CN116780202A - Reflector assembly for an active antenna unit and base station antenna having a reflector assembly - Google Patents

Abstract

The present disclosure relates to a reflector assembly for an active antenna unit and a base station antenna having a reflector assembly. A reflector assembly applicable to an active antenna element and/or a base station antenna is provided that includes a reflector body and a lip extending around a perimeter of the reflector body. The reflector body has a sidewall that may optionally include a plurality of fin structures extending around the perimeter of the reflector body. During use, the sidewalls may be directly exposed to ambient conditions. In use, the fin structure may be formed as a channel member, which may be formed from sheet metal, or provided as a separate extruded or die cast member which may be coupled to the reflector body.

Description

Reflector assembly for an active antenna unit and base station antenna having a reflector assembly

The present application claims priority from chinese patent application No.202210217965.0, filed on 3/8 of 2022, entitled "reflector assembly for active antenna unit and base station antenna with reflector assembly".

Background

The present invention relates generally to radio communications and, more particularly, to a base station antenna for a cellular communication system.

Cellular communication systems are well known in the art. In cellular communication systems, a geographic area is divided into a series of areas or "cells" that are served by respective macrocell base stations. Each macrocell base station may include one or more base station antennas configured to provide two-way radio frequency ("RF") communication with subscribers within a cell served by the base station. In many cases, each base station is divided into "sectors". In one general configuration, a hexagonal cell is divided into three 120 ° sectors in the azimuth plane, and each sector is served by one or more macrocell base station antennas having an azimuth half-power beamwidth (HPBW) of about 65 °. So-called small cell base stations may be used to provide services in high traffic areas within parts of the cell. Typically, the base station antenna is mounted on a tower or other elevated structure, with the radiation pattern generated by the base station antenna directed outwardly.

Certain components of the base station antenna may generate heat. For example, the radio may generate heat. In the past, external heat dissipating fins have been provided in the housing of the base station antenna and in the main body or chassis of the subunit/radio unit to help dissipate the generated heat. Further details of example conventional antennas may be found in co-pending WO2019/236203 and WO2020/072880, the contents of which are incorporated herein by reference as if fully set forth herein.

Disclosure of Invention

According to embodiments of the present invention, a fin structure coupled to the reflector body is provided that does not require the fin structure to be integrated with the reflector body and/or the reflector major surface.

Embodiments of the present invention relate to a reflector assembly for a base station antenna, the reflector assembly comprising: a reflector body having an outer periphery providing a lip extending outwardly from the reflector body; and a plurality of fin structures stacked in the front-rear direction around the outer periphery.

The reflector body may have a front surface. The lip may extend laterally and/or longitudinally behind the front surface. A plurality of fin structures may be located in front of the lip.

The reflector body may be rectangular with a pair of long sides and a pair of short sides. The lip may be provided as a plurality of outwardly extending lip sections, at least one lip section extending outwardly from each of the long and short sides.

The lip may be defined by at least one fold or bend in a portion of the sheet metal providing the reflector body.

The lip may have four lip sections. Adjacent end portions of at least a first and second of the lip sections may be spaced apart and define an open corner space.

The reflector assembly may also include a coupling member extending across the open corner space.

At least some of the plurality of fin structures may be provided by stacked sets of U-shaped channels oriented such that the open end faces of the U-shaped channels face outwardly away from the reflector body and the closed ends of the U-shaped channels are adjacent or in close proximity to the side, top or bottom walls of the reflector body.

At least some of the plurality of fin structures may be provided by stacked sets of L-shaped channels oriented such that the short ends of the L-shaped channels are adjacent or in close proximity to the side, top or bottom walls of the reflector body.

The reflector body may have a pair of laterally spaced apart side walls and longitudinally spaced apart top and bottom walls that surround the front surface of the reflector body, and wherein the side walls, top and bottom walls extend perpendicularly to and rearwardly in a front-to-rear direction between the lip and front surface of the reflector body.

A first subset of the plurality of fin structures may be secured to the side wall and a second subset of the plurality of fin structures may be secured to the top wall or the bottom wall.

At least some of the plurality of fin structures may be welded, soldered, and/or riveted to one or more of the top, bottom, or side walls of the reflector body.

The reflector body may have a plurality of apertures, at least some of the plurality of apertures having a lateral extension in the range of 20-90% of the lateral extension of the reflector body.

At least some of the plurality of apertures may also have a lateral extension in the range of 10-60% of the longitudinal extension of the reflector body.

The reflector body may be provided as a frame providing a lip. The reflector body may be configured to cooperate with one or more substrates for defining a reflector front surface behind the radiating element and in front of the radio.

At least some of the plurality of fin structures may be provided by an elongated channel member that is bendable or foldable to define a respective fin structure comprising first and second sections that are coplanar and orthogonal to each other, whereby bending forms a 90 degree bend joint, and wherein the first and second sections of the elongated channel extend in front of the lip.

The lips may extend laterally outward from and perpendicular to the right and left side walls. The lips may also extend longitudinally from and perpendicular to the top and bottom walls.

At least some of the plurality of fin structures may be provided by an extruded or die cast member that is a separate component from the reflector body.

At least some of the plurality of fin structures may have a fin surface with at least one curvilinear outward facing perimeter defining a recess configured to receive a corresponding securing member.

The reflector body and the plurality of fin structures may have a corrosion resistant surface treatment such as plating and/or coating or electroplating.

Some embodiments relate to an active antenna unit including a reflector assembly and a radio behind the reflector assembly, a radio housing holding the radio, and a radiating element in front of the reflector assembly.

Some embodiments relate to a base station antenna including a reflector assembly as described herein.

Still other embodiments relate to a reflector assembly for a base station antenna, the reflector assembly comprising: a reflector body having a front face with a perimeter and a thermally conductive fin structure including a plurality of stacked channel members. The stacked channel members are coupled to the reflector body and extend laterally and/or longitudinally outward from the perimeter of the reflector body.

The reflector assembly may also include a lip extending outwardly from and rearward of the perimeter of the front face of the reflector body.

The reflector body may have/be formed of sheet metal, and the lip may be formed of at least one of a portion of the sheet metal that is bent.

The stacked channel members may comprise sheet metal U-shaped or L-shaped channels.

The stacked channel members may be provided as extruded or die cast members.

The reflector assembly may also include a dielectric liner between the plurality of stacked channel members and the facing portion of the reflector body.

Other embodiments relate to an active antenna element for a base station antenna, the active antenna element comprising: a reflector body having an outer periphery, thereby providing a lip extending outwardly from the reflector body; a radome coupled to and in front of the reflector body; and a radio coupled to and behind the reflector body.

The reflector body has a front surface and the lip may extend laterally and/or longitudinally behind the front surface. The reflector body may have a plurality of sidewalls extending behind the front surface that couple the front surface to the lip. In use, the sidewalls are directly exposed to ambient conditions.

All of the side walls may be free of outwardly protruding heat sinks and may define a heat outlet for a heat path from the heat source(s) in the radio.

The reflector body may be rectangular with a pair of long sides and a pair of short sides. The lip may be provided as a plurality of outwardly extending lip sections, wherein at least one lip section extends outwardly from each long side and/or each short side.

The lip may be defined by at least one fold or bend in a portion of the sheet metal providing the reflector body.

The lip may have four lip sections. Adjacent end portions of at least a first and second of the lip sections may be spaced apart and define an open corner space.

The active antenna element may include a coupling member extending across the open corner space.

The radome may have an outer peripheral portion with an inner recess that may hold the sealing member. The radome may be sealingly coupled to the front surface of the reflector body.

The sidewalls may have a height in the range of about 20mm to about 50 mm.

At least one of the side walls may have an outwardly projecting fin located in front of the lip.

It should be noted that even if other different embodiments are not specifically described, various aspects of the present disclosure described for one embodiment may be included in other different embodiments. In other words, all embodiments and/or features of any embodiment may be combined in any way and/or combination as long as they do not conflict with each other.

Drawings

FIG. 1 is a front, side perspective and partially exploded view of a reflector assembly according to an embodiment of the present invention.

FIG. 2 is a front, side perspective and assembled view of the reflector assembly shown in FIG. 1.

Fig. 3 is a front, side and partially exploded view of an active antenna module having the reflector assembly shown in fig. 1 and 2, according to an embodiment of the present invention.

Figure 4A is a front, side perspective view of another embodiment of a reflector assembly according to an embodiment of the present invention.

Fig. 4B is a partially exploded front perspective view of a portion of an example active antenna element having the reflector assembly shown in fig. 4A, in accordance with an embodiment of the present invention.

Fig. 4C is a greatly enlarged view of a portion of the reflector assembly and radio shown in fig. 4B.

FIG. 5 is a greatly enlarged front, side perspective view of the corner of the reflector assembly shown in FIG. 2.

Figure 6A is a front perspective view of another reflector assembly in accordance with an embodiment of the present invention.

Fig. 6B and 6C are side, perspective views of an example extruded or die cast fin member including stacked fin groups according to some embodiments of the invention.

Fig. 7 is a front, side perspective and partially exploded view of another embodiment of an active antenna element and reflector assembly according to an embodiment of the present invention.

Fig. 8A and 8B are assembled views of a reflector assembly having different metal surfaces, wherein fig. 8B illustrates the reflector assembly having a surface treatment, thereby facilitating stability under harsh environmental conditions, in accordance with an embodiment of the present invention.

Fig. 9A and 9B are enlarged schematic views of a portion of a plurality of heat fin and reflector assemblies and a thermally conductive liner according to an embodiment of the invention.

Fig. 9C and 9D are enlarged side perspective views showing corner portions of a reflector body according to an alternative embodiment thereof according to an embodiment of the present invention.

Fig. 10A-10E are enlarged schematic views of an example configuration of a plurality of heat fins and a portion of a reflector assembly according to an embodiment of the invention.

Fig. 11A is a schematic diagram of a fin structure bendable to form a fin according to an embodiment of the invention.

FIG. 11B is a schematic illustration of the fin structure shown in FIG. 11A in a bent configuration to provide two sides of the fin structure (e.g., side and top fins or side and bottom fins) in accordance with an embodiment of the invention.

Fig. 12 is a schematic view of a curved fin structure according to an embodiment of the invention, which may be provided by additional bending in the starting fin structure.

FIG. 13A is a top, side perspective view of another example starting fin structure having a plurality of preformed notches for bending in accordance with an embodiment of the present invention.

FIG. 13B is a front, side perspective view of the starting fin structure shown in FIG. 13A bent at multiple places to form a frame-shaped fin structure in accordance with an embodiment of the present invention.

FIG. 13C is a front, side perspective view of the fin structure shown in FIG. 13B assembled to a reflector body, according to an embodiment of the invention.

Fig. 13D is a greatly enlarged view of the corner portion of the assembly shown in fig. 13C.

Fig. 14 is a rear perspective view of a base station antenna including an active antenna element having a reflector assembly that is at least partially retained outside a passive enclosure, in accordance with an embodiment of the present invention.

Fig. 15 is a simplified transverse cross-sectional view of a base station antenna having an active antenna element, wherein a reflector assembly is maintained inside the base station antenna, in accordance with an embodiment of the present invention.

Fig. 16 is a simplified schematic diagram of a lateral cross-section of an example active antenna element illustrating a thermal path from a heat source in a radio device, according to an embodiment of the invention.

Fig. 17 is a simplified schematic diagram of a lateral cross-section of another example active antenna element illustrating a thermal path from a heat source in a radio device, according to an embodiment of the invention.

Fig. 18 is a block diagram of an example thermal flow path of an antenna according to an embodiment of the invention.

Fig. 19 is a front, side perspective view of the active antenna element shown in fig. 18.

Fig. 20 is an enlarged top view of the active antenna element shown in fig. 19.

Fig. 21 is a greatly enlarged view of the corner of the active antenna element shown in fig. 19 and 20.

Fig. 22 is a simplified cross-sectional view of the active antenna element shown in fig. 20, in accordance with an embodiment of the present invention.

Fig. 23 is a partially exploded view of the active antenna element shown in fig. 20.

Fig. 24 is a rear perspective partially exploded view of the active antenna element shown in fig. 23.

Fig. 25 is an enlarged exploded view of a portion of the active antenna element shown in fig. 23.

Detailed Description

The demand for cellular communication capabilities has grown at a high rate. As a result, the number of base station antennas has proliferated in recent years. Base station antennas are relatively large and heavy and, as mentioned above, are typically mounted on antenna towers. Due to wind loads on the antenna and the weight of the antenna and associated radios, cables, etc., antenna towers must be built to support significant loads. This increases the cost of the antenna tower.

In the following description, terms are used to describe active antenna elements and components thereof for a base station antenna that assume that the base station antenna is mounted on a tower for use, with the longitudinal axis of the antenna extending along a vertical (or near vertical) axis, and the front surface of the antenna being mounted opposite the tower or other mounting structure so as to be directed toward the coverage area of the antenna.

Embodiments of the present invention will now be discussed in more detail with reference to the accompanying drawings.

Die cast or extruded reflector structures with integrated heat sinks in active antenna elements are described in co-pending PCT/CN2021/116847, the contents of which are incorporated herein by reference as if fully set forth herein. However, integrating the heat sink into the reflector structure may require relatively expensive tools and/or manufacturing techniques. The present inventive concept provides alternative reflector assembly configurations that may reduce cost and/or weight of the reflector structure.

Referring to fig. 1, 2 and 5, a reflector assembly 10 having a reflector body 10b is shown with a lip 15 extending outwardly from the reflector body 10 b. The lip 15 may have a first 15 extending longitudinally from and perpendicular to the top and bottom walls 10t, 10w, respectively ₁ And a second 15 ₂ Lip section 15s. The lip 15 may have a third 15 extending laterally outward from the right and left side walls 10s and 10s, respectively ₃ And fourth 15 ₄ Lip section 15s. As shown, the lip 15 is perpendicular to each of the right and left side walls 10s and the bottom and top walls 10w and 10 t. A plurality of fin structures 25 may be located in front of the lip 15, the plurality of fin structures 25 being thermally conductive heat dissipating fins. The fin structure 25 may be provided with a plurality of fin surfaces 25f, which may be provided as parallel planar fin surfaces and may be located in front of the lip 15, generally flush with the front surface of the reflector body 10b or behind the front surface of the reflector body 10 b.

In some embodiments, there are a plurality of fin surfaces 25f, typically 3-10, more typically 3-6, extending from all four sides (left and right and top and bottom) of the reflector body 10 b. However, the fin structures 25 may be provided on a subset of the sides, such as two or three sides, rather than all four sides as shown.

The fin surface 25f may extend from the main reflector body 10b a distance equal to, greater than, or less than the distance that the lip 15 extends from the reflector body 10 b. Different fin surfaces 25f may have different extension lengths.

The reflector body 10b may be formed of a sheet-shaped metal such as a metal including aluminum or defined by aluminum. The lip 15 may be formed by bending a portion of sheet metal providing the reflector body 10b. The lip 15 may have an open corner space 11 between adjacent end portions of adjacent 15n lip sections 15 s.

In some embodiments, at least some of the fin structures 25 may be formed from a metal such as sheet metal.

The reflector assembly 10 may include at least one coupling member 29, the at least one coupling member 29 extending between and above and/or behind the corresponding open corners 11. The coupling member 29 may be square or rectangular, but other shapes may be used. As shown, there are four coupling members 29 at the four corners, and the coupling members 29 may cooperate with the lip 15 to define a closed reflector peripheral surface to isolate the radio 50 from the radiating element 40 (fig. 3) and/or to provide a water or water-resistant barrier.

The (main) reflector body 10b may have a rectangular shape in which a pair of long sides and a pair of short sides surround the front surface 10f. In the working position (fig. 14), the long sides may extend longitudinally, while the short sides may extend transversely.

The fin structure 25 may be provided by a mating fin structure attached to at least one of the side walls 10s, top wall 10t or bottom wall 10w of the reflector body 10 b. The fin structure 25 may be a metal stamped or other metal shaped and formed member and may be a separate component from the reflector body 10 b. The fin structure 25 need not be a die cast or extruded fin, but may be so configured (fig. 6A-6C).

The fin structure 25 may be attached to the reflector body 10b using any suitable attachment configuration, such as rivets, welding, soldered joints, brazing, chemical bonding, and the like. For the weld or soldering, one or more spaced apart weld or soldering joints may be provided along the outwardly facing surface of one or all of each of the facing fin structures 25 and each of the end walls 10t, 10w or each of the side walls. For riveting, use can be made ofA staking process to facilitate proper sealing configuration. The TOX riveting process is a cold joining process, also known as "">-rivets ", wherein during the rivet or crimping the sheet metals to be connected are force connected and positively locked to each other in a continuous forming process.

In some embodiments, a subset of the fin structures 25 may be attached together and to the lip 15 without the need to be welded, soldered, or riveted to the side wall 10s, top wall 10t, or bottom wall 10w. For example, the mating components may be secured together using a suitable arrangement and/or frictional engagement, etc. In still other embodiments, the fin structure 25 may be attached to the reflector body in other ways, and a reflector body without a lip 25 may be provided.

Referring to fig. 1, 2, 5 and 10A, for example, at least some of the plurality of fin structures 25 pass through the set 25 of stacked U-shaped channels 25U ₁ 、25 ₂ Is provided oriented such that the open end 25e of the U-shaped channel 25U faces outwardly away from the reflector body 10b and the closed end 25c of the U-shaped channel 25U is adjacent or in close proximity to the side wall 10s, top wall 10t or bottom wall 10w of the reflector body 10 b. It will be appreciated that the term "U-shaped" is used broadly herein and encompasses, for example, channels (e.g., 90 ° angles) where the side walls and bottom wall intersect at sharp angles, as opposed to circular joints, and encompasses structures where the side walls do not extend outwardly the same length.

As shown in fig. 10B-10E, at least some of the plurality of fin structures 25 are provided by a stacked set of L-shaped channels 25L oriented such that the short ends 25s of the L-shaped channels are adjacent or in close proximity to the side walls 10s, top wall 10t, or bottom wall 10w of the reflector body 10B, and the long ends of the L-shaped channels extend outwardly from the short ends.

Referring to fig. 3, the reflector assembly 10 may be provided in an active antenna unit 110. The active antenna unit 110 may include a radome 30 and a radiating element 40 protruding forward of a feed plate 40 f. The reflector assembly 10 is located behind the radiating element 40 and in front of a radio housing 50h containing the radio 50.

In some embodiments, radiating element 40 may be configured as a massive multiple-input multiple-output (mimo) array that may operate in the 3-4GHz frequency range. The radio housing 50h may include rearwardly extending heat/conduction fins 50f.

It is noted that the term "active antenna element" is interchangeably referred to herein as "active antenna module". The active antenna module may be deployed as a stand-alone base station antenna or may be deployed in a base station antenna configured as a larger antenna structure comprising additional active antenna modules and/or a conventional "passive" antenna array of a radio that may be connected to the outside of the antenna structure.

Referring to fig. 4A-4C, at least some of the fin structures 25 of the reflector assembly 10 may have recesses 12. The recess 12 may have a curve, such as a semicircle or an arc. Other recess shapes may be used. The recesses 12 may be provided as a scalloped pattern over the length of the respective surface 25f of the fin structure 25. The recess 12 may be configured to receive a securing member 115 (e.g., a screw) to couple the reflector assembly 10 to the radio housing 50h. The radio housing 50h may include a mating aperture 50a that receives the securing member 115.

Referring to fig. 6A-6C, at least some of the fin structures 25 may be provided as stacked planar fin surfaces 25f provided by the die cast or extruded body 125. The die cast or extruded body 125 may include an inner wall 125w, which inner wall 125w may be coupled to the reflector body 10b, for example, to one of the side walls 10s, top wall 10t, or bottom wall 10 w. In some embodiments, the rear wall 125b may be coupled to and/or located against the lip 15. In some embodiments, the inner wall 125w and the rear wall 125b can be coupled to respective adjacent surfaces (e.g., the side wall 10s and the lip 15) of the reflector body 10 b. Fig. 6B and 6C illustrate die cast or extruded bodies 125 that may be provided in different lengths, for example, a short side length 125s and a long side length 125l for the short side and the longer side of the reflector body 10B, respectively.

As shown in fig. 7, the reflector body 10b may have a frame configuration whereby the front surface 10f has a front perimeter with cutouts and/or apertures 28, the apertures 28 extending between the side walls 10s and having a lateral extension La in the range of 20-99% of the lateral extension La of the reflector body 10 b. At least some of the plurality of apertures 28 may also have a longitudinal extension Lo in the range of 10-90% of the longitudinal extension Lo of the reflector body 10 b.

One or more bridges 128 may provide at least a portion of the front surface 10f and may extend between adjacent apertures 28.

The aperture 28 may be located in front of one or more cavity filters 60 and behind a feed plate 40f having radiating elements 40. The front surface 10f may surround the periphery of the feed plate 40f, and the cavity filter 60 may have a front surface that cooperates with the reflector body 10b to provide a reflective surface to provide a reflector function. The cavity filter 60 may be a resonant cavity filter, as is well known to those skilled in the art. The radio may have a metal cover 50c.

The cavity filter 60 may cooperate with the radio cover 50c and thus the reflector body 10b for defining the reflector for the radiating element 40 eliminates the need for a separate reflector behind the feed plate 40f and in front of the cavity filter 60 in a conventional active antenna unit.

Referring to fig. 8A and 8B, the reflector assembly 10 may have a surface treatment 75 whereby the fin structures 25 and the surface of the reflector body 10B are manufactured to improve preservation in harsh environments such as salt, fog, smoke and other environmental exposure prior to assembly of the radiating element 40. The surface treatment may include plating, coating and/or electroplating of the metal(s) to provide a corrosion resistant surface.

Fig. 9A illustrates that the reflector assembly 10 may include rivets 200, the rivets 200 extending through the walls 10t, 10w, 10s of the reflector body 10b and into the wall provided by the closed end 25e of the U-shaped channel 25U. The rivet 200 may also extend through a dielectric liner 210 located between the reflector body 10 and the U-shaped channel 25U. In some embodiments, the dielectric liner 210 may be formed of a thermally conductive material. Fig. 9B illustrates a dielectric liner 210 on the inner surface of the walls 10t, 10w, 10 s. Where used, the inner and outer liners 210 (not shown) may also be used together in some embodiments.

The dielectric liner 210 may reduce the risk that the interface between the walls 10t, 10w, 10s and the corresponding fin structures 25, 25', 125 (shown by way of example with U-shaped channels 25U) may act as a source of passive intermodulation distortion.

FIG. 9A also illustrates the use of three fin structures 25 ₁ 、25 ₂ 、25 ₃ Thereby providing 6 fin surfaces 25f defined by three stacked U-shaped channels 25U.

Fig. 9C illustrates that the lip 15 may have a forward facing end 15e, the forward facing end 15e protruding forward of the major surface 15p of the lip 15. In some embodiments, a portion of the sheet metal may be bent twice to provide the lip 15 and the front facing end 15e. The fin structure set may be slidably received by the lip 15 within the reflector body 10b and front facing end 15e, thereby facilitating ease of assembly/alignment.

In some embodiments, as shown in fig. 9D, the front facing end 15e may itself be bent inward to provide a clamping surface to the fin structure.

Fig. 10A-10D illustrate examples of reflector assemblies 10 having different arrangements and configurations of fin structures 25, 25'. Fig. 10B-10D illustrate a fin structure 25' having L-shaped channels 25L with short ends 25s adjacent to the reflector body 10B or in close proximity to the reflector body 10B (e.g., walls 10s, 10t, or 10 w).

The term "in close proximity" refers to a location 0-1mm from an adjacent wall, such as the bottom wall 10w, top wall 10t or side wall 10s, to facilitate heat transfer. If the dielectric liner is positioned between the components such that the fin structures 25, 25', 125 and reflector body 10b are adjacent the dielectric liner, this distance may vary and the size of the close proximity increases the width of the dielectric liner.

Fig. 10A and 10D illustrate that different fin surfaces 25f may have different lengths, and some may be longer than the lip 15. Others may be shorter than the lip or have the same length.

Fig. 10B, 10C and 10D illustrate different directions of the short side 25s of the L-shaped channel 25L facing the wall 10s, 10t or 10w of the reflector body 10B. FIG. 10D illustrates four L-shaped channels 25L,25 ₁ '、25 ₂ '、25 ₃ '、25 ₄ '. Fig. 10C illustrates three fin surfaces 25f, and fig. 10D illustrates four fin surfaces 25f.

Fig. 10E illustrates that the fin structure 25 may be provided with an L-shaped channel 25L having an extra long 25xl short side 25s, which extra long 25xl short side 25s may be coupled to one or more other short sides 25s of other channel members such as the L-shaped channel member 25L (or even U-shaped channel member). Thus, the fin structure 25 may provide a nested configuration of L-shaped channels 25L, with one "L" having an extra long 25xl short side, and the other short sides 25s embedded and attachable to the extra long 25xl short side. This configuration may allow the fin structures 25 to be preassembled together and then attached as a unit to the reflector body 10b.

Turning now to fig. 11A-11B, the fin structure may be provided by bending the channel structure at least once. Fig. 11A illustrates a starting fin structure 25 having at least one recess 26 defining a curved region 25 b. Fig. 11B illustrates the resulting fin structure whereby the first fin structure section and the second fin structure section of the fin structure for the reflector assembly 10 are coplanar or parallel to each other and oriented 90 degrees from each other and can be coupled to both sides of the reflector body 10B.

Fig. 12 illustrates a three sided fin structure having two curved sections 25b, the two curved sections 25b forming co-planar first and second fin sides and first and second sections at 90 degrees to each other, whereby the respective bends may define a 90 degree bend joint for adjacent curved sections (which would include two notches 26 in the starting fin structure of fig. 11A).

Referring to fig. 13A-13D, the starting fin structure may be configured to form a four sided "frame" shaped fin structure having three curved sections (which would include three notches 26 in the starting fin structure). The notches 26 may be preformed or continuously manufactured as each successive bend 25b is manufactured, or may be manufactured in a starter piece defining spaced apart locations. The notch section 26 may form a bridge 126 that connects and extends between the curved edges of the folded/bent fin structure. After the formation of the frame fin structure, a corner 129 may be formed by the free ends of the joined or closely spaced channel members.

The use of a multi-sided folded/bent fin channel structure, particularly a double, triple or quad bent channel fin structure, may provide increased rigidity to the reflector body 10b over a single sided fin structure and allow for the use of a thinner reflector body 10b.

In some embodiments, the active antenna unit 110 with the radio 50 may be configured as a 5G module. With the introduction of fifth generation ("5G") cellular technology, currently conventionally deployed base station antennas have active beamforming capabilities. Active beamforming refers to the transmission of RF signals through a multi-column array of radiating elements, wherein the relative amplitudes and phases of the subcomponents of the RF signals transmitted (or received) by different radiating elements of the array are adjusted such that the radiation patterns formed by the individual radiating elements are beneficially combined in one or more desired directions to form a narrower antenna beam with higher gain. Using active beam forming, the shape and pointing direction of antenna beams produced by a multi-column array may be changed, for example, on a time-slot-by-time-slot basis in a time division duplex ("TDD") multiple access scheme. Furthermore, in a multi-user MIMO scenario, different antenna beams may be generated simultaneously on the same frequency resource. More complex active beamforming schemes may apply different beams to different physical resource blocks by applying a combination of frequency and time resources of a beam vector in the digital domain. Base station antennas with active beam forming capability are often referred to as active antennas. When a multi-array includes a large number of columns (e.g., sixteen or more) of radiating elements, the array is often referred to as a massive MIMO array. A module comprising a multi-column array of radiating elements implementing an active antenna and associated RF circuitry (and possibly baseband circuitry) is referred to herein as an active antenna module.

Referring to fig. 14, a base station antenna 100 is shown in accordance with some embodiments. The base station antenna 100 includes a passive antenna assembly 190, the passive antenna assembly 190 having a plurality of internal linear arrays 111 of radiating elements arranged in a plurality of laterally spaced apart and adjacent longitudinally extending columns between the top 100t and bottom 100b of the base station antenna 100. In an example embodiment, there are eight columns of the linear array 111 of radiating elements.

The active antenna element 110 may be held against the rear portion 100r of the housing 100h of the base station antenna 100 including the passive antenna assembly, the active antenna element 110 having a bracket assembly 112, the bracket assembly 112 having laterally extending spaced apart first and second brackets 113, 114. The housing 100h has a front surface 100f and side and rear portions 100s and 100r defining a radome. The bracket assembly 112 may also mount the base station antenna housing 100h with the active antenna element 110 to a target structure such as the mast 10.

Fig. 15 illustrates another embodiment of a base station antenna 100 having a housing 100h, the base station antenna 100 including a passive antenna assembly 190 sized and configured to retain an active antenna element 110 within at least a portion thereof. In some embodiments, the reflector assembly 10 may be at least partially retained within the base station antenna housing 100h without requiring any or all of the components of the active antenna element 110.

The base station antenna 100 may include one or more arrays of low band radiating elements, one or more arrays of mid band radiating elements, and one or more arrays of high band radiating elements. The radiating elements may each be dual polarized radiating elements. Further details of radiating elements can be found in co-pending WO 2019/236203 and WO 2020/072880, the contents of which are incorporated herein by reference as if fully set forth herein. For further details regarding base station antenna housings with passive antenna components and example active antenna modules, see co-pending U.S. patent application Ser. No. 17/209,562 and corresponding PCT patent application Ser. No. PCT/US2021/023617, the contents of which are incorporated herein by reference as if fully set forth herein.

The linear array 111 (of active antenna elements 110) and/or passive antenna assembly 190 may be provided as a low band radiating element, a mid band radiating element or a high band radiating element. The high-band radiating element may be configured to transmit and receive signals in the 3.3-4.2GHz band or a portion thereof and/or signals in the 5.1-5.8GHz band or a portion thereof. The mid-band radiating element may be configured to transmit and receive signals in, for example, the 1.427-2.690GHz band or a portion thereof. The low band radiating element may be configured to transmit and receive signals in, for example, the 0.616-0.960GHz band or a portion thereof.

It will be appreciated that other types of radiating elements may be used, that more or fewer linear arrays may be included in the antenna, that the number of radiating elements per array may vary, and that planar arrays or staggered linear arrays may be used instead of the "straight" linear arrays shown in the figures in other embodiments.

Fig. 16 illustrates an example thermal path Tp of heat from a heat source H in the radio 50. In fig. 16, the thermal path Tp includes a fin 25f coupled to the reflector side 10 s.

Fig. 17 illustrates that the thermal path Tp can directly leave the reflector sidewall 10s without the fins 25f. In this embodiment, the reflector side walls 10s are directly exposed to ambient conditions/air and heat flows out of the active antenna element 110 from the radio device 50 through the side walls 10 s.

Fig. 18 is a block diagram of the thermal path Tp shown in fig. 16 and 17. Heat from the heat source(s) H travels from the radio between radio circuitry in the radio 50 and the filter(s) 60 through a cover 50c on the radio 50. Filter(s) 60 may be resonant cavity filters as known to those skilled in the art. The cover 50c may be provided by the rear surface of the filter(s) 60 or by a separate cover and may be metallic.

Referring to fig. 19-21, the active antenna element 110' is similar to that shown in fig. 1-16, but the reflector body 10b has side walls 10s extending between the radome 30 and the radio 50, these side walls 10s being directly exposed to ambient conditions/air. The side wall 10s may have lips 15, wherein adjacent lip sections 15s leave an open space therebetween at the corners of the reflector body facing the radio device 50.

As discussed above, the reflector assembly 10' may include at least one coupling member 29, the at least one coupling member 29 extending between and above and/or behind the corresponding open corners 11. The coupling member 29 may be square or rectangular, but other shapes may be used. As shown, there are four coupling members 29 at the four corners, and the coupling members 29 may cooperate with the lip 15 to define a closed reflector peripheral surface to isolate the radio 50 from the radiating element 40 (fig. 3) and/or provide a water-blocking or waterproof barrier. The coupling member 29 may be metallic and may be welded, brazed and/or adhesively attached to the adjacent lip segment 15s.

Radome 30 may be a polymeric or co-polymeric material. The radio housing 50h and reflector body 10b and lip 15 may be metallic.

Referring to fig. 21, the bends between the different adjacent surfaces 10n of the sidewalls 10s may be welded, brazed or otherwise sealed together.

Referring to fig. 22-25, the radome 30 of the active antenna element 110' may be sealingly attached to the front surface 10f of the reflector body 10 b. Fig. 22 shows that the radome 30 may include an internal groove 30g for receiving the sealing member 130. The internal recess may be on the outer peripheral portion 30p of the radome 30. The outer peripheral portion 30p of the radome 30 may have an outer surface 30e that is planar. Attachment members 230 (typically on each side) may extend through the radome 30 and into the front surface 10f of the reflector body 10b to attach the components together and provide a water-blocking seal.

The radio housing 50h may be sealingly attached to the lip 15 of the reflector body 10 b. One or both components may include a sealing member, such as a gasket or O-ring, that may assist in the water-blocking seal therebetween. The radio housing 50h may have an outer perimeter with an outwardly projecting planar edge 50e that surrounds the recess 50r of the housing 50h and abuts the major surface of the lip 15. The cover 50c may be located in the recess 50 r. The cavity filter 60 may be at least partially in front of the radio 50 within the reflector body 10 b.

In some embodiments, the side walls 10s of the reflector body 10b may have a height "h" that is typically in the low profile range of about 20-60mm, such as about 30-50mm, for example about 38 mm. The lip 15 may protrude outward from the side wall 10s by a distance smaller than the height h of the side wall 10 (the height measured in the front-rear direction as shown in fig. 20). The lip 15 may protrude outwardly from the side wall 10s a distance that is the same as the height of the side wall 10s or even greater than the height of the side wall 10 s.

The long sides of the reflector body 10b may have lips 15 and sidewalls 10s, which may have a length "L" extending longitudinally and which is greater than the width/lateral extension "W" of the lips 15 on the short sides of the reflector body 10b (i.e., at the top and bottom thereof). In some embodiments, the long edge lip 15 and the side wall 10s are 1.5 to three times the width W. Different side walls 10s may have lips 15 of different sizes (not shown).

The radio fins 50f may have an outward extent of protrusion that is greater than the extent of outward protrusion of the fins 25f of the reflector 10, typically 2-20 times greater when in use. The radio fins 50f may have a degree of outward protrusion that is greater than the height "h" of the reflector sidewall 10 s.

Embodiments of the present invention have been described above with reference to the accompanying drawings in which embodiments of the present invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

In the discussion above, reference is made to a linear array of radiating elements that are typically included in a base station antenna. It will be appreciated that the term "linear array" is used broadly herein to encompass both arrays of radiating elements comprising a single column of radiating elements configured to transmit sub-components of an RF signal and a two-dimensional array (e.g., a plurality of linear arrays) of radiating elements configured to transmit sub-components of an RF signal. It will also be appreciated that in some cases, the radiating elements may not be arranged along a single line. For example, in some cases, a linear array of radiating elements may include one or more radiating elements that are offset from a line along which the remaining radiating elements are aligned. Such "staggering" of radiating elements may be done to design an array with a desired azimuthal beamwidth. Such an interleaved array of radiating elements is configured to transmit sub-components of an RF signal encompassed by the term "linear array" as used herein.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a similar fashion (i.e., "between" and "directly between", "adjacent" and "directly adjacent", etc.).

The term "about" with respect to a number means that the stated number may vary by +/-20%.

As shown in the figures, relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe one element, layer or region's relationship to another element, layer or region. It will be understood that these terms are also intended to encompass different orientations of the device in addition to the orientation depicted in the figures.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used herein, specify the presence of stated features, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, operations, elements, components, and/or groups thereof.

Aspects and elements of all embodiments disclosed above may be combined in any manner and/or with aspects or elements of other embodiments to provide additional embodiments.

Claims (37)

1. A reflector assembly for a base station antenna, comprising:

a reflector body having an outer periphery providing a lip extending outwardly from the reflector body; and

a plurality of fin structures stacked in the front-rear direction around the outer periphery.

2. The reflector assembly of claim 1, wherein the reflector body comprises a front surface, wherein the lip extends laterally and/or longitudinally behind the front surface, and wherein the plurality of fin structures are located in front of the lip.

3. The reflector assembly of claim 1, wherein the reflector body is rectangular with a pair of long sides and a pair of short sides, and wherein the lips are provided as a plurality of outwardly extending lip segments, at least one lip segment extending outwardly from each of the long sides and/or each of the short sides.

4. The reflector assembly of claim 1, wherein the lip is defined by at least one fold or bend in a portion of the sheet metal providing the reflector body.

5. The reflector assembly of claim 4, wherein the lip comprises four lip segments, wherein adjacent end portions of at least a first and second of the lip segments are spaced apart and define an open corner space.

6. The reflector assembly of claim 5, further comprising a coupling member extending across the open corner space.

7. The reflector assembly of claim 1, wherein at least some of the plurality of fin structures are provided by a stacked set of U-shaped channels, oriented such that an open end of the U-shaped channels faces outwardly away from the reflector body and a closed end of the U-shaped channels is adjacent or in close proximity to a side wall, top wall, or bottom wall of the reflector body.

8. The reflector assembly of claim 1, wherein at least some of the plurality of fin structures are provided by stacked sets of L-shaped channels, oriented such that short ends of the L-shaped channels are adjacent or in close proximity to a side wall, top wall, or bottom wall of the reflector body.

9. The reflector assembly of claim 1, wherein the reflector body has a pair of laterally spaced apart side walls and longitudinally spaced apart top and bottom walls, the side walls, top and bottom walls surrounding a front surface of the reflector body, and wherein the side walls, top and bottom walls extend perpendicularly to and rearwardly in a front-to-rear direction between the lip and front surface of the reflector body.

10. The reflector assembly of claim 9, wherein a first subset of the plurality of fin structures is secured to the side wall, and wherein a second subset of the plurality of fin structures is secured to the top wall or the bottom wall.

11. The reflector assembly of claim 1, wherein at least some of the plurality of fin structures are welded, soldered, brazed and/or riveted to one or more of the top, bottom or side walls of the reflector body, optionally wherein a dielectric liner is located between the respective fin structure and the corresponding top, bottom or side wall.

12. The reflector assembly of claim 1, wherein the reflector body comprises a plurality of apertures, at least some of the plurality of apertures having a lateral extension in the range of 20-90% of the lateral extension of the reflector body.

13. The reflector assembly of claim 12, wherein at least some of the plurality of apertures further have a longitudinal extension in the range of 10-60% of the longitudinal extension of the reflector body.

14. The reflector assembly of claim 1, wherein the reflector body is provided as a frame providing a lip, wherein the reflector body is configured to cooperate with one or more substrates for defining a reflector front surface behind a radiating element and in front of a radio.

15. The reflector assembly of claim 1, wherein at least some of the plurality of fin structures are provided by an elongated channel member that is bendable or foldable to define a respective fin structure comprising first and second sections that are coplanar and orthogonal to each other, whereby bending forms a 90 degree bend joint, and wherein the first and second sections of the elongated channel extend in front of the lip.

16. The reflector assembly of claim 1, wherein the lip extends laterally outward from and perpendicular to the right and left side walls, and wherein the lip extends longitudinally from and perpendicular to the top and bottom walls.

17. The reflector assembly of claim 16, wherein at least some of the plurality of fin structures are provided by an extruded or die cast member that is a separate component from the reflector body.

18. The reflector assembly of claim 1, wherein at least some of the plurality of fin structures comprise a fin surface having at least one curvilinear outward facing perimeter defining a recess configured to receive a corresponding securing member.

19. The reflector assembly of claim 1, wherein the reflector body and the plurality of fin structures comprise a corrosion resistant surface treatment, such as plating and/or coating or electroplating.

20. An active antenna element comprising:

the reflector assembly of any one of claims 1-19;

a radio behind the reflector assembly;

a radio housing holding the radio; and

a radiating element in front of the reflector assembly.

21. A base station antenna comprising the reflector assembly of any of claims 1-19.

22. A reflector assembly for a base station antenna, the reflector assembly comprising:

a reflector body including a front face having a perimeter; and

a thermally conductive fin structure comprising a plurality of stacked channel members coupled to a reflector body and extending laterally and/or longitudinally outward from a perimeter of the reflector body.

23. The reflector assembly of claim 22, further comprising a lip extending outwardly from and rearward of the perimeter of the front face of the reflector body.

24. The reflector assembly of claim 23, wherein the reflector body comprises sheet metal, and wherein the lip is formed by bending at least one of a portion of the sheet metal.

25. The reflector assembly of claim 22, wherein the stacked channel member is a sheet metal U-shaped or L-shaped channel.

26. The reflector assembly of claim 22, wherein the stacked channel member is provided as an extruded or die cast member.

27. The reflector assembly of claim 22, further comprising a dielectric liner between the plurality of stacked channel members and the facing portion of the reflector body.

28. An active antenna element for a base station antenna, comprising:

a reflector body having an outer periphery providing a lip extending outwardly from the reflector body;

a radome coupled to and in front of the reflector body; and

a radio coupled to and behind the reflector body.

29. An active antenna element as claimed in claim 28, wherein the reflector body comprises a front surface, wherein the lip extends laterally and/or longitudinally behind the front surface, wherein the reflector body comprises a plurality of side walls extending behind the front surface, and the plurality of side walls are configured to couple the front surface to the lip, and wherein, in use, the side walls are directly exposed to ambient conditions.

30. An active antenna element as claimed in claim 29, wherein all side walls are free of outwardly protruding heat sinks and define a heat outlet for a heat path from one or more heat sources in the radio.

31. An active antenna element as claimed in claim 28, wherein the reflector body is rectangular with a pair of long sides and a pair of short sides, and wherein the lips are provided as a plurality of outwardly extending lip sections, at least one lip section extending outwardly from each long side and/or each short side.

32. An active antenna element as claimed in claim 28, wherein said lip is defined by at least one fold or bend in a portion of sheet metal providing said reflector body.

33. An active antenna element as recited in claim 28, wherein the lip comprises four lip sections, wherein adjacent end portions of at least a first and a second of the lip sections are spaced apart and define an open corner space.

34. An active antenna element as recited in claim 32, further comprising a coupling member extending across the open corner space.

35. An active antenna element as recited in claim 28, wherein the radome comprises an outer perimeter portion including an internal groove that holds a sealing member, and wherein the radome is sealably coupled to the front surface of the reflector body.

36. An active antenna element as claimed in claim 29, wherein said side wall has a height in the range of about 20mm to about 50 mm.

37. An active antenna element as claimed in claim 28, wherein at least one of said side walls comprises an outwardly projecting heat sink located in front of said lip.