Dual polarization planar array antenna and cell elements therefor

• US 20070085744A1
• Filed: 05/25/2006
• Published: 04/19/2007
• Est. Priority Date: 10/16/2005
• Status: Active Grant

• Current Assignee: Panasonic Avionics Corporation (Panasonic Holdings Corporation)
• Original Assignee: Starling Advanced Communications Ltd.
• Inventors: Engel, Benjamin
• Granted Patent: US 7,663,566 B2
• Time in Patent Office: Days
• US Class Current: 343/700.MS
• CPC Class Codes: H01Q 21/064 using horn or slot aerials slotted waveguides arrays H01Q21/005
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001

Abstract

An RF antenna structure (e.g., a planar array) includes at least one radiation cell (and typically many, e.g., 16 or 32 or 64, etc.) having a conductive enclosure and an upper probe and a lower probe located at different heights within the enclosure. The enclosure between the upper probe and a bottom of the cell has at least two different cross-sectional areas. The upper and lower probes are preferably oriented at substantially 90° relative to each other. An upper portion of the enclosure beneath the upper probe may have a larger dimension than a lower portion such that the upper portion allows propagation of waves generated by the upper probe in a predetermined frequency band while the lower portion (e.g., above the lower probe) does not substantially allow propagation of waves generated by the upper probe, in the predetermined frequency band.

Claims

1. An RF antenna structure, comprising:

at least one radiation cell having a conductive enclosure and an upper probe and a lower probe located at different heights within the enclosure,

wherein the enclosure between the upper probe and a bottom of the cell has at least two different cross-sectional areas.

2. An RF antenna structure as in claim 1 comprising at least 16 said radiation cells.

3. An RF antenna structure as in claim 2 wherein the conductive enclosure isolates waves generated within the at least one cell from neighboring cells of the antenna structure.

4. An RF antenna structure as in claim 2 comprising at least 64 said radiation cells.

5. An RF antenna structure as in claim 1 wherein the conductive enclosure comprises a substantially continuous metallic enclosure.

6. An RF antenna structure as in claim 1 wherein the upper and lower probes are oriented at substantially 90°

relative to each other.

7. An RF antenna structure as in claim 1 wherein the antenna comprises a planar array antenna structure.

8. An RF antenna structure as in claim 1 wherein an upper portion of the enclosure beneath the upper probe has a longer width than a lower portion of the enclosure.

9. An RF antenna structure as in claim 8 wherein the upper portion has a width which allows propagation of waves generated by the upper probe of frequencies at least as low as 12 GHz, while the lower portion imposes a cut-off frequency which does not allow propagation of waves from the upper probe of frequencies lower than 13 GHZ.

10. An RF antenna structure as in claim 8 wherein the at least one radiation cell is adapted for transmission of waves of a predetermined frequency band and wherein the upper portion allows propagation of waves generated by the upper probe in the predetermined frequency band while the lower portion does not substantially allow propagation of waves generated by the upper probe, in the predetermined frequency band.

11. An RF antenna structure as in claim 8 wherein the lower portion of the enclosure is above the lower probe.

12. An RF antenna structure as in claim 8 wherein the lower portion of the enclosure is below the lower probe.

13. An RF antenna structure as in claim 8 wherein the height of the upper portion of the enclosure is substantially equal to a quarter wavelength of a frequency that can pass through the upper portion but is blocked from passing below the upper portion.

14. An RF antenna structure as in claim 1 wherein the cross sectional area of the cell between the upper and lower probes is smaller than 100 square millimeters.

15. An RF antenna structure as in claim 1 wherein the cross-sectional area of the cell within the enclosure has a capital “

T”

shape over at least part of its height.

16. An RF antenna structure as in claim 1 comprising at least one dielectric cover above the cell conductive enclosure.

17. An RF antenna structure as in claim 16 wherein the at least one dielectric cover above the cell effectively isolates the cell from dirt and humidity in the environment.

18. An RF antenna structure as in claim 16 wherein the at least one dielectric cover is not perpendicular to a beam direction of the cell.

19. An RF antenna structure as in claim 16 wherein the at least one dielectric cover has a non-uniform thickness.

20. An RF antenna structure as in claim 1 wherein the enclosure comprises a metal ridge, smaller than the upper probe, serving as a single ridge waveguide structure.

21. A planar antenna array having a transmitting face and comprising a plurality of arrayed cells each cell comprising:

a first antenna probe;

a second antenna probe spaced away from the first antenna; and

a reflector structure situated between the first and second antenna probes that is configured to pass RF waves transmitted/received by the second antenna probe and to reflect RF waves transmitted/received by the first antenna probe.

22. A planar antenna array as in claim 21 wherein the first antenna probe has a first RF polarization and the second antenna probe has a different RF polarization.

23. A planar antenna array as in claim 22 wherein the reflector structure includes a waveguide section that passes RF waves with the polarization of the second antenna probe but is cut-off for RF waves with the polarization of the first antenna probe.

24. A planar antenna array as in claim 23 wherein the reflector structure is spaced at a distance from the first antenna probe such that RF waves reflected from the reflector structure reinforce RF waves generated or received at the first antenna probe.

25. A planar antenna array as in claim 21 wherein the first and second antenna probes are oriented perpendicular to each other.