WO2023147696A1

WO2023147696A1 - Active antenna units for base station antennas

Info

Publication number: WO2023147696A1
Application number: PCT/CN2022/075347
Authority: WO
Inventors: Fan He; Fusheng LYU; Zhanming ZHANG; Chengcheng Tang
Original assignee: Commscope Technologies Llc; WU, Ligang
Priority date: 2022-02-07
Filing date: 2022-02-07
Publication date: 2023-08-10

Abstract

Active antenna units for base station antennas are provided that include a radio housing, a radio cover, radiating elements that extend forward of feedboards and a plurality of cavity filter units. The radio cover has spaced apart apertures aligned with one or more cavity filter units. The cavity filter units can have die cast metal bodies or non-metallic bodies with one or metallized surfaces and can be electrically coupled to a radio cover and/or a metallized surfaces of a non-metallic substrate to define a ground plane without requiring a separate reflector.

Description

ACTIVE ANTENNA UNITS FOR BASE STATION ANTENNAS

BACKGROUND

The present invention generally relates to radio communications and, more particularly, to base station antennas for cellular communications systems.

Cellular communications systems are well known in the art. In a cellular communications system, a geographic area is divided into a series of regions or "cells" that are served by respective macrocell base stations. Each macrocell base station may include one or more base station antennas that are configured to provide two-way radio frequency ( "RF" ) communications with subscribers that are within the cell served by the base station. In many cases, each base station is divided into "sectors. " In one common configuration, a hexagonally-shaped cell is divided into three 120° sectors in the azimuth plane, and each sector is served by one or more macrocell base station antennas that generate radiation patterns (referred to herein as "antenna beams" ) that have an azimuth Half Power Beamwidth (HPBW) of approximately 65°. So-called small cell base stations may be used to provide service in high-traffic areas within portions of a cell. Typically, the base station antennas are mounted on a tower or other raised structure, with the antenna beams that are generated by the base station antennas directed outwardly.

FIG. 1 is an exploded perspective view of a conventional active antenna unit 11. The active antenna unit 11 may be used as a standalone base station antenna or may be mounted to a passive base station antenna to provide active antenna functionality to the passive base station antenna. Referring to FIG. 1, the active antenna unit 11 includes a radome 11r, radiating elements 12 projecting forward from feedboards 14, a reflector 15, a calibration board 17, cavity filters 20, a radio cover 22 and radio 25r with a heat sink body 25. The reflector 15, cavity filter with shielding cover 20c and the radio cover 22 can each be formed of metal defining respective separate ground planes.

SUMMARY

Pursuant to embodiments of the invention, active antenna units for base station antennas are provided that include a radio cover with a plurality of spaced apart apertures that can reduce weight thereof relative to conventional radio covers. The radio cover apertures can be sized and configured to receive at least a part of one or more cavity filters.

The cavity filters can comprise a body with a three-dimensional structure that can be formed of a nonmetallic substrate with metal on at least part of one or more surfaces (metallized surface (s) ) of the non-metallic substrate. Optionally, the non-metallic substrate and metal surfaces may be provided as a plastic with one or metallized surface (s) .

The cavity filters can comprise a body with a three-dimensional structure that can be formed of a die cast metal.

The active antenna unit can include an array of radiating elements that can optionally be provided as patch radiating elements.

The cavity filters can cooperate with the radio cover to define a ground plane for the plurality of linear arrays of radiating elements.

The cavity filters and feedboards can act as a reflector for the linear arrays of radiating elements while the cavity filters and radio cover can act as an electromagnetic interference (EMI) shield thereby isolating the antenna and radio.

The cavity filters can each have a metallized or metal front cover that cooperate to define a ground plane for the linear arrays of radiating elements.

Further aspects of the present invention are directed to an active antenna unit that includes: a radio; a radio housing holding the radio; and a radio cover coupled to the radio housing. The radio cover has a plurality of spaced apart apertures. The active antenna unit also includes a plurality of cavity filters residing at least partially in front of the radio cover.

One or more of the cavity filters can be aligned with a respective one of the plurality of spaced apart apertures.

The radio housing can extend in a lateral direction and a longitudinal direction that is orthogonal to the lateral direction. The plurality of spaced apart apertures can each have a shape or shapes that is/are elongate in the lateral direction, elongate in the longitudinal direction or elongate in both the lateral and longitudinal directions.

At least one cavity filter of the plurality of cavity filters can be at least partially received into one aperture of the plurality of spaced apart apertures of the radio cover whereby a rearward portion of the at least one cavity filter resides behind a primary surface of the radio cover.

At least some of the plurality of cavity filters can have a perimeter with an outwardly extending lip that can electrically couple to a metal surface of the radio cover to thereby define an electrical ground plane and/or EMI (electromagnetic interference) shield.

The active antenna unit can further include a radome mounted forwardly of the radio housing and can include at least one feedboard, typically a plurality of feedboards, with a plurality of radiating elements projecting forward of the feedboard (s) residing between the radio cover and the radome.

The plurality of radiating elements can be provided as or include a massive multiple input multiple output (MIMO) antenna array.

The cavity filters can have respective metal die cast cavity filter bodies

The cavity filters can have respective non-metallic bodies with at least one surface that is metallized.

The active antenna unit can further include a non-metallic substrate residing behind the feedboards and in front of the radio cover.

The non-metallic substrate can include a plurality of non-metallic substrate segments that substantially (e.g., within +/-10 degrees) reside in a common plane.

The non-metallic substrate can have at least one metallized outer surface that can be configured to define at least part of a reflector for the radiating elements.

The non-metallic substrate can be devoid of metallized outer surfaces and can be sized and configured to provide structural support for the feedboards.

At least some of the plurality of non-metallic substrate segments can include apertures that can be aligned with one or more of the plurality of cavity filters.

The radio housing can have a chamber with a primary surface facing the radio cover. The radio cover can be metal. The cavity filters can have a metal or metallized front surface that covers a respective cavity. The cavity filters can have a rearwardly extending cavity body. The cavity body can reside at least partially behind the radio cover and can reside adjacent the primary surface of the chamber.

A front of each of the cavity filters can cooperate with a metallized surface of the non-metallic substrate to define a reflector and/or ground plane for the feedboards and/or radiating elements.

A front of each of the cavity filters can cooperate with the radio cover to define a ground plane for the feedboards and/or radiating elements and/or to define an isolation layer between the radio and the radiating elements.

The cavity filters can cooperate with the radio cover to define a closed surface layer when viewed from a front to back direction to thereby isolate the radiating elements from a radio behind the radio cover.

The active antenna unit can further include a radome, and a plurality of radiating elements extending forward of a plurality of feedboards. The feedboards and the plurality of radiating elements can reside behind the radome and in front of the non-metallic substrate. A front surface of the non-metallic substrate can have a surface area that is greater than a cumulative surface area defined by a sum of respective surface areas of front surfaces of each of the feedboards.

At least some of the cavity filters can have a front or front portion with a lip on an outer perimeter thereof. The lip of at least some neighboring cavity filters may overlap.

The position of the outer perimeters of the cavity filters can be misaligned or staggered with the outer perimeters of the feedboards to minimize or prevent aligned gap spaces of respective outer perimeters.

Yet other aspects of the present invention are directed to an active antenna unit that includes: a radome and a plurality of radiating elements extending forward of a plurality of feedboards. The feedboards and the plurality of radiating elements reside behind the radome. The active antenna unit also includes a radio housing holding a radio and a radio cover coupled to the radio housing. The radio cover includes a plurality of spaced apart apertures. The active antenna unit also includes a plurality of cavity filters residing at least partially in front of the radio cover. At least one cavity filter of the plurality of cavity filters is at least partially received into one aperture of the plurality of spaced apart apertures of the radio cover whereby a rearward portion of the plurality of cavity filters reside behind a primary surface of the radio cover.

A front portion of at least some of the cavity filters can cooperate with the radio cover to define a reflector and/or ground plane for the feedboards and/or radiating elements.

The active antenna unit can also include a non-metallic substrate positioned between the radio cover and the feedboards.

A front of at least some, typically of each, of the cavity filters can cooperate with the non-metallic substrate to define a reflector and/or ground plane for the feedboards and/or the radiating elements.

The non-metallic substrate can be provided by a plurality of coupled substrate segments that can be arranged to be substantially in a common plane (e.g., +/-10 degrees) when coupled together.

The plurality of cavity filters can have respective bodies of a non-metallic substrate with one or more metallized surfaces.

The plurality of cavity filters can have respective bodies of die cast metal.

At least some of the cavity filters can have a front portion with a lip on an outer perimeter thereof. The lips of neighboring cavity filters overlap and/or the lip of at least some of the cavity filters can include metal and can electrically couple to the radio cover.

The active antenna unit can be provided in combination with a passive antenna housing of a base station antenna. The active antenna can be held at least partially inside the passive antenna housing.

The active antenna unit can be provided in combination with a passive antenna housing of a base station antenna. The active antenna can be held external to a rear of the passive antenna housing.

Other aspects of the present invention are directed to a base station antenna that includes: a passive antenna housing with a radome and an active antenna unit held inside or coupled to a rear of the passive antenna housing. The active antenna unit includes: a radome and a plurality of radiating elements extending forward of a plurality of feedboards. The feedboards and the plurality of radiating elements reside behind the radome. The active antenna unit also includes: a radio housing holding a radio; and a radio cover coupled to the radio housing. The radio cover has a plurality of spaced apart apertures. The active antenna unit also includes a plurality of cavity filters residing at least partially in front of the radio cover. At least one cavity filter of the plurality of cavity filters is at least partially received into one aperture of the plurality of spaced apart apertures of the radio cover whereby a rearward portion of the plurality of cavity filters reside behind a primary surface of the radio cover.

The plurality of cavity filters can have metal bodies and/or have one or more metallized surfaces. The radio cover can be metal. The plurality of cavity filters can cooperate with the radio cover to define an electromagnetic interference (EMI) shield and/or ground plane for the radiating elements.

The base station antenna can further include a non-metallic substrate residing between the feedboards and the radio cover.

A front of each of the cavity filters cooperate with a metallized surface or metallized surfaces of the non-metallic substrate to define a reflector and/or ground plane for the feedboards and/or radiating elements.

The non-metallic substrate can be provided by a plurality of substrate segments that are coupled together and arranged to substantially be in a common plane when coupled together.

The non-metallic substrate segments can include apertures, which can be elongate in at least one dimension.

The plurality of cavity filters can have respective bodies of a non-metallic substrate with one or metallized surfaces

The plurality of cavity filters can have respective bodies of die cast metal

At least some of the cavity filters can have a front portion with a lip on an outer perimeter thereof. The lip of respective neighboring cavity filters can overlap. The lip of at least some of the cavity filters can be metallized and/or be metal and electrically couple to the radio cover.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front, side perspective, partially exploded view of a prior art active antenna unit.

FIG. 2 is a front, side perspective, partially exploded view of an active antenna unit according to embodiments of the present invention.

FIG. 3A is a front, side, partially exploded view of an active antenna unit according to further embodiments of the present invention.

FIG. 3B is a greatly enlarged view of neighboring cavity filters shown in FIG. 3A.

FIG. 4 is a front, side perspective, partially exploded view of an active antenna unit according to still further embodiments of the present invention.

FIG. 5A is a front, side perspective, partially exploded view of an active antenna unit according to additional embodiments of the present invention.

FIG. 5B is a greatly enlarged view of neighboring segments of a non-metallic substrate shown in FIG. 5A.

FIG. 6 is a front, side perspective, partially exploded view of an active antenna unit according to still further embodiments of the present invention.

FIG. 7A is a front, side perspective, partially exploded view of an active antenna unit according to yet additional embodiments of the present invention.

FIG. 7B is a greatly enlarged view of neighboring segments of a non-metallic substrate shown in FIG. 7A.

FIG. 8 is a is a front, side perspective, partially exploded view of the active antenna unit shown in FIG. 3A illustrated with the cavity filters and radio cover in an example assembled configuration.

FIG. 9 is a is a front, side perspective, partially exploded view of the active antenna unit shown in FIG. 5A illustrated with the cavity filters and radio cover in an example assembled configuration.

FIG. 10 is a is a front, side perspective, partially exploded view of the active antenna unit shown in FIG. 7A illustrated with the cavity filters and radio cover in an example assembled configuration.

FIG. 11A is a greatly enlarged, side perspective, partially exploded view of a cavity filter and radio cover with a shielding coupling member therebetween according to embodiments of the present invention.

FIG. 11B is an assembled view of the cavity filter, shielding coupling member and radio cover shown in FIG. 11A.

FIG. 12A is an enlarged front, side perspective view of feedboards with radiating elements mounted thereon and a conductor interface for inner conductors of respective cavity filters according to embodiments of the present invention.

FIG. 12B is a greatly side perspective view of the inner conductor to feedboard interface/connections shown in FIG. 12A.

FIG. 13A is an enlarged front, side perspective view of feedboards with radiating elements mounted thereon and a conductor interface for an inner conductor of respective cavity filters according to other embodiments of the present invention.

FIG. 13B is a greatly side perspective view of the inner conductor to feedboard interface/connections shown in FIG. 13A.

FIG. 14 is a front, side perspective view of feedboards and cavity filters according to embodiments of the present invention.

FIGs. 15-17 are schematic side views of example width/lengths of feedboards and cavity filters according to embodiments of the present invention.

FIG. 18 is a front view of feedboards and a radio cover according to embodiments of the present invention.

FIG. 19 is a front view of feedboards and a non-metallic substrate according to embodiments of the present invention.

FIG. 20 is a rear view of a radome and feedboards according to embodiments of the present invention.

FIG. 21 is an enlarged, side, front perspective view of another embodiment of a radio cover and adjacent cavity filters according to embodiments of the present invention.

FIG. 22 is a rear view of the radio cover and cavity filters shown in FIG. 21 illustrated assembled together.

FIGs. 23-25 are partially exploded, side views of example active antenna units according to embodiments of the present invention.

FIGs. 26A-26D are side perspective views of an example assembly sequence for assembling the radiating elements and cavity filters to the radio cover according to embodiments of the present invention.

FIG. 27 is a rear perspective view of a base station antenna comprising the active antenna unit held at least partially external to the passive antenna housing according to embodiments of the present invention.

FIG. 28 is a simplified lateral cross-section view of a base station antenna with the active antenna unit held inside the base station antenna according to embodiments of the present invention.

DETAILED DESCRIPTION

The demand for cellular communications capacity has been increasing at a high rate. As a result, the number of base station antennas has proliferated in recent years. Base station antennas are both relatively large and heavy and, as noted above, are typically mounted on antenna towers. Due to the wind loading on the antennas and the weight of the antennas and associated radios, cabling and the like, antenna towers must be built to support significant loads. This increases the cost of the antenna towers.

In the description that follows, active antenna units for base station antennas and the components thereof are described using terms that assume that the base station antennas are mounted for use on a tower with the longitudinal axis of the antenna extending along a vertical (or near vertical) axis and the front surface of the antenna mounted opposite the tower or other mounting structure pointing toward the coverage area for the antenna.

Embodiments of the present invention will now be discussed in greater detail with reference to the attached figures.

With reference to FIG. 2, an active antenna unit 110 is shown. It is noted that the term “active antenna unit” is interchangeably referred to herein as an “active antenna module” . The active antenna unit 110 can include a radome 111, radiating elements 120, feedboards 140, cavity filters 150, a radio cover 170 and a radio housing 180 comprising a radio 182. The cavity filters 150 can be resonant cavity filters as is well known to those of skill in the art. The radio cover 170 can be metal.

Active antenna modules may be deployed as standalone base station antennas or may be deployed in base station antennas configured as larger antenna structures that include additional active antenna modules and/or conventional "passive" antenna arrays that may be connected to radios that are external to the antenna structures.

The cavity filters 150 can have primary bodies 150b that have an internal cavity with a front 150f that covers the internal cavity 150c and the front 150 can merge into a rear portion 150r. The rear portion 150r can have a smaller lateral and/or longitudinal extent than the front 150f. The cavity filters 150 can have an outer perimeter with an outer projecting lip 151 on at least one side thereof, shown as on all four sides.

The radio cover 170 can include a plurality of apertures 171 that are spaced apart along a length L and/or width W dimension of the radio cover 170 and/or active antenna unit 110. The length dimension corresponds to a longitudinal direction of the base station antenna and/or active antenna unit 110.

The apertures 171 can be elongate in at least one dimension. Each of the apertures 171 can be sized and configured to slidably receive at least a rear portion 150r of at least one cavity filter 150. The “nested” configuration of the cavity filters 150 and radio cover 170 can reduce the depth (back to front direction) and/or weight of the active antenna unit 110 relative to active antenna units 110 with sold radio covers 170.

The cavity filters 150 can cooperate with the radio cover 170 to define a ground plane for the radiating elements 120

The cavity filters 150 can cooperate with the feedboards 140 or the radio cover 170 to define a reflector thus eliminating the need for a separate reflector behind the feedboards 140 and in front of the cavity filters 150 as in conventional active antenna units.

The cavity filters 150 can electrically couple to a metal surface of the radio cover 170 to thereby define an electrical ground plane and/or EMI (electromagnetic interference) shield.

In some embodiments, the cavity filters 150 can have three-dimensional bodies 150b that are formed of non-metallic substrates with one or more surfaces thereof metallized 150m. For example, the front 150f can be metallized and/or the lip 151 can be metallized on at least one external surface thereof. In some embodiments, the non-metallic substrate is preformed, e.g., injection molded, and the metal is thereafter applied. Suitable methods for applying the metal to the non-metallic substrate may include coating the substrate with the metal, for example, by spraying, dipping, painting, (electro) plating, and flooding. Suitable methods for applying the metallization to the body 150b formed by the non-metallic substrate may also include laminating a metal onto the substrate. In some embodiments, the metallization can be co-laminated, coextruded, or co-molded (e.g., insert molded or thermoformed) with the substrate. Different surfaces of the cavity filter body 150b may have different metal and the different metal may be provided in different manners. In some embodiments, a common metal can be applied to all surfaces that are desired to be metallized and the common metal can be provided in a common thickness or different thicknesses, on average. The non-metallic substrate of the cavity filter 150 can be any suitable material and may comprise a polymer, copolymer and/or plastic such as a sheet molding compound or fiber reinforced ceramic.

The metal for the metallized surface (s) 150m can comprise aluminum or an aluminum alloy. In some embodiments, the metal can comprise one or more of copper, aluminum, silver, tin, nickel, or combinations or alloys thereof. In some embodiments, the metal comprises a metal having an electrical conductivity in the range of from about 9x10 ⁶ to 6.3x10 ⁷ siemens per meter (S/m) .

Alternatively, the cavity filters 150 can have three-dimensional bodies 150b that are metal die cast bodies.

Referring to FIG. 2, the cavity filters 150 can be spaced apart longitudinally and/or laterally with the radio cover 170 filling any gap space between cavity filters 150 so that the cavity filters 150 and the radio cover 170 together define a continuous surface. As shown in FIG. 2, adjacent pairs 150p of cavity filters 150 can be attached at inner facing sides. Neighboring pairs 150p can be longitudinally spaced apart with the radio cover 170 defining a solid surface therebetween.

As shown in FIG. 3A, the cavity filters 150 can be provided as a filter bank 153 of attached cavity filters 150 provided in rows and at least one column. The rows R may extend laterally or longitudinally. As shown, each row R extends laterally. Each row R (shown as four rows R ₁-R ₄) of cavity filters 150 can have a plurality of rearwardly extending projections forming the rear portion 150r of the cavity filter and residing at least partially in an aligned aperture 171 of the radio cover 170.

The lip 151 and/or front 150f of the cavity filters 150 can be metal or a non-metallic substrate that is metallized 150m on at least one primary surface, typically at least the primary surface facing the radio cover 170, to electrically couple/connect to the underlying radio cover 170.

Referring to FIG. 3B, neighboring lips 151n of neighboring cavity filters 150 can be slidably coupled with a first lip 151 of a first filter 150 extending over a second lip 151 of a second filter 150 so that the two lips 150 overlap to prevent an exposed open space therebetween. The primary surfaces of the lips 151 abutting/facing each other can be metallized or metal 150m, e.g., a primary surface 151b of a front (shown as upper) lip 151f and a primary surface of a back (shown as a bottom) lip 151b can be metallized or metal. However, other configurations of cavity filters 150 and couplers can be used to couple the cavity filters 150 to define a “closed” layer” with the radio cover 140 having the apertures to thereby minimize open spaces for providing sufficient EMI shielding with the radio cover 140.

It is noted that the position of the outer perimeters of the front of the cavity filters 150 can be misaligned or staggered with the outer perimeters of the feedboards 140s to minimize or prevent aligned gap spaces of respective outer perimeters. For example, the line defining one side of the outer perimeter of one column or row of cavity filters can be offset from a line defining one side of the outer perimeter of a corresponding one column or row of feedboards 140. The lines of both may be straight or one line can be offset and the other may be zig-zagged or staggered.

Turning now to FIGs. 4 and 5A, in other embodiments, the active antenna unit 110 can also include a non-metallic substrate 190 that can have at least one primary surface 190p that can be at least partially (typically totally) metallized 190m. The front and/or back primary surface 190 can be metallized 190m. The non-metallic substrate 190 can define a reflector for the radiating elements 120. The non-metallic substrate 190 can be more economic or have less weight than conventional aluminum reflectors. As discussed above for embodiments of the cavity filters 150, the nom-metallic substrate 190 can be planar with sufficient rigidity to support the feedboards 140. The non-metallic substrate 190 can comprise any suitable non-metallic material including those discussed above. The metal for the metallized surface (s) 190m can comprise aluminum or an aluminum alloy. In some embodiments, the metal can comprise one or more of copper, aluminum, silver, tin, nickel, or combinations or alloys thereof.

FIG. 5A illustrates that in some embodiments the non-metallic substrate 190 can be provided as a plurality of substrate segments 190s that can be coupled together and arranged to reside substantially in a common plane so as to be parallel with the feedboards 140 and/or radio cover 170.

The term “substantially in a common plane” means that slight variations may occur over a length and or width. For example, edge to edge, the primary planes of each of the assembled substrate segments 190s reside within +/-10 degrees of a primary plane of one another and/or of a primary plane of the radome 111 and/or radio cover 170.

The substrate segments 190s can be arranged in a plurality of rows R (shown as R ₁-R ₄) and a plurality of columns C (shown as C ₁ and C ₂) . FIG. 5B illustrates that the substrate segments 190s can comprise lips 191 and neighboring lips 191n can slidably couple together with a front lip 191f over a back lip 191b to prevent gaps between adjacent/neighboring substrate segments 190s.

Referring now to FIGs. 6 and 7A, in some embodiments, the non-metallic substrate 190 can define a frame 190f that has a plurality of apertures 192 that are longitudinally and/or laterally spaced apart. The apertures 192 can have the same size and shape as the apertures 171 of the radio cover 170. The apertures 190 can be smaller than the apertures 171 in the radio cover 170.

The frame 190f of the non-metallic substrate 190 can be coupled to the cavity filters 150 and can be configured to support the feedboard 140. The frame 190f can be configured to reside on the lips 151 of the cavity filters 150, spaced apart from and in front of the radio cover.

In some embodiments, the non-metallic substrate 190 is devoid of metallization.

In some embodiments, the non-metallic substrate 190 does not extend a full length and/or width of the feedboards 140 while providing mechanical support to the structure.

In some embodiments, at least part of one primary surface 190p is metallized 190m, typically substantially (about 70%or greater) of an entire front primary surface facing the feedboards 140.

FIG. 7A illustrates that the non-metallic substrate 190 can be provided as a plurality of substrate segments 190s that can be coupled together and arranged to reside substantially in a common plane so as to be parallel with the feedboards 140 and/or radio cover 170. The substrate segments 190s can be arranged in a plurality of rows R (shown as R ₁-R ₄) and a plurality of columns C (shown as C ₁ and C ₂) . FIG. 7B illustrates that the substrate segments 190s can comprise lips 191 and neighboring lips 191n can slidably couple together with a front lip 191f over a back lip 191b to prevent gaps between adjacent, neighboring substrate segments 190s.

FIGs. 8-10 illustrates example nested configurations of the cavity filters 150 and radio cover 170 according to embodiments of the present invention.

Still referring to FIGs. 8-10, the radio housing 180 can define or include heat sink components and one or more surfaces can have heat fins 180f. The radio housing 180 can include a chamber 181 with a primary surface 181p that faces the feedboards 140 and radome 111. The radio cover 170 can extend over the primary surface 181p of the chamber 181.

Referring to FIGs. 11A and 11B, a cavity filter 150 is shown in alignment with an aperture 171 of the radio cover 170. A shielding coupling member 250 such as a metal member or a shielding gasket comprising conductive material such as graphite can be positioned between a rear portion 150p of the cavity filter 150 and radio cover 170. The shielding coupling member 250 can reside behind the front lip 151 and may be pushed forward at assembly to the radio cover 170 as shown between position A in FIG. 11A whereby the shielding coupling member 250 is spaced apart a first distance from the lip 151 that is greater than the assembled position B in FIG. 11B.

Referring to FIGs. 1-10, the feedboards 140 can be coupled together to substantially reside in a common plane. The term “substantially with respect to a common plane” means that slight variations may occur over a length and or width but that edge to edge, the feedboards 140 can reside within about +/-10 degrees of a primary plane of each other and/or of a primary plane of the radome 111 and/or radio cover 170.

The feedboards 140 can be provided in any suitable number, typically in a range of 2-20, such as 4-8, in some embodiments. For example, where there are 8 cavity filters 150, the feedboards 140 can be provided as 4-8 feedboards and each feedboard can have 12-24 radiating elements 120 mounted thereon.

The radiating elements 120 can be arranged as columns of radiating elements as shown. The radiating elements 120 can define columns 121 of radiating elements 120 that can be configured as massive Multiple Input, Multiple Output (mMIMO) arrays. The radiating elements can be provided as patch radiating elements, in some embodiments. The radiating elements 120 can be provided as cross dipole radiating elements in other embodiments.

In some particular embodiments, the feedboards 140 can be provided as multi-layer printed circuit boards that incorporate calibration circuitry.

Turning now to FIGs. 12A and 12B, the cavity filters 150 can comprise integrated inner conductors 152 connected to and/or aligned with an interface 142 of a corresponding feedboard 140. Each cavity filter 150 can comprise a plurality of inner conductors 152 that project forward from the front 150f of the cavity filters 150. The inner conductors 152 can extend through the feedboards 140 to provide the feedboard connections 142. These inner conductors 152 can be soldered to the respective feedboards 140. Each inner conductor 152 may comprise, for example, a metal pin or rod.

FIGs. 13A and 13B illustrate that the integrated inner conductors 152’ of the cavity filters 150 can, in some embodiments, be configured as pogo pin contacts and do not require soldering for attachment/assembled connection thereby allowing for easier disassembly from the cavity filter 150.

The

inner conductor

152, 152' may pass RF signals from the cavity filter 150 to the feedboard 140.

Each cavity filter 150 is associated with a corresponding feedboard 140 in some embodiments. In the depicted embodiments, each feedboard 140 includes four columns of dual-polarized radiating elements 120, with three radiating elements 120 per column. As shown in FIGs. 12A, 13A and 21, in such an embodiment, eight inner conductors 152 may be provided per cavity filter 150, so that two inner conductors are coupled to each column of radiating elements, namely one inner conductor 152 for each polarization. Thus, the active antenna unit 110 may include a total of 64 inner conductors 152 in this example embodiment. Other numbers and arrangements may be used.

FIG. 14 illustrates that the feedboards 140, shown as a plurality of feedboards 140 ₁-140 ₄ can extend wider and/or longer than the cavity filters 150 ₁-150 ₄ coupled to corresponding feedboards 140 ₁-140 ₄.

FIGs. 15-17 illustrate examples of different configurations and example spacing relative to widths and length dimensions of the cavity filters 150 and feedboards 140.

FIG. 18 illustrates that the feedboards 140 can be arranged to occupy a smaller surface area than the radio cover 170.

FIG. 19 illustrates that the feedboards 140 can occupy a smaller space than the non-metallic substrate 190 and/or frame 190f. Stated differently, a front surface of the non-metallic substrate 190 can have a surface area that is greater than a cumulative surface area defined by a sum of surface areas of respective front surfaces of each of the feedboards 140.

FIG. 20 illustrates that the feedboards 140 (shown with the rear surface 140r behind the radiating elements 120) can occupy a smaller surface area than the radome 111 and may be offset from one end portion as shown.

FIGs. 21 and 22 illustrate that the aperture 171 of the radio cover 170 can have a width sufficient to receive two

cavity filters

150 ₁, 150 ₂, rather than a single one in some embodiments. The two

cavity filters

150 ₁, 150 ₂ can be coupled together with inner facing edges or lips 151 attached without a gap therebetween and provided as a unit for assembly.

FIGs. 23-25 illustrate example aligned components of embodiments of the active antenna units 110 discussed above. When assembled, a rear portion of the cavity filters 150 reside closer to the radio than conventional and allows the active antenna unit 110 to be formed with a more compact, back-to-front size, reducing weight and wind loading, in some embodiments.

Internal surfaces or components of the active antenna unit 110, such as a primary surface 181 of a chamber 180 of the radio housing 180, can comprise a flame retardant material. However, it is contemplated that thermal-conductive resistant coatings or materials may be used, such as placed on the primary surface 181p of the chamber of placed in the chamber 181 and/or on a rear surface of the cavity filters 150.

FIGs. 26A-26D illustrate an example sequence of assembly actions for assembling components of the active antenna unit 110 according to some embodiments of the present invention. As shown, a segment 190s of the non-metallic substrate frame 190f can be attached to a respective cavity filter 150 to form a cavity filter sub-assembly 155. The sub-assembly 155 can then be coupled to a corresponding feedboard 140 with radiating elements 120 to form a radiating element and cavity filter sub-assembly set 175 with the feedboard 140 supported by the frame segment 190s. The cavity filter 150 can alternatively be coupled to the feedboard 140 after the feedboard 140 is coupled to the frame segment 190s. Each set 175 is assembled to the radio cover 170. Each set 175 can be slidably coupled together so that lips 191 of the frame 190f overlap. Each set 175 is aligned with a respective at least one aperture 172 so that rear portions 150r of the cavity filters 150 reside at least partially inside the aperture (s) 171 of the radio cover 170. To form the active antenna unit 110, a plurality of

sets

175 ₁, 175 ₂, 175 ₃, 175 ₄ are assembled to the radio cover 170 while the radio cover 170 is mounted to the radio housing 180 or before the radio cover 170 is mounted to the radio housing 180.

The active antenna unit 110 with the radio 182 can be configured as a 5G module in some embodiments. With the introduction of fifth generation ( "5G" ) cellular technologies, base station antennas are now routinely being deployed that have active beamforming capabilities. Active beamforming refers to transmitting RF signals through a multi-column array of radiating elements in which the relative amplitudes and phases of the sub-components of an RF signal that are transmitted (or received) through the different radiating elements of the array are adjusted so that the radiation patterns that are formed by the individual radiating elements constructively combine in one or more desired directions to form narrower antenna beams that have higher gain. With active beamforming, the shape and pointing direction of the antenna beams generated by the multi-column array may, for example, be changed on a time slot-by-time slot basis of a time division duplex ( "TDD" ) multiple access scheme. Moreover, different antenna beams can be generated simultaneously on the same frequency resource in a multi-user MIMO scenario. More sophisticated active beamforming schemes can apply different beams to different physical resource blocks that are a combination of time and frequency resources by applying the beam vector in the digital domain. Base station antennas that have active beamforming capabilities are often referred to as active antennas. When the multi-column array includes a large number of columns of radiating elements (e.g., sixteen or more) , the array is often referred to as a massive MIMO array. A module that includes a multi-column array of radiating elements and associated RF circuitry (and perhaps baseband circuitry) that implement an active antenna is referred to herein as an active antenna module.

Referring to FIG. 27, a base station antenna 100 according to some embodiments is shown. The base station antenna 100 includes a passive antenna assembly 190 with a plurality of internal linear arrays 1111 of radiating elements arranged in a plurality of laterally spaced apart and adjacent longitudinally extending columns between a top 100t and a bottom 100b of the base station antenna 100. In an example embodiment, there are eight columns of linear arrays 1111 of radiating elements.

The active antenna unit 110 can be held against a rear 100r of a housing 100h of the base station antenna 100 comprising the passive antenna assembly with a bracket assembly 112 having first and second laterally extending spaced apart

brackets

113, 114. The housing 100h has a front surface 100f defining a radome and sides 100s and a rear 100r. The bracket assembly 112 can also mount the base station antenna housing 100h with the active antenna unit 110 to a target structure such as a pole 10.

FIG. 28 illustrates another embodiment of a base station antenna 100 with a housing comprising a passive antenna assembly 190 sized and configured to hold the active antenna unit 110 at least partially internally thereof. The radome 100 is shown schematically in FIG. 2 (in broken line about an outer perimeter of the radiating elements 112) .

The base station antenna 100 can 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 hereby incorporated by reference as if recited in full herein. For further details regarding example active antenna modules and base station antenna housings with passive antenna assemblies, see, co-pending U.S. Patent Application Serial Number 17/209,562 and corresponding PCT Patent Application Serial Number PCT/US2021/023617, the contents of which are hereby incorporated by reference as if recited in full herein.

The linear arrays 121 (of the active antenna unit 110) and/or 1111 of the passive antenna assembly 190, can be provided as low, mid or high band radiating element. Typically, the linear arrays will include mid-band or high-band radiating elements. When high-band radiating elements are used, they may be configured to transmit and receive signals in a first frequency band. In some embodiments, the first frequency band may be the 3.3-4.2 GHz frequency band or a portion thereof. In other embodiments, the first frequency band may be the 5.1-5.8 GHz frequency band or a portion thereof. When mid-band radiating elements are used, the first frequency band may be, for example, the 1.695-2.690 GHz frequency 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 be varied, and that planar arrays or staggered linear arrays may be used instead of the “straight” linear arrays illustrated in the figures in other embodiments.

Embodiments of the present invention have been described above with reference to the accompanying drawings, in which embodiments of the 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 the linear arrays of radiating elements that are commonly included in base station antennas. It will be appreciated that herein the term "linear array" is used broadly to encompass both arrays of radiating elements that include a single column of radiating elements that are configured to transmit the sub- components of an RF signal as well as to two-dimensional arrays of radiating elements (i.e., multiple linear arrays) that are configured to transmit the sub-components of an RF signal. It will also be appreciated that in some cases the radiating elements may not be disposed 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 remainder of the radiating elements are aligned. This "staggering" of the radiating elements may be done to design the array to have a desired azimuth beamwidth. Such staggered arrays of radiating elements that are configured to transmit the sub-components of an RF signal are 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. 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 like fashion (i.e., "between" versus "directly between" , "adjacent" versus "directly adjacent" , etc. ) .

The term “about” with respect to a number, means that the stated number can vary by +/-20%.

Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe a relationship of one element, layer or region to another element, layer or region as illustrated in the figures. It will be understood that these terms are 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" "comprising, " "includes" and/or "including" 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 of the embodiments disclosed above can be combined in any way and/or combination with aspects or elements of other embodiments to provide a plurality of additional embodiments.

Claims

An active antenna unit, comprising:

a radio;

a radio housing holding the radio;

a radio cover coupled to the radio housing, wherein the radio cover comprises a plurality of spaced apart apertures; and

a plurality of cavity filters residing at least partially in front of the radio cover.
The active antenna unit of Claim 1, wherein the radio housing extends in a lateral direction and a longitudinal direction that is orthogonal to the lateral direction, wherein the plurality of spaced apart apertures each have a shape or shapes that is/are elongate in the lateral direction, elongate in the longitudinal direction or elongate in both the lateral and longitudinal directions.
The active antenna unit of Claim 1, wherein at least one cavity filter of the plurality of cavity filters is at least partially received into one aperture of the plurality of spaced apart apertures of the radio cover whereby a rearward portion of the at least one cavity filter resides behind a primary surface of the radio cover.
The active antenna unit of Claim 3, wherein at least some of the plurality of cavity filters comprise a perimeter with an outwardly extending lip that electrically couples to a metal surface of the radio cover to thereby define an electrical ground plane and/or EMI (electromagnetic interference) shield.
The active antenna unit of Claim 1, further comprising a radome mounted forwardly of the radio housing and a plurality of feedboards with a plurality of radiating elements projecting forward of the plurality of feedboards residing between the radio cover and the radome.
The active antenna unit of Claim 5, wherein the plurality of radiating elements comprise a massive multiple input multiple output (MIMO) antenna array.
The active antenna unit of Claim 1, wherein the cavity filters comprise respective metal die cast cavity filter bodies.
The active antenna unit of Claim 1, wherein the cavity filters comprise respective non-metallic bodies with at least one surface that is metallized.
The active antenna unit of Claim 5, further comprising a non-metallic substrate residing behind the feedboards and in front of the radio cover.
The active antenna unit of Claim 9, wherein the non-metallic substrate comprises a plurality of non-metallic substrate segments that substantially reside in a common plane.
The active antenna unit of Claim 9, wherein the non-metallic substrate comprises at least one metallized outer surface configured to define at least part of a reflector for the radiating elements.
The active antenna unit of Claim 9, wherein the non-metallic substrate is devoid of metallized outer surfaces and is sized and configured to provide structural support for the feedboards.
The active antenna unit of Claim 10, wherein at least some of the plurality of non-metallic substrate segments comprise apertures aligned with one or more of the plurality of cavity filters.
The active antenna unit of Claim 1, wherein the radio housing has a chamber with a primary surface facing the radio cover, wherein the radio cover is metal, wherein the cavity filters comprise a metal or metallized front surface that covers a respective cavity and rearwardly extending cavity body, and wherein the cavity body resides at least partially behind the radio cover, adjacent the primary surface of the chamber.
The active antenna unit of Claim 9, wherein a front of each of the cavity filters cooperate with a metallized surface of the non-metallic substrate to define a reflector and/or ground plane for the feedboards and/or radiating elements.
The active antenna unit of Claim 5, wherein a front portion of each of the cavity filters cooperate with the radio cover to define a ground plane for the feedboards and/or radiating elements, optionally wherein the cavity filters cooperate with the radio cover to define a closed surface layer when viewed from a front to back direction to thereby isolate the radiating elements from a radio behind the radio cover.
The active antenna unit of Claim 9, further comprising a radome, and a plurality of radiating elements extending forward of a plurality of feedboards, wherein the feedboards and the plurality of radiating elements reside behind the radome and in front of the non-metallic substrate, and wherein a front surface of the non-metallic substrate has a surface area that is greater than a cumulative surface area defined by a sum of surface areas of respective front surfaces of each of the feedboards.
The active antenna unit of Claim 1, wherein at least some of the cavity filters comprise a front with a lip on an outer perimeter thereof, and wherein the lip of at least some neighboring cavity filters overlap.
An active antenna unit, comprising:

a radome;

a plurality of radiating elements extending forward of a plurality of feedboards, wherein the feedboards and the plurality of radiating elements reside behind the radome;

a radio housing holding a radio;

a radio cover coupled to the radio housing, wherein the radio cover comprises a plurality of spaced apart apertures; and

a plurality of cavity filters residing at least partially in front of the radio cover, wherein at least one cavity filter of the plurality of cavity filters is at least partially received into one aperture of the plurality of spaced apart apertures of the radio cover whereby a rearward portion of the plurality of cavity filters reside behind a primary surface of the radio cover.
The active antenna unit of Claim 19, wherein a front portion of at least some of the cavity filters cooperate with the radio cover to define a ground plane for the feedboards and/or radiating elements, optionally wherein the cavity filters cooperate with the radio cover to define a closed surface layer when viewed from a front to back direction to thereby isolate the radiating elements from the radio behind the radio cover.
The active antenna unit of Claim 19, further comprising a non-metallic substrate positioned between the radio cover and the feedboards.
The active antenna unit of Claim 21, wherein a front of each of the cavity filters cooperates with the non-metallic substrate to define a reflector and/or ground plane for the feedboards and/or the radiating elements.
The active antenna unit of Claim 21, wherein the non-metallic substrate is provided by a plurality of coupled substrate segments that are arranged to be substantially in a common plane when coupled together.
The active antenna unit of Claim 19, wherein the plurality of cavity filters have respective bodies of a non-metallic substrate with one or more metallized surfaces.
The active antenna unit of Claim 19, wherein the plurality of cavity filters have respective bodies of die cast metal.
The active antenna unit of Claim 19, wherein at least some of the cavity filters comprise a front portion with a lip on an outer perimeter thereof, wherein the lips of neighboring cavity filters overlap and/or wherein the lip of at least some of the cavity filters comprise metal and electrically couple to the radio cover.
The active antenna unit of Claim 19, in combination with a passive antenna housing of a base station antenna, wherein the active antenna is held at least partially inside the passive antenna housing.
The active antenna unit of Claim 19, in combination with a passive antenna housing of a base station antenna, wherein the active antenna is held external to a rear of the passive antenna housing.
A base station antenna, comprising:

a passive antenna housing with a radome;

an active antenna unit held inside or coupled to a rear of the passive antenna housing,

wherein the active antenna unit comprises:

a radome;

a plurality of radiating elements extending forward of a plurality of feedboards, wherein the feedboards and the plurality of radiating elements reside behind the radome;

a radio housing holding a radio;

a radio cover coupled to the radio housing, wherein the radio cover comprises a plurality of spaced apart apertures; and

a plurality of cavity filters residing at least partially in front of the radio cover, wherein at least one cavity filter of the plurality of cavity filters is at least partially received into one aperture of the plurality of spaced apart apertures of the radio cover whereby a rearward portion of the plurality of cavity filters reside behind a primary surface of the radio cover.
The base station antenna of Claim 29, wherein the plurality of cavity filters have metal bodies or comprise one or more metallized surfaces, wherein the radio cover comprises metal, and wherein the plurality of cavity filters cooperate with the radio cover to define an electromagnetic interference (EMI) shield and/or ground plane for the radiating elements.
The base station antenna of Claim 29, further comprising a non-metallic

substrate residing between the feedboards and the radio cover.
The base station antenna of Claim 31, wherein a front of each of the cavity filters cooperate with a metallized surface or metallized surfaces of the non-metallic substrate to define a reflector and/or ground plane for the feedboards and/or radiating elements.
The base station antenna of Claim 31, wherein the non-metallic substrate is provided by a plurality of substrate segments that are coupled together and that reside in a substantially common plane when coupled together.
The base station antenna of Claim 33, wherein the non-metallic substrate segments comprise apertures, optionally wherein the apertures of the non-metallic substrate are elongate in at least one dimension.
The base station antenna of Claim 29, wherein the plurality of cavity filters have respective bodies of a non-metallic substrate with one or metallized surfaces.
The base station antenna of Claim 29, wherein the plurality of cavity filters have respective bodies of die cast metal.
The base station antenna of Claim 29, wherein at least some of the cavity filters comprise a front portion with a lip on an outer perimeter thereof, wherein the lips of neighboring cavity filters overlap and/or wherein the lip of at least some of the cavity filters are metallized or comprise metal and electrically couple to the radio cover.