Integrated ultra wideband element card for array antennas

• US 7,012,572 B1
• Filed: 07/16/2004
• Issued: 03/14/2006
• Est. Priority Date: 07/16/2004
• Status: Expired due to Fees

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Schaffner, James H., Bridges, William B.
• Primary Examiner(s): Nguyen, Hoang V.
• Application Number:
  US10/892,947
• Time in Patent Office: 606 Days
• Field of Search: 343/725, 343/772, 343/785, 343/900
• US Class Current: 343/725
• CPC Class Codes: H01Q 13/02 Waveguide horns
• CPC Class Codes: H01Q 13/24 constituted by a dielectric or ferromagnetic rod or pipe H01Q13/28 takes precedence
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 21/067 using endfire radiating aerial units transverse to the plane of the array
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H01Q 3/36 with variable phase-shifters

Abstract

An element card for an ultra-wideband array antenna is disclosed. The element card has one or more integrated antennas and can be designed to operate over multiple decades of bandwidth. The element card may be arranged as part of an array of element cards to achieve operation in multiple frequency bands.

Claims

1. A device, comprising:

an element card having one or more embedded dielectric rod antennas disposed on a first side of said element card and a TEM horn antenna disposed on a second side of said element card, the one or more embedded dielectric rod antennas being tuned for relatively higher frequencies in a frequency band of interest and the TEM horn antenna being tuned for relatively lower frequencies in the frequency band of interest.

2. The device of claim 1, wherein each of the one or more dielectric rod antennas comprises an image guide feed section and a tapered dielectric rod antenna section.

3. The device of claim 2, wherein the image guide feed section contains a core of dielectric material of dielectric constant ∈

₂ embedded within a cladding of dielectric material of dielectric constant ∈

₁.

4. The device of claim 3, wherein the core and cladding are disposed immediately adjacent a conductive ground plane associated with the element card.

5. The device of claim 4, wherein additional cladding layers are arranged such that the core has the highest dielectric constant and each subsequent relatively outer cladding layer has a lower dielectric constant than a previous relatively inner layer.

6. The device of claim 3, wherein dielectric constant ∈

₂ is greater than dielectric constant ∈

₁.

7. The device of claim 3, wherein the cladding of the image guide feed section is tapered to outer edges of the core on a first end of the image guide feed section.

8. The device of claim 3, wherein the cladding and the core of the image guide feed section are tapered to a ridge on a second end of the image guide feed section.

9. The device of claim 8, wherein a microstrip-to-image guide RF transition connects the core to a microstrip transmission line feed.

10. The device of claim 9, wherein the input microstrip transmission line is fabricated as part of a multi-layer printed circuit board on the element card.

11. The antenna comprising an array of element cards according to claim 1.

12. The device of claim 1, wherein the TEM horn antenna is operatively coupled to a microstrip transmission line feed.

13. The device of claim 12, wherein a shaped dielectric insert is used for impedance matching the TEM horn with the microstrip transmission line.

14. A device, comprising:

an element card having one or more embedded dielectric rod antennas on a first side and a TEM horn antenna on a second side, the one or more dielectric rod antennas comprising an image guide feed section and a tapered dielectric rod antenna section, the element card having a ground plane disposed adjacent one or more image guide feed sections with the tapered dielectric rod antenna section of the one or more dielectric rod antennas being disposed beyond an edge of said ground plane.

15. The device of claim 14, wherein the image guide feed section contains a core of dielectric material of dielectric constant ∈

₂ embedded within a cladding of dielectric material of dielectric constant ∈

₁.

16. The device of claim 15, wherein the cladding of the image guide feed section is tapered to outer edges of the core on a first end of the image guide feed section.

17. The device of claim 16, wherein on a second end of the image guide feed section the core and the cladding separate into individual non-embedded image guides of higher and lower dielectric constant material.

18. The device of claim 17 wherein the non-embedded image guides of higher and lower dielectric constant material are connected to separate input microstrip transmission lines by image guide launchers.

19. The device of claim 18, wherein the input microstrip transmission lines are fabricated on a single printed circuit board on the element card.

20. The device of claim 18, wherein the image guide launchers are grounded-bow tie antennas.

21. The device of claim 17, wherein the image guide of higher dielectric material is inserted into the image guide of lower dielectric material to become the core of the embedded image guide section at a shallow angle in order to reduce RF signal scattering.

22. The device of claim 14, wherein the TEM horn antenna is connected to a microstrip transmission line feed.

23. The device of claim 22, wherein a shaped dielectric insert is used to impedance match the TEM horn antenna with the microstrip transmission line.

24. A method of achieving beam steering, comprising:

achieving course beam steering by dividing a field of view into two or more regions;

using embedded dielectric rod antennas located on each element card in an array of element cards to cover each region; and

switching a signal from one embedded dielectric rod antenna to another.

25. The method of claim 24, further comprising configuring at least two of the embedded dielectric rod antennas on each card to point in different directions.

26. The method of claim 24, further comprising disposing image guides at a desired angle relative to radiating tapers.

27. The method of claim 25, wherein fine beam steering is achieved through phase shifters in a beam forming manifold.

28. The method of claim 27, further comprising switching course scan angles on/off.

29. The method of claim 27, further comprising using separate signal processing circuits for multiple beams from an aperture.

30. A device, comprising:

an array of one or more element cards having two or more dielectric rod antennas disposed thereon, each dielectric rod antenna representing a divided region of a field of view;

switching means to achieve course beam steering by switching a signal from one embedded dielectric rod antenna to another; and

phase shifters in a beam forming manifold for performing fine beam steering.

31. A device, comprising:

an ultra wideband platform having a plurality of embedded dielectric rod antennas; and

a discone antenna, the plurality of embedded dielectric rod antennas being disposed in a circular configuration on said wideband platform, the circular configuration of the plurality of embedded dielectric rod antennas being centered on an axis of said discone antenna.

32. The device of claim 31, wherein high frequency bands radiate via the ultra wideband platform and the low frequency bands radiate via the discone antenna.

33. The device of claim 32, further comprising a switch matrix circuit for controlling high frequency beam steering.

34. An antenna array comprising:

a plurality of element cards arranged in a geometric arrangement, each element card having a substrate and a ground plane covering at least a portion of the substrate, a set comprising at least a majority of the element cards, the elements cards of said set having an associated core dielectric rod disposed thereon over a portion of the ground plane thereof and having a tapered portion which is located beyond the ground plane thereof; and

a subset of said set of element cards wherein the associated core dielectric rod is cladded by a cladded portion that partially covers the associated core dielectric rod with a dielectric material having a lower dielectric constant than the dielectric constant of the core dielectric rod antenna, the cladded portion having a tapered portion which is also located beyond the ground plane.

35. The antenna array of claim 34 wherein another subset of said set of element cards has a TEM horn antenna disposed on a second side of said substrate.

36. The antenna array of claim 35 wherein a number of members of said subset is greater than a number of members of said another subset.

37. The antenna array of claim 35 wherein the certain ones of said members of said another subset are also members of the first mentioned subset.