Dual Band Interleaved Phased Array Antenna

• US 20140111396A1
• Filed: 06/10/2013
• Published: 04/24/2014
• Est. Priority Date: 10/19/2012
• Status: Abandoned Application

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Hyjazie, Fayez, Watson, Paul, Boutayeb, Halim
• Application Number:
  US13/914,046
• Publication Number:
  US 20140111396A1
• Time in Patent Office: Days
• US Class Current: 343/798
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H01Q 21/26 Turnstile or like antennas comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence

Abstract

The height of crossed-dipoles antenna elements can be reduced by including an additional bend/segment in the feed-line and/or tuning-stub of the antenna dipole having the upper slot. The extra bend allows the crossed-dipoles antenna element to be shortened by as much as twenty percent without reducing the feed-line length. Additionally, the height of crossed-dipoles antenna elements can be reduced by shaping a winged portion of the balun-fed dipoles to match the contour of a radome contour, which allows the crossed-dipoles antenna element to accommodate a shallower radome and achieve a thinner antenna module. Additionally, the height of crossed-dipoles antenna elements can be reduced by positioning periodic structures around the base of low-band radiating elements to provide artificial magnetic conductor (AMC) functionality, which enables constructive interference between reflected and non-reflected signals at profile spacings of less than one-quarter wavelength.

Claims

1. A balun-fed dipole of a crossed-dipoles antenna element, the balun-fed dipole comprising:

a substrate comprising a lower region and an upper region, wherein the lower region is positioned below the upper region;

a feed-line printed on a first face of the substrate, the feed-line extending at least partially across the lower region of the substrate; and

a first conductive layer printed on the first face of the substrate, the first conductive layer at least partially covering the upper region of the substrate.

2. The balun-fed dipole of claim 1, further comprising a second conductive layer printed on a second face of the substrate, wherein the second face of the substrate opposes the first face of the substrate.

3. The balun-fed dipole of claim 1, wherein the first conductive layer is positioned above the feed-line on the first face of the substrate.

4. A crossed-dipoles antenna element comprising:

a first balun-fed dipole comprising a first substrate, a lower slot carved out of the first substrate, and a first feed-line printed on the first substrate, the first feed-line being routed around the lower slot; and

a second balun-fed dipole comprising a second substrate, an upper slot carved out of the second substrate, and a second feed-line printed on the second substrate, wherein the second feed-line is routed beneath the upper slot,

wherein a longest segment of the first feed-line is longer than a longest segment of the second feed-line, and

wherein the second feed-line includes at least one more segment than the first feed-line.

5. The crossed-dipoles antenna element of claim 4, wherein the at least one more segment causes the second feed-line to have approximately the same length as the first feed-line.

6. The crossed-dipoles antenna element of claim 4, wherein the first balun-fed dipole is configured to be mounted to the second first balun-fed dipole by sliding the upper slot onto the lower slot.

7. The crossed-dipoles antenna element of claim 4, wherein the first balun-fed dipole further comprises a first tuning-stub,

wherein the second balun-fed dipole further comprises a second tuning-stub, wherein a longest segment of the first tuning-stub is longer than a longest segment of the second tuning-stub, and

wherein the second tuning-stub includes at least one more segment than the first tuning-stub, the at least one additional segment causing the second tuning-stub to have approximately the same length as the first tuning-stub.

8. The crossed-dipoles antenna element of claim 7, wherein the first tuning-stub is straight.

9. The crossed-dipoles antenna element of claim 7, wherein the first balun-fed dipole further comprises a first conductive layer printed on an opposing side of the first substrate, wherein the first tuning-stub is etched out of the first conductive layer, and

wherein the second crossed-dipoles balun further comprises a second conductive layer printed on an opposing side of the second substrate, wherein the second tuning-stub is etched out of the second conductive layer.

10. A base station antenna comprising:

an antenna reflector;

an array of crossed-dipoles antenna elements mounted to the antenna reflector; and

a radome encasing the array of crossed-dipoles antenna elements, wherein the array of crossed-dipoles antenna elements are positioned in between the radome and the antenna reflector, and

wherein an uppermost portion of at least one crossed-dipoles antenna element in the array of crossed-dipoles antenna elements conforms to a contour of the radome.

11. The base station antenna of claim 10, wherein an outermost edge of the uppermost portion of the at least one crossed-dipoles antenna is rounded to conform to the contour of the radome.

12. The base station antenna of claim 10, further comprising a compartment for housing active antenna components, the compartment being positioned below the antenna reflector.

13. A phased array antenna comprising:

an array of low-band radiating elements; and

an array of high-band radiating elements configured to radiate at a higher frequency band than the array of low-band radiating elements, wherein the high-band radiating elements are separated from one another by a narrower spacing than the low-band radiating elements.

14. The phased array antenna of claim 13, wherein a ratio of radiating frequencies between the high-band radiating elements and the low-band radiating elements is between about 1.9:

1 and about 1;

1.

15. The phased array antenna of claim 13, wherein the ratio of radiating frequencies between the high-band radiating elements and the low-band radiating elements is about 1.3:

1.

16. A phased array antenna comprising:

an antenna reflector;

a plurality of radiating elements mounted to the antenna reflector, the plurality of radiating elements including an array of low-band radiating elements and an array of high-band radiating elements, wherein the high-band radiating elements are configured to radiate at a higher frequency than the low-band radiating elements; and

periodic structures mounted to the antenna reflector, the periodic structures being positioned around the bases of the radiating elements.

17. The phased array antenna of claim 16, wherein the periodic structures include a first set of periodic structures positioned around the bases of the high-band radiating elements, the first set of periodic structures being configured to reduce mutual coupling between adjacent high-band radiating elements by providing an Electromagnetic Band Gap (EBG) between adjacent high-band elements.

18. The phased array antenna of claim 17, wherein the periodic structures further comprise a second set of periodic structures positioned around the bases of the low-band radiating elements, the second set of periodic structures being configured to provide Artificial Magnetic Conductor (AMCs) functionality.

19. The phased array antenna of claim 18, wherein the second set of structures provide AMC functionality by reflecting signals in a manner that causes the reflected signals to constructively interfere with non-reflected signals when a profile of the low-band radiating element is less than or equal to one-quarter of a wavelength emitted by the low-band radiating elements.

20. The phased array antenna of claim 19, wherein the low-band radiating elements comprise dipole arms, and wherein the profile of the low-band radiating elements corresponds to a vertical separation between the dipole arms and the antenna reflector.

21. A phased array antenna comprising:

an antenna reflector;

a set of columns of low-band radiating elements mounted to the antenna reflector;

a set of columns of high-band radiating elements mounted to the antenna reflector, wherein the set of columns of high-band radiating elements are interleaved with the set of columns of low-band radiating elements; and

conductive fences running vertically adjacent to the set of columns of low-band radiating elements.

22. The phased array antenna of claim 21, wherein the conductive fences comprise central conductive fences positioned in-between adjacent columns in the set of columns of low-band radiating elements.

23. The phased array antenna of claim 22, wherein the central conductive fences are configured to reduce low-band interference by at least partially isolating horizontally adjacent low-band radiating elements from one another.

24. The phased array antenna of claim 22, wherein the central conductive fences are further positioned in-between adjacent columns in the set of columns of high-band radiating elements, and wherein the conductive fences are configured to reduce high-band interference by at least partially isolating horizontally adjacent high-band radiating elements from one another.

25. The phased array antenna of claim 22, wherein the central conductive fences comprise a plurality of conductive segments separated by voids, the voids at least partially isolating adjacent conductive segments from one another.

26. The phased array antenna of claim 25, wherein the conductive segments have a length that is equal to about 1.6 times the radiating frequency of the low-band radiating elements.

27. The phased array antenna of claim 25, wherein the voids are configured to prevent at least some modes from propagating between adjacent conductive segments.

28. The phased array antenna of claim 25, wherein the conductive fences further comprise edge fences positioned outside the outermost columns in the set of columns of low-band radiating elements, and wherein each of the edge fences comprise a continuous conductive segment that excludes voids.

29. A phased array antenna comprising:

an antenna reflector;

a set of columns of low-band radiating elements mounted to the antenna reflector; and

a set of columns of high-band radiating elements mounted to the antenna reflector, wherein the set of columns of high-band radiating elements are interleaved with the set of columns of low-band radiating elements, and

wherein adjacent columns in the set of high-band radiating elements are vertically offset with respect to one another.

30. The phased array antenna of claim 29, wherein the vertical offset increases a separation between horizontally adjacent high-band radiating elements.

31. The phased array antenna of claim 29, wherein adjacent columns in the set of low-band radiating elements are vertically offset with respect to one another, and wherein the vertical offset between adjacent columns in the set of low-band radiating elements increases a separation between horizontally adjacent low-band radiating elements.

32. A balun-fed dipole of a crossed-dipoles antenna element, the balun-fed dipole comprising:

a substrate;

a feed-line printed on a face of the substrate, the feed-line extending at least partially across the lower region of the substrate; and

a conductive layer printed on an opposing face of the substrate, the conductive layer comprising a bottommost end that is configured to be conductively joined to a ground plane, wherein the bottommost end is notched to reduce a surface area in contact with ground plane.

33. The balun-fed dipole of claim 32, wherein at least some portion of the bottommost end has been removed to reduce the surface area in contact with the ground plane.

34. The balun-fed dipole of claim 32, wherein the bottommost end is notched to reduce a likelihood of intermodulation distortion.