Compact antenna structure with a coupling device

• US 9,524,602 B2
• Filed: 12/19/2012
• Issued: 12/20/2016
• Est. Priority Date: 12/29/2011
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive GmbH (Continental AG)
• Inventors: Chakam, Guy-Aymar, Weinberger, Martin
• Primary Examiner(s): Rushing, Mark
• Application Number:
  US14/369,950
• Publication Number:
  US 20150042452A1
• Time in Patent Office: 1,462 Days
• Field of Search: 340/5.64
• US Class Current: 1/1
• CPC Class Codes: G07C 2009/00769 with data transmission performed by wireless means
• CPC Class Codes: G07C 9/00944 Details of construction or manufacture
• CPC Class Codes: G07C 9/20 involving the use of a pass
• CPC Class Codes: H01Q 1/3241 particular used in keyless entry systems
• CPC Class Codes: H01Q 9/26 with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength resonant loop antennas H01Q7/00
• CPC Class Codes: H04B 1/03 Constructional details, e.g. casings, housings

Abstract

A transmission arrangement for a radio station of an access system may include a printed circuit board with an upper main surface and a first metallization plane in which conducting paths are formed. A drive circuit for supplying a frequency signal and an antenna structure are also provided. The antenna structure includes a coupling device, a conductor structure and a continuous, electrically conductive path having first and second ends opposite each other. The coupling device is configured to couple a frequency signal supplied by the drive circuit into the conductor structure. The first and/or second ends form end(s) of the conductor structure. The printed circuit board is retained at a distance from the first and/or second end by a gas or an electrically non-conductive material.

Claims

1. A transmission arrangement for a radio station of an access system, the transmission arrangement comprising:

a circuit board having an upper main surface, and a first metallization plane in which conducting tracks are formed;

control electronics configured to provide a frequency signal;

an antenna structure comprising a coupling device, a conductor structure, and a continuous, electrically conducting path extending from the coupling device having a first end and a second end opposite the first end, both the first end and the second end remote from the coupling device;

wherein the coupling device is configured to couple a frequency signal provided by the control electronics to the conductor structure;

wherein the electrically conducting path comprises a generally rectangular cross-section normal to the path as it extends from the coupling device to the first end and to the second end and at least one of the first and second ends of the electrically conducting path includes a section of the electrically conducting path with an increased rectangular cross section that forms an end of the conductor structure; and

wherein at least one of the first and second ends of the electrically conducting path is separated from the circuit board by a gas or an electrically non-conducting material.

2. The transmission arrangement of claim 1, wherein the conductor structure comprises a vertical segment extending perpendicular to the upper main surface of the circuit board and disposed on a side of the conductor structure opposite the first end and the second end of the electrically conducting path.

3. The transmission arrangement of claim 1, wherein the first and second ends of the electrically conducting path are opposite each other in a vertical direction normal to the upper main surface.

4. The transmission arrangement of claim 1, wherein a distance between the first end and the second end lies in the range of 0.1 mm to 10 mm.

5. The transmission arrangement of claim 1, wherein the conductor structure is formed as a unitary piece.

6. The transmission arrangement of claim 1, wherein the conductor structure comprises a first partial structure and a second partial structure.

7. The transmission arrangement of claim 6, wherein the first end of the electrically conducting path forms one end of the first partial structure, and the second end of the electrically conducting path forms one end of the second partial structure.

8. The transmission arrangement of claim 6, wherein the control electronics is coupled to the conductor structure in one of the following manners:

inductively and galvanically isolated;

capacitively and galvanically isolated;

galvanically;

inductively, capacitively and galvanically isolated;

inductively and galvanically; and

inductively, capacitively and galvanically.

9. The transmission arrangement of claim 8, wherein:

the circuit board comprises a second metallization plane parallel to the first metallization plane;

a first conductor loop, which is connected to the control electronics, is formed in the first metallization plane;

a second conductor loop, which is connected to the conductor structure and which forms a component of the electrically conducting path, is formed in the second metallization plane; and

the first conductor loop is inductively coupled to the second conductor loop, thereby inductively coupling the control electronics to the conductor structure.

10. The transmission arrangement of claim 1, wherein the conductor structure comprises a segment extending parallel to the normal direction of the upper main surface neither above nor below the circuit board.

11. The transmission arrangement of claim 1, wherein the conductor structure at least one of a stamped metal sheet and a bent metal sheet.

12. The transmission arrangement of claim 1, wherein the control electronics is configured to provide a frequency signal with a center frequency;

and

wherein the coupling device, the antenna structure, and an optional connecting line for connecting the control electronics to the coupling device form components of a unit connected downstream of the control electronics, which has a frequency bandwidth centered about the center frequency in a KHz or MHz range.

13. The transmission arrangement of claim 1, wherein the antenna structure has an impedance of 50 Ohms.

14. An electronic vehicle key, comprising:

a transmission arrangement comprising;

a circuit board having an upper main surface, and a first metallization plane in which conducting tracks are formed;

control electronics configured to provide a frequency signal;

an antenna structure comprising a coupling device, a conductor structure, and a continuous, electrically conducting path extending from the coupling device and having a first end and a second end opposite the first end, both the first end and the second end remote from the coupling device;

wherein the coupling device is configured to couple a frequency signal provided by the control electronics to the conductor structure;

wherein the electrically conducting path comprises a generally rectangular cross-section normal to the path as it extends from the coupling device to the first end and to the second end and at least one of the first and second ends of the electrically conducting path includes a section of the electrically conducting path with increased rectangular cross-section that forms an end of the conductor structure; and

wherein at least one of the first and second ends of the electrically conducting path is separated from the circuit board by a gas or an electrically non-conducting material.

15. The electronic vehicle key of claim 14, wherein the conductor structure comprises a vertical segment extending perpendicular to the upper main surface of the circuit board and disposed on a side of the conductor structure opposite the first end and the second end of the electrically conducting path.

16. The electronic vehicle key of claim 14, wherein the first and second ends of the electrically conducting path are opposite each other in a vertical direction normal to the upper main surface.

17. The electronic vehicle key of claim 14, wherein:

the conductor structure comprises a first partial structure and a second partial structure,

the first end of the electrically conducting path forms one end of the first partial structure, and

the second end of the electrically conducting path forms one end of the second partial structure.

18. The electronic vehicle key of claim 14, wherein:

the circuit board comprises a second metallization plane parallel to the first metallization plane;

a first conductor loop, which is connected to the control electronics, is formed in the first metallization plane;

a second conductor loop, which is connected to the conductor structure and which forms a component of the electrically conducting path, is formed in the second metallization plane; and

the first conductor loop is inductively coupled to the second conductor loop, thereby inductively coupling the control electronics to the conductor structure.