Antenna Design

• US 20100013728A1
• Filed: 07/15/2009
• Published: 01/21/2010
• Est. Priority Date: 07/15/2008
• Status: Active Grant

• Current Assignee: Charles Machine Works Incorporated The
• Original Assignee: Charles Machine Works Incorporated The
• Inventors: McLain, Sean A., Harak, David J.
• Granted Patent: US 8,674,894 B2
• Time in Patent Office: Days
• US Class Current: 343/790
• CPC Class Codes: H01Q 1/04 Adaptation for subterranean or subaqueous use
• 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

Abstract

An antenna core design. An antenna assembly is provided for use in tracking and locating equipment used to track and locate tools with underground drilling systems. The antenna assembly comprises an elongate core, a plurality of metal strips supported on an external surface of the core, an insulating material adapted to insulate each of the plurality of metal strips from the other metal strips and the core, and a wire disposed around the external surface of the strips. Alternatively the antenna assembly comprises an elongate core, an insulating material disposed around a perimeter of the core, and a wire disposed around the insulating material. The core has a plurality of slots cut from one end of the core so that the core defines a plurality of metal strips. A support ring is disposed on the internal surface of the core to support the metal strips.

Claims

1. An antenna assembly comprising:

an elongate core;

a plurality of metal strips supported on an external surface of the core, the plurality of strips defining a perimeter;

an insulating material adapted to insulate each of the plurality of metal strips from the other metal strips and the core; and

a wire disposed around the perimeter formed by the strips.

2. The antenna assembly of claim 1 wherein the core comprises a metal tube.

3. The antenna assembly of claim 2 wherein the tube comprises at least one support adapted to maintain the metal strips in a position relative to the core.

4. The antenna assembly of claim 3 wherein the at least one support is integrally formed as part of the tube.

5. The antenna assembly of claim 3 wherein the at least one support comprises two supports and wherein each of the supports comprises a plurality of slots.

6. The antenna assembly of claim 1 wherein the insulating material comprises a non-conductive polyester tape.

7. The antenna assembly of claim 1 wherein the metal strips comprise mu-metal.

8. The antenna assembly of claim 7 wherein the metal strips are rectangular in cross-section.

9. The antenna assembly of claim 1 wherein the plurality of strips comprises six strips.

10. The antenna assembly of claim 1 further comprising an adhesive adapted to secure each of the plurality of metal strips to the core.

11. The antenna assembly of claim 1 wherein the wire is wrapped around the perimeter in a first layer and a second layer.

12. The antenna assembly of claim 11 wherein the first layer extends substantially the full length of the strips and the second layer extends only a portion of the length of the strips.

13. An antenna assembly comprising:

an elongate core, the core defining a plurality of metal strips;

an insulating material disposed around a perimeter of the core; and

a wire disposed around the insulating material.

14. The antenna assembly of claim 13 wherein the core comprises a metal tube having a first end and a second end and defining a plurality of circumferentially disposed longitudinal slots, each of the slots extending from the second end of the tube to a point proximate the first end of the tube;

such that the portions of the tube between adjacent slots represent the metal strips.

15. The antenna assembly of claim 14 further comprising at least one support ring disposed on an internal surface of the tube.

16. The antenna assembly of claim 15 wherein the core is integrally formed by milling a rod such that the at least one support ring is left inside the tube and the slots are cut in the surface of the tube.

17. An antenna assembly comprising:

an elongate core, the core comprising a plurality of metal strips;

an insulating material disposed on a surface of the metal strips; and

a wire disposed around a perimeter of the core.

18. The antenna assembly of claim 17 wherein the core comprises a metal tube having a first end and a second end, the tube defining a plurality of circumferentially disposed longitudinal slots, each of the slots extending from the second end of the tube to a point proximate the first end of the tube;

such that the portions of the tube between adjacent slots represent the metal strips.

19. The antenna assembly of claim 17 wherein the core comprises:

a metal tube; and

at least one support disposed around a perimeter of the tube, the support adapted to maintain the metal strips in a longitudinal position on the tube; and

wherein the insulating material is wrapped around each of the metal strips.