PLANAR DIPOLE ANTENNA

• US 20110006911A1
• Filed: 07/08/2010
• Published: 01/13/2011
• Est. Priority Date: 07/10/2009
• Status: Active Grant

• Current Assignee: Aclara Technologies LLC (Hubbell, Inc.)
• Original Assignee: Aclara RF Systems, Inc. (ESCO Technologies, Inc.)
• Inventors: Wilbur, Mark S., Hennigan, Justin M., Pollock, James R.
• Granted Patent: US 8,427,337 B2
• Time in Patent Office: Days
• US Class Current: 340/870.02
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

A planar dipole antenna is described. The antenna may include a ground element, a feed point, a matching element, and first and second radiating elements disposed on a substrate, and a feed point. The ground element may have a substantially rectangular shape and the feed point may be arranged adjacent to the ground element. The matching element may be connected to the feed point and may include a central bar connected to a first and second arm. The first and second arms may be substantially symmetrically disposed on the substrate in respect to the central bar. The first and second radiating elements may have substantially trapezoidal shapes and may be extend from the first and second arms of the matching element, respectively. The first and second radiating elements may be substantially symmetrically disposed on the substrate in respect to the central bar of the matching element.

Claims

1. A planar dipole antenna comprising:

a substrate;

a ground element disposed on the substrate having a substantially rectangular shape;

a feed point to which an input signal is supplied, the feed point being arranged adjacent to a side of the ground element;

a matching element disposed on the substrate and connected to the feed point, the matching element comprising a central bar connected to a first arm and a second arm, wherein the central bar extends from the feed point, and the first and second arms are substantially symmetrically disposed on the substrate in respect to the central bar;

a first radiating element disposed on the substrate having a substantially trapezoidal shape and connected to the matching element, the first radiating element extending from the first arm of the matching element; and

a second radiating element disposed on the substrate having a substantially trapezoidal shape and connected to the matching element, the second radiating element extending from the second arm of the matching element, wherein the first radiating element and the second radiating element are substantially symmetrically disposed on the substrate in respect to the central bar of the matching element.

2. The planar dipole antenna of claim 1 wherein the planar dipole antenna has a substantially low Q factor such that near field detuning of the planar dipole antenna is substantially minimized.

3. The planar dipole antenna of claim 1 wherein the impedance of the antenna at a resonant frequency, including the matching element, substantially matches that of the feed point where the input signal is supplied.

4. The planar dipole antenna of claim 1 wherein the first radiating element extends from a distal end of the first arm in respect to the central bar and the second radiating element extends from a distal end of the second arm in respect to the central bar.

5. The planar dipole antenna of claim 4 wherein the distal ends of the first and second arms in respect to the central bar extend further than a distal end of the central bar in respect to the feed point.

6. The planar dipole antenna of claim 1 wherein the first radiating element is connected substantially perpendicularly to the first arm of the matching element and the second radiating element is connected substantially perpendicularly to the second arm of the matching element.

7. The planar dipole antenna of claim 1 wherein the substrate further comprises a first surface and a second surface, and the ground plane, matching element, first radiating element and second radiating element are disposed on the first surface of the substrate.

8. The planar dipole antenna of claim 7 wherein a second ground plane is disposed on the second surface of the substrate.

9. The planar dipole antenna of claim 1 wherein the matching element has a form factor comprising of at least one of a three finger-like form factor, a pitchfork-like form factor, a trident-like form factor, or a three prong-like form factor.

10. The planar dipole antenna of claim 1 wherein the ground element, the matching element, the first radiating element and the second radiating element comprise at least one of a copper material, an aluminum material, or a brass material.

11. The planar dipole antenna of claim 1 wherein the substrate comprises at least one of a fiberglass reinforced epoxy resin or a Bismaleimide-triazine resin.

12. The planar dipole antenna of claim 1 wherein the planar dipole antenna operates at a resonant frequency in the range of 450 MHz to 470 MHz.

13. The planar dipole antenna of claim 1 wherein the ground element comprises an opening on the side of the ground element adjacent to the feed point.

14. The planar dipole antenna of claim 13 wherein the feed point is located within the opening of the ground element.

15. The planar dipole antenna of claim 1 wherein the planar dipole antenna is horizontally polarized.

16. A planar dipole antenna comprising:

a substrate;

a ground element disposed on the substrate having a rectangular shape;

a feed point to which an input signal is supplied, the feed point being arranged adjacent to the ground element;

a matching element disposed on the substrate and connected to the feed point;

a first radiating element disposed on the substrate having a trapezoidal shape and connected to the matching element; and

a second radiating element disposed on the substrate having a trapezoidal shape and connected to the matching element, wherein the first radiating element and the second radiating element are symmetrically disposed on the substrate in respect to the matching network;

wherein near-field detuning of the antenna is substantially eliminated.

17. The planar dipole antenna of claim 16 wherein the impedance of the antenna, including the matching element, matches that of the feed point where the input signal is supplied.

18. The planar dipole antenna of claim 16 wherein the planar dipole antenna is horizontally polarized.

19. A method of manufacturing a planar dipole antenna comprising:

forming a substrate;

disposing a ground element on the substrate, wherein the ground element has a substantially rectangular shape;

connecting a feed point to the substrate, the feed point being arranged adjacent to a side of the ground element, wherein an input signal is supplied to the feed point;

disposing a matching element on the substrate and connected to the feed point, the matching element comprising a central bar connected to a first arm and a second arm, wherein the central bar extends from the feed point, and the first and second arms are substantially symmetrically disposed on the substrate in respect to the central bar;

disposing a first radiating element on the substrate having a substantially trapezoidal shape and connected to the matching element, the first radiating element extending from the first arm of the matching element; and

disposing a second radiating element on the substrate having a substantially trapezoidal shape and connected to the matching element, the second radiating element extending from the second arm of the matching element, wherein the first radiating element and the second radiating element are substantially symmetrically disposed on the substrate in respect to the central bar of the matching element.

20. The method of claim 19 wherein the first radiating element extends from a distal end of the first arm in respect to the central bar and the second radiating element extends from a distal end of the second arm in respect to the central bar.

21. The method of claim 20 wherein the distal ends of the first and second arms in respect to the central bar extend further than a distal end of the central bar in respect to the feed point.

22. The method of claim 19 wherein the first radiating element is connected substantially perpendicularly to the first arm of the matching element and the second radiating element is connected substantially perpendicularly to the second arm of the matching element.

23. The method of claim 19 wherein the matching element has a form factor comprising of at least one of a three finger-like form factor, a pitchfork-like form factor, a trident-like form factor, or a three prong-like form factor.

24. The method of claim 19 wherein the ground element, the matching element, the first radiating element and the second radiating element comprise at least one of a copper material, an aluminum material, or a brass material.

25. The method of claim 19 wherein the substrate comprises at least one of a fiberglass reinforced epoxy resin or a Bismaleimide-triazine resin.

26. A method of wirelessly transmitting utility meter information, comprising:

reading a utility meter data item from a utility meter; and

transmitting, by an electrically small antenna comprising a substantially self-contained matching element, the utility meter data item to a remote system, wherein the electrically small antenna is substantially resistant to near-field detuning.

27. The method of claim 26 wherein the electrically small antenna is mounted on an inside surface of the utility meter.

28. The method of claim 26 wherein the electrically small antenna is mounted on an outside surface of the utility meter.

29. The method of claim 26 wherein the electrically small antenna is mounted near a metallic structure or a component of the utility meter.

30. The method of claim 26 wherein an electrical length of the electrically small antenna is approximately an eighth wavelength or less in a frequency band.

31. The method of claim 26 wherein the matching element comprises a copper material.

32. The method of claim 26 wherein the remote system comprises a data collector unit.

33. The method of claim 26 wherein the utility meter data item comprises a utility meter reading.

34. A method of radiating a signal, comprising:

receiving, via a feed point, a signal; and

radiating, by an electrically small antenna comprising a substantially self-contained matching element, the signal, wherein the electrically small antenna is substantially resistant to near-field detuning.