RF local area network antenna design

• US 20080068216A1
• Filed: 09/06/2007
• Published: 03/20/2008
• Est. Priority Date: 09/15/2006
• Status: Active Grant

• Current Assignee: Itron, Inc.
• Original Assignee: Itron, Inc.
• Inventors: Pontin, Joseph, Borisov, Vladimir
• Granted Patent: US 7,843,391 B2
• Time in Patent Office: Days
• US Class Current: 340/870.02
• CPC Class Codes: H01Q 1/2233 used in consumption-meter devices, e.g. electricity, gas or water meters
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making
• CPC Class Codes: Y10T 29/49018 with other electrical component

Abstract

Disclosed are apparatus and methodology subject matters relating to an antenna configured for mounting under the glass in a utility meter. The antenna is configured as a patch antenna where a radiating element is mounted on one side of a plastic substrate while a conductive ground plane element is mounted on the other side of the substrate. The ground plane element faces the meter electronics and thereby provides protection to the electronics from the electromagnetic field of the antenna. Both the radiating element and ground plane element may be provided by hot stamping conductive material directly on to the front and rear surfaces of the substrate. The antenna may be feed by a microstrip feedline mounted on the printed circuit board supporting other meter components.

Claims

1. An improved antenna for mounting under the glass of utility meters for coupling thereof by radio frequency signals to other system components in an open operational framework, said antenna comprising:

an insulating substrate having major front and rear surfaces, and respective lateral ends;

a first conductive layer secured on said rear surface of said substrate, and defining a slot shaped opening therein, said first conductive layer except for said slot shaped opening thereof covering substantially the entire rear surface of said substrate; and

a second conductive layer secured on said front surface of said substrate, and covering substantially equally portions of said substrate from said slot shaped opening of said first conductive layer toward said lateral ends of said substrate but short of said lateral ends so as to leave predetermined substantially equal area substrate portions left uncovered on said substrate front surface.

2. An antenna is in claim 1, wherein:

said insulating substrate is generally arc-shaped; and

said first conductive layer comprises a conductive ground plane element for said antenna, configured for facing the electronics of an associated utility meter, while said second conductive layer comprises a radiating element of said antenna, which structurally in combination with a utility meter isolates associated non-radio frequency electronics of such utility meter from an electromagnetic field generated by said antenna while permitting omni-directional transmission of radio frequency signals via said antenna to other system components in an open operational framework.

3. An antenna as in claim 2, wherein the length of said second conductive layer is approximately half-wavelength of the operating frequency of said antenna.

4. An antenna as in claim 1, further including mechanical devices for respectively securing said first and second conductive layers directly on said substrate.

7. An antenna as in claim 1, wherein said substrate comprises a plastic material, and said first and second conductive layers respectively comprise one of aluminum, copper, and brass.

5. An antenna as in claim 5, wherein said first and second conductive layers respectively comprise hot stamped material supported directly on said substrate.

6. An antenna as in claim 5, further including solder associated with said first conductive layer, for securing said antenna to a supporting printed circuit board of an associated utility meter with a microstrip feedline of such printed circuit board positioned perpendicularly across a generally central portion of said slot shaped opening of said first conductive layer, so that an inductive aperture coupling is provided between said antenna and such printed circuit board.

8. A meter with an under the glass antenna for use with an open operational framework employing a radio frequency local area network, comprising:

a metrology printed circuit board including components relating to the collection and display of metrology information;

radio transmission components received on said circuit board;

a microstrip feedline connected with said radio transmission components and received on said circuit board; and

an antenna secured to said printed circuit board for support thereof, and electrically grounded thereto, said antenna including an insulating substrate, with respective first and second conductive layers on opposite surfaces of said substrate, and with said antenna positioned relative to said circuit board and said microstrip feedline received thereon for inductive coupling therewith.

9. A meter as in claim 8, wherein:

said substrate has major rear and front surfaces, on which said first and second conductive layers are respectively supported, and said substrate has respective lateral ends;

said first conductive layer secured on said rear surface of said substrate defines a slot shaped opening therein, said first conductive layer except for said slot shaped opening thereof covering substantially the entire rear surface of said substrate; and

said second conductive layer secured on said front surface of said substrate covers substantially equally portions of said substrate from said slot shaped opening of said first conductive layer toward said lateral ends of said substrate but short of said lateral ends so as to leave predetermined substantially equal area substrate portions left uncovered on said substrate front surface.

10. A meter as in claim 9, wherein:

said insulating substrate is generally arc-shaped; and

said antenna is secured to said printed circuit board such that said first conductive layer is facing the electronics of said meter so as to comprise a conductive ground plane element for said antenna, while said second conductive layer comprises a radiating element of said antenna, which combined structure isolates associated non-radio frequency electronics of said meter from an electromagnetic field generated by said antenna while permitting omni-directional transmission of radio frequency signals via said antenna to other system components in an open operational framework.

11. A meter as in claim 9, wherein the length of said second conductive layer is approximately half-wavelength of the operating frequency of said antenna.

12. A meter as in claim 9, wherein said antenna is positioned relative to said circuit board such that said microstrip feedline received on said printed circuit board is positioned perpendicularly across a generally central portion of said slot shaped opening of said first conductive layer, so that an inductive aperture coupling is provided between said antenna and such printed circuit board.

13. A meter as in claim 8, wherein said insulating substrate comprises a plastic material, and said first and second conductive layers respectively comprise one of aluminum, copper, and brass.

14. Methodology for providing a patch antenna for mounting under the glass of utility meters for coupling thereof by radio frequency signals to other system components in an open operational framework, comprising:

providing an insulating substrate having major front and rear surfaces, and respective lateral ends;

securing a first conductive layer on such rear surface of the substrate, covering substantially the entire rear surface of such substrate except for a slot shaped opening defined in such first conductive layer; and

securing a second conductive layer on such front surface of the substrate, such that substantially equal portions of such substrate are covered from the slot shaped opening of such first conductive layer toward the lateral ends of such substrate but short of such lateral ends so as to leave predetermined substantially equal area substrate portions left uncovered on the substrate front surface.

15. Methodology as in claim 14, wherein:

the insulating substrate is generally arc-shaped; and

such methodology further comprises securing the antenna relative to an associated utility meter such that the first conductive layer comprises a conductive ground plane element for such antenna, facing the electronics of such associated utility meter, while the second conductive layer comprises a radiating element of such antenna, which structurally in combination with such utility meter isolates associated non-radio frequency electronics of such utility meter from an electromagnetic field generated by such antenna while permitting omni-directional transmission of radio frequency signals via such antenna to other system components in an open operational framework.

16. Methodology as in claim 15, wherein the length of the second conductive layer is approximately half-wavelength of the operating frequency of the antenna.

17. Methodology as in claim 14, further including respectively securing the first and second conductive layers directly on the substrate through the use of mechanical devices.

18. Methodology as in claim 14, further comprising providing the first and second conductive layers respectively as hot stamped material supported directly on the substrate.

19. Methodology as in claim 18, further including associating solder with the first conductive layer, for securing such antenna to a supporting printed circuit board of an associated utility meter with a microstrip feedline of such printed circuit board positioned perpendicularly across a generally central portion of the slot shaped opening of the first conductive layer, so that an inductive aperture coupling is provided between such antenna and such printed circuit board.

20. Methodology as in claim 14, wherein the substrate comprises a plastic material, and the first and second conductive layers respectively comprise one of aluminum, copper, and brass.

21. Methodology for providing a meter with an under the glass antenna for use with an open operational framework employing a radio frequency local area network, comprising:

providing a metrology printed circuit board having thereon components relating to the collection and display of metrology information;

providing radio transmission components on such circuit board;

supporting on such circuit board a microstrip feedline connected with such radio transmission components;

providing an antenna including an insulating substrate, and respective first and second conductive layers on opposite surfaces of such substrate; and

securing the antenna to the printed circuit board for support thereof, and electrically grounded thereto, and with such antenna positioned relative to the circuit board and the microstrip feedline received thereon for inductive coupling therewith.

22. Methodology as in claim 21, further comprising:

providing such substrate with major rear and front surfaces, and with such first and second conductive layers respectively supported thereon, and providing the substrate with respective lateral ends;

providing such first conductive layer secured on the rear surface of such substrate so as to define a slot shaped opening therein, with the first conductive layer except for the slot shaped opening thereof covering substantially the entire rear surface of such substrate; and

providing such second conductive layer secured on the front surface of such substrate so as to cover substantially equally portions of such substrate from the slot shaped opening of such first conductive layer toward the lateral ends of the substrate but short of such lateral ends so as to leave predetermined substantially equal area substrate portions left uncovered on such substrate front surface.

23. Methodology as in claim 22, wherein:

the insulating substrate is generally arc-shaped; and

such methodology further comprises securing the antenna relative to the printed circuit board such that the first conductive layer is facing the electronics of the meter so as to comprise a conductive ground plane element for such antenna, while the second conductive layer comprises a radiating element of such antenna, which combined structure isolates associated non-radio frequency electronics of the meter from an electromagnetic field generated by the antenna while permitting omni-directional transmission of radio frequency signals via such antenna to other system components in an open operational framework.

24. Methodology as in claim 22, wherein:

the length of the second conductive layer is approximately half-wavelength of the operating frequency of such antenna; and

the insulating substrate comprises a plastic material, and the first and second conductive layers respectively comprise one of aluminum, copper, and brass.

25. Methodology as in claim 22, further comprising positioning the antenna relative to the circuit board such that the microstrip feedline received on such printed circuit board is positioned perpendicularly across a generally central portion of the slot shaped opening of the first conductive layer, so that an inductive aperture coupling is provided between such antenna and such printed circuit board.