Dual-band helical antenna

• US 6,184,844 B1
• Filed: 03/27/1997
• Issued: 02/06/2001
• Est. Priority Date: 03/27/1997
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Tassoudji, Ali, Tidwell, Stephen B., Filipovic, Daniel
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Nguyen, Hoang
• Application Number:
  US08/826,289
• Time in Patent Office: 1,412 Days
• Field of Search: H01/Q.136, H01/Q 1.108, 343/895, 343/853, 343/700.MS, 343/702
• US Class Current: 343/895
• CPC Class Codes: H01Q 1/362 for broadside radiating helical antennas
• CPC Class Codes: H01Q 11/08 Helical antennas
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 5/378 Combination of fed elements with parasitic elements
• CPC Class Codes: H01Q 5/40 Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements

Abstract

A dual-band helical antenna provides operation in two frequency bands. The dual-band helical antenna includes two single-band antennas, each having a feed network, a ground plane opposite the feed network, and a set of one or more radiators extending from feed network. According to one aspect of the invention, a tab extends from the feed network of one of the antennas which provides a feed for that antenna. The tab also provides a path for current to flow from the radiators of the second antenna along the axis of the second antenna to thereby increase the energy radiated in the directions perpendicular to the axis. According to another feature of the invention, the ground plane of one antenna is used as a shorting ring for the other antenna.

Claims

1. A dual band helical antenna, comprising:

a first antenna section comprising;

a first feed network disposed on a first side of a substrate on a first feed portion of the first antenna,

a first ground plane disposed on a second side of said substrate and opposite said feed network,

a first set of one or more radiators disposed on said substrate and extending from said feed network, and

a tab extending from said first feed portion of said first antenna section positioned substantially along the axis of the antenna; and

a second antenna section comprising;

a second feed network disposed on said substrate on a second feed portion,

a second ground plane disposed on said substrate opposite said feed network, and

a second set of one or more radiators disposed on said substrate and extending from said feed network.

2. The antenna according to claim 1, wherein said first ground plane electrically connects one end of said second set of one or more radiators.

3. The antenna according to claim 1, wherein said tab is positioned substantially along the axis of the antenna.

4. The antenna according to claim 1, wherein said tab extends from an end of said first feed portion that is closest to said second antenna.

5. The antenna according to claim 1, further comprising a connector connected to said tab.

6. The antenna according to claim 1, wherein said tab comprises means for providing a path for current to flow from said radiators of said second antenna section along the axis of said second antenna to thereby increase the energy radiated in the directions perpendicular to the axis.

7. The helical antenna of claim 1, wherein said first and second radiator segments are comprised of strip segments deposited on a dielectric substrate, wherein said dielectric substrate is shaped such that the radiators are wrapped in a helical fashion.

8. The helical antenna of claim 7, wherein said dielectric substrate is formed into a cylindrical, conical or other appropriate shape.

9. The antenna according to claim 1, wherein at least one of said first and second sets of one or more radiators comprise:

a first radiator segment extending in a helical fashion from a first end of the radiator portion toward the second end of the radiator portion; and

a second radiator segment extending in a helical fashion from a second end of the radiator portion toward the first end of the radiator portion;

wherein said first radiator segment is in proximity with said second radiator segment such that said first and second radiator segments are electromagnetically coupled to one another.

10. The antenna of claim 9, wherein said first radiator segment is equal in length to said second radiator segment.

11. The antenna of claim 9, wherein said first and second radiator segments are λ

/4 in length, where λ

is the wavelength of a resonant frequency of the antenna.

12. The antenna of claim 9, wherein said radiators further comprise one or more intermediate radiator segments positioned between said first and second radiator segments.

13. The antenna section of claim 1, wherein each antenna comprises four radiators and a feed network for providing a quadrature phase signal to said four radiators.

14. The antenna of claim 1, further comprising a feed point for each said radiator that is positioned at a distance from said first end along said first segment, wherein said distance is chosen to match the impedance of the radiators to a feed network.

15. The helical antenna section of claim 1, wherein said first antenna is stacked coaxially with said second antenna section.

16. A dual band helical antenna, comprising:

a first antenna section comprising;

a first feed network disposed on a first side of a substrate on a first feed portion of the first antenna,

a first ground plane disposed on a second side of said substrate and opposite said feed network, and

a first set of one or more radiators disposed on said substrate and extending from said feed network;

a second antenna section comprising;

a second feed network disposed on said substrate on a second feed portion,

a second ground plane disposed on said substrate opposite said feed network;

a second set of one or more radiators disposed on said substrate and extending from said feed network; and

a tab extending from said first feed portion of said first antenna section and running along the axis of said second antenna section for feeding said first antenna section for providing a path for current to flow from said radiators of said second antenna section along the axis of said second antenna section to thereby increase the energy radiated in the directions perpendicular to the axis.

17. The antenna according to claim 16, wherein said tab is positioned substantially along the axis of the antenna.

18. The antenna according to claim 16, wherein said tab extends from an end of said first feed portion that is closest to said second antenna section.

19. The antenna according to claim 16, wherein at least one of said first and second sets of one or more radiators comprise:

a first radiator segment extending in a helical fashion from a first end of the radiator portion toward the second end of the radiator portion; and

a second radiator segment extending in a helical fashion from a second end of the radiator portion toward the first end of the radiator portion;

wherein said first radiator segment is in proximity with said second radiator segment such that said first and second radiator segments are electromagnetically coupled to one another.

20. The antenna of claim 19, wherein said first radiator segment is equal in length to said second radiator segment.

21. The antenna of claim 19, wherein said first and second radiator segments are λ

/4 in length, where λ

is the wavelength of a resonant frequency of the antenna.

22. The antenna of claim 19, wherein said radiators further comprise one or more intermediate radiator segments positioned between said first and second radiator segments.

23. The antenna of claim 16, wherein each antenna section comprises four radiators and a feed network for providing a quadrature phase signal to said four radiators.

24. The antenna of claim 16, further comprising a feed point for each said radiator that is positioned at a distance from said first end along said first segment, wherein said distance is chosen to match the impedance of the radiators to a feed network.

25. A dual-band communication device having a dual band helical antenna, comprising:

a first antenna section comprising;

a first feed network disposed on a first side of a substrate on a first feed portion of the first antenna section,

a first ground plane disposed on a second side of said substrate and opposite said feed network, and

a first set of one or more radiators disposed on said substrate and extending from said feed network;

a second antenna section comprising;

a second feed network disposed on said substrate on a second feed portion,

a second ground plane disposed on said substrate opposite said feed network;

a second set of one or more radiators disposed on said substrate and extending from said feed network; and

a tab extending from said first feed portion of said first antenna section positioned substantially along the axis of the antenna for providing a path for current to flow from said radiators of said second antenna section along the axis of said second antenna section to thereby increase the energy radiated in the directions perpendicular to the axis.