Omni-directional antenna with extended frequency range

• US 9,608,323 B1
• Filed: 10/22/2013
• Issued: 03/28/2017
• Est. Priority Date: 10/22/2013
• Status: Active Grant

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Berens, Peter Stuart, Arney, David Vincent, Morales, Susan Lynn, Simonds, Hale Bradford, Bermeo, Dennis
• Primary Examiner(s): Levi, Dameon E
• Assistant Examiner(s): Islam, Hasan
• Application Number:
  US14/059,520
• Time in Patent Office: 1,253 Days
• Field of Search: 343/773, 343/774
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• CPC Class Codes: H01Q 13/0283 Apparatus or processes specially provided for manufacturing horns
• CPC Class Codes: H01Q 13/04 Biconical horns biconical dipoles comprising two conical surfaces having collinear axes and adjacent apices and fed by a two-conductor transmission line H01Q9/28
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00

Abstract

An omni-directional antenna can include a feed disk, which can terminate at a feed disk apex, and a top element, which can include a nipple that terminates a top element apex. The feed disk and top element can be positioned so that the feed disk apex and the top element apex can be spaced-apart by a distance “d”, which can be chosen according to the desired frequency range and cable feed impedance. The feed disk and top element can also have respective bottom conical and top conical surfaces. When the feed disk and top element are positioned, the top and bottom conical surfaces can establish a respective first predefined angle relative to a horizontal plane and a second predefined angle relative to the horizontal plane, thereby extending the antenna frequency range. The predefined angles can be chosen according to the desired frequency range of operation and cable feed impedance.

Claims

1. A bi-cone antenna having a frequency range, the antenna comprising:

a bottom cone and a top cone;

said bottom cone having a feed disk, said feed disk having a bottom conical surface that merges into a feed disk apex, said feed disk also being formed with a hole;

said bottom conical surface having a first portion that establishes a constant angle θ

₁ with resect to a horizontal plane, said first portion merging outwardly from said feed disk apex into a second portion having a constant angle θ

₂ with resect to said horizontal plane, with said θ

₂ less than said θ

₁;

said top cone including a top element, said top element having a nipple that terminates at a top element apex, a top conical surface and a log radial surface, said top element being formed with an aperture;

a spacer axially aligned with and disposed between the feed disk and the top element to establish a distance “

d”

between the feed disk and the top element, said spacer being made of a material that allows said feed disk and said top element to be press-fit into said spacer;

a coaxial cable feed having an inner conductor and an outer conductor, said cable feed extending through said aperture and into said hole so that said inner conductor is in electrical contact with said top element and said outer conductor is in electrical contact with said feed disk; and

,

a ground element attached to said feed disk.

2. The antenna of claim 1, wherein said distance “

d”

is chosen according to a desired said frequency range.

3. A bi-cone antenna having a frequency range, comprising:

a top cone and a bottom cone;

a spacer formed with an upper conical recess and a lower conical recess, said upper and lower conical recesses merging into an opening;

said bottom cone having a feed disk, said feed disk attached to said spacer said feed disk being formed with a hole and having a bottom conical surface that terminates at a bottom apex, said bottom conical surface being in contact with said lower conical recess;

said bottom conical surface having a first portion that establishes a constant angle θ

₁ with respect to a horizontal plane, said first portion merging outwardly from said apex of said feed disk into a second portion having a constant angle θ

₂ with respect to said horizontal plane, with said θ

₂ less than said θ

₁;

said top cone having a top element attached to said spacer, said top element being formed with an aperture and having a top conical surface and a nipple that terminates at a top apex, said top element being in contact with said upper conical recess, said top conical surface establishing an angle θ

₃ with said horizontal plane;

a coaxial feed line having an inner conductor and an outer conductor, said opening, said hole and said aperture cooperating to establish an conduit for insertion of said feed line so that said inner conductor being in electrical contact with said top element, said outer conductor being in electrical contact with said feed disk;

a ground element attached to said feed disk; and

,

said spacer positioning said top apex and said bottom apex apart by a distance “

d”

that is chosen according to a desired said frequency range.

4. The antenna of claim 3 wherein said spacer is made of a material that allows said feed disk and said top element to be press-fit into said spacer to establish said distance “

d”

.

5. A method for extending the frequency range of an bi-cone antenna, comprising the steps of:

A) choosing a frequency range of operation, a coaxial feed line having an inner conductor and an out conductor, and an impedance;

B) providing a bottom cone having a feed disk, said feed disk being formed with a hole and having a bottom conical surface that terminates at a bottom apex;

B1) forming said bottom conical surface with a first portion and a second portion, said first portion establishing a constant angle θ

₁ with respect to a horizontal plane, said first portion merging outwardly from said apex of said feed disk into said second portion, said second portion having a constant angle θ

₂ with respect to said horizontal plane, so that said θ

₂ is less than said θ

₁;

C) affording a top cone with a top element, said top element being formed with an aperture and having a top conical surface and a nipple that terminates at a top apex;

D1) providing a spacer formed with an upper conical recess, a lower conical recess and an opening;

D2) press-fitting said feed disk into said lower conical recess;

D3) inserting said top element into said top conical recess to establish a distance “

d”

said distance “

d”

being chosen according to the results of said step A);

E) inserting an antenna feed line through said hole, said opening and said aperture so that said inner conductor electrically contacts said top element and said outer conductor electrically contacts said feed disk; and

,

F) attaching a ground element to said feed disk.