Radiating elements having angled feed stalks and base station antennas including same
Radiating elements of first and second linear arrays of radiating elements have respective feed stalks that can reside at an angle to provide a balanced dipole arm with an inner end portion laterally offset to be closer to a right or left side of the base station antenna and reflector than an outer end portion that faces a radome of the base station antenna. The feed stalk can include sheet metal legs and printed circuit boards providing an RF transmission line(s).
1. A radiating element for a base station antenna, comprising:
a plurality of dipole arms; and
a feed stalk coupled to the dipole arms,
wherein the feed stalk has longitudinally spaced apart opposing first and second end portions, wherein the second end portion is adjacent the dipole arms and the first end portion is behind the second end portion, wherein the second end portion resides at a first lateral position and is configured to reside closer to a front of the base station antenna than the first end portion, wherein the first end portion is laterally offset from the first lateral position and resides closer to an adjacent most right or left side of the base station antenna than the second end portion, and wherein the plurality of dipole arms are configured as a cross-dipole radiating element.
2. The radiating element of claim 1 , wherein the plurality of dipole arms are parallel to a primary surface of a reflector that resides behind the plurality of dipole arms, wherein the feed stalk has at least one angled segment that resides between the first and second end portions, and wherein the at least one angled segment extends at an angle β measured between the at least one angled segment and the reflector that is in a range of about 30-60 degrees.
3. The radiating element of claim 2 , wherein the feed stalk has at least one angled segment that resides between the first and second end portions, wherein the at least one angled segment is a single angled segment that starts at a location above a rear facing end of the first end portion and below a medial location of the feed stalk and that extends at a constant angle between the first and second end portions at an angle of inclination β that is different than an angle of inclination of the feed stalk behind the single angled segment.
4. The radiating element of claim 2 , wherein the plurality of dipole arms are provided by a printed circuit board that is coupled to the second end portion of the feed stalk at a medial location thereof, and wherein the first and second end portions of the feed stalk comprise at least an end segment that is perpendicular to the printed circuit board.
5. The radiating element of claim 1 , wherein the feed stalk comprises a feed stalk body that has first and second segments that reside between the first and second end portions and that are at different angles from each other.
6. The radiating element of claim 1 , wherein the feed stalk comprises:
at least one leg of sheet metal; and
a first printed circuit board coupled to the at least one leg of sheet metal.
7. The radiating element of claim 6 , wherein the at least one leg of sheet metal is arranged as a plurality of cooperating legs of sheet metal, and wherein first and second legs of the plurality of cooperating legs of sheet metal comprise an RF transmission line coupled thereto.
8. The radiating element of claim 1 , wherein the feed stalk comprises a first printed circuit board that is coupled to a pair of spaced apart cooperating sheet metal legs.
9. The radiating element of claim 1 , wherein the feed stalk comprises first and second cooperating sheet metal legs and a printed circuit board comprising an RF transmission line held conformally to a sub-length of the first and second sheet metal legs, and wherein the printed circuit board comprises a cross-segment that spans across a gap space between the first and second legs at a location closer to and below the second end portion of the feed stalk than the first end portion of the feed stalk.
10. The radiating element of claim 9 , wherein the printed circuit board is a first printed circuit board, the feed stalk further comprising a second printed circuit board having a rigid or semi-rigid and self-supporting shape that is spaced apart from the at least two sheet metal legs and comprises an RF transmission line, wherein the second printed circuit board is orthogonal to the first printed circuit board.
11. The radiating element of claim 10 , wherein the second printed circuit board is coupled to the first and second sheet metal legs and comprises a slot, and wherein the cross-segment of the first printed circuit board extends through the slot.
12. The radiating element of claim 1 , wherein the feed stalk comprises at least two elongate legs of sheet metal that extend at least a major length of the feed stalk between the first and second end portions, wherein the at least two elongate legs of sheet metal are provided as four elongate legs of sheet metal arranged in first and second pairs of elongate legs of sheet metal, wherein the first pair of legs of sheet metal is coupled to a first printed circuit board and the second pair of elongate legs of sheet metal is coupled to a second printed circuit board.
13. The radiating element of claim 1 , wherein the feed stalk comprises a second printed circuit board that is orthogonal to the first printed circuit board, and wherein the first and second printed circuit boards each include a respective hook balun.
14. The radiating element of claim 1 , wherein the first printed circuit board is orthogonal to the second printed circuit board.
15. A base station antenna, comprising:
a reflector;
a first array comprising a first vertically-extending column of cross-dipole radiating elements and mounted to be forward of the reflector; and
a second array comprising a second vertically-extending column of cross-dipole radiating elements and mounted to be forward of the reflector,
wherein at least some of the radiating elements of the first and second arrays each comprise a feed stalk that extends in a front-to-back direction of the base station antenna, wherein the feed stalk has spaced apart opposing first and second end portions, wherein the first end portion is rearward of the second end portion and is configured to couple to a feed network, and wherein the first end portion resides closer to an adjacent most one of a right or left side of the base station antenna than the second end portion.
16. The base station antenna of claim 15 , further comprising a multiple column array that is positioned laterally between the first array and the second array of radiating elements.
17. The base station antenna of claim 16 , wherein the radiating elements of the first array and the second array are low-band radiating elements, wherein the radiating elements of the multiple column array are higher-band radiating elements than the low-band radiating elements, and wherein some columns of the multiple column array reside behind and overlap with cross-dipole radiating elements of the first array or the second array.
18. The base station antenna of claim 15 , wherein the feed stalk has at least one angled segment that resides between the first and second end portions, and wherein the at least one angled segment that starts at a location above a rear facing end of the first end portion and below a medial location of the feed stalk and that extends at an angle β measured between the at least one angled segment and a reflector that is in a range of about 30-60 degrees.
19. The base station antenna of claim 15 , wherein the feed stalk comprises a first printed circuit board that is coupled to a pair of spaced apart cooperating sheet metal legs.
20. The base station antenna of claim 19 , wherein the feed stalk comprises a second printed circuit board that is orthogonal to the first printed circuit board.
21. The base station antenna of claim 15 , wherein the feed stalk comprises first and second cooperating sheet metal legs and a printed circuit board comprising an RF transmission line held conformally to a sub-length of the first and second sheet metal legs, and wherein the printed circuit board comprises a cross-segment that spans across a gap space between the first and second legs at a location closer to and below the second end portion of the feed stalk than the first end portion of the feed stalk.
22. The base station antenna of claim 15 , wherein the feed stalk comprises four elongate legs of sheet metal arranged as first and second pairs of elongate legs of sheet metal, wherein the first pair of legs of sheet metal is coupled to a first printed circuit board and the second pair of elongate legs of sheet metal is coupled to a second printed circuit board, and wherein the first printed circuit board is orthogonal to the second printed circuit board and reside under a printed circuit board providing a respective radiating element of the first and second arrays.
23. The base station antenna of claim 15 , wherein the first and second arrays are each provided as a single column of radiating elements, the first array on a right side of the base station antenna and the second array on a left side of the base station antenna.
24. The base station antenna of claim 15 , wherein the first end portion of the feed stalk is coupled to and/or resides adjacent to a side wall of a housing of the base station antenna and extends laterally inwardly relative to the side wall.
25. The base station antenna of claim 15 , wherein the reflector comprises a reflector side wall that is orthogonal to a primary surface of the reflector, and wherein the first end portion of the feed stalk projects laterally inwardly from the reflector side wall.
26. A base station antenna comprising:
a first reflector;
a second reflector;
a plurality of radiating elements, wherein a first segment of a respective radiating element overlaps the first reflector and a second segment of the respective radiating element overlaps the second reflector; and
a radome between adjacent segments of the first and the second reflector.
27. The base station antenna of claim 26 , wherein the first and second reflectors are capacitively coupled.