Passive/active base station antenna systems having passive reflector assemblies with an opening for an active antenna array
A base station antenna comprises a reflector assembly and a first radiating element having a first feed stalk and a first radiator. A base of the first feed stalk is adjacent the reflector assembly and the first radiator is adjacent a distal end of the first feed stalk. A center of the first radiator is offset from the base of the first feed stalk in a longitudinal direction that is parallel to a longitudinal axis of the base station antenna.
1 . A base station antenna that extends along a longitudinal axis, the base station antenna comprising:
a reflector assembly; and
a first radiating element having a first feed stalk, a first radiator and a second radiator, where a base of the first feed stalk is adjacent the reflector assembly and the first radiator and the second radiator are adjacent a distal end of the first feed stalk,
wherein a center of the first radiator is offset from the base of the first feed stalk in a longitudinal direction that is parallel to the longitudinal axis, and a center of the second radiator is offset from the base of the first feed stalk in the longitudinal direction, and
wherein the first and second radiators have different polarizations and centers of the first and second radiators are offset from the base of the first feed stalk in a same direction.
2 . The base station antenna of claim 1 , wherein the reflector assembly includes a main reflector, longitudinally-extending first and second reflector strips that extend from the main reflector and are spaced apart from each other in a transverse direction that is perpendicular to the longitudinal direction, and a transversely-extending third reflector strip that extends between the first and second reflector strips.
3 . The base station antenna of claim 2 , wherein the first radiating element is mounted to extend forwardly from the third reflector strip.
4 . The base station antenna of claim 3 , wherein the reflector assembly includes an opening that is bounded by an upper edge of the main reflector and the first through third reflector strips.
5 . The base station antenna of claim 4 , wherein at least half of the first radiator overlaps the opening in a direction perpendicular to the main reflector.
6 . The base station antenna of claim 2 , wherein front surfaces of the respective first and second reflector strips extend in a first plane that is positioned rearwardly of a plane defined by a front surface of the main reflector.
7 . A base station antenna that extends along a longitudinal axis, the base station antenna comprising:
a reflector assembly; and
a first radiating element having a first feed stalk and a first radiator, where a base of the first feed stalk is adjacent the reflector assembly and the first radiator is a distal end of the first feed stalk;
a first radio frequency (“RF”) port,
wherein the first radiating element is part of a first array of radiating elements that are all coupled to the first RF port, and wherein a second radiating element that is part of the first array of radiating elements is mounted to extend forwardly from the first reflector strip,
wherein the reflector assembly includes a main reflector, longitudinally-extending first and second reflector strips that extend from the main reflector and are spaced apart from each other in a transverse direction that is perpendicular to the longitudinal direction, and a transversely-extending third reflector strip that extends between the first and second reflector strips,
wherein the first radiating element is mounted to extend forwardly from the third reflector strip, and
wherein a center of the first radiator is offset from the base of the first feed stalk in a longitudinal direction that is parallel to the longitudinal axis.
8 . The base station antenna of claim 7 , wherein a third radiating element that is part of the first array of radiating elements is mounted to extend forwardly from the main reflector.
9 . The base station antenna of claim 7 , wherein the second radiating element has a second feed stalk and a second radiator, where a base of the second feed stalk is adjacent the reflector assembly and the second radiator is adjacent a distal end of the second feed stalk, and wherein a center of the second radiator is offset from the base of the second feed stalk in the transverse direction.
10 . The base station antenna of claim 9 , wherein the first feed stalk is a tilted feed stalk that extends forwardly from the third reflector strip in a first plane and the second feed stalk is a tilted feed stalk that extends forwardly from the first reflector strip in a second plane, where the first plane is substantially perpendicular to the second plane.
11 . The base station antenna of claim 7 , wherein the second radiating element extends forwardly from a portion of the first reflector strip that is widened in the transverse direction.
12 . The base station antenna of claim 7 , wherein the first reflector strip comprises a first integrated strip that is monolithic with the main reflector and a first auxiliary strip that is mounted on the first integrated strip, and the second reflector strip comprises a second integrated strip that is monolithic with the main reflector and a second auxiliary strip that is mounted on the second integrated strip.
13 . The base station antenna of claim 12 , wherein the first auxiliary strip includes a front wall that is parallel to a front surface of the main reflector and a sidewall that extends rearwardly from the front wall, and the first integrated strip includes a rear wall that is parallel to the front surface of the main reflector and a sidewall that extends forwardly from the rear wall.
14 . The base station antenna of claim 12 , wherein the second radiating element is mounted to extend forwardly from a feed board, and the feed board is mounted on the first auxiliary strip.
15 . A base station antenna, comprising:
a reflector assembly having a main reflector that includes a forwardly-facing planar main reflector surface and spaced-apart first and second reflector strips that extend from respective first and second opposed sides of the main reflector; and
wherein the first reflector strip includes a front wall that has a widened region that is wider in a transverse direction than are first and second narrowed regions of the front wall that are on either side of the widened region in a longitudinal direction of the first reflector strip, wherein the longitudinal direction is perpendicular to the transverse direction,
further comprising a feedboard mounted on the widened region.
16 . The base station antenna of claim 15 , wherein the first reflector strip further includes an outer sidewall and an inner sidewall, wherein the inner sidewall comprises a plurality of discontinuous segments.
17 . The base station antenna of claim 15 , wherein the first reflector strip is a tubular reflector strip that has the front wall, a rear wall and first and second sidewalls.
18 . The base station antenna of claim 15 , wherein the reflector assembly further comprising a first radio frequency (“RF”) choke that is positioned behind the main reflector, wherein a width of the first RF choke in the transverse direction is greater than widths of the first and second narrowed regions of the front wall.
19 . The base station antenna of claim 15 , wherein the first reflector strip comprises a first integrated strip that is monolithic with the main reflector and a first auxiliary strip that is mounted on the first integrated strip.