3D-LF antenna includes three coils each oriented relative to X, Y and Z axes that define a Cartesian coordinate system for a three-dimensional space. The HF antenna is oriented along one of the axes of the LF coils and in the same antenna package as the 3D-LF antenna. The 3D-LF antenna is configured to be used in connection with an LF signal of between 3 kHz and 300 kHz. The HF antenna is configured to be used in connection with an HF signal between 3 MHz and 30 MHz.

Claims

1. A multipurpose antenna assembly comprising:

a surface mount package that includes

a first coil antenna oriented parallel to an X plane and configured to receive a low frequency (LF) signal having a carrier frequency between 30 kHz to 300 kHz;

a second coil antenna oriented parallel to a Y plane and configured to receive a low frequency (LF) signal having a carrier frequency between 30 kHz to 300 kHz;

a third coil antenna oriented parallel to a Z plane and configured to receive a low frequency (LF) signal having a carrier frequency between 30 kHz to 300 kHz; and

a fourth coil antenna oriented parallel to a Z plane and configured to receive a high frequency (HF) signal having a carrier frequency between 3 MHz and 30 MHz.

2. The assembly of claim 1, wherein the surface mount package has a width between 5 mm and 20 mm, a length between 5 mm and 20 mm and a height between 2 mm and 10 mm.

3. The assembly of claim 1, wherein the fourth coil antenna is provided using a tap of the third coil antenna that allows for use of less than all of a set of windings of the third coil antenna.

4. The assembly of claim 1, wherein the coil antennas have an air core.

5. The assembly of claim 1, wherein the fourth coil antenna includes a set of coil windings independent of a set of coil windings for the third coil.

6. The assembly of claim 1, wherein the fourth coil antenna and the third coil antenna share a common core.

7. The assembly of claim 1, wherein the windings of the fourth coil antenna are wound around the outside of the third coil antenna relative to the third coil antenna core.

8. The assembly of claim 1, wherein the first coil antenna, the second coil antenna, and the third coil antenna are configured to receive a common carrier frequency.

9. The assembly of claim 2, wherein the first coil antenna, the second coil antenna and the third coil antenna each have an inductance being between 1 mH and 8 mH.

10. A portable passive keyless entry device comprising:

a printed circuit board (PCB) having

a low frequency (LF) receiver circuit configured and arranged for communicating an LF signal having a carrier frequency between 30 kHz to 300 kHz;

a high frequency (HF) transceiver circuit configured and arranged for producing a high frequency (HF) signal having a carrier frequency between 3 MHz and 30 MHz;

a microprocessor circuit configured and arranged for receiving an activation signal from the LF receiver circuit and in response thereto, communicating authentication information using the HF transceiver circuit; and

an antenna package that connects to the PCB and that houses

a first coil antenna oriented parallel to a X plane and configured to receive the LF signal,

a second coil antenna oriented parallel to a Y plane and configured to receive the LF signal,

a third coil antenna oriented parallel to a Z plane and configured to receive the LF signal; and

a fourth coil antenna oriented parallel to the Z plane and configured to receive and transmit the HF signal.

11. The device of claim 10, wherein the portable passive keyless entry device is a key fob.

12. The device of claim 10, wherein the fourth coil antenna is provided using a tap of the third coil antenna that allows for use of less than all of a set of windings of the third coil antenna.

13. The device of claim 10, wherein the LF coil antennas have an inductance that is between 1 mH and 8 mH.

14. The device of claim 10, wherein the fourth coil antenna includes a separate set of windings relative to windings of the third coil antenna.

15. The device of claim 10, wherein the fourth coil antenna has an inductance between 1.5 μ

H and 6.0 μ

H.

16. The device of claim 10, wherein windings of the fourth coil antenna are intermixed with windings of the third coil antenna.

17. The device of claim 10, wherein the fourth coil antenna windings are between the PCB and the winding of the third coil antenna windings.

18. A communication circuit comprising:

printed circuit board (PCB);

an antenna package connected to the PCB and including

three-dimensional radio antenna configured to receiving radio frequency signals in three dimensions according to axes X, Y and Z and including

a first coil oriented parallel to a plane of the X axis,

a second coil oriented parallel to a plane of the Y axis, and

a third coil oriented parallel to a plane of the Z axis; and

a first communication circuit on the PCB and for communicating a low frequency (LF) signal having a carrier frequency between 30 kHz to 300 kHz, the first communication circuit including

one or more processing circuits configured to code communications carried on the LF signal;

a first electrical connection configured to communicate the LF signal between the one or more processing circuits and the first coil;

a second electrical connection configured to communicate the LF signal between the one or more processing circuits and the second coil;

a third electrical connection configured to communicate the LF signal between the one or more processing circuits and the third coil; and

a second communication circuit on the PCB and for producing a high frequency (HF) signal having a carrier frequency between 3 MHz and 30 MHz, the second communication circuit including

one or more processing circuits configured to code communications carried on the HF signal; and

a fourth electrical connection configured to communicate the HF signal between the one or more processing circuits and the third coil.

19. The circuit of claim 18, wherein the PCB includes a top surface upon which the first communication circuit is located, the top surface perpendicular to the Z axis.

20. The circuit of claim 18, wherein the third coil includes a first set of windings connected to the third electrical connection and a second set of windings connected to the fourth electrical connection.