Broadband stacked multi-spiral antenna array integrated into an aircraft structural element

• US 10,096,892 B2
• Filed: 08/30/2016
• Issued: 10/09/2018
• Est. Priority Date: 08/30/2016
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Lavin, Ronald O'Neil, Urcia, Manny S.
• Primary Examiner(s): NGUYEN, HOANG V
• Application Number:
  US15/252,122
• Publication Number:
  US 20180062250A1
• Time in Patent Office: 770 Days
• CPC Class Codes: H01Q 1/282 Modifying the aerodynamic properties of the vehicle, e.g. projecting type aerials
• CPC Class Codes: H01Q 1/286 substantially flush mounted with the skin of the craft
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 21/06 Arrays of individually energised antenna units similarly polarised and spaced apart
• 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
• CPC Class Codes: H01Q 5/50 Feeding or matching arrangements for broad-band or multi-band operation
• CPC Class Codes: H01Q 9/27 Spiral antennas

Abstract

A broadband stacked multi-spiral antenna array comprising two or more spiral antennas with a dielectric layer having a generally uniform thickness positioned between each pair of stacked antennas, which are all center-fed and in-phase. The antenna array may be embedded in a non-conductive material, such as fiberglass embedded in a resin, a honeycomb core sandwich, or structural foam, that may be used to form a structural element of a mobile platform. The structural element may include a via providing a pathway for coaxial cables. If two structural elements are hatch covers on the port and the starboard sides of an aircraft, the use of a stacked multi-spiral antenna array in each structural element provides two roughly hemispherical coverage patterns which together provide an omni-directional coverage pattern. The stacked multi-spiral antenna array may also include a reflecting cavity placed at the bottom of one of the spiral antennas.

Claims

1. A broadband stacked multi-spiral antenna array comprising:

two or more stacked spiral antennas including

a first spiral antenna, and

a second spiral antenna,

wherein the first spiral antenna and the second spiral antenna and are stacked with a low dielectric layer with a generally uniform thickness positioned between the first spiral antenna and the second spiral antenna and

wherein the first spiral antenna and the second spiral antenna are center-fed and in-phase.

2. The broadband stacked multi-spiral antenna array of claim 1,

wherein the two or more stacked spiral antennas are

two or more Archimedean spiral antennas,

two or more equiangular spiral antennas,

two or more sinuous spiral antennas, or

two or more slotted spiral antennas, and

wherein each of the two or more stacked spiral antennas are dual-arm spiral antennas with each spiral antenna having two arms.

3. The broadband stacked multi-spiral antenna array of claim 2,

wherein the low dielectric layer includes air, a vacuum, or a non-conductive low dielectric laminate,

wherein the generally uniform thickness of the low dielectric layer is a spacer distance between the first and second spiral antennas,

wherein a capacitance is created between the first and second spiral antennas, and

wherein the capacitance tunes an input impedance of the broadband stacked multi-spiral antenna array.

4. The broadband stacked multi-spiral antenna array of claim 3, further including

a reflecting cavity having a depth, and

a composite laminate including

the first spiral antenna,

the second spiral antenna, and

the low dielectric layer,

wherein the composite laminate includes an inner-surface,

wherein the reflecting cavity is positioned at a side adjacent to the inner-surface,

wherein the broadband stacked multi-spiral antenna array is configured to operate at a center-operating frequency corresponding to a center-operating wavelength (λ

_{center-operating}), and

wherein the depth of the reflecting cavity is approximately equal to one-fourth of the λ

_{center-operating}.

5. The broadband stacked multi-spiral antenna array of claim 4,

wherein an operating frequency range of the broadband stacked multi-spiral antenna array is about 0.225 gigahertz (GHz) to about 2.0 GHz,

wherein the center-operating frequency approximately equal to 1.112 GHz,

wherein the λ

_{center-operating} is approximately equal to 266.48 cm, and

wherein the low dielectric layer has a uniform thickness of less than approximately 10.0% of the λ

_{center-operating}.

6. The broadband stacked multi-spiral antenna array of claim 3,

wherein the first spiral antenna and the second spiral antenna are center-fed by feed lines electrically connected to the arms of the first and second spiral antennas at their respective centers and

wherein the feed lines are coaxial cables, microstrip lines, or striplines.

7. The broadband stacked multi-spiral antenna array of claim 1,

wherein the two or more stacked spiral antennas are seven stacked spiral antennas having three pairs of adjacent stacked spiral antennas,

wherein the seven stacked spiral antennas are

seven stacked Archimedean spiral antennas,

seven stacked equiangular spiral antennas,

seven stacked sinuous spiral antennas, or

seven stacked slotted spiral antennas,

wherein a low dielectric layer having a generally uniform thickness is positioned between each pair of the adjacent stacked spiral antennas, and

wherein an outside diameter of an outermost spiral antenna of the seven stacked spiral antennas has a largest diameter, with an outside diameter of each adjacent innermost spiral antenna of the seven stacked spiral antennas having a smaller outside diameter.

8. A conformal broadband stacked multi-spiral antenna assembly for use in a mobile platform, the conformal broadband stacked multi-spiral antenna assembly comprising:

two or more stacked spiral antennas including

a first dual-arm spiral antenna, and

a second dual-arm spiral antenna,

wherein the first dual-arm spiral antenna and the second dual-arm spiral antenna are stacked with a low dielectric layer with a generally uniform thickness positioned between the first dual-arm spiral antenna and the second dual-arm spiral antenna, and

wherein the first dual-arm spiral antenna and the second dual-arm spiral antenna are center-fed and in-phase; and

a composite laminate in which the first dual-arm spiral antenna, the second dual-arm spiral antenna, and the low dielectric layer are embedded.

9. The conformal broadband stacked multi-spiral antenna assembly of claim 8,

wherein each of the first and the second dual-arm spiral antennas include two arms,

wherein the two or more stacked spiral antennas are

two or more Archimedean spiral antennas,

two or more equiangular spiral antennas,

two or more sinuous spiral antennas, or

two or more slotted spiral antennas, and

wherein each stacked spiral antenna has

a number of turns that are the same,

an arm width that is the same, and

a spacing between the arms that is the same.

10. The conformal broadband stacked multi-spiral antenna assembly of claim 9, wherein the composite laminate includes any one of a fibrous material embedded in a resinous matrix, a honeycomb core sandwich, and a structural foam.

11. The conformal broadband stacked multi-spiral antenna assembly of claim 10,

wherein the fibrous material is fiberglass, KEVLAR®

, carbon fiber, or a carbon KEVLAR®

hybrid fabric, and

wherein the resinous matrix is an epoxy resin, a vinyl ester resin, or a polyester resin.

12. The conformal broadband stacked multi-spiral antenna assembly of claim 9, further comprising a reflecting cavity positioned at a bottom of an innermost dual-arm spiral antenna of the conformal broadband stacked multi-spiral antenna assembly.

13. The conformal broadband stacked multi-spiral antenna assembly of claim 9, wherein the composite laminate comprises a via that provides a pathway for coaxial cables that provide a center feed to each of the first and the second dual-arm spiral antennas.

14. The conformal broadband stacked multi-spiral antenna assembly of claim 9, wherein the composite laminate is shaped in a form of a non-load-bearing structural element or a load-bearing structural element of an aircraft.

15. The conformal broadband stacked multi-spiral antenna assembly of claim 14, where the non-load-bearing structural element is selected from a group consisting of a stowage bay access door, a hatch cover, and an access panel of an aircraft.

16. The conformal broadband stacked multi-spiral antenna assembly of claim 14, where the load-bearing structural element is selected from a group consisting of a fuselage, a wing, and an empennage of an aircraft.

17. A method of forming a conformal integrated broadband stacked multi-spiral antenna assembly, comprising:

forming a stacked multi-spiral antenna array comprising two or more stacked spiral antennas with each pair of adjacent stacked spiral antennas separated by a low dielectric layer;

forming a non-load-bearing structural element of a mobile platform by forming a composite laminate comprising a non-conductive material;

forming a via in the composite laminate that provides a pathway for coaxial cables providing a center feed to each of the two or more stacked spiral antennas; and

embedding the stacked multi-spiral antenna array in the non-load-bearing structural element to form the conformal integrated broadband stacked multi-spiral antenna assembly,

wherein the two or more stacked spiral antennas are selected from a group consisting of

two or more Archimedean spiral antennas,

two or more equiangular spiral antennas,

two or more sinuous spiral antennas, and

two or more slotted spiral antennas,

wherein each of the two or more stacked spiral antennas includes a copper coil etched onto a polyimide film and being center-fed and fed in-phase.

18. The method of forming a conformal integrated broadband stacked multi-spiral antenna assembly of claim 17, wherein the composite laminate is selected from a group consisting of a fibrous material embedded in a resinous matrix, non-conductive face sheets and a honeycomb sandwich core, or a structural foam.

19. The method of forming a conformal integrated broadband stacked multi-spiral antenna assembly of claim 17, wherein the step of embedding a stacked multi-spiral antenna array in the non-load-bearing structural element includes co-curing the broadband stacked multi-spiral antenna array and the non-load-bearing structural element to form the conformal integrated broadband stacked multi-spiral antenna assembly.