CN114142211A - Base station antenna, feed subassembly and frame - Google Patents

Abstract

The present invention relates to a base station antenna. The base station antenna includes: a reflector; a first radiator located at a front side of the reflector; first and second ground plates extending rearwardly from the reflector substantially perpendicular to the reflector and parallel to each other; and a first conductor strip extending between the first and second ground plates and configured to feed the first radiator, the first conductor strip and the first and second ground plates constituting a first stripline transmission line, wherein the reflector and the first and second ground plates are configured as a single piece such that the reflector is grounded via the first and second ground plates without soldering. The invention also relates to a feed assembly and a frame.

Description

Base station antenna, feed subassembly and frame

Technical Field

The present invention relates to communication systems, and more particularly, to a base station antenna and a feed assembly and frame for the base station antenna.

Background

Wireless base stations are well known in the art and typically include a baseband unit, a radio and an antenna, among other components. The antennas are configured to provide two-way radio frequency ("RF") communications with fixed and mobile subscribers ("users") located throughout the cell. Typically, the antenna is typically mounted on a tower or raised structure such as a pole, roof, water tower, etc., to which separate baseband units and radios are connected.

Fig. 1 is a schematic structural diagram of a conventional base station 60. The base station 60 includes a base station antenna 50 that may be mounted on the tower 30. The base station 60 also includes a baseband unit 40 and a radio 42. To simplify the drawing, a single baseband unit 40 and a single radio 42 are shown in fig. 1. It should be understood that more than one baseband unit 40 and/or radio 42 may be provided. Additionally, while the radio 42 is shown co-located with the baseband unit 40 at the bottom of the tower 30, it should be understood that in other cases, the radio 42 may be a remote radio head mounted on the tower 30 adjacent to the antenna 50. The baseband unit 40 may receive data from another source, such as a backhaul network (not shown), and may process the data and provide a data stream to the radio 42. Radio 42 may generate RF signals including data encoded therein and may amplify and transmit these RF signals to antenna 50 via coaxial transmission line 44. It should also be understood that the base station 60 of fig. 1 may generally include various other devices (not shown), such as a power supply, a battery backup, a power bus, an Antenna Interface Signal Group (AISG) controller, and the like. Typically, a base station antenna comprises one or more phased arrays of radiating elements, wherein the radiating elements are arranged in one or more columns when the antenna is mounted for use.

In order to transmit and receive RF signals to and from the defined coverage area, the antenna beams of the antennas 50 are typically tilted at a certain downward angle (referred to as a "downtilt") with respect to the horizontal plane. In some cases, antenna 50 may be designed such that the "electronic downtilt" of antenna 50 may be adjusted from a remote location. With an antenna 50 comprising such an electronic tilt capability, the physical orientation of the antenna 50 is fixed, but the effective angle of the antenna beam can still be adjusted electronically, for example by controlling phase shifters that adjust the phase of the signal provided to each radiating element of the antenna 50. The phase shifter and other associated circuitry are typically built into the antenna 50 and may be controlled from a remote location. Typically, the AISG control signal is used to control the phase shifter.

Various types of phase shifters are known in the art, including rotary slide arm (cam) phase shifters, trombone (trombone) phase shifters, sliding dielectric (sliding) phase shifters, and sliding metal (sliding metal) phase shifters. The phase shifters and power splitters are typically constructed together as part of a feed network (or feed assembly) for feeding the phased array. The power divider divides an RF signal input to the feed network into a plurality of sub-components, and the phase shifter applies a respective phase shift to each sub-component that is changeable so that each sub-component is fed to one or more radiators.

Disclosure of Invention

One of the objects of the present invention is to provide a base station antenna and a feeding component for the base station antenna.

According to a first aspect of the present invention, there is provided a base station antenna comprising: a reflector; a first radiator located at a front side of the reflector; first and second ground plates extending rearwardly from the reflector substantially perpendicular to the reflector and parallel to each other; and a first conductor strip extending between the first and second ground plates and configured to feed the first radiator, the first conductor strip and the first and second ground plates constituting a first stripline transmission line, wherein the reflector and the first and second ground plates are configured as a single piece such that the reflector is grounded via the first and second ground plates without soldering.

According to a second aspect of the present invention, there is provided a base station antenna comprising: a reflector; a first radiator located at a front side of the reflector; a first cavity element located at a rear side of the reflector, wherein the first cavity element comprises first and second mutually parallel ground plates extending rearwardly substantially perpendicularly from the rear side of the reflector, the first and second ground plates each having a first edge proximate the reflector; a first conductor strip extending between the first and second ground plates and configured to feed the first radiator, the first conductor strip and the first and second ground plates constituting a first stripline transmission line; and a first dielectric layer between the first edge portions of the first and second ground plates and the reflector, wherein the first edge portion of the first ground plate extends laterally away from the first conductor strip by a first coupling portion substantially parallel to the back surface of the reflector; a second coupling portion extending laterally away from the first conductor strip, substantially parallel to the rear surface of the reflector, from the first edge of the second ground plate; the first and second coupling portions are each electrically coupled to the reflector via the first dielectric layer such that the reflector is grounded via the first cavity element without soldering.

According to a third aspect of the present invention, there is provided a feed assembly for feeding a column of radiators of a base station antenna configured to operate in a first polarisation direction, the feed assembly comprising a stripline transmission line located at a rear side of a reflector substantially perpendicular to the reflector, the stripline transmission line comprising first and second ground plates parallel to each other and a conductor strip extending between the first and second ground plates, the conductor strip having an input and a plurality of outputs, wherein the first and second ground plates are electrically connected to an outer conductor of a coaxial transmission line for feeding power to the column, the input is electrically connected to an inner conductor of the coaxial transmission line, the plurality of outputs are configured to be electrically connected to the column for feeding power to the column, and the first and second ground plates are configured as a single piece with the reflector, such that the reflector is grounded via the first and second ground plates without soldering.

According to a fourth aspect of the present invention, there is provided a frame for a base station antenna, comprising: a first planar element extending along a first plane, a first side of the first planar element configured to reflect electromagnetic radiation of the base station antenna; and second and third mutually parallel planar elements extending substantially perpendicularly from a second side of the first planar element, the second and third planar elements being configured to define a first cavity for a first conductor strip, wherein the first to third planar elements are configured as one piece so as to be commonly grounded.

According to a fifth aspect of the present invention, there is provided a reflector for a base station antenna, comprising: a plurality of sub-reflectors extending in a longitudinal direction of the base station antenna, wherein each of the plurality of sub-reflectors is configured to mount a radiating element of the base station antenna thereon; and the plurality of sub-reflectors are fixedly positioned such that the plurality of sub-reflectors are separated from each other, wherein the plurality of sub-reflectors are commonly grounded.

According to a sixth aspect of the present invention, there is provided a reflector for a base station antenna, comprising: a first cavity element; and a second cavity element, wherein each cavity element comprises a planar portion extending in a longitudinal direction of the base station antenna and a cavity portion extending from the planar portion substantially perpendicularly to a rear of the base station antenna, wherein the planar portion is configured to mount a radiating element of the base station antenna thereon and to reflect electromagnetic radiation of the base station antenna, the cavity portion being configured to accommodate therein at least part of a circuit for feeding the radiating element; the first and second cavity elements are positioned such that the first cavity element is separated from the second cavity element.

According to a seventh aspect of the present invention, there is provided a column component for a base station antenna, comprising: a reflector extending in a longitudinal direction of the base station antenna; a linear array of radiating elements extending along a longitudinal direction of the base station antenna, each radiating element in the linear array being mounted to the reflector so as to extend forwardly from the reflector; and a cavity extending substantially perpendicularly from the reflector to the rear of the base station antenna, the cavity configured to receive therein at least part of a circuit for feeding the linear array, wherein the column assembly is positioned apart from other column assemblies.

According to an eighth aspect of the present invention, there is provided a base station antenna comprising: a plurality of reflectors extending in a longitudinal direction of the base station antenna; and a plurality of linear arrays extending in a longitudinal direction of the base station antenna, each linear array including a plurality of radiating elements mounted to a corresponding one of the reflectors so as to extend forward from the corresponding one of the reflectors, wherein the plurality of reflectors are fixedly positioned such that the plurality of reflectors are separated from each other and each linear array has a same azimuthal boresight pointing direction.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a schematic structural diagram of a conventional base station.

Fig. 2A and 2B are schematic views for explaining radiators and radiating elements of the present invention.

Fig. 3A to 3E illustrate a base station antenna according to an embodiment of the present invention, in which fig. 3A is a front view of the antenna, fig. 3B is a rear view of the antenna, fig. 3C is a bottom view of the antenna, and fig. 3D and 3E are perspective views of the front and rear surfaces of the antenna, respectively.

Fig. 3F is a bottom view of the frame in the antenna of fig. 3A-3E.

Fig. 4A is an enlarged view of the frame of fig. 3F at one cavity assembly.

Fig. 4B is an enlarged view of the antenna of fig. 3C at one cavity component.

Fig. 5A is a bottom view of a base station antenna according to another embodiment of the present invention.

Fig. 5B is a perspective view of a portion of the cavity element in the antenna of fig. 5A.

Fig. 5C is a bottom view of the cavity member of fig. 5B.

Fig. 5D is an enlarged view of the antenna of fig. 5A at one of the cavity elements.

Fig. 6A is a side view of a portion of a conductor strip assembly in a base station antenna according to an embodiment of the present invention.

Fig. 6B is a perspective view of a portion of a content assembly placed in a chamber in a base station antenna according to an embodiment of the present invention.

Fig. 6C is a perspective view of the entraining mechanism of the content assembly shown in fig. 6B, viewed from the back of the antenna.

Figure 7A is a schematic view of a containment assembly loaded into a chamber according to one embodiment of the present invention.

Fig. 7B is a bottom view of the contents assembly of fig. 7A after loading into the chamber.

Figure 8A is a schematic view of a containment assembly loaded into a chamber according to one embodiment of the present invention.

Fig. 8B is a schematic view of the contents assembly of fig. 8A after loading into the chamber.

Fig. 8C is a schematic view of the contents assembly of fig. 8A after loading the support member into the chamber.

Fig. 9A is a perspective view of a transition between a coaxial transmission line and a stripline transmission line in a base station antenna according to an embodiment of the present invention.

Fig. 9B is a sectional view taken along a-a' direction in fig. 9A.

Fig. 9C is a perspective view of a transition between a coaxial transmission line and a stripline transmission line in a base station antenna in accordance with another embodiment of the invention.

Fig. 9D is a sectional view taken along the direction B-B' in fig. 9A.

Fig. 9E is a perspective view of a transition between a coaxial transmission line and a stripline transmission line in a base station antenna in accordance with one embodiment of the present invention.

Fig. 9F is a cross-sectional view of the transition between a coaxial transmission line and a stripline transmission line in a base station antenna in accordance with one embodiment of the present invention.

FIG. 9G is a perspective view of one of the transition pieces of FIG. 9F.

FIG. 9H is a perspective view of another transition piece of FIG. 9F.

Fig. 10A is a perspective view of the transition between a stripline transmission line and a feed board in a base station antenna in accordance with one embodiment of the present invention.

Fig. 10B is a perspective view of the transition between a stripline transmission line and a feed board in a base station antenna in accordance with one embodiment of the present invention.

Fig. 10C and 10D are schematic diagrams of transitions between stripline transmission lines and feed plates in a base station antenna in accordance with one embodiment of the present invention.

Fig. 11A is a side view of a segmented conductor strip in a base station antenna in accordance with one embodiment of the present invention.

Fig. 11B is a perspective view of a segmented conductor strip in a base station antenna in accordance with one embodiment of the present invention.

Fig. 11C is a bottom view of a base station antenna with a segmented conductor strip at one cavity assembly in accordance with one embodiment of the present invention.

Fig. 12A is a perspective view of at least a portion of a frame in a base station antenna, in accordance with one embodiment of the present invention.

Fig. 12B is a perspective view of one of the chamber elements of fig. 12A.

Fig. 12C is a bottom view of the cavity member of fig. 12B.

Fig. 13A and 13B are a perspective view at one cavity element and a perspective view at one feed plate, respectively, in the base station antenna according to one embodiment of the present invention.

Fig. 14A is a perspective view of the front of a base station antenna according to one embodiment of the present invention.

Fig. 14B is a perspective view of the back side of the base station antenna shown in fig. 14A.

Fig. 14C is a perspective view of the cavity element in the base station antenna shown in fig. 14A.

Fig. 14D is a bottom view of the cavity member shown in fig. 14C.

Fig. 14E is an enlarged view of a partial structure of the cavity member shown in fig. 14C.

Fig. 14F is a schematic view of the mounting of the radiating element to the cavity element shown in fig. 14C.

Fig. 14G is a perspective view of the column assembly in the base station antenna shown in fig. 14A.

Fig. 15A is a perspective view of a bracket in a base station antenna according to an embodiment of the present invention.

Fig. 15B and 15C are schematic views of the bracket of fig. 15A mated with a cavity member.

Fig. 16A is a perspective view of a bracket in a base station antenna according to an embodiment of the present invention.

Fig. 16B and 16C are schematic views of the bracket of fig. 16A mated with a cavity member.

Fig. 17A is a perspective view of the front of a base station antenna according to one embodiment of the present invention.

Fig. 17B is a perspective view of the back side of the base station antenna shown in fig. 17A.

Fig. 17C is an enlarged view of a partial structure of the base station antenna shown in fig. 17A.

Fig. 18 is a bottom view of a base station antenna according to one embodiment of the present invention.

Note that in the embodiments described below, the same reference numerals are used in common between different drawings to denote the same portions or portions having the same functions, and a repetitive description thereof will be omitted. In some cases, similar reference numbers and letters are used to denote similar items, and thus, once an item is defined in one figure, it need not be discussed further in subsequent figures.

For convenience of understanding, the positions, sizes, ranges, and the like of the respective structures shown in the drawings and the like do not sometimes indicate actual positions, sizes, ranges, and the like. Therefore, the present invention is not limited to the positions, dimensions, ranges, and the like disclosed in the drawings and the like.

Detailed Description

The present invention will now be described with reference to the accompanying drawings, which illustrate several embodiments of the invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, the embodiments described below are intended to provide a more complete disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art. It is also to be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

It is understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. All terms (including technical and scientific terms) used herein have the meaning commonly understood by one of ordinary skill in the art unless otherwise defined. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

When an element is referred to herein as being "on," attached to, "" connected to, "coupled to," or "contacting" another element, etc., it can be directly on, attached to, connected to, coupled to or contacting the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly attached to," directly connected to, "directly coupled to," or "directly contacting" another element, there are no intervening elements present. In this context, one feature being disposed "adjacent" another feature may refer to one feature having a portion that overlaps or is above or below the adjacent feature.

In this document, reference may be made to elements or nodes or features being "coupled" together. Unless expressly stated otherwise, "coupled" means that one element/node/feature may be mechanically, electrically, logically, or otherwise joined to another element/node/feature in a direct or indirect manner to allow for interaction, even though the two features may not be directly connected. That is, to "couple" is intended to include both direct and indirect joining of elements or other features, including connection with one or more intermediate elements.

In this document, spatial relationship terms such as "upper", "lower", "left", "right", "front", "back", "high", "low", and the like may describe one feature's relationship to another feature in the drawings. It will be understood that the terms "spatially relative" encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, features originally described as "below" other features may be described as "above" other features when the device in the figures is inverted. The device may also be otherwise oriented (rotated 90 degrees or at other orientations) and the relative spatial relationships may be interpreted accordingly.

Herein, the term "a or B" includes "a and B" and "a or B" rather than exclusively including only "a" or only "B" unless otherwise specifically stated.

In this document, the term "exemplary" means "serving as an example, instance, or illustration," and not as a "model" that is to be reproduced exactly. Any implementation exemplarily described herein is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the detailed description.

In this document, the term "substantially" is intended to encompass any minor variations due to design or manufacturing imperfections, tolerances of the devices or components, environmental influences and/or other factors. The term "substantially" also allows for differences from a perfect or ideal situation due to parasitics, noise, and other practical considerations that may exist in a practical implementation.

In addition, "first," "second," and like terms may also be used herein for reference purposes only, and thus are not intended to be limiting. For example, the terms "first," "second," and other such numerical terms referring to structures or elements do not imply a sequence or order unless clearly indicated by the context.

It will be further understood that the terms "comprises/comprising," "includes" and/or "including," when used herein, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, and/or components, and/or groups thereof.

Referring to fig. 2A and 2B, in this document, when referring to a "radiator", unless otherwise specified, reference is made to a radiator comprising one or more radiating arms, such as the dipole radiator 10 shown in fig. 2B comprising radiating arms 11 and 12. When referring to a "radiating element", unless otherwise specified, reference is made to a radiating element comprising a radiator 10 and a support/feed element 13 therefor. Reference herein to a "dual polarized radiating element" encompasses two radiating elements arranged orthogonally to each other, which may be, for example, a crossed dipole radiating element as shown in fig. 2A, comprising a radiator 10 and a radiator 20 (which comprises radiating arms 14 and 15) arranged in a cross.

Fig. 3A to 3E show a base station antenna 100 according to an embodiment of the invention. Fig. 3F is a bottom view of the frame 110 in the antenna 100. Fig. 4A is an enlarged bottom view at one cavity assembly of the frame 110. Fig. 4B is an enlarged bottom view at one cavity assembly.

A plurality of dual polarized radiating elements 121, 131, 141, 151, 161 are mounted to extend forward from the front surface of the reflector 113. The radiating elements include a low-band radiating element 121, mid-band radiating elements 131, 141, and high- band radiating elements 151, 161. The low band radiating elements 121 are mounted in two columns to form two linear arrays 120-1, 120-2 of low band radiating elements 121. The mid-band radiating elements 131 are mounted in two columns to form two linear arrays 130-1, 130-2 of mid-band radiating elements 131. The mid-band radiating elements 141 are mounted in two columns to form two linear arrays 140-1, 140-2 of mid-band radiating elements 141. Linear arrays 130-1 are adjacent to 140-1. Arrays 130-1 and 140-1 may extend substantially the entire length of antenna 100. Linear arrays 130-2 and 140-2 are adjacent to each other. Arrays 130-2 and 140-2 may also extend substantially the entire length of antenna 100. The high-band radiating elements 151 are mounted in four columns to form an array 150 of high-band radiating elements 151. The high-band radiating elements 161 are mounted in four columns to form an array 160 of high-band radiating elements 161. Array 150 is stacked above array 160. It should be noted that similar elements may be referred to herein individually by their full reference number (e.g., linear array 120-1) or collectively by the first portion of their reference number (e.g., linear array 120).

In other embodiments, the number of low, mid, and/or high band radiating elements and their linear arrays may be different from the number shown in fig. 3A through 3E. In the depicted embodiment, the array 150 of high-band radiating elements 151, and the array 160 of high-band radiating elements 161 are positioned between the linear arrays 120-1, 120-2 of low-band radiating elements 121, and each linear array 120 of low-band radiating elements 121 is positioned between a respective one of the arrays 150, 160 of high- band radiating elements 151, 161 and a respective one of the linear arrays 130, 140 of mid-band radiating elements 131, 141. The linear array 120 of low-band radiating elements 121 may or may not extend the entire length of the antenna 100, and the entirety of the arrays 150, 160 of high- band radiating elements 151, 161 may or may not extend the entire length of the antenna 100.

Each radiating element 121, 131, 141, 151, 161 may be mounted on a feed board printed circuit board 51. The feed board printed circuit board 51 is also referred to herein as a "feed board 51". Feed plate 51 couples RF signals to and from individual radiating elements 121, 131, 141, 151, 161. One or more radiating elements 121, 131, 141, 151, 161 may be mounted on each feed plate 51.

The frame 110 includes a reflector 113 and a plurality of cavity assemblies 111 extending rearward from the reflector 113. The cavity assembly 111 extends perpendicular to the reflector 113. Each cavity assembly 111 provides a chamber 24 for housing a conductor strip assembly 310. Each cavity assembly 111 may extend substantially the entire length of the reflector 113 in the longitudinal direction. The frame 110 may be constructed as a unitary piece of metal (e.g., aluminum) and may be integrally formed through a pultrusion process to facilitate the reflector 113 to be commonly grounded with the cavity assembly 111 such that the reflector 113 may provide a ground plane for the radiating elements 121, 131, 141, 151, 161. The frame 110 is constructed as a single piece such that the reflector 113 may be grounded via the cavity assembly 111 without soldering, which may significantly improve Passive Intermodulation (PIM) performance of the base station antenna.

The structure of each chamber body assembly 111 is shown in fig. 4A and 4B. The chamber assembly comprises a planar element 21. Planar element 21 may be implemented as part of reflector 113 in the embodiment depicted in fig. 3A to 3F, and as part of reflector 211 in the embodiment depicted in fig. 5A to 5D, and thus planar element 21 is also referred to herein as "reflector 21". Planar elements 22-1 and 22-2, which are parallel to each other (hereinafter referred to as "ground planes" because the planar elements are grounded), extend from the planar element 21 substantially perpendicular to the rear side of the planar element 21 to define the side walls of the cavity 24-1 for housing the conductor strip assembly 310-1. A second pair of mutually parallel ground plates 22-3 and 22-4 extend from the planar element 21 substantially perpendicular to the rear side of the planar element 21 to define side walls of the cavity 24-2 for receiving the conductor strip assembly 310-2. Conductor strip assembly 310-1 is used to feed radiators of a first polarization of the linear array of dual-polarized radiating elements and conductor strip assembly 310-2 is used to feed radiators of a second polarization of the linear array of dual-polarized radiating elements. The ground plate 22 may be arranged such that the chambers 24-1 and 24-2 are closely adjacent and the ground plates 22-2 and 22-4 may be the same planar element. The chamber body assembly 111 further includes planar members 23-1 and 23-2 (hereinafter referred to as "partition plates" since the planar members partition the chamber 24 from the outside) located at the rear side of the planar member 21 substantially in parallel with the planar member 21. The isolation plate 23-1 is connected to the rear edges of the ground plates 22-1 and 22-2 so that the chamber 24-1 is closed. The separator plate 23-2 is connected to the rear edges of the ground plates 22-3 and 22-4 so that the chamber 24-2 is also closed. Since the ground plates 22-2 and 22-4 are implemented as a single planar element, the isolation plates 23-1 and 23-2 can be connected to each other at the ground plates 22-2, 22-4. The planar element 21, the ground plate 22, the isolation plate 23 are constructed in one piece, for example integrally formed on the basis of a metal material using a pultrusion process, so that the planar element 21, the ground plate 22, the isolation plate 23 are commonly grounded therebetween without welding.

Fig. 6A is a schematic diagram of a conductor strip component 310 of a base station antenna according to an embodiment of the invention. Fig. 6B is a perspective view of the contents assembly 300 placed in a chamber in a base station antenna according to an embodiment of the present invention. The conductor strip assembly 310 includes a conductor strip 313. The conductor strip 313 has an input portion 311 and a plurality of output portions 312. It should be noted that the reference to the component 311 as an "input" and the reference to the component 312 as an "output" describes the situation when the base station antenna is transmitting RF signals. It should be understood that when the base station antenna receives an RF signal, component 312 will operate as an "input" and component 311 will operate as an "output" due to the reversal of the direction of travel of the RF signal. The input 311 may be electrically connected to the inner conductor of a coaxial transmission line (as will be described below with reference to fig. 9A-9E), and the output 312 may be electrically connected to a radiator in the corresponding radiating element (e.g., via a transmission line on a feed board).

The conductor strip 313 in the conductor strip assembly 310 extends between adjacent ground plates 22 such that the conductor strip 313 constitutes a stripline transmission line with the ground plates 22 on either side thereof to feed the radiator. Since the conductor strip 313 is disposed inside the cavity assembly 111, the energy radiated from the RF signal transmitted on the conductor strip 313 to the outside of the cavity assembly 111 can be reduced, and the interference from the radiation outside the cavity assembly 111 can be reduced. In the conductor strip assembly 310 shown in fig. 6A, the conductor strip 313 is a conductor line printed on the dielectric substrate 314. It should be appreciated that in other embodiments, the conductor strip 313 may be implemented by sheet metal. In these embodiments, the conductor strip assembly 310 may not include the dielectric substrate 314, but only the conductor strip 313. In the case where the conductor strip 313 is formed by conductor lines printed on the dielectric substrate 314, in order to reduce losses caused by the dielectric substrate 314 (for example when the dielectric substrate 314 is thick), the conductor strip 313 may comprise first and second lines printed on opposite first and second surfaces of the dielectric substrate 314 respectively (for example, visible in fig. 6A as the first surface of the dielectric substrate 314 and the first line printed on the first surface), the projection of the first line on the dielectric substrate 314 being completely coincident with the projection of the second line on the dielectric substrate, i.e. the first and second lines are symmetrical about the plane in which the dielectric substrate 314 lies. The first and second lines are galvanically connected by conductive vias 317 (e.g., Plated Through Holes (PTHs)) through the dielectric substrate 314.

The conductor strip 313 provides from the input 311 to the plurality of outputs 312 power dividers (power combiners in the receive path of the antenna) for dividing the RF signal input at the input 311 into a plurality of sub-components output through the respective outputs 312. Further, in the content assembly 300 shown in fig. 6B, a moving element 32 movable relative to the conductor strip 313 is further included. By the movement of the moving element 32 relative to the conductor strip 313, the relative phase shift applied to the respective sub-components of the RF signal output by the respective output portions 312 of the conductor strip 313 can be adjusted. In the depicted embodiment, the moving element 32 is a dielectric element that is slidable relative to the conductor strip 313, and the relative phase shift is adjusted by changing the footprint or length of the moving element 32 on different portions of the conductor strip 313, such that the inclusion component 300 forms a sliding dielectric phase shifter integrated with the power divider. It should be understood, however, that in other embodiments, the moving element 32 may be a slider rotatable relative to the conductor strip 313, a trombone transmission line slidable relative to the conductor strip 313, or metal slidable relative to the conductor strip 313, such that the containment assembly 300 is formed as a rotating slider arm phase shifter, a trombone phase shifter, a sliding metal phase shifter, or the like, respectively, integrated with the power divider.

The containment assembly 300 also includes a retention member 33 made of a dielectric material positioned between the conductor strip assembly 310 and the ground plates 22 to retain the conductor strip 313 substantially intermediate the adjacent two ground plates 22, which may be useful where the conductor strip 313 is thin and/or soft. In a stripline transmission line, a higher dielectric constant of the dielectric between the conductor strip and the ground plate results in a lower speed of the RF signal transmitted on the conductor strip, so the holder 33 may be designed to cover only a small portion of the conductor strip 313, so that the dielectric between the conductor strip 313 and the ground plate 22 is mostly air (which has a lower dielectric constant). As shown in fig. 6B, the holder 33 is configured with an opening 331 to reduce the area covered by the holder 33 with the conductor strip 313. In one embodiment, the retention element 33 covers less than 10% of the area of the conductor strip 313, for example. Furthermore, the holder 33 may also be positioned only between the dielectric substrate 314 and the ground plate 22, such that the holder 33 does not substantially cover the conductor strip 313. Furthermore, in one embodiment, as shown in fig. 9F and 13A, the surface of the holder 33 near the conductor strip assembly 310 and/or the surface near the ground plate 22 may have an indentation 332 to cause the holder 33 to have a reduced thickness (the thickness of the holder 33 refers to the dimension of the holder 33 in the direction from the conductor strip assembly 310 to the respective ground plate 22), so that the dielectric constant of the dielectric between the conductor strip 313 and the respective ground plate 22 may be reduced. Since the moving element 32 covering the conductor strip 313 and moving relative to the conductor strip 313 is further provided between the conductor strip 313 and the holder 33, a yielding structure (not shown) is provided at a corresponding position of the holder 33 to facilitate placement and movement of the moving element 32.

In the embodiment depicted in fig. 3A-3F, the frame 110 includes chamber body assemblies 111-1 through 111-8. Each cavity assembly 111 houses two of the above-described containment assemblies 300 therein, one for feeding a first polarization of the linear array of dual-polarized radiating elements and the other for feeding a second polarization of the linear array of dual-polarized radiating elements. The cavity assembly 111-1 is used for the linear arrays 130-1 and 140-1, with the conductor strip assembly feeding the linear array 130-1 disposed in the upper portion of the cavity assembly 111-1 and the conductor strip assembly feeding the linear array 140-1 disposed in the lower portion of the cavity assembly 111-1. Cavity assemblies 111-2 and 111-7 are used for linear arrays 120-1 and 120-2, respectively, and corresponding conductor strip assemblies feeding linear arrays 120-1 and 120-2 are disposed within cavity assemblies 111-2 and 111-7, respectively. The cavity assemblies 111-3 to 111-6 are used for the arrays 150 and 160, with the respective conductor strip assemblies feeding each linear array in the array 150 being disposed in the upper portion of the respective cavity assemblies 111-3 to 111-6, respectively, and the respective conductor strip assemblies feeding each linear array in the array 160 being disposed in the lower portion of the respective cavity assemblies 111-3 to 111-6, respectively. The cavity assembly 111-8 is used for the linear arrays 130-2 and 140-2, with the conductor strip assembly feeding the linear array 130-2 being disposed in the upper portion of the cavity assembly 111-8 and the conductor strip assembly feeding the linear array 140-2 being disposed in the lower portion of the cavity assembly 111-8. It can be seen that the dimensions (in particular the lateral width) of the cavity assembly 111 for the linear array of radiating elements of different frequency bands are the same, i.e. the distance between the two ground plates 22 of each cavity 24 is the same, which facilitates the manufacture of the frame 110 and the cavity elements 212 to be described below. The thickness of the stripline transmission line feeding the linear array of radiating elements of different frequency bands may be the same, but its impedance characteristics may be adjusted by varying the line width of the conductor strip 313 so as to be suitable for transmitting RF signals in the frequency band in which the radiating elements fed by the stripline transmission line operate.

As shown in fig. 3C and 3F, the isolation plates 23 of the cavity assemblies 111-1 and 111-2 located at both sides of the frame 110 may have extensions 112-1 and 112-2 extending beyond the ground plate 22 toward both sides of the frame 110, respectively, to be connected to corresponding mounting brackets 171-1 and 171-2 for mounting the base station antenna.

How the contents assembly 300 is loaded into the frame 110 will be described with reference to fig. 8A to 8C. The opening of the chamber 24 for loading the content assembly 300 in the frame 110 in the embodiment depicted in fig. 3A to 3F is directed toward the bottom and the top of the frame 110, and thus, the content assembly 300 needs to be loaded into the chamber 24 from the bottom or the top of the frame 110, as shown by the arrow direction in fig. 8A. For example, the content assembly 300 for feeding the linear array 120-1 may be loaded into the chamber 24 from the bottom or top of the cavity assembly 111-2, the content assembly 300 for feeding the linear array 130-1 may be loaded from the top of the cavity assembly 111-1, and the content assembly 300 for feeding the linear array 140-1 may be loaded from the bottom of the cavity assembly 111-1. A side view of the contents assembly 300 after loading into the chamber 24 is shown in fig. 8B. Since the output portion 312 needs to extend from the cavity block 111 to the front of the planar member 21 (i.e., reflector) after the installation is completed in order to connect the circuit components located at the front side of the planar member 21, the output portion 312 of the content block 300 is aligned with the corresponding opening 215 of the planar member 21 so as to protrude after the content block 300 is installed in place. For example, in FIG. 8B, output 312-1 is aligned with opening 215-1 and output 312-2 is aligned with opening 215-2. Further, a support member 42 is provided to jack the content assembly 300 forward (upward in the direction shown in fig. 8C). As shown in fig. 8C, the partition plate 23 is provided with an opening 231, and the supporting member 42 having the clip 421 can extend into the cavity 24 from the outside of the cavity assembly 111 through the opening 231 and is fixedly mounted to the partition plate 23 by the clip 421, so that the supporting member 42 can apply a force to the content assembly 300 forward to facilitate the output portion 312 to extend out of the cavity assembly 111 from the opening 215 forward.

The implementation of the movement of the moving element 32 in the contents assembly 300 as shown in fig. 6B is described below in conjunction with fig. 6C. As shown in the figure, the outer surface of the isolation plate 23 is provided with a support 81 for supporting a slide rail 82, and a slide block 83 which can slide based on the slide rail is arranged on the slide rail 82. The slider 83 is fixedly connected to the moving element 32 to slide the moving element 32. As shown in fig. 6B, when the conductor strip 313 extends in a long length along the length direction (i.e., "longitudinal direction") of the base station antenna, it may include a plurality of moving elements 32, such as moving elements 32-1 and 32-2, which are mechanically connected to each other. The slider 83 only needs to be fixedly connected with one of the moving elements 32 to drive all the moving elements 32 to slide synchronously. Further, in the case where the first and second lines symmetrical with respect to the plane in which the dielectric substrate 314 is located are printed on the first and second surfaces of the dielectric substrate 314 as described above, it is necessary to arrange the moving elements 32 for both the first and second lines, and the moving elements 32 for the first and second lines are also symmetrical with respect to the plane in which the dielectric substrate 314 is located. The moving element 32 for the first line and the moving element 32 for the second line may be mechanically connected to each other via a through hole 315 opened on a dielectric substrate 314 so as to synchronously slide by being driven by a slider 83.

Fig. 12A is a perspective view of at least a portion of a frame 410 in a base station antenna according to another embodiment of the present invention. Fig. 12B and 12C show the cavity element 411 in the frame 410. As shown, the chamber body member 411 has substantially the same structure as the chamber body assembly 111, including a planar member 21 and planar members 22, 23 forming a chamber body. The frame 410 includes a plurality of laterally adjacent cavity elements 411, each cavity element 411 may be used for an array of cross-polarized radiating elements. In the depicted embodiment, adjacent cavity elements 411 are connected to each other (including electrically and mechanically) by a friction stir welding process, i.e., the planar element 21 of each cavity element 411 is connected to the planar element 21 of the adjacent cavity element 411 along the length thereof by a friction stir welding process, such that the plurality of planar elements 21 of the plurality of cavity elements 411 are connected to form the reflector 413. Friction stir welded reflector 413 has similar performance to an integrally formed reflector (e.g., reflector 113). Thus, in this embodiment, the entire frame 410 need not be integrally formed to manufacture the frame 410, and only the individual cavity elements 411 need to be integrally formed, which reduces the requirements for the integrally forming process, contributing to cost reduction and increased success rate. In addition, such a frame 410 is more flexible and can easily accommodate antenna platforms having different numbers of linear arrays.

Fig. 5A is a bottom view of a base station antenna 200 according to one embodiment of the present invention. Fig. 5B is a perspective view of a portion of the cavity element 212 in the antenna 200. Fig. 5C is a bottom view of the cavity member 212. Fig. 5D is an enlarged view of the antenna 200 at one of the cavity elements 212. The antenna 200 includes a reflector 211, a plurality of dual polarized radiation elements 221, 222, 223 mounted to extend forward from a front surface of the reflector 211, and a plurality of cavity elements 212 located at a rear surface of the reflector 211. The cavity member 212 provides a cavity 24 for housing the conductor strip assembly 310. Each cavity element 212 extends substantially the entire length of the reflector 211 for accommodating a conductor strip assembly feeding the linear array of radiating elements. The cavity member 212 includes ground plates 22-1 and 22-2 extending substantially perpendicular to the reflector 211 and parallel to each other, defining a chamber 24-1 for housing a conductor ribbon assembly 310-1. Respective front edges of the ground plates 22-1 and 22-2 extend laterally away from the chamber 24-1 with coupling portions 25-1 and 25-2, respectively, substantially parallel to the reflector 211, the coupling portions 25-1 and 25-2 each being electrically coupled (e.g., capacitively coupled) to the reflector 211 (also identified as planar element 21 in the figures) via the dielectric layer 27, such that the reflector 211 is commonly grounded with the ground plates 22-1 and 22-2 without solder grounding, thereby improving Passive Intermodulation (PIM) performance of the base station antenna. Similarly, the cavity member 212 further includes ground plates 22-3 and 22-4 extending substantially perpendicular to the reflector 211 and parallel to each other, defining a chamber 24-2 for receiving the conductor ribbon assembly 310-2. Respective front portions of ground plates 22-3 and 22-4 extend laterally away from chamber 24-2 to coupling portions 25-3 and 25-4, respectively, substantially parallel to reflector 211, coupling portions 25-3 and 25-4 being electrically coupled to reflector 211, respectively, via dielectric layer 27, which may be, for example, a polypropylene PP material. Wherein the coupling parts 25-2 and 25-4 between the cavities 24-1 and 24-2 are constructed as one and the same coupling part.

To ensure that the mechanical connection between the chamber body 212 and the reflector 211 is stable, it may be fixed by screws or clamps. In one specific example, the coupling portions 25-1 and 25-3 are fixedly connected to the reflector 211 by screws (e.g., screws 55 in fig. 13A and 13B), and the coupling portion 25-2(25-4) is fixedly connected to the reflector 211 by a plastic clamp. The thickness of the dielectric layer 27 should not be too thick in order to ensure the effectiveness of the ground connection between the cavity member 212 and the reflector 211. In one particular example, dielectric layer 27 may be 0.1mm thick. It is also necessary to ensure that the coupling area between the cavity member 212 and the reflector 211 is sufficient to achieve that the cavity member 212 and the reflector 211 can be effectively grounded together. In one particular example, the lateral width of each of the coupling portions 25-1 and 25-2 (i.e., the length over which the edge portions of the ground plate 22 extend laterally) may be 12 mm. Further, to secure the grounding performance of the ground plates 22-2 and 22-4 positioned between the two cavities 24, the coupling portion 25-2(25-4) may laterally extend not less than half of the length of either of the coupling portions 25-1 and 25-2, and in a specific example, the coupling portion 25-2(25-4) may have a lateral width of 8 mm.

The antenna 200 further comprises a feeding board 51 at the front surface of the reflector 211 for feeding the radiating elements 221, 222, 223. The front surface of each feed plate 51 is printed with conductor traces configured to feed the individual radiating elements (for electrical connection with the conductor strip 313 as described below), and the rear surface of each feed plate 51 is printed with a conductor plane (also referred to herein as a "ground plane") for grounding. The ground plane is electrically coupled to the reflector 211 so as to be commonly grounded with the reflector 211. In this embodiment, the cavity member 212 and the reflector 211 are commonly grounded in an electrically coupled manner, and the ground plane of the feeding board 51 and the reflector 211 are also commonly grounded in an electrically coupled manner. Therefore, to further ensure the continuity of the ground connection of the cavity element 212, the reflector 211, and the ground plane of the feeding board 51 (i.e., to make the ground potentials of the three the same to truly realize a common ground), in one embodiment, as shown in fig. 13A and 13B, the antenna further includes a pin 54. Each pin 54 galvanically connects the cavity member 212 to the ground plane of the feed plate 51 to ensure continuity of ground between the cavity member 212, the reflector 21 and the ground plane of the feed plate 51.

In the embodiment depicted in fig. 13A and 13B, the coupling portion 25-2(25-4), the reflector 21, and the feeding board 51 include first to third openings corresponding in position, respectively. The feed plate 51 is provided with a conductive through hole (PTH)53 through its dielectric substrate that electrically connects the conductor trace on its upper surface to the ground plane on its lower surface. The front surface of each feed board 51 is printed with a conductor trace 56, the conductor trace 56 including a land surrounding the third opening, and a line portion electrically connecting the land to the PTH 53. The pins 54 pass through the first to third openings in this order. At the lower section of the pin 54, the pin 54 is galvanically connected to the coupling portion 25-2(25-4) through the first opening by the clinching process so as to be galvanically connected to the cavity member 212. In the upper section of the pin 54, the pin 54 is galvanically connected to a pad on the upper surface of the feeding board 51 by means of a soldering process after passing through the third opening, thereby further galvanically connecting to the ground plane of the feeding board 51 via the conductor trace 56 and the PTH 53. In the middle of the pin 54, the pin 54 passes through the second opening but is not in galvanic connection with the reflector 21. In this way, on the basis of the electrical coupling connection between the cavity element 212 and the reflector 211 and the electrical coupling connection between the ground plane of the feeding board 51 and the reflector 211, the cavity element 212 and the ground plane of the feeding board 51 are in current connection, so that the continuity of the ground among the cavity element 212, the reflector 21 and the ground plane of the feeding board 51 is ensured.

Similar to the embodiment depicted in fig. 3A to 3F, in the embodiment depicted in fig. 5A to 5D the conductor strip 313 in the conductor strip assembly 310 extends in a plane between adjacent ground plates 22, such that the conductor strip 313 and the ground plates 22 on both sides thereof constitute a stripline transmission line for feeding the radiator. Since the cavity member 212 has an opening facing upward (toward the front side of the base station antenna), the contents assembly 300 can be easily loaded into the cavity member 212 as shown by the arrow direction in fig. 7A. The bottom view of the contents assembly 300 after being loaded into the chamber member 212 is shown in fig. 7B, and the output portion 312 may protrude forward of the planar member 21 (i.e., reflector), as shown in fig. 5D. In this embodiment, therefore, the support member 42 in the previous embodiment is not required, so that the depth of the chamber body member 212 (the distance from the plane member 22 to the partition plate 23) can be smaller than the depth of the chamber body assembly 111.

The transition between the strip line transmission line formed by the conductor strip 313 and the ground plate 22 on both sides thereof and the coaxial transmission line 70 that transmits RF signals between the radio equipment and the base station antenna is described below with reference to fig. 9A to 9H. The coaxial transmission line 70 includes an inner conductor 72 and an outer conductor 71, the inner conductor 72 being galvanically connected to the input 311 of the conductor strip 313 via a transition 620, the outer conductor 71 being electrically coupled to the isolator plate 23 via a transition 610. Transition piece 620 includes a joint 621 configured as a bend (e.g., a cambered surface) to facilitate welding to inner conductor 72 in a manner that at least partially surrounds inner conductor 72. The curved joint 621 can have a large joint area with the inner conductor 72, and can be configured as a container for accommodating solder and can hold the inner conductor 72 at the same time. Transition piece 620 also includes an engagement portion 622 configured to be flat to facilitate connection (e.g., welding) to input 311 in planar contact. The joint 622 may extend into the cavity 24 through an opening in the isolation plate 23 and/or the ground plate 22 to be galvanically connected (e.g. in the embodiment depicted in fig. 9A and 9B in which the conductor strip 313 is a conductor track printed on the dielectric substrate 314) or soldered and screwed (e.g. in the embodiment depicted in fig. 9C to 9E in which the conductor strip 313 is implemented in sheet metal) to the input 311, for example by soldering. It should be understood that the engagement portion 621 and the engagement portion 622 of the transition piece 620 are configured as a unitary piece or electrical connection.

The transition piece 610 includes a joint portion 612 configured to be bent so as to be welded to the outer conductor 71 in a manner of at least partially surrounding the outer conductor 71, and a joint portion 611 configured to be flat so as to be electrically connected to the separator plate 23 in an electrically coupled manner so as to be grounded to the ground plate 22 configured as a single piece with the separator plate 23. In the embodiment shown in fig. 9A to 9D, the coaxial transmission line 70 is fixed to the outside of the isolation plate 23 by the fixing member 41, and the transition piece 610 is configured in a substantially "L" shape. One leg of the "L" is constituted as a joint portion 612 so as to engage and support the outer conductor 71 above, and the other leg is constituted as a joint portion 611 so as to be coupled to the partition plate 23 below. In the embodiment shown in fig. 9E, the coaxial transmission line 70 is fixed to the outside of the ground plate 22 by the fixing member 41, and the transition member 610 is generally configured in a zigzag shape matching the shape of the bottom of the cavity assembly 111 or the cavity element 212. A joint 611 is constructed in the middle of the transition piece 610 and positioned at the outer surface of the separation plate 23, and two joints 612 are constructed at the ends of the two legs of the "little" respectively, so as to be connected to the outer conductors 71 of the coaxial cables 70 respectively serving as two polarized signals of a linear array of dual-polarized radiating elements. It should be understood that interface 611 and interface 612 of transition piece 610 are configured as a unitary piece or electrical connection.

In one embodiment, the transition between the stripline transmission line and the coaxial transmission line 70 is accomplished through a transition element 630 and a transition printed circuit board 64 as shown in fig. 9F to 9H. Unlike the embodiment depicted in fig. 9A to 9E, in which the input 311 of the conductor strip 313 is located at the edge of the stripline transmission line remote from the reflector 21, for example near the isolation plate 23, in this embodiment the input 311 of the conductor strip 313 is located at the edge of the stripline transmission line close to the reflector 21. The input 311 extends through the reflector 21 and the transition printed circuit board 64 forward of the reflector 21. The coaxial transmission line 70 is positioned on the rear side of the reflector 21 in parallel with the reflector 21 and near the input portion 311. A transition printed circuit board 64 is placed on the front surface of the reflector 21. The rear surface of the transition printed circuit board 64 is provided with a ground plane which is electrically coupled to the reflector 21.

As shown in fig. 9H, the transition printed circuit board 64 for one cavity element 212 or one cavity assembly 111 is formed with two slots 645-1 and 645-2 through the plate 64 for the input portions 311-1 and 311-2 of the conductor strip assemblies 310-1 and 310-2 to pass through to project forward from the plate 64. The front surface of the transition printed circuit board 64 further includes annular grooves 641, and four PTHs 642 are disposed in each groove 641 and uniformly distributed along the circumferential direction, and the PTHs 642 are conductively connected to the ground plane of the rear surface of the transition printed circuit board 64. A through hole 643 is provided at a substantially center of the annular groove 641, and a conductor trace is printed between the through hole 643 and the annular groove 641 to form a pad 644.

As shown in fig. 9G, the transition element 630 for one coaxial transmission line 70 includes a joint portion 631 having a curved surface for engaging the outer conductor 71 of the coaxial transmission line 70. As shown in fig. 9F, the outer conductor 71 projects from one end of the joint portion 631 into the space surrounded by the arc surface of the joint portion 631, so that the joint portion 631 is welded to the outer conductor 71 in such a manner as to at least partially surround the outer conductor 71. The arc has an opening 638 for feeding flux material during welding. At least a portion of the other end of the engaging portion 631 is connected (including mechanical connection and electrical connection) to the cylindrical portion 632, and four protruding portions 633 extend from the end of the cylindrical portion 632. The engaging portion 631 is substantially at right angles to the extending direction of the cylindrical portion 632 to convert the direction of electrical connection, for example, from a direction substantially parallel to the reflector 21 to a direction substantially perpendicular to the reflector 21. The tabs 633 pass through respective PTHs 642 on the board 64 and are electrically connected (e.g., soldered) to the PTHs 642 for galvanic connection to the ground plane of the transition printed circuit board 64. Since the ground plane of the plate 64 is electrically coupled to the reflector 21, the reflector 21 is coupled to ground with the ground plate 22 or is constructed as a unitary piece, the transition element 630 may enable the outer conductor 71 to be electrically connected to the reflector 21 and the ground plate 22 such that the reflector 21 and the ground plate 22 are commonly grounded.

Transition element 630 also includes a transition piece 635 for transition connection of inner conductor 72. Transition piece 635 includes engagement portions 636 and 637 at its two ends, respectively. One end of the joint portion 631 has an opening 639 so that the inner conductor 72 protrudes from the opening 639 (the inner conductor 72 is longer than the outer conductor 71), so that the joint portion 636 having an arc surface is welded to the inner conductor 72 in such a manner as to at least partially surround the inner conductor 72. Bonding portion 637 passes through a through hole 643 in board 64 and projects up out of board 64, and is soldered to pad 644. The pads 644 may be galvanically connected to the input 311, which also extends upwards out of the board 64, by conductor tracks printed on the upper surface of the board 64. In this manner, the transition element 63 may also galvanically connect the inner conductor 72 of the coaxial transmission line 70 to the input 311 of the conductor strip 313.

The transition between the conductor strip 313 and a feed plate 51 (realized by a printed circuit board) for feeding the radiating element 52 on the front side of the reflector 21 is described below with reference to fig. 10A to 10D. In the embodiment depicted in fig. 10A and 10B, the output 312 of the conductor strip 313 may protrude through respective openings on the reflector 21 and the feed plate 51 to the front side of the feed plate 51 (hence also referred to as a protrusion), so that the output 312 is soldered directly to the conductor tracks on the feed plate 51. In the embodiment depicted in fig. 10C and 10D, output 312 may not protrude to the front side of reflector 21 or feed board 51 (in the orientation shown above feed board 51), and PINs (also referred to as "PIN PINs") 63 electrically connect output 312 to conductor traces on feed board 51. For example, a first end of each pin 63 extends between the ground plates 22 to be soldered to the corresponding output 312, and a second end of the pin 63 extends to the front side of the dielectric substrate of the feeding plate 51 to be soldered to the conductor trace.

The front surface of the feeding board 51 is printed with a conductor trace and the rear surface is provided with a ground plane, so that the conductor trace on the feeding board 51 is formed as a microstrip line transmission line feeding the radiating element. Since the reflector 21 and the ground plate 22 are commonly grounded, the ground plane of the feeding plate 51 only needs to be grounded to the reflector 21, and does not need to be grounded to the ground plate 22 of the stripline transmission line. A connection (typically soldering) between the ground plane of the microstrip transmission line and the ground plate of the stripline transmission line can be omitted. In one embodiment, the rear surface of the feed board 51 is printed with a conductor plane that is capacitively coupled to the reflector 21 (e.g., the feed board 51 is mounted to the front surface of the reflector 21 such that the conductor plane printed on the rear surface thereof is electrically coupled to the reflector 21 via solder resist ink coated on the conductor plane) so as to be commonly grounded with the reflector 21. In one embodiment, the back surface of the feed board 51 is free of printed conductors, but the back surface of the dielectric substrate of the feed board 51 is proximate to the front surface of the reflector 21, such that the reflector 21 acts as a ground plane for the conductor traces of the feed board 51.

In the example shown in fig. 10A, a pair of outputs 312 (for two polarized radiators, respectively) and one feed board 51 are used to feed a single radiating element 52. In this case, the conductor strip 313 is configured to have the same number of output portions 312 as the number of radiating elements in the linear array it feeds. For example, in the embodiment depicted in fig. 3A through 3F, the number of output portions 312 of the conductor strip 313 disposed in one chamber 24 of the cavity assembly 111-3 may be equal to the number of radiating elements 161 in a corresponding one of the linear arrays 160. In the example shown in fig. 10B, a pair of output sections 312 and one feeding board 51 are used to feed two radiating elements 52. In this case, the conductor strip 313 may be configured to have a number of output portions 312 equal to half the number of radiating elements in the linear array it feeds. An antenna beam obtained using the feeding scheme shown in fig. 10A may have better side lobe performance than an antenna beam obtained using the feeding scheme shown in fig. 10B.

The depth of the cavity assembly 111 or the cavity member 212 may be limited by the size of the antenna. In some cases, for example when the conductor strip 313 is implemented as sheet metal, the depth of the cavity assembly 111 or the cavity element 212 under antenna size limitations may not be sufficient to accommodate the conductor strip 313. In such a case, two cavities 24 (even more if desired) placed laterally side by side may be provided for a linear array of polarized radiators, and correspondingly the conductor strip 313 may also be divided into two portions and placed in the two cavities 24, respectively, i.e. the stripline transmission line used to feed the linear array of polarized radiators is divided into two laterally side by side sections, thereby reducing the depth of the cavity assembly 111 or cavity element 212. Described below in conjunction with 11A to 11C.

In the embodiment depicted in fig. 11A, the first section of the stripline transmission line used to feed the linear array of one polarized radiator of the radiating element 52 comprises the portion 31-1 of the conductor strip 313 that is farther from the electrical distance of the radiator, and the second section of the stripline transmission line comprises the portion 31-2 of the conductor strip 313 that is closer to the electrical distance of the radiator. The portions 31-1 and 31-2 are laterally adjacent at least partially overlapping such that both the first and second sections of the stripline transmission line extend rearwardly from the reflector 21. In the illustrated embodiment, the portion 31-1 of the conductor strip 313 is a 1-5 power divider from the input 311 to the divider 318, and the portion 31-2 is a 1-2 power divider from each divider 319 to the corresponding output 312. The respective segments 318 and 319 are electrically coupled to each other by a connector 316.

As shown in fig. 11C, outputs 312-1 and 312-2 are used to feed radiators of the first and second polarizations of radiating element 52, respectively. For the conductor strip 313-1 with the output 312-1, the ground plates 26-1 and 26-2 extending backwards from the planar element 21 form a first chamber for housing the portion 31-2, the ground plates 26-2 and 26-3 form a second chamber for housing the portion 31-1, the bottom of both chambers being enclosed by the separation plate 23-1. The partition plate 23-1 is provided with a hole 232-1 through which the connection piece 316-1 passes in order to connect the corresponding partitions in the portions 31-1 and 31-2 located in the first and second chambers, respectively. For the conductor strip 313-2 with the output 312-2, the ground plates 26-4 and 26-5 form a first chamber for accommodating the portion 31-2, the ground plates 26-5 and 26-6 form a second chamber for accommodating the portion 31-1, and the bottoms of both chambers are substantially separated from the outside by the separation plate 23-2. The partition plate 23-2 is provided with a hole 232-2 through which the connection piece 316-2 passes in order to connect the corresponding partitions in the parts 31-1 and 31-2 located in the first and second chambers, respectively.

Fig. 14A to 14F show a base station antenna 500 according to an embodiment of the present invention. The base station antenna 500 includes a plurality of cavity elements 510-1 and 510-2 extending in the longitudinal direction, a plurality of metal plates 550-1 to 550-3, and a plurality of linear arrays 520-1 and 520-2 arranged by the radiation elements 521 in the longitudinal direction. As shown in fig. 14C and 14D, the chamber body member 510 has a structure similar to that of the chamber body member 411 shown in fig. 12B. The cavity element 510 comprises a planar element 21, which may be used as a reflector for reflecting electromagnetic radiation emitted by the radiation element 521. The respective cavity elements 510-1 and 510-2 are positioned substantially coplanar with the substantially planar forward surfaces of each other such that each linear array 520-1 and 520-2 has the same azimuthal boresight pointing direction. The cavity element 510 further comprises a mutually parallel planar element 22 extending substantially perpendicularly from the planar element 21 to the rear side of the planar element 21 and a planar element 23 located at the rear side of the planar element 21 substantially parallel to the planar element 21, the planar elements 21 to 23 together defining a cavity 24 for accommodating a conductor strip (not shown) feeding the linear array 520. The manner in which the conductor strip is loaded into the cavity 24 is similar to the manner in which the containment assembly 300 is loaded into the frame 110 as described with reference to fig. 8A through 8C and will not be described again. Each cavity element 510 extends substantially the entire length of the base station antenna 500 in the longitudinal direction. The planar elements 21 to 23 are constructed as one piece, for example, integrally formed using a pultrusion process based on a metal material, so that the planar elements 21 to 23 are commonly grounded therebetween without welding.

The planar element 21 of the cavity element 510, which serves as a reflector, may have a narrower width than the cavity element 411 shown in fig. 12B, for example, may be slightly wider than the feeding board 51 at the front surface of the reflector for feeding the radiating element 521. Thus, the cavity elements 510 of the base station antenna 500 may be separated from each other, as compared to the frame 410 shown in fig. 12A. In order to ensure lateral continuity and lateral width of the reflector for the entire base station antenna 500, and in order to commonly ground the reflectors (i.e., the respective planar elements 21) provided by the respective cavity elements 510-1 and 510-2, the base station antenna 500 further includes a metal plate 550. The first side portion of metal plate 550-1 and the side portion of planar element 21 of cavity element 510-1 are overlapped back and forth (and understandably, a thin layer of dielectric material is filled therebetween) to form a first capacitive coupling connection (see fig. 17C), and the second side portion of metal plate 550-1 and the side portion of planar element 21 of cavity element 510-2 are overlapped back and forth to form a second capacitive coupling connection, such that the reflectors provided by each of cavity elements 510-1 and 510-2 are commonly grounded. The metal plates 550-2 and 550-3 are symmetrically disposed at both side portions of the base station antenna 500 in the lateral direction. Each of the metal plates 550-2 and 550-3 has a first portion extending parallel to the substantially flat forward surface of the reflector provided by each of the cavity elements 510-1 and 510-2, and a second portion extending from the first portion toward the front of the base station antenna 500. The edges of the first portions of the metal plates 550-2 and 550-3 and the edges of the planar element 21 of the respective cavity element 510 overlap back and forth to form a capacitive coupling connection such that the metal plates 550-2 and 550-3 and the reflector provided by the respective cavity element 510 are commonly grounded. The second portions of the metal plates 550-2 and 550-3 are used to adjust the radiation pattern of the linear array 520.

The two chambers 24-1 and 24-2 provided by the cavity element 510 have a greater lateral separation distance than the cavity element 411 shown in figure 12B so that each radiating element 521 in the linear array 520 is mounted to the planar element 21 of the corresponding cavity element 510. As shown in fig. 14E and 14F, the planar element 21 is provided with openings 215-1 and 215-2 at positions corresponding to the cavities 24-1 and 24-2, respectively, so that the respective outputs 312-1 and 312-2 of the conductor strips protrude from the cavities 24-1 and 24-2, respectively, to the front side of the planar element 21 via the openings 215-1 and 215-2, respectively, to feed the corresponding radiating elements 512 via the transmission lines on the feeding board 51. The transition between the outputs 312-1 and 312-2 and the corresponding transmission lines on the feeding board 51 is similar to that between the conductor strip 313 and the feeding board 51 described with reference to fig. 10A to 10D, and a repeated description thereof will not be provided. Planar element 21 is provided with an opening 216 at a position between chambers 24-1 and 24-2, and the bottom of support/feed element 57 of radiating element 512 may pass through feed plate 51 and opening 216 to be mounted to planar element 21. The two chambers 24-1 and 24-2 of the cavity element 510 are laterally spaced apart by a relatively large distance to avoid opening the planar element 22, which serves as a sidewall of the chamber 24, thereby providing a more efficient transmission of the stripline transmission line formed by the conductor strip and the planar element 22.

The linear array 520 is mounted to the cavity element 510 to form the column assembly shown in fig. 14G. In manufacturing the base station antenna, column component elements matching the desired number of linear arrays may be included and positioned according to the desired position of each linear array, for example fixedly positioned by a bracket 530 and/or a bracket 540, which will be described below, which facilitates the manufacturing process of the base station antenna. Furthermore, since the chamber member 510 has a smaller width, the respective planar members 21 to 23 of the chamber member 510 can be allowed to have a smaller thickness, for example, about 1.5mm, 1.3mm, or even thinner, as compared with the frame 110 shown in fig. 3F or the chamber member 411 shown in fig. 12B. The metal plate 550 (e.g., sheet metal of aluminum) that is not required to support the radiating element 512 is also allowed to have a smaller thickness than conventional reflectors, e.g., about 1.5mm, 1.3mm, or even thinner. Therefore, the weight and cost of the base station antenna 500 as a whole can be reduced.

Fig. 17A to 17C show a base station antenna 700 according to an embodiment of the present invention, which has a similar design concept to the base station antenna 500. The linear arrays 720-1 through 720-6 are mounted to corresponding chamber elements 710-1 through 710-6, respectively, to form respective column assemblies (not shown). The column assemblies are fixedly positioned in a desired lateral positional relationship by brackets 530 and 540 such that the reflectors provided by each cavity element 710 having a generally planar forward facing surface are substantially coplanar and separated from one another. The base station antenna 700 further includes metal plates 750-1 to 750-7 that function similarly to the metal plates 550-1 to 550-3 in the base station antenna 500, as described in detail below with reference to fig. 17C. The metal plate 750-1 is located in the middle of the base station antenna 700 with a first edge located in front of and overlapping back and forth with an edge of the reflector provided by the cavity element 710-5 to form a capacitive coupling connection and a second edge located in front of and overlapping back and forth with an edge of the reflector provided by the cavity element 710-6 to form a capacitive coupling connection, such that the metal plate 750-1 commonly grounds the reflectors provided by the cavity elements 710-5 and 710-6, respectively. Similarly, metal plate 750-4 commonly grounds the reflectors provided by each of the cavity elements 710-1 and 710-3, metal plate 750-5 commonly grounds the reflectors provided by each of the cavity elements 710-1 and 710-5, metal plate 750-6 commonly grounds the reflectors provided by each of the cavity elements 710-2 and 710-6, and metal plate 750-7 commonly grounds the reflectors provided by each of the cavity elements 710-2 and 710-4. The metal plates 750-2 and 750-3 are symmetrically disposed at both side portions of the base station antenna 700 in the lateral direction. Each of the metal plates 750-2 and 750-3 has a first portion extending parallel to the generally planar forward surface of the reflector provided by the respective cavity element 710, and a second portion extending forwardly from the first portion. The edges of the first portions of the metal plates 750-2 and 750-3 are positioned on the front side of and overlap the edges of the reflectors provided by the cavity members 710-3 and 710-4, respectively, to form a capacitive coupling connection such that the metal plates 750-2 and 750-3 are commonly grounded with the reflectors provided by the cavity members 710-3 and 710-4, respectively. The second portions of the metal plates 750-2 and 750-3 are used to adjust the radiation pattern of each linear array 720. As such, each reflector (provided by each cavity element 710) and each metal plate 750, which together have the function of reflecting electromagnetic radiation of each linear array 720 of the base station antenna 700, are commonly grounded.

Fig. 18 shows a base station antenna 800 according to an embodiment of the invention. The base station antenna 800 comprises a plurality of cavity elements 810-1 to 810-3, each cavity element 810 having a planar element 21-1 to 21-3 that can be used as a reflector. Each cavity element 810 of the base station antenna 800 is positioned such that the plurality of reflectors (provided by each cavity element 810) are separated from each other in the front-to-back direction (i.e., do not have galvanic connections as in the embodiment shown in fig. 12A). As shown, the cavity element 810-2 is located in the middle of the base station antenna 800. A first edge portion of planar element 21-2 of cavity element 810-2 is positioned on a front side of and overlaps (with a thin layer of dielectric material therebetween, as will be appreciated) an edge portion of planar element 21-1 of cavity element 810-1 to form a capacitively coupled connection, and a second edge portion of planar element 21-2 of cavity element 810-2 is positioned on a front side of and overlaps an edge portion of planar element 21-3 of cavity element 810-3 to form a capacitively coupled connection, such that the reflectors provided by each of cavity elements 810-1 through 810-3 are commonly grounded. In this embodiment, the base station antenna 800 may not include a metal plate for commonly grounding the reflectors provided by the respective cavity elements 810, have a simplified structure and facilitate assembly.

Brackets 530 and 540 for fixedly positioning each cavity element (or column assembly) in a base station antenna are described below with reference to fig. 15A-16C. Both brackets 530 and 540 are formed of a dielectric material. Since the brackets 530 and/or 540 need to function as a fixing and supporting member, it is required to have a high rigidity. In the base station antennas 500 and 700, the bracket 530 is fixed to the end portions (i.e., the upper end and/or the lower end) of the base station antennas 500 and 700 in the longitudinal direction, and the bracket 540 is fixed to the middle portion of the base station antennas 500 and 700 in the longitudinal direction (a plurality of brackets 540 may be arranged as necessary). Each cavity member has a slot 532 extending in a front-to-rear direction and the carrier has a plurality of slots 531 that mate with the respective slots 532. The bracket 530 fixedly positions the plurality of cavity members by the fit between the corresponding grooves 531 and 532, and the screws 534 for fastening. The rear surface (bottom surface, which may include planar member 23 and planar member 22 near planar member 23) of each cavity member has a hole 542, and the bracket 540 has a plurality of protrusions 541 corresponding to the positions of the respective holes 542. The bracket 540 fixedly positions the plurality of cavities by inserting the protrusions 541 into the corresponding holes 542 in the longitudinal direction of the antenna, and the locker 543 for fastening. The cradle 540 may also be mechanically connected to a mounting bracket 771 for mounting the base station antenna, as shown in fig. 17B. In other embodiments, the brackets 530 and/or 540 may be made of a metallic material. Such brackets 530 and/or 540 may collectively ground the cavity elements and the reflectors they provide.

In addition, embodiments of the present invention may also include the following examples:

1. a base station antenna, comprising:

a reflector;

a first radiator located at a front side of the reflector;

first and second ground plates extending rearwardly from the reflector substantially perpendicular to the reflector and parallel to each other; and

a first conductor strip extending between the first and second ground plates and configured to feed the first radiator, the first conductor strip and the first and second ground plates constituting a first stripline transmission line,

wherein the reflector and the first and second ground plates are configured as a unitary piece such that the reflector is grounded via the first and second ground plates without welding.

2. The base station antenna according to 1, further comprising:

a printed circuit board located between the reflector and the first radiator, a front surface of the printed circuit board printed with a conductor trace configured to feed the first radiator, a rear surface of the printed circuit board printed with a conductor plane, wherein the first conductor strip is galvanically connected to the conductor trace and the conductor plane is grounded by means of being electrically coupled to the reflector.

3. The base station antenna according to 1, further comprising:

a printed circuit board positioned between the reflector and the first radiator, a front surface of the printed circuit board printed with a conductor trace configured to feed the first radiator, wherein the first conductor strip is galvanically connected to the conductor trace and a rear surface of the printed circuit board is in close proximity to the front surface of the reflector such that the reflector acts as a ground plane for the conductor trace.

4. The base station antenna according to claim 2 or 3, wherein the first conductor strip has a projection extending through the reflector and the printed circuit board forward of the reflector, the projection being soldered to the conductor trace.

5. The base station antenna according to 1, further comprising:

a second radiator located at a front side of the reflector, wherein the first and second radiators are configured to transceive radio frequency signals along first and second polarization directions, respectively;

third and fourth ground plates extending rearwardly from the reflector substantially perpendicular to the reflector and parallel to each other; and

a second conductor strip extending between the third and fourth ground plates configured to feed the second radiator, the second conductor strip and the third and fourth ground plates configured as a second stripline transmission line laterally adjacent to the first stripline transmission line,

wherein the reflector and the first to fourth ground plates are configured as a single piece such that the reflector is grounded via the first to fourth ground plates without welding; and is

The second and fourth ground plates are configured as a common ground plate.

6. The base station antenna according to 1, further comprising:

a transition configured to connect a coaxial transmission line feeding the base station antenna to the first stripline transmission line.

7. The base station antenna of claim 6, wherein the coaxial transmission line comprises an inner conductor and an outer conductor, the transition comprising a first transition and a second transition, wherein the inner conductor is galvanically connected to the first conductor strip via the first transition, and the outer conductor is electrically coupled to the first and second ground plates via the second transition.

8. The base station antenna according to claim 1, wherein the first conductor strip is a sheet metal.

9. The base station antenna according to claim 1, wherein the first conductor strip is a conductor line printed on a dielectric substrate.

10. The base station antenna according to claim 9, wherein the conductor line comprises first and second lines printed on opposite first and second surfaces of the dielectric substrate, respectively, a projection of at least a first portion of the first line on the dielectric substrate being fully coincident with a projection of the second line on the dielectric substrate, wherein the first line and the second line are galvanically connected by a conductive via through the dielectric substrate.

11. The base station antenna according to 1, further comprising:

a moving element movable relative to the first conductor strip, the moving element configured to be able to change a phase shift imparted by the first stripline transmission line to a signal transmitted thereon by its movement.

12. The base station antenna according to 1, further comprising:

a holder configured to hold the first conductor ribbon assembly substantially intermediate the first and second ground plates, the holder being made of a dielectric material.

13. The base station antenna of claim 12, wherein the retainer is configured with an aperture to reduce an area of coverage of the first conductor strip assembly by the retainer.

14. The base station antenna of claim 12, wherein a surface of the retainer proximate to the first conductor strip assembly has a setback.

15. The base station antenna of claim 12, wherein the area covered by the retainer on the first conductor strip assembly is less than 10% of the area of the first conductor strip assembly.

16. The base station antenna of claim 12, wherein the retainer comprises first and second portions, wherein the first portion has a reduced thickness in a thickness direction of the retainer from the first conductor strip assembly to the respective ground plate than the second portion to reduce a dielectric constant of a medium between the first conductor strip assembly and the respective ground plate.

17. The base station antenna of claim 12, wherein the retainer has a reduced thickness proximate a surface of the first conductor strip assembly and/or proximate a surface of the ground plate.

18. The base station antenna of claim 12, the first conductor strip assembly comprising a dielectric substrate and the first conductor strip printed on the dielectric substrate, wherein the retainers are positioned between the dielectric substrate and the first ground plate and between the dielectric substrate and the second ground plate such that the retainers do not substantially cover the first conductor strip.

19. The base station antenna according to 1, further comprising:

a spacer plate extending substantially parallel to the reflector on the rear side of the reflector, the spacer plate being connected to the edges of the first and second ground plates, respectively, remote from the reflector, wherein the spacer plate is constructed in one piece with the first and second ground plates.

20. The base station antenna of claim 19, further comprising:

a support member mounted to the isolation board, the support member configured to support the first conductor strip forward such that a first portion of the first conductor strip projects forward of the reflector through the reflector for connection with a circuit element located on a front side of the reflector.

21. The base station antenna according to claim 1, wherein the first stripline transmission line comprises first and second sections each configured to extend from the reflector, wherein the conductor strip of the first section and the conductor strip of the second section are electrically coupled by a connector.

22. The base station antenna of claim 21, wherein the second segment is laterally adjacent to the first segment, and ground plates of the first and second segments that are adjacent to each other are configured as a common ground plate.

23. The base station antenna of claim 22, further comprising:

a pair of isolation plates extending substantially parallel to the reflector on the rear side of the reflector, the isolation plates being connected to respective edges of the ground plates of the first and second segments remote from the reflector, wherein the isolation plates are constructed in one piece with the ground plates of the first and second segments, and wherein the isolation plates and/or the same ground plate are provided with holes through which the connectors pass.

24. The base station antenna of claim 21, wherein the first segment comprises a first portion of the first stripline transmission line having a first electrical distance to the first radiator and the second segment comprises a second portion of the first stripline transmission line having a second electrical distance to the first radiator, wherein the second electrical distance is less than the first electrical distance.

25. A base station antenna, comprising:

a reflector;

a first radiator located at a front side of the reflector;

a first cavity element located at a rear side of the reflector, wherein the first cavity element comprises first and second mutually parallel ground plates extending rearwardly substantially perpendicularly from the rear side of the reflector, the first and second ground plates each having a first edge proximate the reflector;

a first conductor strip extending between the first and second ground plates and configured to feed the first radiator, the first conductor strip and the first and second ground plates constituting a first stripline transmission line; and

a first dielectric layer between the first edge portions of the first and second ground plates and the reflector, wherein,

a first coupling portion extending laterally away from the first conductor strip, substantially parallel to the rear surface of the reflector, from a first edge of the first ground plate;

a second coupling portion extending laterally away from the first conductor strip, substantially parallel to the rear surface of the reflector, from the first edge of the second ground plate;

the first and second coupling portions are each electrically coupled to the reflector via the first dielectric layer such that the reflector is grounded via the first cavity element without soldering.

26. The base station antenna of claim 25, further comprising:

a printed circuit board located between the reflector and the first radiator, a front surface of the printed circuit board printed with a conductor trace configured to feed the first radiator, a rear surface of the printed circuit board printed with a conductor plane, wherein the first conductor strip is galvanically connected to the conductor trace and the conductor plane is grounded by means of being electrically coupled to the reflector.

27. The base station antenna of claim 26, further comprising a pin configured to galvanically connect the first cavity element to the conductor plane such that the first cavity element, the conductor plane, and the reflector are all commonly grounded.

28. The base station antenna according to 27, wherein the second coupling part, the reflector and the printed circuit board respectively include first to third openings corresponding in position, the pin sequentially passes through the first to third openings, wherein the pin is galvanically connected to the second coupling part by a clinch process, and the pin is galvanically connected to a conductor trace printed on an upper surface of the printed circuit board by a soldering process and further galvanically connected to the conductor plane by a conductive through hole passing through the printed circuit board, wherein the pin is galvanically connected to the reflector.

29. The base station antenna of claim 25, further comprising:

a printed circuit board positioned between the reflector and the first radiator, a front surface of the printed circuit board printed with a conductor trace configured to feed the first radiator, wherein the first conductor strip is galvanically connected to the conductor trace and a rear surface of the printed circuit board is in close proximity to the front surface of the reflector such that the reflector acts as a ground plane for the conductor trace.

30. The base station antenna according to 26 or 29, wherein the first conductor strip has a projection extending through the reflector and the printed circuit board forward of the reflector, the projection being soldered to the conductor trace.

31. The base station antenna of claim 25, wherein the first cavity element further comprises third and fourth mutually parallel ground plates extending rearwardly from and substantially perpendicular to the rear surface of the reflector, the third and fourth ground plates each having a first edge proximate the reflector, the base station antenna further comprising:

a second radiator located at a front side of the reflector, wherein the first and second radiators are configured to transceive radio frequency signals along first and second polarization directions, respectively;

a second conductor strip extending between the third and fourth ground plates configured to feed the second radiator, the second conductor strip and the third and fourth ground plates configured as a second stripline transmission line laterally adjacent to the first stripline transmission line; and

a second dielectric layer between the first edge portions of the third and fourth ground plates and the reflector, wherein,

a third coupling portion extending laterally away from the second conductor strip, substantially parallel to the rear surface of the reflector, from the first edge of the third ground plate;

a fourth coupling portion extending laterally away from the second conductor strip, substantially parallel to the rear surface of the reflector, from the first edge of the fourth ground plate;

the third and fourth coupling portions are each electrically coupled to the reflector via the second dielectric layer such that the reflector is grounded via the first cavity element without soldering; and is

The second and fourth coupling parts adjacent to each other are configured as the same coupling part.

32. The base station antenna of claim 31, wherein the same coupling portion extends laterally no less than half the length of either of the first and third coupling portions.

33. The base station antenna of claim 25, wherein the first conductor strip is a conductor line printed on a dielectric substrate, the conductor line comprising first and second lines printed on opposite first and second surfaces of the dielectric substrate, respectively, a projection of a first portion of the first line on the dielectric substrate being substantially coincident with a projection of the second line on the dielectric substrate, wherein the first line and the second line are galvanically connected by a conductive via through the dielectric substrate.

34. The base station antenna of claim 25, further comprising:

a holder configured to hold the first conductor strip substantially intermediate the first and second ground plates, wherein the holder is configured with an aperture to reduce an area of coverage of the first conductor strip by the holder.

35. The base station antenna of claim 25, further comprising:

a holder configured to hold the first conductor strip substantially intermediate the first and second ground plates, wherein a first portion of the holder has a reduced thickness to reduce a dielectric constant of a dielectric between the first conductor strip and the respective ground plate.

36. The base station antenna of claim 25, the first cavity element further comprising:

a separator plate extending substantially parallel to the reflector on the rear side of the reflector, the separator plate being connected to a second edge of the first and second ground plates, respectively, opposite the first edge, wherein the separator plate and the first and second ground plates are constructed as a single piece.

37. A feed assembly for feeding a column of radiators of a base station antenna configured to operate in a first polarisation direction, the feed assembly comprising a stripline transmission line located on a rear side of a reflector substantially perpendicular to the reflector, the stripline transmission line comprising first and second ground plates parallel to each other and a conductor strip extending between the first and second ground plates, the conductor strip having an input and a plurality of outputs, wherein,

the first and second ground plates are electrically connected to the outer conductor of a coaxial transmission line for feeding the column,

the input is electrically connected to the inner conductor of the coaxial transmission line,

the plurality of output sections are configured to be electrically connected to the column to feed the column, an

The first and second ground plates are configured as a unitary piece with the reflector such that the reflector is grounded via the first and second ground plates without welding.

38. The feed assembly of 37, further comprising a plurality of microstrip transmission lines on the front side of the reflector for feeding the columns, each microstrip transmission line comprising a conductor trace printed on the front surface of a dielectric substrate and a conductor plane printed on the rear surface of the dielectric substrate, wherein each output is electrically connected to a respective one of the conductor traces and the conductor plane is grounded by means of an electrical coupling to the reflector.

39. The feed assembly of claim 38, wherein each output extends forward of the reflector through the reflector and the dielectric substrate to be soldered to a respective conductor trace.

40. The feed assembly of claim 38, further comprising a plurality of pins extending through the reflector and the dielectric substrate, wherein a first end of each pin extends between the first and second ground plates to be electrically connected to the respective output, and a second end of the pin extends to the front side of the dielectric substrate to be electrically connected to the corresponding conductor trace.

41. The feed assembly of claim 38, wherein the column comprises a first radiator, the plurality of outputs comprises a first output, and the plurality of microstrip transmission lines comprises a first microstrip transmission line, wherein the first output is galvanically connected to the conductor trace of the first microstrip transmission line, the conductor trace of the first microstrip transmission line configured to feed the first radiator without feeding any radiator other than the first radiator.

42. The feed assembly of claim 38, wherein the column comprises adjacent first and second radiators, the plurality of outputs comprises a first output, and the plurality of microstrip transmission lines comprises a first microstrip transmission line, wherein the first output is galvanically connected to the conductor trace of the first microstrip transmission line, the conductor trace of the first microstrip transmission line configured to feed the first and second radiators.

43. The feed assembly of 37, further comprising a first transition electrically connecting the input to the inner conductor, wherein the first transition comprises:

a first joint portion configured to be bent so as to be soldered to the inner conductor to at least partially surround the inner conductor; and

a second joint configured to be electrically connected to the input part.

44. The feeding assembly of 43, wherein an input of the conductor strip is formed at an edge of the stripline transmission line distal from the reflector, the coaxial transmission line being positioned near the input, wherein the second joint is configured to extend between the first and second ground plates so as to be electrically connected to the input.

45. The feeding assembly of 44, wherein the second engagement portion is configured to be flat to facilitate welding and/or threading to the input portion in a planar contact.

46. The feed assembly of 43, further comprising a transition printed circuit board on a front surface of the reflector, wherein an input of the conductor strip is configured to extend through the reflector and the transition printed circuit board forward of the reflector, the coaxial transmission line being positioned near the input on a rear side of the reflector, wherein the first transition extends through the reflector and the transition printed circuit board such that the first junction is located on the rear side of the reflector and the second junction is located on a front side of the transition printed circuit board, and wherein the second junction is electrically connected to the input via conductor traces printed on the transition printed circuit board.

47. The feeding assembly of 37, further comprising a second transition electrically connecting the first and second ground plates to the outer conductor, wherein the second transition comprises:

a first engaging portion configured to be bent so as to be welded to the outer conductor in a manner of at least partially surrounding the outer conductor; and

a second joint configured to be electrically connected to the first and second ground plates.

48. The feed assembly of claim 47, wherein the edge portions of the first and second ground plates distal from the reflector extend toward and out of an extension substantially parallel to the reflector, and the second bond is planar and electrically coupled to the extension for electrical connection to the first and second ground plates.

49. The feed assembly of 47, further comprising a transition printed circuit board at a front surface of the reflector, a rear surface of the transition printed circuit board printed with a conductor plane electrically coupled to the reflector, wherein the coaxial transmission line is positioned proximate the reflector at a rear side of the reflector, wherein the transition printed circuit board is provided with a conductive via thereon, the second joint passing through and electrically connecting to the conductive via to electrically connect to the conductor plane to electrically connect to the first and second ground plates.

50. The feeding assembly of 37, further comprising:

a moving element movable relative to the conductor strip, the moving element configured to be able to change a phase shift imparted by the stripline transmission line to a signal transmitted thereon by its movement.

51. A frame for a base station antenna, comprising:

a first planar element extending along a first plane, a first side of the first planar element configured to reflect electromagnetic radiation of the base station antenna; and

second and third mutually parallel planar elements extending substantially perpendicularly from a second side of the first planar element, the second and third planar elements being configured to define a first cavity for a first conductor strip,

wherein the first to third planar elements are configured as a single piece so as to be commonly grounded.

52. The frame of 51, further comprising:

a fourth planar element parallel to the third planar element extending substantially perpendicularly from the first planar element to the second side of the first planar element,

wherein the third and fourth planar elements are configured to define a second cavity for a second conductor strip, and the first through fourth planar elements are configured as a unitary piece so as to be commonly grounded.

53. The frame of 52, further comprising:

a fifth planar element parallel to the first plane on the second side of the first planar element,

wherein the fifth planar element is connected with a rear edge portion of each of the second to fourth planar elements so that each of the first and second chambers is substantially closed, and the fifth planar element and the first to fourth planar elements are constituted as one piece so as to be commonly grounded.

54. The frame according to 53, wherein said fifth planar element has a first opening for connection of said first and second conductor strips to circuit elements located outside said first and second cavities, respectively.

55. The frame according to 53, wherein the fifth planar element has a second opening for mounting a support for supporting the first and second conductor strips in a direction towards the first side of the first planar element.

56. The frame of 51, wherein the first planar element has a third opening such that the first conductor strip protrudes to the first side of the first planar element for connection with a circuit element located on the first side of the first planar element.

57. The frame of 53, wherein at least one end of the first chamber in the length direction is open for receiving the first conductor strip and at least one end of the second chamber in the length direction is open for receiving the second conductor strip.

58. The frame of claim 53, wherein the first through fifth planar elements are configured as a first cavity element, the frame further comprising a second cavity element having the same structure as the first cavity element, wherein the first cavity element is connected to the second cavity element by a friction stir welding process.

59. The frame of 58, wherein the first cavity element is connected to the second cavity element lengthwise.

60. The frame of 53 wherein the first through fifth planar elements are configured as a first cavity element, the frame further comprising a second cavity element of the same configuration as the first cavity element, wherein the first and second cavity elements are positioned laterally adjacent and spaced apart from one another such that the first planar element of the first cavity element is substantially coplanar with the first planar element of the second cavity element.

61. The frame of 53, wherein the first through fifth planar elements are configured as a first cavity element, the frame further comprising a second cavity element of the same construction as the first cavity element, wherein the first and second cavity elements are positioned apart from one another such that a lengthwise edge of the first planar element of the first cavity element overlaps a lengthwise edge of the first planar element of the second cavity element.

62. The frame according to 52, wherein said base station antenna comprises a dual polarized radiating element located on a first side of said first planar element, wherein said second to fourth planar elements are positioned so that said first and second conductor strips feed a radiator of said dual polarized radiating element operating in two polarization directions, respectively.

63. The frame of 51, wherein the base station antenna comprises first and second columns of radiators arranged lengthwise on a first side of the first planar element, wherein the frame further comprises:

a sixth and seventh planar element parallel to each other extending substantially perpendicularly from the first planar element to a second side of the first planar element, the sixth and seventh planar elements configured to define a third chamber for a third conductor strip, wherein,

the first to third, sixth and seventh planar elements are constructed as a single piece so as to be commonly grounded,

the second and third planar elements are positioned to facilitate feeding of the first conductor strip to the first column of radiators, an

The sixth and seventh planar elements are positioned to facilitate feeding of the third conductor strip to the second column of radiators.

64. The frame of 63, wherein the first column of radiators operates at a first frequency band and the second column of radiators operates at a second frequency band, wherein the width of the first chamber is substantially equal to the width of the second chamber.

65. The frame of 53, wherein the fifth planar element has an extension that extends beyond the second and/or fourth planar elements to attach a mounting bracket for mounting the base station antenna.

66. The frame of claim 65, wherein the second planar element is proximate the first edge of the first planar element, and the extension extends beyond the second planar element at least in a direction toward the first edge.

67. The frame of 53, wherein the first through fifth planar elements are integrally formed based on a metallic material using a pultrusion process.

68. The frame of 53, wherein each of the first through fifth planar elements extends substantially the entire length of the base station antenna.

69. A reflector for a base station antenna, comprising:

a plurality of sub-reflectors extending in a longitudinal direction of the base station antenna, wherein,

each of the plurality of sub-reflectors is configured to mount a radiating element of the base station antenna thereon; and

the plurality of sub-reflectors are fixedly positioned such that the plurality of sub-reflectors are separated from each other, wherein the plurality of sub-reflectors are commonly grounded.

70. The reflector of 69, wherein the plurality of sub-reflectors are fixedly positioned such that the substantially planar forward-facing surface of a first sub-reflector of the plurality of sub-reflectors is substantially coplanar with the substantially planar forward-facing surface of a second sub-reflector of the plurality of sub-reflectors that is adjacent to the first sub-reflector.

71. The reflector of 70, wherein the substantially planar forward surface of the first sub-reflector and the substantially planar forward surface of the second sub-reflector are each galvanically connected to an outer conductor of a radio frequency cable feeding a radiating element of the base station antenna such that the first and second sub-reflectors are commonly grounded.

72. The reflector of 70, further comprising:

a metal bracket, wherein,

the plurality of sub-reflectors are mounted to the metal bracket so as to be fixedly positioned; and

the substantially flat forward surface of the first sub-reflector and the substantially flat forward surface of the second sub-reflector are both galvanically connected to the metal bracket such that the first and second sub-reflectors are commonly grounded.

73. The reflector of 70, further comprising:

a metal plate, wherein,

a first edge of the metal plate and an edge of the first sub-reflector adjacent the second sub-reflector overlap to form a first capacitively coupled connection, and a second edge of the metal plate and an edge of the second sub-reflector adjacent the first sub-reflector overlap to form a second capacitively coupled connection, such that the first and second sub-reflectors are commonly grounded.

74. The reflector of 69, wherein the plurality of sub-reflectors are fixedly positioned such that an edge of a first sub-reflector of the plurality of sub-reflectors adjacent to a second sub-reflector overlaps an edge of the second sub-reflector adjacent to the first sub-reflector to form a capacitively coupled connection between the first and second sub-reflectors such that the first and second sub-reflectors are commonly grounded.

75. The reflector of 69, further comprising:

a metal element having a first portion extending in parallel with a substantially flat forward-facing surface of a third sub-reflector of the plurality of sub-reflectors located at a lateral edge of the reflector, and a second portion extending from the first portion toward a front of the base station antenna,

wherein an edge of the first portion and an edge of the forward-facing surface of the third sub-reflector overlap to form a capacitive coupling connection such that the metallic element and the third sub-reflector are commonly grounded, and the second portion is configured to adjust a radiation pattern of the base station antenna.

76. A reflector for a base station antenna, comprising:

a first cavity element; and

a second chamber element, wherein,

each cavity element comprises a planar portion extending in a longitudinal direction of the base station antenna and a cavity portion extending substantially perpendicularly from the planar portion towards a rear of the base station antenna, wherein the planar portion is configured to mount a radiating element of the base station antenna thereon and to reflect electromagnetic radiation of the base station antenna, the cavity portion being configured to receive at least part of a circuit therein for feeding the radiating element;

the first and second cavity elements are positioned such that the first cavity element is separated from the second cavity element.

77. The reflector of 76, wherein the first and second cavity elements are further positioned such that the planar portion of the first cavity element is laterally adjacent and substantially coplanar with the planar portion of the second cavity element.

78. The reflector of 77, further comprising:

a metal plate, wherein,

a first edge of the metal plate and an edge of the planar portion of the first cavity element adjacent to the second cavity element overlap to form a first capacitively coupled connection, and a second edge of the metal plate and an edge of the planar portion of the second cavity element adjacent to the first cavity element overlap to form a second capacitively coupled connection, such that the planar portion of the first cavity element and the planar portion of the second cavity element are commonly grounded.

79. The reflector of 76, wherein the first and second cavity elements are further positioned such that an edge of the planar portion of the first cavity element adjacent the second cavity element overlaps an edge of the planar portion of the second cavity element adjacent the first cavity element to form a capacitive coupling connection such that the planar portion of the first cavity element is commonly grounded with the planar portion of the second cavity element.

80. The reflector of claim 76, further comprising:

a first carrier formed of a dielectric material,

wherein the cavity portion of each of the first and second cavity members has a first slot extending in a front-to-rear direction, the first bracket has a second slot respectively matching each of the first slots, the first bracket is configured to position the first and second cavity members by cooperation of the first slots and the corresponding second slots.

81. The reflector of claim 76, further comprising:

a second carrier formed of a dielectric material,

wherein a rear surface of the cavity portion of each of the first and second cavity members has an aperture, the second bracket has a protrusion matching each of the apertures, the second bracket is configured to position the first and second cavity members by insertion of the protrusion into the respective aperture in the longitudinal direction.

82. A column assembly for a base station antenna, comprising:

a reflector extending in a longitudinal direction of the base station antenna;

a linear array of radiating elements extending along a longitudinal direction of the base station antenna, each radiating element in the linear array being mounted to the reflector so as to extend forwardly from the reflector; and

a cavity extending substantially perpendicularly from the reflector to the rear of the base station antenna, the cavity configured to receive therein at least part of a circuit for feeding the linear array,

wherein the column assembly is positioned separate from other column assemblies.

83. The column assembly of 82, wherein the column assembly is further positioned such that the substantially planar forward facing surface of the reflector is substantially coplanar with the substantially planar forward facing surfaces of the reflectors of the other column assemblies.

84. The column assemblies of 82, wherein the column assemblies are further positioned such that the substantially flat forward facing surface of the reflector overlaps the substantially flat forward facing surface of the reflector of a first one of the other column assemblies adjacent to the column assembly.

85. A base station antenna, comprising:

a plurality of reflectors extending in a longitudinal direction of the base station antenna; and

a plurality of linear arrays extending in a longitudinal direction of the base station antenna, each linear array including a plurality of radiating elements mounted to a corresponding one of the reflectors so as to extend forward from the corresponding one of the reflectors, wherein,

the plurality of reflectors are fixedly positioned such that the plurality of reflectors are separated from each other and each linear array has the same azimuthal boresight pointing direction.

86. The base station antenna of 85, wherein the plurality of reflectors are fixedly positioned such that the substantially planar forward surface of a first reflector of the plurality of reflectors is substantially coplanar with the substantially planar forward surfaces of other reflectors of the plurality of reflectors other than the first reflector.

87. The base station antenna of 86, further comprising:

a metal plate, wherein,

a first edge of the metal plate and an edge of the first reflector adjacent the second reflector overlap to form a first capacitively coupled connection, and a second edge of the metal plate and an edge of the second reflector adjacent the first reflector overlap to form a second capacitively coupled connection, such that the first and second reflectors are commonly grounded.

88. The base station antenna of 85, wherein the plurality of reflectors are fixedly positioned such that an edge of a first reflector of the plurality of reflectors adjacent to a second reflector overlaps an edge of the second reflector adjacent to the first reflector to form a capacitive coupling connection between the first and second reflectors such that the first and second reflectors are commonly grounded.

89. The base station antenna of 85, further comprising:

a metal element having a first portion extending in parallel with a substantially flat forward surface of a third reflector of the plurality of reflectors located at a lateral side of the base station antenna, and a second portion extending from the first portion toward a front of the base station antenna,

wherein an edge of the first portion and an edge of the forward-facing surface of the third reflector overlap to form a capacitive coupling connection such that the metallic element and the third reflector are commonly grounded, and the second portion is configured to adjust a radiation pattern of the base station antenna.

90. The base station antenna of 85, further comprising:

a plurality of cavities extending in a longitudinal direction of the base station antenna,

wherein each of the cavities extends substantially perpendicularly from a respective one of the reflectors to the rear of the base station antenna, the cavities being configured to form a stripline transmission line with at least part of circuitry housed therein for feeding a respective one of the linear arrays.

91. The base station antenna of 90, wherein each of said cavities and said respective one reflector are constructed as a unitary piece.

92. The base station antenna according to 90, wherein said radiating elements are dual polarized radiating elements, each of said cavities comprising first and second cavities configured to respectively receive therein at least part of a circuit for feeding a respective one of said polarizations of said radiating elements, wherein said first and second cavities are laterally spaced apart by a predetermined distance for mounting said radiating elements to said respective one of said reflectors.

93. The base station antenna of claim 90, further comprising:

a first carrier formed of a dielectric material,

wherein each of the plurality of cavities has a first slot extending in a front-to-rear direction, the first bracket has a plurality of second slots respectively mating with the first slots, the first bracket is configured to fixedly position the plurality of cavities by mating of the first slots and the respective second slots.

94. The base station antenna of 93, wherein the first bracket is fixed to an end of the base station antenna in a longitudinal direction.

95. The base station antenna of claim 90, further comprising:

a second carrier formed of a dielectric material,

wherein a rear surface of each of the plurality of cavities has a hole, the second bracket has a plurality of protrusions respectively corresponding to positions of the holes, and the second bracket is configured to fixedly position the plurality of cavities by inserting the protrusions into the respective holes in the longitudinal direction.

96. The base station antenna according to 95, wherein the second bracket is fixed to a middle portion of the base station antenna in a longitudinal direction.

97. The base station antenna of 95, wherein the second bracket is configured to attach a mounting bracket for mounting the base station antenna.

Although some specific embodiments of the present invention have been described in detail by way of illustration, it should be understood by those skilled in the art that the above illustration is only for the purpose of illustration and is not intended to limit the scope of the invention. The various embodiments disclosed herein may be combined in any combination without departing from the spirit and scope of the present invention. It will also be appreciated by those skilled in the art that various modifications may be made to the embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims (10)

1. A base station antenna, comprising:

a reflector;

a first radiator located at a front side of the reflector;

first and second ground plates extending rearwardly from the reflector substantially perpendicular to the reflector and parallel to each other; and

a first conductor strip extending between the first and second ground plates and configured to feed the first radiator, the first conductor strip and the first and second ground plates constituting a first stripline transmission line,

wherein the reflector and the first and second ground plates are configured as a unitary piece such that the reflector is grounded via the first and second ground plates without welding.

2. The base station antenna of claim 1, further comprising:

a printed circuit board located between the reflector and the first radiator, a front surface of the printed circuit board printed with a conductor trace configured to feed the first radiator, a rear surface of the printed circuit board printed with a conductor plane, wherein the first conductor strip is galvanically connected to the conductor trace and the conductor plane is grounded by means of being electrically coupled to the reflector.

3. The base station antenna of claim 1, further comprising:

a printed circuit board positioned between the reflector and the first radiator, a front surface of the printed circuit board printed with a conductor trace configured to feed the first radiator, wherein the first conductor strip is galvanically connected to the conductor trace and a rear surface of the printed circuit board is in close proximity to the front surface of the reflector such that the reflector acts as a ground plane for the conductor trace.

4. A base station antenna, comprising:

a reflector;

a first radiator located at a front side of the reflector;

a first cavity element located at a rear side of the reflector, wherein the first cavity element comprises first and second mutually parallel ground plates extending rearwardly substantially perpendicularly from the rear side of the reflector, the first and second ground plates each having a first edge proximate the reflector;

a first conductor strip extending between the first and second ground plates and configured to feed the first radiator, the first conductor strip and the first and second ground plates constituting a first stripline transmission line; and

a first dielectric layer between the first edge portions of the first and second ground plates and the reflector, wherein,

a first coupling portion extending laterally away from the first conductor strip, substantially parallel to the rear surface of the reflector, from a first edge of the first ground plate;

a second coupling portion extending laterally away from the first conductor strip, substantially parallel to the rear surface of the reflector, from the first edge of the second ground plate;

the first and second coupling portions are each electrically coupled to the reflector via the first dielectric layer such that the reflector is grounded via the first cavity element without soldering.

5. A feed assembly for feeding a column of radiators of a base station antenna configured to operate in a first polarisation direction, the feed assembly comprising a stripline transmission line located on a rear side of a reflector substantially perpendicular to the reflector, the stripline transmission line comprising first and second ground plates parallel to each other and a conductor strip extending between the first and second ground plates, the conductor strip having an input and a plurality of outputs, wherein,

the first and second ground plates are electrically connected to the outer conductor of a coaxial transmission line for feeding the column,

the input is electrically connected to the inner conductor of the coaxial transmission line,

the plurality of output sections are configured to be electrically connected to the column to feed the column, an

The first and second ground plates are configured as a unitary piece with the reflector such that the reflector is grounded via the first and second ground plates without welding.

6. A frame for a base station antenna, comprising:

a first planar element extending along a first plane, a first side of the first planar element configured to reflect electromagnetic radiation of the base station antenna; and

second and third mutually parallel planar elements extending substantially perpendicularly from a second side of the first planar element, the second and third planar elements being configured to define a first cavity for a first conductor strip,

wherein the first to third planar elements are configured as a single piece so as to be commonly grounded.

7. A reflector for a base station antenna, comprising:

a plurality of sub-reflectors extending in a longitudinal direction of the base station antenna, wherein,

each of the plurality of sub-reflectors is configured to mount a radiating element of the base station antenna thereon; and

the plurality of sub-reflectors are fixedly positioned such that the plurality of sub-reflectors are separated from each other, wherein the plurality of sub-reflectors are commonly grounded.

8. A reflector for a base station antenna, comprising:

a first cavity element; and

a second chamber element, wherein,

each cavity element comprises a planar portion extending in a longitudinal direction of the base station antenna and a cavity portion extending substantially perpendicularly from the planar portion towards a rear of the base station antenna, wherein the planar portion is configured to mount a radiating element of the base station antenna thereon and to reflect electromagnetic radiation of the base station antenna, the cavity portion being configured to receive at least part of a circuit therein for feeding the radiating element;

the first and second cavity elements are positioned such that the first cavity element is separated from the second cavity element.

9. A column assembly for a base station antenna, comprising:

a reflector extending in a longitudinal direction of the base station antenna;

a linear array of radiating elements extending along a longitudinal direction of the base station antenna, each radiating element in the linear array being mounted to the reflector so as to extend forwardly from the reflector; and

a cavity extending substantially perpendicularly from the reflector to the rear of the base station antenna, the cavity configured to receive therein at least part of a circuit for feeding the linear array,

wherein the column assembly is positioned separate from other column assemblies.

10. A base station antenna, comprising:

a plurality of reflectors extending in a longitudinal direction of the base station antenna; and

a plurality of linear arrays extending in a longitudinal direction of the base station antenna, each linear array including a plurality of radiating elements mounted to a corresponding one of the reflectors so as to extend forward from the corresponding one of the reflectors, wherein,

the plurality of reflectors are fixedly positioned such that the plurality of reflectors are separated from each other and each linear array has the same azimuthal boresight pointing direction.

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