MICROWAVE ANTENNA FOR WIRELESS NETWORKING OF DEVICES IN AUTOMATION TECHNOLOGY

• US 20110043432A1
• Filed: 05/25/2010
• Published: 02/24/2011
• Est. Priority Date: 11/26/2007
• Status: Active Grant

• Current Assignee: PILZ GmbH & Company KG
• Original Assignee: PILZ GmbH & Company KG
• Inventors: Godau, Thorsten, INEICHEN, Alois
• Granted Patent: US 8,232,929 B2
• Time in Patent Office: Days
• US Class Current: 343/876
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• 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

Abstract

A microwave antenna for wireless interconnection of automation devices has a first printed circuit board, on which a first conductor loop is arranged as a printed conductor track. A second printed circuit board having a second conductor loop in the form of a printed conductor track is arranged transversely with respect to the first printed circuit board. The second printed circuit board is attached to the first printed circuit board. The conductor loops are connected to a common feed connection. A bypass line connects one end of each the first and the second conductor loops.

Claims

1. A microwave antenna for wireless interconnection of remote sensors, remote actuators and a central control unit of an automated installation, the microwave antenna being designed for transmitting or receiving radio signals having a defined wavelength and the antenna comprising:

a first circuit board having a front face and a rear face;

a first rectangular conductor track arranged about half on the front face and about half on the rear face, said first conductor track forming a first conductor loop having a first end on the front face and a second end on the rear face;

a second printed circuit board transversely attached to the first printed circuit board;

a second rectangular conductor track arranged on the second circuit board and forming a second conductor loop having a third end and a fourth end;

a coaxial connector secured to the first printed circuit board, the coaxial connector comprising an inner conductor and an outer conductor;

a solder connection conductively connecting the first end and the third end;

a bypass line having a length corresponding to approximately one quarter of the wavelength, the bypass line conductively connecting the second end and the fourth end; and

a front conductor track on the front face and a rear-face conductor track on the rear face, wherein the front conductor track is configured to conductively connect the outer conductor and the first end, and wherein the rear-face conductor track is configured to conductively connect the inner conductor and the second end.

2. The microwave antenna of claim 1, wherein at least one of the first and second printed circuit boards defines a slot, into which the other one from the first and second printed circuit boards is inserted.

3. The microwave antenna of claim 1, wherein at least one first metal surface is arranged on the first printed circuit board, and at least one second metal surface is arranged on the second printed circuit board, wherein the first and second metal surfaces each are isolated from the first and second conductor loops, and wherein the first and second metal surfaces are directly soldered to one another.

4. A microwave antenna for wireless interconnection of remote devices of an automated installation, the microwave antenna being designed for transmitting or receiving radio signals having a defined wavelength and the antenna comprising:

a first printed circuit board comprising a first conductor loop having a first end and a second end and comprising a second conductor loop having a third end and a fourth end, the first printed circuit board defining a plane in which the first and second conductor loops are offset with respect to one another in two orthogonal directions;

a second printed circuit board transversely attached to the first printed circuit board in the vicinity of the first conductor loop, the second printed circuit board comprising a third conductor loop which is conductively connected to the first conductor loop via a bypass line having a length corresponding to approximately one quarter of the wavelength;

a third printed circuit board transversely attached to the first printed circuit board in the vicinity of the second conductor loop, the third printed circuit board comprising a fourth conductor loop which is conductively connected to the second conductor loop via a further bypass line having a length corresponding to approximately one quarter of the wavelength;

a coaxial connector secured to the first printed circuit board; and

an antenna switching unit integrated on the first printed circuit board and designed to alternatively connect the coaxial connector to either the first conductor loop or the second conductor loop.

5. A microwave antenna for wireless networking of automation devices, the microwave antenna being designed for transmitting or receiving radio signals having a wavelength, said antenna comprising:

a first printed circuit board, on which a first conductor loop is arranged as a printed conductor track, the first conductor loop having a first end and a second end;

a second printed circuit board, on which a second conductor loop is arranged as a printed conductor track, the second conductor loop having a third end and a fourth end, and the second printed circuit board being arranged transversely with respect to the first printed circuit board;

a common feed connection arranged on the first printed circuit board for feeding the first and second conductor loops at the first and third ends; and

a bypass line having a length corresponding to approximately one quarter of the wavelength of the radio signals, the bypass line conductively connecting the second end and the fourth end.

6. The microwave antenna of claim 5, wherein at least one of the first and second printed circuit boards defines a slot, into which the other one from the first and second printed circuit boards is inserted.

7. The microwave antenna of claim 5, wherein at least one first metal surface is arranged on the first printed circuit board, and at least one second metal surface is arranged on the second printed circuit board, wherein the first and second metal surfaces each are isolated from the first and second conductor loops, and wherein the first and second metal surfaces are soldered to one another.

8. The microwave antenna of claim 7, wherein each of the first and second printed circuit boards has a front face and a rear face, and wherein at least one of the first and second metal surfaces comprises a front metal surface on the front face and a rear-face metal surface on the rear face, the front metal surface and the rear-face metal surface being conductively connected by plated through holes, thereby forming a plated-through double metal surface.

9. The microwave antenna of claim 5, wherein the bypass line is a printed conductor track arranged on the first printed circuit board.

10. The microwave antenna of claim 5, wherein the first and the third ends are soldered to one another substantially directly.

11. The microwave antenna of claim 5, comprising a further printed conductor track, which is arranged on the first printed circuit board and which conductively connects the feed connection and the first end.

12. The microwave antenna of claim 11, wherein the first printed circuit board has a front face and a rear face, and wherein the printed conductor track further comprises a front conductor track on the front face and a rear-face conductor track on the rear face, wherein the feed connection is a coaxial connection with an inner conductor and an outer conductor, wherein the front conductor track conductively connects the outer conductor and the first end, and wherein the rear-face conductor track conductively connects the inner conductor and the second end.

13. The microwave antenna of claim 12, wherein the front conductor track has a conductor track width which is broad in an area of the feed connection and which tapers symmetrically toward the first end.

14. The microwave antenna of claim 5, wherein the first printed circuit board has a front face and a rear face, and wherein the first conductor loop is arranged approximately half on the front face and approximately half on the rear face.

15. The microwave antenna of claim 5, wherein the conductor loops each are square.

16. The microwave antenna of claim 5, wherein the first and second printed circuit boards each have an outer edge, and wherein the first and second conductor loops each of run at the outer edge.

17. The microwave antenna of claim 5, further comprising a third conductor loop arranged as a printed conductor track on the first printed circuit board, the first printed circuit board defining a plane where the first conductor loop and the third conductor loop are offset in two orthogonal directions, and comprising a third printed circuit board having a fourth conductor loop, wherein the third printed circuit board is attached to the first printed circuit board substantially parallel with respect to the second printed circuit board.

18. The microwave antenna of claim 17, further comprising an antenna switching unit which is designed to alternatively connect the feed connection to either the first conductor loop or the third conductor loop.

19. The microwave antenna of claim 18, wherein the antenna switching unit is arranged on the first printed circuit board.

20. The microwave antenna of claim 5, wherein each conductor loop has an overall path length that is substantially equal to the wavelength.