Loop antenna configuration for printed wire board applications

• US 6,067,052 A
• Filed: 09/18/1998
• Issued: 05/23/2000
• Est. Priority Date: 09/18/1998
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Tran, Cuong, Rawles, Michael S.
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Ho, Tan
• Application Number:
  US09/156,929
• Time in Patent Office: 613 Days
• Field of Search: 343/741, 343/702, 343/742, 343/744, 343/713, 343/866, 343/867, 343/868, 343/855, 343/860, 333/24 C, 333/32, 333/17.3
• US Class Current: 343/741
• 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 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H05K 1/16 incorporating printed electric components, e.g. printed resistor, capacitor, inductor

Abstract

A loop antenna includes a dielectric substrate, and an antenna conductor forming a loop that extends over a surface of the substrate. A matching circuit near the conductor is dimensioned and arranged for electromagnetically coupling a radio frequency circuit with the antenna conductor. In one embodiment, the antenna conductor forms a closed loop on a surface of a first substrate layer, and the matching network includes a strip transmission line on a surface of a second substrate layer overlying the antenna conductor on the first substrate layer. The substrate layers form part of an interface unit that provides a wireless data link with a residential electric utility meter.

Claims

1. A loop antenna, comprising:

a first substrate layer of dielectric material;

an antenna conductor forming a loop that extends over a surface of the substrate layer;

a matching circuit in the vicinity of the antenna conductor, wherein the matching circuit is dimensioned and arranged for electromagnetically coupling a radio frequency circuit with the antenna conductor; and

a second substrate layer overlying the first substrate layer, and the matching circuit is arranged on the second substrate layer.

2. A loop antenna according to claim 1, wherein the antenna conductor forms a closed loop.

3. A loop antenna according to claim 2, wherein the antenna conductor has a generally polygonal configuration.

4. A loop antenna according to claim 3, wherein the antenna conductor has a generally octagonal configuration.

5. A loop antenna according to claim 1, wherein the matching circuit includes a strip transmission line.

6. A loop antenna, comprising:

a first substrate layer of dielectric material;

an antenna conductor forming a loop that extends over a surface of the first substrate layer; and

a matching circuit in the vicinity of the antenna conductor, wherein the matching circuit is dimensioned and arranged for electromagnetically coupling a radio frequency circuit with the antenna conductor;

wherein the matching circuit includes a strip transmission line that extends over a portion of the antenna conductor and is spaced a certain distance from said conductor.

7. A loop antenna according to claim 6, including a second substrate layer overlying the first substrate layer, the matching circuit is arranged on the second substrate layer, and said certain distance corresponds to a sum of thicknesses of the first and the second substrate layers.

8. A wireless interface unit, comprising:

a housing constructed and arranged to be supported in the region of a device to or from which information is to be communicated via a wireless link;

a communications unit mounted inside the housing, said communications unit including a loop antenna comprising;

a first substrate layer of dielectric material;

an antenna conductor forming a loop that extends over a surface of the substrate layer; and

a matching circuit in the vicinity of the antenna conductor, wherein the matching circuit is dimensioned and arranged for electromagnetically coupling a radio frequency circuit with the antenna conductor; and

a second substrate layer overlying the first substrate layer, and the matching circuit is arranged on the second substrate layer.

9. A wireless interface unit according to claim 8, wherein the antenna conductor forms a closed loop.

10. A wireless interface unit according to claim 9, wherein the antenna conductor has a generally polygonal configuration.

11. A wireless interface unit according to claim 10, wherein the antenna conductor has a generally octagonal configuration.

12. A wireless interface unit according to claim 8, wherein the matching circuit includes a strip transmission line.

13. A wireless interface unit according to claim 8, wherein said housing is constructed and arranged to be supported in the region of an electric utility meter.

14. A wireless interface unit according to claim 13, wherein said first substrate layer has slots for accommodating a number of blades extending from the electric utility meter, said slots being located inside the periphery of the antenna conductor forming said loop.

15. A wireless interface unit, comprising

a housing constructed and arranged to be supported in the region of a device to or from which information is to be communicated via a wireless link;

a communications unit mounted inside the housing, said communications unit including a loop antenna comprising

a first substrate layer of dielectric material;

an antenna conductor forming a loop that extends over a surface of the substrate layer; and

a matching circuit in the vicinity of the antenna conductor, wherein the matching circuit is dimensioned and arranged for electromagnetically coupling a radio frequency circuit with the antenna conductor; and

wherein the matching circuit includes a strip transmission line that extends over a portion of the antenna conductor and is spaced a certain distance from said conductor.

16. A wireless interface unit according to claim 15, including a second substrate layer overlying the first substrate layer, the matching circuit is arranged on the second substrate layer, and said certain distance corresponds to a sum of thicknesses of the first and the second substrate layers.