FORM FACTOR AND ELECTROMAGNETIC INTERFERENCE PROTECTION FOR PROCESS DEVICE WIRELESS ADAPTERS

• US 20090311976A1
• Filed: 06/16/2009
• Published: 12/17/2009
• Est. Priority Date: 06/17/2008
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Hurd, Ronald F., Westfield, Brian L., McGuire, Chad M., Paullus, Steven B., Grunig, Christina A., Vanderaa, Joel D.
• Granted Patent: US 8,694,060 B2
• Time in Patent Office: Days
• US Class Current: 455/90.300
• CPC Class Codes: G08C 17/04 using magnetically coupled devices

Abstract

A process device wireless adapter includes a wireless communications module, a metallic housing, and an antenna. The wireless communications module is configured to communicatively couple to a process device and to a wireless receiver. The metallic housing surrounds the wireless communication module and has a first end and a second end. The first end is configured to attach to the process device. In one embodiment, a metallic shield contacts the housing second end such that the metallic shield and the housing form a substantially continuous conductive surface. The antenna is communicatively coupled to the wireless communication module and separated from the wireless communication module by the metallic shield. Preferably, the wireless communications module illustratively includes a printed circuit board that has a length that is greater than its width.

Claims

1. A process device wireless adapter comprising:

a wireless communications module configured to communicatively couple to a process device and to a wireless receiver;

a metallic housing that surrounds the wireless communications module, the metallic housing having a first end and a second end, the first end configured to attach to the process device;

a metallic shield that contacts the housing second end such that the metallic shield and the housing form a substantially continuous conductive surface; and

an antenna communicatively coupled to the wireless communications module and separated from the wireless communications module by the metallic shield.

2. The process device wireless adapter of claim 1, wherein the wireless communications module comprises a printed circuit board, the printed circuit board having a length and a width, the length extending between the metallic housing first end and the metallic housing second end, and wherein the length is greater than the width.

3. The process device wireless adapter of claim 2, wherein the wireless communications module comprises a second printed circuit board, the second printed circuit board having a length and a width, the length of the second printed circuit board extending between the metallic housing first end and the metallic housing second end, and wherein the second printed circuit board length is greater than the second printed circuit board width.

4. The process device wireless adapter of claim 1, further comprising:

a non-metallic end cap that attaches to the housing and that encloses the antenna.

5. The process device wireless adapter of claim 4, wherein the non-metallic end cap is a plastic radome.

6. The process device wireless adapter of claim 1, wherein the metallic housing comprises aluminum.

7. The process device wireless adapter of claim 1, wherein the metallic housing comprises metalized plastic.

8. The process device wireless adapter of claim 1, wherein the metallic shield comprises stamped metal.

9. The process device wireless adapter of claim 1, wherein the metallic shield comprises plastic plated with a conductive material.

10. The process device wireless adapter of claim 1, wherein the metallic shield contacts the housing second end through spring fingers.

11. The process device wireless adapter of claim 1, wherein the metallic shield contacts the housing second end through a conductive elastomeric gasket.

12. A process device wireless adapter comprising:

a metallic housing having a length and a radius;

a printed circuit board within the metallic housing, the printed circuit board having a width and a length, the length of the printed circuit board running along the length of the metallic housing, the length of the printed circuit board being greater than the width of the printed circuit board, the printed circuit board configured to be communicatively coupled to a process device;

a metallic shield that forms a continuous conductive surface with the metallic housing, the metallic shield having a first side and a second side, the printed circuit board positioned proximate the first side; and

an antenna electrically connected to the printed circuit board through an aperture in the metallic shield, the antenna positioned proximate the metallic shield second side, the antenna configured to wirelessly transmit communications to a wireless receiver and to wirelessly receive communications from the wireless receiver.

13. The process device wireless adapter of claim 12, wherein the antenna is a “

rubber duck”

style whip antenna.

14. The process device wireless adapter of claim 12, wherein the metallic shield is part of the ground plane of the antenna.

15. The process device wireless adapter of claim 12, wherein potting is included within the metallic housing.

16. The process device wireless adapter of claim 12, further comprising a mechanical attachment region configured to attach to a process device conduit.

17. The process device wireless adapter of claim 16, wherein the mechanical connection region includes a threaded surface.

18. A method of improving wireless communication capabilities of a process device comprising:

coupling a wireless communications module to the process device;

coupling an antenna to the wireless communications module;

at least partially surrounding the wireless communications module with a conductive surface to reduce electromagnetic interference with the module; and

positioning the antenna outside of the conductive surface to enable wireless communications between the process device and a control system.

19. The method of claim 18, further comprising:

enclosing the antenna in a non-metallic cover that environmentally protects the antenna and that allows wireless signals to pass through the cover to the control system.

20. The method of claim 18, further comprising:

reducing a width and increasing a length of the wireless communications module such that the length is greater than the width.

21. A process device wireless adapter comprising:

a wireless communications module configured to communicatively couple to a process device and to a wireless receiver;

a metallic housing that surrounds the wireless communications module, the metallic housing having a first end and a second end, the first end configured to attach to the process device;

a printed circuit board within the metallic housing, the printed circuit board having a width and a length, the length of the printed circuit board running along the length of the metallic housing, the length of the printed circuit board being greater than the width of the printed circuit board, the printed circuit board configured to be communicatively coupled to a process device; and

an antenna communicatively coupled to the wireless communications module and separated from the wireless communications module.