Base station antenna with at least one grid reflector and associated apparatus

Abstract

The base station antenna includes at least one passive internal grid reflector having an array of low-frequency radiating elements protruding in front of the preceding grid reflector. An mMIMO antenna array is located behind the following grid reflector and is configured to transmit signals through the grid reflector and outward from the front radome of the base station antenna.

Description

[0001] Related applications

[0002] This patent application claims priority to Chinese Patent Application Serial No. 202122068204.7, filed August 31, 2021, and U.S. Provisional Patent Application Serial No. 63 / 254,446, filed October 11, 2021, the contents of which are incorporated herein by reference as if they were described in their entirety herein. Background Technology

[0003] This invention generally relates to radio communications, and more specifically to base station antennas for cellular communication systems.

[0004] Cellular communication systems are well known in the art. In a cellular communication system, a geographical area is divided into a series of areas called “cells” served by corresponding base stations. A base station may include one or more antennas configured to provide bidirectional radio frequency (“RF”) communication with mobile users within the cell served by the base station. In many cases, each cell is divided into “sectors”. In a common configuration, a hexagonal cell is divided into three 120º sectors in the azimuth plane, and each sector is served by one or more base station antennas having an azimuth half-power beamwidth (HPBW) of approximately 65º. Typically, base station antennas are mounted on towers or other elevated structures, where the radiation pattern (also referred to herein as an “antenna beam”) is generated by the outwardly pointing base station antennas. Base station antennas are typically implemented as linear or planar phased arrays of radiating elements.

[0005] To accommodate the increasing volume of cellular traffic, cellular operators have expanded cellular services across various new frequency bands. To increase capacity without further increasing the number of base station antennas, multi-band base station antennas have been introduced, comprising multiple linear arrays of radiating elements. Additionally, base station antennas now being deployed that include beamforming arrays of radiating elements, comprising multiple rows of radiating elements. Radio devices for these beamforming arrays can be integrated into the antenna, enabling the antenna to perform active beamforming (i.e., the shape of the antenna beam generated by the antenna can be adaptively changed to improve antenna performance). These beamforming arrays typically operate in higher frequency bands, such as portions of the 3.3–5.8 GHz band. Antennas with integrated radio devices are called “active antennas,” which can adjust the amplitude and / or phase of sub-components of the RF signal transmitted through individual radiating elements or their sub-groups. Active antennas can generate narrow-beamwidth, high-gain antenna beams by varying the amplitude and / or phase of sub-components of the RF signal transmitted through the antenna, and the generated antenna beams can be manipulated in different directions.

[0006] With the development of wireless communication technology, integrated base station antennas, including passive modules and active antenna modules with active antennas, have emerged. Passive modules may include one or more passive arrays of radiating elements configured to generate a relatively static antenna beam, such as an antenna beam configured to cover a 120-degree sector (in the azimuth plane) of the base station antenna. Passive arrays may include arrays operating according to second-generation (2G), third-generation (3G), or fourth-generation (4G) cellular standards. These passive arrays are not configured to perform active beamforming operations, but they typically have remote electronic tilt (RET) capability, which allows the shape of the antenna beam to be changed via electromechanical means to alter the coverage area of ​​the antenna beam. Active antenna modules may include one or more arrays of radiating elements operating according to fifth-generation (or later) cellular standards. These arrays typically perform individual amplitude and phase control on a subset of their radiating elements and perform active beamforming.

[0007] Figures 1 and 2 illustrate an example of a prior art base station antenna 10 including a pair of beamforming arrays and associated beamforming radio devices. When the antenna 10 is mounted for normal operation, the base station antenna 10 is typically mounted with its longitudinal axis L extending along a vertical axis (e.g., the longitudinal axis L may be substantially perpendicular to a plane defined by the horizon). The front surface of the antenna 10 is mounted opposite a tower or other mounting structure, pointing towards the coverage area of ​​the antenna 10. The antenna 10 includes a radome 11 and a top cover 20. The antenna 10 also includes a bottom cover 30, which includes a plurality of connectors 40 mounted therein. As shown, the radome 11, top cover 20, and bottom cover 30 define an outer housing 10h of the antenna 10. The antenna assembly is housed within the housing 10h.

[0008] Figure 2 illustrates that antenna 10 may include one or more radio devices 50 mounted to housing 10h. Since radio devices 50 can generate significant amounts of heat, it may be suitable to dissipate heat from the active antenna to prevent overheating of the radio devices 50. Therefore, each radio device 50 may include a (molded) heat sink 54, shown as mounted on the rear surface of the radio device 50. The heat sink 54 is thermally conductive and includes multiple fins 54f. Heat generated in the radio device 50 is transferred to the heat sink 54 and diffused to the fins 54f. As shown in Figure 2, the fins 54f are external to the antenna housing 10h. This allows heat to be transferred from the fins 54f to the external environment. Further details of exemplary conventional base station antennas can be found in co-pending WO2019 / 236203 and WO2020 / 072880, the contents of which are incorporated herein by reference as if described in their entirety herein. Summary of the Invention

[0009] Embodiments of the present invention relate to a base station antenna having at least one grid reflector configured to allow high-frequency band radiating elements to propagate electromagnetic waves through an aperture, and to reflect lower-frequency band signals from a low-frequency band radiating element in front of the grid reflector.

[0010] Embodiments of the present invention relate to a base station antenna, which includes at least one grid reflector having a corresponding unit cell array.

[0011] The unit cell may be defined by a conductive patch.

[0012] The unit cell may be defined by a pattern in a metal sheet.

[0013] Embodiments of the present invention relate to a base station antenna, which includes: a first frequency selective surface (FSS), a second FSS located behind the first FSS, and an active antenna located behind the first FSS.

[0014] The first FSS may have a first primary surface, and the second FSS may have a second primary surface. The first primary surface and the second primary surface may be parallel to each other.

[0015] The base station antenna may also include a first plurality of radiating elements located in front of the first FSS and a second plurality of radiating elements located behind the first FSS and the second FSS.

[0016] The first plurality of radiating elements can operate in the first frequency band, and the second plurality of radiating elements can operate in the second frequency band.

[0017] The first plurality of radiating elements may include low-frequency band radiating elements configured to operate in a first frequency band, and the second plurality of radiating elements may include higher-frequency band radiating elements configured to operate in a second frequency band. The second frequency band may contain frequencies higher than the first frequency band.

[0018] At least one of the first FSS and / or the second FSS may include a unit cell pattern in the metal sheet.

[0019] At least one of the first FSS and / or the second FSS may have a unit cell pattern provided by conductive patches in or on a dielectric substrate.

[0020] Both the first and second FSSs can be configured to allow RF energy in the second frequency band to propagate through them.

[0021] The second FSS can be attached to the radome.

[0022] The second FSS can be attached to the inward-facing surface of the rear radome of the base station antenna. The rear radome can cooperate with the first FSS for its dielectric loading.

[0023] The base station antenna may further include a main reflector coupled to the first FSS. The main reflector may have a first sub-length and a second sub-length. The second sub-length may have a spaced-out right side and a left side separated by a lateral extension opening. The first FSS may extend longitudinally and laterally across the lateral extension opening.

[0024] The base station antenna may also include a primary reflector. The first FSS may be parallel to or coplanar with the primary reflector. The first FSS may have a shorter length than the primary reflector.

[0025] The first FSS can be attached to the main reflector.

[0026] The main reflector and the first FSS can be defined by a single, integral metal sheet body.

[0027] The first FSS can have a three-dimensional shape.

[0028] The first FSS may have a longitudinally extending, laterally spaced right and left portion. The right and left portions may define corners with orthogonal wall segments defining portions of the first FSS. Optionally, one or both wall segments may comprise unit cells of the first FSS's grid.

[0029] The base station antenna may also include at least one matching layer behind the first FSS.

[0030] The base station antenna may also include at least one matching layer in front of the first FSS.

[0031] The first FSS may have a unit cell grid configured to transmit RF energy in the second frequency band, and may also be configured to absorb and / or reflect at least one of the RF energy in the first frequency band and the RF energy in the third frequency band. The third frequency band may include frequencies between the first and second frequency bands.

[0032] The first FSS may include a unit cell grid having a first subset of unit cells tuned to block and / or reflect RF energy in a first frequency band while allowing RF energy in a second frequency band to propagate through it. The first FSS may also include a second subset of unit cells tuned to block and / or reflect RF energy in both the first and third frequency bands. The third frequency band may include frequencies between the first and second frequency bands.

[0033] The first subset of the unit cells may be located at the upper portion of the base station antenna. The second subset of the unit cells may include unit cells located behind the first subset of the unit cells, wherein some of the unit cells in the second subset of the unit cells may be located to the right of the first subset of the unit cells, and other unit cells in the second subset of the unit cells may be located to the left of the first subset of the unit cells.

[0034] Other embodiments relate to a base station antenna that includes a front radome and a three-dimensional frequency selective surface (FSS) located behind the front radome.

[0035] The FSS may have a right corner and a left corner, the right corner and the left corner having orthogonal first wall segments and second wall segments. The first wall segment may extend laterally, and the second wall segment may extend rearward from the first wall segment in a front-back direction.

[0036] The FSS may include a grid with an array of unit cells, and some unit cells may exist on at least one of the first wall segment and the second wall segment.

[0037] The right and left portions may be located on opposite sides of an open lateral and longitudinally extending space, and the FSS may have a front surface extending across at least a portion of the laterally extending space.

[0038] The base station antenna may also include a first plurality of radiating elements located behind the FSS and a second plurality of radiating elements located in front of the FSS.

[0039] The first plurality of radiating elements can operate in the first frequency band, and the second plurality of radiating elements can operate in the second frequency band.

[0040] The first plurality of radiating elements may include high-frequency band radiating elements operating in at least a portion of the 3.2-4.1 GHz frequency band. The second plurality of radiating elements may include radiating elements operating in at least a portion of a frequency band lower than the high-frequency band radiating elements.

[0041] FSS may include a unit cell pattern in a metal sheet.

[0042] FSS can have a unit cell pattern provided by conductive patches in or on a dielectric substrate.

[0043] The dielectric substrate / conductive patch can be provided by flexible circuitry or printed circuit board.

[0044] The FSS can be configured to allow RF energy to propagate through it in at least a portion of the 3.2–4.1 GHz band.

[0045] The base station antenna may also include at least one matching layer located behind the FSS.

[0046] The second or more radiating elements can be placed in the active antenna module (also known as "active antenna").

[0047] Other embodiments relate to a base station antenna, which includes a radome, a frequency selective surface (FSS) inside the radome, and a matching layer behind the FSS inside the radome.

[0048] The base station antenna may further include a main reflector within the radome. The main reflector may have right and left portions located on opposite sides of an open lateral and longitudinally extending space. The FSS may have a front surface extending across at least a portion of the laterally extending space.

[0049] The base station antenna may also include a first plurality of radiating elements located behind the FSS and a second plurality of radiating elements located in front of the FSS.

[0050] The first plurality of radiating elements can operate in a first frequency band, and the second plurality of radiating elements can operate in a second frequency band, the second frequency band containing frequencies lower than the first frequency band.

[0051] The first plurality of radiating elements may include at least a portion of a frequency band of 2.5 GHz or higher, such as high-frequency band radiating elements operating in the 3.1-4.2 GHz band. The second plurality of radiating elements includes radiating elements operating in a lower frequency band than the said high-frequency band radiating elements.

[0052] FSS can have a unit cell pattern in a metal sheet.

[0053] FSS can have a unit cell pattern provided by conductive patches in or on a dielectric substrate.

[0054] The FSS can be configured to allow RF energy to propagate through it in at least a portion of the 3.1–4.2 GHz band.

[0055] Other embodiments relate to a base station antenna comprising a housing having a front radome, a rear radome, and an internal compartment. The base station antenna also includes a frequency selective surface (FSS) attached to the front-facing surface of the rear radome.

[0056] The base station antenna may also include a first plurality of radiating elements located in front of the FSS and a second plurality of radiating elements located behind the FSS.

[0057] The second plurality of radiating elements may include a large-scale multiple-input multiple-output (mMIMO) array disposed in an active antenna module.

[0058] The first plurality of radiating elements can operate in the first frequency band, and the second plurality of radiating elements can operate in the second frequency band.

[0059] The first plurality of radiating elements may include radiating elements operating in a first frequency band, and the second plurality of radiating elements may include radiating elements operating in a second frequency band.

[0060] FSS may include a unit cell pattern in a metal sheet.

[0061] FSS may include a unit cell pattern provided by conductive patches in or on a dielectric substrate.

[0062] The FSS can be configured to allow RF energy to propagate through it in at least a portion of the 3.1–4.2 GHz band.

[0063] The rear radome can cooperate with the FSS for its dielectric loading. Optionally, the FSS can be attached to the rear radome and extend in front of, adjacent to or adjacent to the inward-facing surface of the rear radome.

[0064] Other embodiments relate to a base station antenna comprising: a grid reflector having an array of unit cells arranged in a metal sheet; a main reflector incorporated into and / or coupled to the grid reflector; and a passive antenna assembly comprising a plurality of linear arrays of radiating elements extending in front of the main reflector.

[0065] The unit may have a corresponding open central space that can be surrounded by a metal perimeter, and the corresponding open central space may be free of metal.

[0066] The first linear array in the linear array may include a first plurality of first radiating elements extending in front of the grid reflector, and a second plurality of first radiating elements extending in front of the main reflector.

[0067] The grid reflector and the main reflector can be defined by a single metal sheet structure. The right and left sides of the grid reflector can be incorporated into the right and left sides of the main reflector. The right and left sides of the main reflector can extend longitudinally and laterally together with a continuous metal closed surface, and the right and left sides of the main reflector can each have a smaller lateral extent than the lateral extent of the grid reflector.

[0068] The primary reflector may have a solid, continuous primary surface that extends at least most of its lateral and longitudinal extents.

[0069] The base station antenna may also include a dielectric cover attached to and located in front of and / or behind the grid reflector, and extending over at least most of the unit cell.

[0070] Adjacent unit cells in a unit cell array may have a shared metal segment forming part of their respective perimeter. A grid reflector may be configured such that adjacent unit cells have at least one shaped metal region extending across the shared metal segment and terminating off-center from the center point of the respective unit cell, thereby increasing the current path for radio frequency (RF) energy.

[0071] The formed metal area can be a box with an open central space.

[0072] The formed metal zone can be a box with a closed central space.

[0073] Each unit cell may have multiple formed metal zones spaced apart around its perimeter.

[0074] The forming metal area is shaped into a rectangle.

[0075] The grid reflector may include metal wires that may be formed as part of the periphery of a first unit cell and a second unit cell adjacent to each other. At least one shaped metal region having a first portion and a second portion may extend inwardly from the metal wires into the respective first and second unit cells in opposite directions, such that the first portion of the shaped metal region is located inside the first unit cell, and the second portion of the shaped metal region is located inside the second unit cell.

[0076] Multiple formed metal zones may have a perimeter surrounding an open space, which is smaller than the open space of a unit cell and has opposing first and second ends. The first end may extend into a first unit cell, and the second end may extend into a second unit cell immediately adjacent to the first unit cell.

[0077] Each unit may have a metal perimeter with corners and a shaped metal area extending along the sub-length of the perimeter between two of the corners.

[0078] Each unit cell may have at least four formed metal zones spaced apart around a corresponding perimeter. Each of the four formed metal zones may extend around a shared perimeter segment of the adjacent unit cell.

[0079] The base station antenna may further include a plurality of shaped metal regions spaced apart around a corresponding perimeter. The number of shaped metal regions spaced apart around a corresponding perimeter may be equal to the number of unit cells adjacent to the corresponding unit cell.

[0080] The multiple linear arrays may include a first laterally spaced linear array and a second laterally spaced linear array of low-frequency band radiating elements. The base station antenna may also include multiple linear arrays of mid-frequency band radiating elements that are longitudinally spaced from the main reflector and extend in front of the main reflector or from the grid reflector.

[0081] The base station antenna can be combined with an active antenna module attached to the rear of the base station antenna. The active antenna module may have an array of radiating elements facing a grid reflector. The array of radiating elements of the active antenna module is configured to propagate RF energy through the grid reflector.

[0082] The array of radiating elements of an active antenna module may be an mMIMO array with radiating elements located behind a grid reflector.

[0083] The grid reflector may have a lateral range of sub-distances for the lateral range of the housing of the base station antenna, and may be located in the upper part of the base station antenna, aligned with the array of radiating elements of the active antenna module.

[0084] A grid reflector can be configured to allow RF energy of one or more defined frequency ranges to pass through and reflect RF energy of different frequency bands.

[0085] A grid reflector can be configured to reflect low-frequency RF energy and transmit higher-frequency RF energy.

[0086] Multiple linear arrays may include low-frequency band dipole antennas with feed handles. The feed handles may protrude in front of the grid reflector.

[0087] The active antenna module may have an antenna radome, which may be positioned adjacent to and facing the rear of the base station antenna.

[0088] An additional embodiment relates to a base station antenna assembly comprising: a plurality of rows of first radiating elements configured to operate in a first operating frequency band, each row of first radiating elements including a plurality of first radiating elements arranged in a longitudinal direction; and a grid reflector located behind the plurality of rows of first radiating elements. The grid reflector is configured to reflect electromagnetic waves within the first operating frequency band.

[0089] The base station antenna may further include multiple rows of second radiating elements configured to operate in a second operating frequency band, which is different from and does not overlap with the first operating frequency band. Each row of second radiating elements may have multiple second radiating elements arranged in the longitudinal direction. The grid reflector is also configured such that electromagnetic waves within the second operating frequency band can propagate through the reflector.

[0090] The second operating frequency band can be higher than the first operating frequency band.

[0091] A grid reflector can be defined by a metal sheet constructed with an array of unit cells. Each unit cell can have an open central space surrounded by a metal perimeter, the open central space being free of metal.

[0092] The base station antenna may further include a dielectric cap attached to and located in front of and / or behind the grid reflector, extending above the unit cell to improve low-frequency band reflections relative to the unit cell having an interior with communicating atmosphere. Optionally, the dielectric cap may have a dielectric constant of at least one.

[0093] A grid reflector may provide a pair of adjacent unit cells, wherein a shared metal segment forms part of a respective perimeter. The grid reflector may have at least one shaped metal region extending across the shared metal segment and terminating within each of the pair of adjacent unit cells, offset from the center point of each of the pair of adjacent unit cells of the grid reflector.

[0094] The formed metal area can be a box with an open central space.

[0095] The formed metal zone can be a box with a closed central space.

[0096] A grid reflector can be configured such that multiple shaped metal regions are spaced apart around the perimeter of a unit cell.

[0097] The forming metal area can be formed into a rectangle.

[0098] The grid reflector may include metal wires forming a portion of the periphery of adjacent first and second unit cells. The grid reflector may also include at least one shaped metal region having a first portion and a second portion, the at least one shaped metal region extending inwardly from the metal wires in opposite directions into the respective first and second unit cells, such that the first portion of the shaped metal region is located inside the first unit cell, and the second portion of the shaped metal region is located inside the second unit cell.

[0099] At least some of the plurality of formed metal regions may have a perimeter surrounding an open space, said open space being smaller than the open space of a unit cell and having opposing first and second ends. The first end may extend into a first unit cell, and the second end may extend into an adjacent second unit cell.

[0100] A grid reflector can be defined by a metal sheet constructed with an array of unit cells, wherein the unit cells, having an open center without metal, are surrounded by a metal periphery.

[0101] The grid reflector can be defined by a single metal sheet body that provides a closed metal surface for both the grid reflector and the main reflector.

[0102] Mesh reflectors can have an asymmetric array of unit cells.

[0103] The grid reflector can have a larger unit cell density at the first position relative to the unit cell density it has at the second position.

[0104] The grid reflector has a larger lateral and / or longitudinal range of unit cells at the first position compared to the unit cells at the second position.

[0105] Multiple rows of first radiating elements can be installed in the base station antenna.

[0106] The second operating frequency band is higher than the first operating frequency band.

[0107] Multiple rows of second radiating elements can be provided by an active antenna module attached to the rear of the base station antenna.

[0108] Other embodiments relate to a reflector for a base station antenna, comprising: a sheet-like metal mesh reflector having an array of unit cells; and a dielectric cover attached to the mesh reflector and located in front of and / or behind the mesh reflector and extending over at least a majority of the unit cells.

[0109] The dielectric cap may have a dielectric constant of 1 or greater.

[0110] The dielectric cap can be made of fiberglass.

[0111] Mesh reflectors can have an asymmetric array of unit cells.

[0112] The grid reflector can have a larger unit cell density at the first position relative to the unit cell density it has at the second position.

[0113] The grid reflector may have a larger lateral and / or longitudinal range (width and / or height) of unit cells at the first position compared to the unit cells at the second position.

[0114] Unit cell arrays can be symmetrical.

[0115] Other aspects relate to a frequency selective reflector, which includes a body and a frequency selective section disposed within the body. The frequency selective section is composed of a plurality of patterned units arranged periodically in the transverse and longitudinal directions. Each of the patterned units has a predetermined pattern and includes a capacitor structure and an inductor structure connected in series with the capacitor structure, such that the frequency selective section allows electromagnetic waves within a predetermined frequency range to pass through.

[0116] Multiple pattern units (unit units) can be electrically connected to each other through an inductor structure.

[0117] Each of the pattern units can be in the shape of a triangle, square, rectangle, rhombus, pentagon, hexagon, circle, and ellipse and / or a combination thereof.

[0118] Each of the patterned units may include a sheet structure and a linear structure, the sheet structure forming a capacitor structure and the linear structure forming an inductor structure.

[0119] In multiple pattern units, the area of ​​the sheet-like structure and the length of the linear structure can be configured to change in a predetermined manner.

[0120] Some of the multiple pattern units may have different constructions.

[0121] Frequency-selective sections / surfaces can be configured to allow high-frequency electromagnetic waves in the range of 2300 MHz to 4000 MHz to pass through.

[0122] The frequency selection zone and the main body can be formed integrally from a metal plate.

[0123] The frequency selective section and the main body can be constructed as separate components and fixedly connected to each other to form a frequency selective reflector.

[0124] The frequency selection band and the main body can be made of different materials.

[0125] Frequency-selective segments can be manufactured by direct structuring through perforation or laser.

[0126] The frequency selection segment may include a substrate and a plurality of metal pattern units disposed on the substrate.

[0127] Multiple metal pattern units can be formed on the substrate by selective electroplating or metal ink transfer printing.

[0128] The substrate can be formed of plastic, and the metal pattern units can be formed of any of copper, aluminum, gold, and silver.

[0129] A base station antenna including a frequency-selective reflector according to this disclosure may be provided.

[0130] The base station antenna may include passive modules and / or passive antenna assemblies and active antenna modules, and the active antenna modules may be installed at a location corresponding to the frequency selection segment of the frequency selective reflector.

[0131] According to embodiments of this disclosure, a frequency selection segment can be configured to allow electromagnetic waves emitted by an active module to pass through.

[0132] It should be noted that various aspects of this disclosure described for one embodiment may be included in other different embodiments, even if those other embodiments are not specifically described. In other words, features of all embodiments and / or any embodiments may be combined in any way and / or in any combination, as long as they do not contradict each other. Attached Figure Description

[0133] Figure 1 is a perspective view of a base station antenna in the prior art.

[0134] Figure 2 is a rear view of a base station antenna of another prior art.

[0135] Figure 3A This is a rear perspective view of an exemplary base station antenna connected to an active antenna module according to an embodiment of the present invention.

[0136] Figure 3B This is a side rear perspective view of another exemplary base station antenna connected to an active antenna module according to an embodiment of the present invention.

[0137] Figure 4 According to an embodiment of the present invention, it can be installed in a base station antenna, for example... Figure 3A or Figure 3B A perspective view of an exemplary primary reflector in a base station antenna shown.

[0138] Figure 5A This is a front perspective view of the grid reflector of a base station antenna according to an embodiment of the present invention.

[0139] Figure 5B yes Figure 5A The front view of the grid reflector shown.

[0140] Figure 6A This is a front view of a section of a grid reflector according to an embodiment of the present invention.

[0141] Figure 6B yes Figure 6A The enlarged front view of a unit cell of the grid reflector shown.

[0142] Figure 7A This is a front view of a segment of another embodiment of a mesh reflector according to an embodiment of the present invention.

[0143] Figure 7B yes Figure 7A The enlarged front view of a unit cell of the grid reflector shown.

[0144] Figure 8A This is a front view of a segment of another embodiment of a mesh reflector according to an embodiment of the present invention.

[0145] Figure 8B yes Figure 8AThe enlarged front view of a unit cell of the grid reflector shown.

[0146] Figure 9A This is a front view of a segment of another embodiment of a mesh reflector according to an embodiment of the present invention.

[0147] Figure 9B yes Figure 9A The enlarged front view of a unit cell of the grid reflector shown.

[0148] Figure 10 This is a front view of another embodiment of the mesh reflector according to an embodiment of the present invention.

[0149] Figure 11 This is a front view of another embodiment of the mesh reflector according to an embodiment of the present invention.

[0150] Figure 12A This is a front view of another embodiment of a grid reflector for a base station antenna according to an embodiment of the present invention.

[0151] Figure 12B yes Figure 12A The image shows a magnified front view of a unit cell of the grid reflector.

[0152] Figure 13A This is a front view of an exemplary grid reflector for a base station antenna according to an embodiment of the present invention.

[0153] Figure 13B yes Figure 13A The image shows a magnified front view of a unit cell of the grid reflector.

[0154] Figure 14A This is a front view of an exemplary grid reflector for a base station antenna according to an embodiment of the present invention.

[0155] Figure 14B yes Figure 14A The image shows a magnified front view of a unit cell of the grid reflector.

[0156] Figure 15A This is a front view of an exemplary grid reflector for a base station antenna according to an embodiment of the present invention.

[0157] Figure 15B yes Figure 15A The image shows a magnified front view of a unit cell of the grid reflector.

[0158] Figure 16A This is a front view of an exemplary grid reflector for a base station antenna according to an embodiment of the present invention.

[0159] Figure 16B yes Figure 16AThe image shows a magnified front view of a unit cell of the grid reflector.

[0160] Figure 17A This is a front view of an exemplary grid reflector for a base station antenna according to an embodiment of the present invention.

[0161] Figure 17B yes Figure 17A The image shows a magnified front view of a unit cell of the grid reflector.

[0162] Figure 18A This is a front view of an exemplary grid reflector for a base station antenna according to an embodiment of the present invention.

[0163] Figure 18B yes Figure 18A The image shows a magnified front view of a unit cell of the grid reflector.

[0164] Figures 19A-19D This is a front view of another embodiment of the grid reflector according to an embodiment of the present invention.

[0165] Figure 20-22 This is a front view of some other embodiments of a mesh reflector according to an embodiment of the present invention.

[0166] Figure 23A This is a front side perspective view of an antenna assembly and an exemplary grid reflector of a base station antenna according to an embodiment of the present invention.

[0167] Figure 23B yes Figure 23A An enlarged front side perspective view of the top portion of the antenna assembly and grid reflector shown.

[0168] Figure 23C This is a front schematic diagram of a reflector including a first grid reflector, a second grid reflector, and a main reflector, according to an embodiment of the present invention.

[0169] Figure 24 The front and rear radomes of the base station antenna, with an mMIMO antenna array placed behind a grid reflector, are omitted in an embodiment of the present invention.

[0170] Figure 25 This is a partially exploded view of an exemplary active antenna module according to an embodiment of the present invention.

[0171] Figure 26A and 26B This is a simplified side cross-sectional view of an exemplary base station antenna and its cooperating active antenna module according to an embodiment of the present invention.

[0172] Figure 27This is an enlarged and simplified cross-sectional view of an exemplary base station antenna and a cooperating active antenna module according to an embodiment of the present invention.

[0173] Figure 28A This is a front view of a portion of a base station antenna according to an embodiment of the present invention, without showing the front radome, which shows an exemplary mesh reflector (e.g., FSS).

[0174] Figure 28B This is an embodiment of the present invention. Figure 28A The image shows a rear view of a portion of the base station antenna, without showing the rear antenna cover.

[0175] Figure 28C This is an embodiment of the present invention. Figure 28A , 28B The diagram shows a simplified schematic side cross-sectional view of the top portion of the base station antenna, illustrating an exemplary position of the FSS relative to the rear radome.

[0176] Figure 28D This is an embodiment of the present invention. Figure 28A , 28B A simplified schematic side cross-sectional view of the top portion of the base station antenna shown, illustrating the FSS relative to... Figure 28C Alternative positions for the embodiments shown.

[0177] Figure 28E This is a rear view of a base station antenna without a rear radome according to an embodiment of the present invention, showing the FSS and the matching layer.

[0178] Figure 28F This is an embodiment of the present invention. Figure 28E The image shows a front perspective view of the base station antenna, without showing the front antenna cover.

[0179] Figure 28G This is an embodiment of the present invention. Figure 28E A simplified lateral cross-sectional view of the base station antenna shown in / 28F.

[0180] Figure 29A This is a front view of a portion of a base station antenna according to an embodiment of the present invention, which does not show the front antenna cover, but shows another exemplary FSS.

[0181] Figure 29B This is an embodiment of the present invention. Figure 29A The image shows a rear view of a portion of the base station antenna, without showing the rear antenna cover.

[0182] Figure 29C It is according to an embodiment of the present invention and Figure 29A The image shows a rear view of a portion of a similar base station antenna, without showing the rear antenna cover.

[0183] Figure 29D This is an embodiment of the present invention. Figure 29C The diagram shows a front perspective view of the base station antenna, which does not show the front antenna cover and the side antenna covers.

[0184] Figure 29E This is an embodiment of the present invention. Figure 29C A simplified side cross-sectional view of the base station antenna shown in / 29D.

[0185] Figure 30 This is a front side perspective view of a portion (without the antenna cover) of a base station antenna according to an embodiment of the present invention.

[0186] Figure 31 This is a front side perspective view of a portion (without the radome) of a base station antenna according to another embodiment of the present invention.

[0187] Figure 32 This is a front view of a portion of a base station antenna (without the radome shown) according to some other embodiments of the present invention.

[0188] Figure 33 This is an embodiment of the present invention. Figure 32 The rear view of a portion of the base station antenna shown.

[0189] Figure 34 This is a front side perspective view of an exemplary three-dimensional reflector configured for use as a base station antenna according to an embodiment of the present invention.

[0190] Figure 35 yes Figure 34 The end view of the reflector shown.

[0191] Figure 36 This is a simplified side cross-sectional view of a base station antenna having multiple reflectors stacked in the front-to-back direction according to an embodiment of the present invention.

[0192] Figure 37 This is a simplified side cross-sectional view of a base station antenna having multiple reflectors stacked in the front-to-back direction and a matching layer according to an embodiment of the present invention.

[0193] Figure 38A This is a front side perspective view of another exemplary reflector of a base station antenna according to an embodiment of the present invention.

[0194] Figure 38B This is an embodiment of the present invention. Figure 38A The simplified end view of the reflector shown illustrates the mating radiating element.

[0195] Figure 39AThis is a front side perspective view of a portion of a base station antenna according to an embodiment of the present invention, which does not show the front antenna cover, but shows another exemplary FSS.

[0196] Figure 39B This is an embodiment of the present invention. Figure 39A The image shows a rear view of a portion of the base station antenna, without showing the rear antenna cover.

[0197] Figure 39C This is an embodiment of the present invention. Figure 39A A simplified side cross-sectional view of the base station antenna shown in / 39B.

[0198] Figure 40 This is a simplified side cross-sectional view of a base station antenna according to an embodiment of the present invention, showing a matching layer adjacent to the rear radome and behind a reflector such as an FSS and / or a grid reflector.

[0199] Figure 41A-41G This is a transparent view of the front side portion of various parts of a base station antenna according to an embodiment of the present invention, which shows an example of a stacked reflector construction. Detailed Implementation

[0200] Figure 3A A base station antenna 100 according to certain embodiments of the present invention is shown. In the following description, the base station antenna 100 will be described using the following terms, which assume that the base station antenna 100 is mounted for use on a tower, pole, or other mounting structure, wherein the longitudinal axis L of the base station antenna 100 extends along a vertical axis, the front portion of the base station antenna 100 is mounted opposite the tower, pole, or other mounting structure and points towards the target coverage area of ​​the base station antenna 100, and the rear portion 100r of the base station antenna 100 faces the tower or other mounting structure. It should be understood that the base station antenna 100 may not always be mounted such that its longitudinal axis L extends along a vertical axis. For example, the base station antenna 100 may be slightly tilted relative to the vertical axis (e.g., less than 10º), such that the resulting antenna bundle formed by the base station antenna 100 each has a small mechanical downward tilt.

[0201] Base station antenna 100 may be coupled to or include at least one active antenna module 110. The terms "active antenna module" are used interchangeably with "active antenna element," "AAU," and "active antenna," and refer to a cellular communication unit that includes radio circuitry and associated radiating elements. The radio circuitry is capable of electronically adjusting the amplitude and / or phase of sub-components of the RF signal output to different radiating elements of an array or group thereof. Active antenna module 110 includes radio circuitry and radiating elements (e.g., a multiple-input multiple-output (mMIMO) beamforming antenna array) and may include other components such as filters, calibration networks, antenna interface signal group (AISG) controllers, etc. The active antenna module 110 can be provided as a single integrated unit or as multiple stackable units, including, for example, a first sub-unit and a second sub-unit (e.g., a wireless sub-unit (box) with radio circuitry and an antenna sub-unit (box) with a multi-row array of radiating elements), and the first and second sub-units are stackably attached together in the front-rear direction of the base station antenna 100, wherein the radiating element 1195 of the antenna assembly 1190 ( Figure 25 , 26A 26B) The front radome 111f / antenna radome 111 of the housing 100h of the base station antenna 100 is closer to the radio circuit unit 1120 than the base station antenna 100. In some embodiments, the radiating element 1195 may include a sub-unit separate from the radio circuit, and the radiating element sub-unit may be installed inside the base station antenna 100 rather than outside the base station antenna 100.

[0202] As will be further discussed below, the base station antenna 100 includes an antenna assembly 190, which may be referred to as a "passive antenna assembly". The term "passive antenna assembly" refers to an antenna assembly having arrays of radiating elements, which are coupled to a radio device external to the antenna, typically a remote radio head mounted adjacent to the base station antenna 100. The arrays of radiating elements included in the passive antenna assembly 190 ( Figure 23A , 24 The passive antenna assembly 190 is configured to form a static antenna bundle (e.g., each antenna bundle configured to cover a sector of the base station). The passive antenna assembly 190 may include reflectors 170, 214 having radiating elements projecting in front of the reflectors, and the radiating elements may include one or more linear arrays of low-frequency band radiating elements operating in all or part of the 617-960 MHz frequency band and / or one or more linear arrays of mid-frequency band radiating elements operating in all or part of the 1427-2690 MHz frequency band. The passive antenna assembly 190 is mounted within the housing 100h of the base station antenna 100, and one or more active antenna modules 110 may be releasably (detachably) coupled (e.g., directly or indirectly attached) to the base station antenna 100.

[0203] The base station antenna 100 has a housing 100h. The housing 100h may be substantially rectangular, having a flat rectangular cross-section. The housing 100h may be configured to define at least a portion of a radome 111, wherein at least the front side 111f is configured as a dielectric cover to allow RF energy to pass through in a particular frequency band. The housing 100h may also be configured such that a rear portion 100r defines a rear radome 111r opposite to the front radome 111f. Optionally, the housing 100h and / or the radome 111 may also include two (narrow) sidewalls 100s, 111s facing each other and extending rearward between the front side 111f and the rear side 111r. Typically, the top side 100t of the housing 100h may be waterproof-sealed and may include an end cap 120, and the bottom 100b of the housing 100h may be sealed with a separate end cap 130. At least a portion of the front side 111f, the sidewalls 111s, and the rear side 111r of the typical radome 111 substantially transmits radio frequency (RF) energy within the operating frequency band of the base station antenna 100 and the active antenna module 110. The radome 111 may be formed of, for example, fiberglass or plastic.

[0204] Still referencing Figure 3A In some embodiments, the active antenna module 110 can be attached to the base station antenna 100 using the frame 112 and accessory mounting brackets 113, 114. The rear portion 111r of the housing 100h can be a flat surface extending along a common plane over its entire longitudinal extent or extending along at least a portion of its longitudinal extent.

[0205] Figure 3B The rear surface 100r is shown to include a recessed and / or stepped section 102 facing the active antenna module 110. The stepped section 102 is closer to the front portion 100f of the housing than the rear wall, which is defined by the main section of the rear portion 100r of the housing 100h. The stepped section 102 may have the same or greater lateral and longitudinal extent as the active antenna module 110. The rear surface 100r may also include a pair of spaced-apart longitudinally extending tracks 118 that engage an adapter mounting bracket 1118 on the active antenna module 110 to attach the active antenna module 110 to the base station antenna housing 100h.

[0206] Refer again Figure 3AIn another embodiment, the rear surface 100r may include a plurality of longitudinally spaced mounting structure brackets extending rearward from the housing 100h, shown as an upper bracket 115, a middle bracket 116, and a lower bracket 117, respectively. In some embodiments, the mounting structure brackets 115, 116, and 117 may be configured to be attached to one or more mounting structures, such as towers, poles, or buildings (not shown). At least two of the mounting structure brackets 115 and 116 may also be configured to be attached to a frame 112 of the base station antenna assembly in use. The frame 112 may extend over a sub-length of the longitudinal range L of the base station antenna 100, wherein the sub-length is within Figure 3A The image shows at least 50% of its main portion. Frame 112 may include a top 112t, a bottom 112b, and two opposing long sides 112 extending between the top 112t and the bottom 112b. Frame 112 may have an open central space 112c extending laterally between the sides 112s and longitudinally between the top 112t and the bottom 112b.

[0207] In use, frame 112 can be configured to allow various active antenna modules 110 to be mounted onto frame 112 using appropriate accessory mounting brackets 113, 114. Therefore, various active antenna modules 110 can be interchangeably attached to the same base station antenna 100. Although frame 112 is shown by way of example, other mounting systems can be used.

[0208] In some embodiments, multiple active antenna modules 110 may be simultaneously attached to the same base station antenna 100 at different longitudinal positions using one or more frames 112. Such active antenna modules 110 may have different dimensions, such as different lengths and / or different widths and / or different thicknesses.

[0209] Now refer to Figure 4 An exemplary primary reflector 214 of a base station antenna 100 is shown. As shown, the primary reflector 214 has a first segment 2141 that extends a first longitudinal distance and merges into a second segment 2142, the second segment having spaced-apart right and left segments 214s, the second segment having a lateral range d2 smaller than the lateral range d1 of the first segment 2141. An open intermediate region 14 may extend longitudinally and laterally around the second segment 2142. In some embodiments, the open intermediate region 14 may have a lateral range d3 that is 60-95% of the lateral range d1. In some embodiments, the first segment 2141 may have a larger longitudinal range than the second segment 2142, typically at least 20% larger, for example, 30%-80% larger.

[0210] Figure 5A and 5BAn exemplary grid reflector 170 of a base station antenna 100 is shown. The grid reflector 170 includes a frequency selective surface and may be interchangeably referred to as a "frequency selective reflector". The grid reflector 170 may extend a portion or the entire lateral range of the base station antenna 100 and at least a portion of the length of the base station antenna 100.

[0211] In some embodiments, the mesh reflector 170 may be electrically and / or mechanically coupled to the main reflector 214. In some embodiments, the mesh reflector 170 may be positioned in the open central region 14 between the right and left sides 214s of the main reflector. Figure 4 ).

[0212] The grid reflector 170 can be provided as a non-metallic substrate, wherein the metal patches are arranged to define an array of unit cells 171 (which may also be referred to interchangeably as “patterned cells”), or it can be a metal grid and include an array of unit cells 171.

[0213] The non-metallic substrate can be provided as a multilayer printed circuit board, which can be a rigid, semi-rigid, or flexible circuit. The non-metallic substrate can be a plastic, a polymer, or a copolymer having a metallized surface for providing conductive patches.

[0214] The grid reflector 170 may be a sheet of metal, such as aluminum, wherein the grid is formed to form an array of unit cells 171 through perforations in the sheet of metal, or by laser forming or otherwise.

[0215] The grid reflector 170 provides a frequency selective surface and / or substrate configured to allow the passage of RF energy (electromagnetic waves) within one or more first defined frequency ranges and configured to reflect RF energy in a different second frequency band. The frequency selective surface and / or substrate may be interchangeably referred to herein as "FSS". The reflector 170 of the base station antenna 100 may be located on at least some antenna elements (see...). Figure 26A , 26B Behind the radiating element 222, and can selectively reject some frequency bands and allow others to pass through by including a frequency-selective surface and / or substrate to act as a “spatial filter.” See, for example, Ben A. Munk, Frequency Selective Surfaces: Theory and Design, ISBN: 978-0-471-37047-5; DOI: 10.1002 / 0471723770; April 2000, Copyright © 2000 John Wiley & Sons, Inc., the contents of which are incorporated herein by reference as if they were described in their entirety herein.

[0216] The frequency-selective surface and / or substrate material of the grid reflector 170 may include one or more of a metamaterial, a suitable RF material, or even air (although air may require more complex assembly). The term "metamaterial" refers to a composite electromagnetic (EM) material. Metamaterials may include subwavelength periodic microstructures.

[0217] The FSS material can be provided as one or more cooperative layers. The FSS material may include a substrate having a dielectric constant in the range of about 2-4 (e.g., about 3.7) and a thickness of about 5 mils, and a metallic pattern formed on the dielectric substrate. The thickness can vary, but thinner materials can provide lower losses.

[0218] In some embodiments, the frequency-selective substrate / surface of the mesh reflector 170 can be configured to act as a high-pass filter, which essentially allows low-band energy to be completely reflected (the FSS can act as a sheet metal) while allowing higher-band energy (e.g., about 3.5 GHz or higher) to pass through completely. Therefore, the frequency-selective substrate / surface is transparent or invisible to higher-band energy and can achieve a suitable out-of-band rejection response from the FSS. The FSS material can allow for reduction of the filter, or even elimination of the retroreflective radio device 1120 (…). Figure 25 , 26A The filter requirements in ).

[0219] As discussed above, in some embodiments, the grid reflector 170 with an FSS can be implemented by forming a frequency selective surface on a printed circuit board, optionally a flexible circuit board. In some embodiments, for example, the reflector 170 can be implemented as a multilayer printed circuit board, one or more of which have a frequency selective surface formed thereon, the frequency selective surface being configured such that electromagnetic waves in a predetermined frequency range cannot propagate through the grid reflector 170, and wherein one or more other predetermined frequency ranges associated with one or more of the multilayer printed circuit board are allowed to pass through it.

[0220] refer to Figure 5A and 5B A grid (frequency-selective) reflector 170 according to an embodiment of the present disclosure is shown. For example, the grid reflector 170 can be used... Figure 3A , 3BIn the base station antenna 10 shown, the grid reflector / frequency selective reflector 170 may include a body 21 and a frequency selective section 22 disposed in the body 21. At least the body 21 may be metallic (e.g., formed of aluminum). The frequency selective section 22 may be disposed at a position on the frequency selective reflector 170 corresponding to the mounting position of the active antenna module 110 of the base station antenna 100, and may be configured to allow electromagnetic waves within a predetermined frequency range (e.g., high-frequency electromagnetic waves within or a portion of the 2300 to 4200 MHz range). Thus, when the base station antenna 100 is assembled, high-frequency electromagnetic waves emitted by the active antenna module 110 may pass through the frequency selective reflector 20 via the frequency selective section 22.

[0221] Frequency selection segment 22 may be composed of a plurality of patterned elements or unit elements 171 periodically arranged in the lateral and longitudinal directions of the base station antenna. Each of the patterned elements / unit elements 171 may have a predetermined pattern and may include a capacitor structure and an inductor structure connected in series with the capacitor structure. In addition, each of the patterned elements 171 may be electrically connected to each other via inductor structures. For example, the inductor structure in each patterned element / unit element 171 may be electrically connected to the inductor structure of an adjacent patterned element.

[0222] The resonant frequency of the frequency selection segment 22 can be configured by selecting or designing the pattern and size of the capacitor and inductor structures of each pattern unit / unit unit 171, as well as the spacing and arrangement of multiple pattern units 171, so that electromagnetic waves within a predetermined frequency range can pass through the frequency selection segment 22.

[0223] refer to Figure 6A-11 An exemplary grid reflector 170 is shown, in which embodiments of frequency selection segments and pattern units / unit units 171 according to different embodiments of the present disclosure are illustrated.

[0224] Figure 6A A frequency selection segment 221 with an array is shown according to an embodiment of the present disclosure. Figure 6B It shows Figure 6A A schematic diagram of a single unit cell 171 with patterned elements 2210 in the array shown in frequency selection segment 221. Figure 6A and Figure 6BAs shown, the patterned unit 2210 may be substantially square. The patterned unit 2210 may include a sheet structure 2211 and a plurality of linear structures 2212. The linear structures 2212 may extend outward from the concave portions 2213 of the sheet structure 2211. The sheet structure 2211 may have a substantially square shape with four recessed openings 2213, from which the linear structures protrude outward. The substantially square shape of the sheet structure 2211 allows the linear structures 2212 to be electrically connected to the linear structures 2212 in adjacent patterned units. The sheet structure 2211 forms a capacitor structure, and the linear structures 2212 form an inductor structure.

[0225] refer to Figure 6A A circuit in which a capacitor and an inductor are connected in series can be used Figure 6B The patterned unit / unit 171 shown is formed. The capacitance value can be adjusted by adjusting the distance between adjacent patterned units (e.g., the distance between adjacent sheet structures 2211) and the size of the sheet structure 2211 (e.g., area, side length, etc.). Additionally, the inductance value can be adjusted by adjusting the size of the linear structure 2212 (e.g., length, width, etc.). The resonant frequency of the frequency selection segment 22 can be adjusted by adjusting various parameters of the patterned unit 2210 to allow electromagnetic waves within a predetermined frequency range to pass through. Figure 6B In the example shown, by increasing the “depth” of the concave portion 2213, the length of each linear structure 2212 can be increased, thereby increasing the inductance value of the patterned unit 2210. Additionally, the gaps between the concave portion 2213 and the spaced-apart patterned units can extend through the entire frequency selection segment 22.

[0226] Figure 7A A front view of a grid reflector 170 having a frequency selection segment 222 according to another embodiment of the present disclosure. Figure 7B This is a schematic front view of a single unit cell 171, which shows... Figure 7A Pattern unit 2220 in frequency selection segment 222 shown. As shown... Figure 7A and Figure 7BAs shown, the pattern unit 2220 can be rectangular or substantially square, for example defined by four boundaries of equal or approximately equal length. For a "substantially" square configuration, the lengths can vary within a range of approximately + / - 20% from each other. The pattern unit 2220 may include sheet structures 2221 and a plurality of linear structures 2222. The linear structures 2222 may extend outward from corresponding concave portions 2223 of the sheet structures 2221. The sheet structures 2221 have a substantially square shape. The linear structures 222 are electrically connected to corresponding linear structures 2222 in adjacent pattern units 2220. The sheet structures 2221 form capacitor structures, and the linear structures 2222 form corresponding inductor structures. The concave portions 2223 are located at the corners of the square. Therefore, the linear structures 2222 extend along the diagonal direction of the square, which facilitates increasing the length of each linear structure 2222. In addition, to further increase the length of the linear structures 2222, each linear structure 2222 may also have portions 2224 parallel to the sides of the square. The parallel portion 2224 can significantly increase the length of the linear structure 2222, thereby increasing the inductance of the patterned unit 2220.

[0227] Figure 8A This is a front view of a grid reflector 170 having a frequency selection segment 223 and a unit cell 171 according to another embodiment of the present disclosure. Figure 8B This is a schematic front view of a single unit cell 171, which shows... Figure 8A The pattern unit 2230 in the frequency selection segment 223 shown. As shown, the pattern unit 2230 can be substantially square or rectangular, similar to the pattern unit 2230 in the frequency selection segment 223 shown. Figure 7A The surrounding area discussed in / 7B. Pattern unit 2230 may include a sheet structure 2231 and a plurality of linear structures 2232, each linear structure 2232 extending outward from a corresponding concave portion 2233 of the sheet structure 2231. The sheet structure 2231 may have a substantially square shape. Each linear structure 2232 may be electrically connected to a corresponding linear structure 2232 in an adjacent pattern unit 2230. The sheet structure 2231 forms a capacitor structure, and the linear structures 2232 form an inductor structure. Additionally, to increase the length of each linear structure 2232, the linear structure 2232 may also have portions 2234, 2235 extending parallel to the sides of the substantially square sheet structure 2231. The length of each linear structure 2232 can be increased by the two parallel portions 2234, 2235 to increase the inductance value of the pattern unit 2230.

[0228] Figure 9A This is a schematic front view of a grid reflector 170 having a frequency selection segment 224 according to some other embodiments of the present disclosure. Figure 9B yes Figure 9AA schematic front view of a single unit cell 171 with patterned unit 2240 in the frequency selection segment 224 shown. Figure 9A , 9B As shown, pattern unit 2240 may include a sheet structure 2241 and a plurality of linear structures 2242. The linear structures 2242 extend outward from corresponding sides of the substantially square sheet structure 2241 to be electrically connected to the linear structures 2242 in adjacent pattern units 2240. The sheet structure 2241 forms a capacitor structure, and the linear structures 2242 form corresponding inductor structures.

[0229] In some embodiments according to this disclosure, one or more, or even each, unit cell / pattern cell 171 may have different sizes. Figure 10 This is a schematic front view of a grid reflector 170 having a frequency selection segment 225 according to an embodiment of the present disclosure, wherein the area of ​​the sheet structure 2251 in each pattern unit gradually decreases from left to right. Correspondingly, the length of the linear structure 2252 in each pattern unit gradually increases from left to right. Of course, the present disclosure is not limited to this, and the area of ​​the sheet structure 2251 in each pattern unit may also gradually increase from left to right and / or have other configurations. Correspondingly, the length of the linear structure 2252 in each pattern unit gradually decreases from left to right. Furthermore, the area of ​​the sheet structure 2251 and the length of the linear structure 2252 in each pattern unit may also be changed in other ways, for example, they may be alternately increased and decreased. By reasonably setting parameters, such as the area of ​​the sheet structure 2251 and the length of the linear structure 2252, it is possible to achieve the desired effect by using... Figure 10 An exemplary embodiment of the frequency selection section 225 shown herein enables the transmission of electromagnetic waves within a predetermined frequency range.

[0230] In some embodiments according to this disclosure, the grid reflector 170 may have a frequency selection segment, which may alternatively or also have a plurality of unit cells / pattern cells 171 with different configurations. Figure 11 A grid reflector 170 with frequency selection segments 226, according to an embodiment of the present disclosure, is shown, the frequency selection segments having patterned cells / unit cells 171 with different configurations. As... Figure 11 As shown, the frequency selection segment 226 may include pattern units 2260 and 2270 with two different configurations. Pattern units 2260 and 2270 may be arranged alternately. It should be noted that... Figure 11 A specific configuration of pattern elements 2260 and 2270 is not shown. Those skilled in the art can design suitable configurations and parameters, such as the spacing of the pattern elements according to the teachings of this disclosure, such that… Figure 11The frequency selection segment 226 shown can allow electromagnetic waves within a predetermined frequency range to pass through. For example, each unit cell 171 and / or pattern cell 2260 can have any of the pattern cell configurations discussed above, and each pattern cell 2270 can have any of the pattern cell configurations discussed above.

[0231] Furthermore, although the pattern units in the illustrated embodiments are rectangular or substantially square, this disclosure is not limited thereto. The unit unit / pattern unit 171 can have various shapes, such as triangles, rectangles, rhombuses, pentagons, hexagons, circles, ellipses, etc., as well as combinations of different shapes for different unit units.

[0232] In some embodiments according to this disclosure, the frequency selection segment can be configured as a slotted frequency selection segment, which can be formed by periodically opening slots in metal units on a metal plate, as shown in example... Figures 5A to 11 This is achieved by various patterned units arranged periodically as shown. To this end, in embodiments according to this disclosure, the slots can be formed by perforating or laser direct structuring (LSD) at corresponding locations on the metal body 21 to form frequency-selective segments. The body 21 and the frequency-selective segments 22 can be integrally formed from a metal plate, thereby ensuring that the formed frequency-selective reflector 20 has sufficient strength. In other embodiments, the body 21 and the frequency-selective segments 22 can be formed as separate components and then joined or fixed together in a suitable manner to form a grid (frequency-selective) reflector 170. In some embodiments, the body 21 and the frequency-selective segments 22 can also be made of different materials.

[0233] In some embodiments according to this disclosure, the grid reflector 170 may include patch-type frequency selective segments, which can be implemented by forming periodically arranged metal patterned units on a substrate. Multiple metal patterned units can be formed on the substrate by a selective electroplating process or a metal ink transfer printing process. In some embodiments, the substrate may be formed of plastic, and the metal patterned units may be formed of a metallic material such as copper, aluminum, gold, and silver. To increase the strength of the frequency selective reflector 170, the substrate may be formed of a high-strength plastic.

[0234] Now go to Figure 12A-22 The grid reflector 170 may be constructed with unit cells 171 having an open central interior 172 without metal, and each unit cell 171 may include a metal periphery 173. The grid reflector 170 may be provided as a single layer of metal sheet, thereby providing the unit cells 171 with an open central interior 172 without metal.

[0235] In some embodiments, the open center 172 may be connected to atmospheric / local environmental conditions. In other embodiments, the mesh reflector 170 includes a dielectric cap 271 extending above the unit cell 171. Figure 23C Dielectric cap 271 may comprise fiberglass, printed circuit board, or plastic, such as a polymer or copolymer. Dielectric cap 271 may improve low-frequency band reflections and / or mid-frequency band reflections. Dielectric cap 271 ( Figure 23C It can be attached to the grid reflector 170 to extend above (in front and / or behind) each unit cell 171.

[0236] The grid reflector 170 is configured to allow the passage of one or more first defined frequency ranges of RF energy (electromagnetic waves) and is also configured to reflect RF energy of different second frequency ranges / bands.

[0237] A pair of adjacent unit cells 171 can share a metal (wire) segment 174 that defines a portion of the outer perimeter 173 of each unit cell. As shown, a unit cell 171c can be surrounded by multiple adjacent unit cells 171n, each of which (shown as four adjacent unit cells 171n in this embodiment) shares the peripheral metal wire segment 174 with the central unit cell 171c.

[0238] refer to Figure 13A and 13B In this example, the grid reflector 170 includes at least one shaped metal region 1173 positioned around the perimeter 173 of the respective unit cell 171'. A shared metal segment 174 (which may be a metal wire) forming part of the respective perimeter 173 of the adjacent 171n unit cells 171 may be incorporated into or extend across the at least one shaped metal segment 1173. The shaped metal region 1173 may extend beyond the shared metal segment 174 such that opposing inner free ends 1173e may project inward toward the central space 172 and terminate at a location laterally and / or longitudinally offset from the center of the respective unit cell 171'.

[0239] Figure 14A and 14B Another example of a mesh reflector 170 is shown. Similar to... Figure 13A , 13B The grid reflector 170 includes at least one shaped metal region 1173 positioned around the perimeter 173 of a corresponding unit cell 171''. The shaped metal region 1173 may have an open internal space 1173i, rather than... Figure 13AThe closed formed metal region 1173 shown in / 13B. The formed metal region 1173 may have a periphery 1173p surrounding an open internal space 1173i, which is smaller than the open space 172 of the unit cell 171. The formed metal region 1173 may have opposing first and second ends 1173e, the first end 1173e extending into a first unit cell and the second end 1173e extending into a second unit cell. A grid reflector 170 having a formed metal region 1173 with an open internal space 1173i can reduce the weight of the reflector while providing an increased current path.

[0240] refer to Figure 13A , 13B 14A, 14B, a shared metal segment 174 of a metal perimeter line 173 shared by adjacent 171n unit cells 171 may be attached to at least one formed metal region 1173 (above and below it or to its right and left), a first portion of the formed metal region 1173 being located inside the first unit cell 171 of a pair of adjacent 171p unit cells, and a second portion of the formed metal region 1173 being located inside the second unit cell 171 of a pair of adjacent 171n unit cells 171.

[0241] The formed metal area 1173 is shown as a rectangle, but other shapes may be used. When in use, the rectangle may be oriented such that the two long sides extend laterally and the two long sides extend longitudinally around the perimeter 173 of the respective unit cell 171.

[0242] In some embodiments, unit cell 171 includes a periphery 173 having corners 173c, and grid reflector 170 may be configured such that shaped metal region 1173 extends along a sub-length of a shared metal segment 174 (adjacent adjacent unit cell 171) of periphery 173 between a pair of spaced corners 173c, the shared metal segment being shown as a metal line segment.

[0243] refer to Figure 13B and 14B In some embodiments, the formed metal region 1173 is configured such that the first axis of symmetry A1-A1 is aligned with the shared metal segment 174 of the metal periphery 173. The formed metal region 1173 may also be configured such that the second axis of symmetry A2-A2, perpendicular to the first axis of symmetry A1-A1, is aligned with the center point Cp of the corresponding unit cell 171.

[0244] Figure 15A , 15BImages 16A and 16B illustrate further examples of a grid reflector 170 having shaped metal regions 1173' spaced apart from the peripheries 173 of unit cells 171''' and 171'''' respectively, each having an open central space 172 of a unit cell. In these embodiments, the shaped metal regions 1173' have a circular outer periphery 1173p in the grid 170 and are arcuate when displayed relative to a single unit cell 171''. Figure 15B , 16B ). Figure 16A , 26B The formed metal region 1173' is shown to have an open internal space 1173i. The open internal space 1173i can be circular as shown, or have other shapes, such as polygons, ellipses, triangles, etc. As before, a pair of 171p adjacent 171n units 171''' ( Figure 15A ) or 171'''' ( Figure 16A The metal line segment 174 is shared to form part of the corresponding surrounding area 173.

[0245] Figure 17A , 17B Figures 18A and 18B illustrate additional exemplary grid reflectors 170. In these embodiments, each unit cell 171'''' has a hollow "X" shape defining an open space 172 having an open center point Cp and an open angular space across the center point Cp to form the "hollow" X shape. A metal periphery 173 may have an inner periphery 173i having a different shape from the outer periphery 173o forming the metal periphery 173. The inner periphery 173 is shaped to provide the angular space of the open center 172. A shaped metal region 1173'' positioned around the periphery 173 may include a triangular shape for the corresponding unit cell 171''''', with its long side facing the other long side of the adjacent triangular shape 1173' in the grid reflector 170. The shaped metal region 1173' may define a portion of the peripheral segment 174 of the adjacent unit cell 171'''''. Figure 18A , 18B The shaped metal region 1173' is shown to have an open or hollow interior space 1173i with a two-dimensional cutout in the shape of a "diamond" formed in the grid reflector 170.

[0246] Figures 19A-19D Further examples of grid reflectors 170 with different shapes of open interior space 174 having corresponding unit cells 171 are shown. The different shapes are shown as circles, rhombuses and polygons, such as octagons and heptagons.

[0247] The unit cell 171 of the grid reflector 170 can have other shapes and can be symmetrical.

[0248] In some embodiments, unit cell 171 may have an asymmetric structure.

[0249] The grid reflector 170 can be configured such that the array of unit cells 171 can be asymmetric about one or more axes.

[0250] Because the RF energy from the radiating element behind the grid reflector 170 can propagate forward in multiple angular directions, the metal periphery of the corresponding unit cell 171 can be narrow enough to accommodate the angle of incidence of the RF energy from the radiating element behind the grid reflector while allowing the RF energy to propagate forward and reflecting the RF energy from the radiating element in front of the grid reflector 170.

[0251] refer to Figure 20-22 The grid reflector 170 can be configured such that unit cells 171 of different densities exist at different locations. In some embodiments, the grid reflector 170 can be configured such that the unit cells 171 can be asymmetrical about one or more axes to, for example, improve cross-polarization performance. The width of the metal perimeter 173 can vary around the corresponding perimeter of the unit cell 171.

[0252] Figure 20 The higher density of unit cells 171 is shown relative to the middle portion 170m, the left portion 170r, and the right portion 170l. Figure 20 It is also shown that the unit cell 171 located in the middle portion 170m of the grid reflector 170 may have a larger surface area, height and / or width than the unit cells 171 located in the left portion 170r and the right portion 170l, shown as a common height dimension and different width dimensions (and having a larger central space 172).

[0253] Figure 21 It is shown that the density of unit cells 171 in the middle portion 170m of the grid reflector 170 is greater than that in the unit cells 171 in the right and / or left portions 170r, 170l. Figure 21 It is also shown that the unit cell 171 located in the right portion 170r and the left portion 170l may have a larger surface area, height and / or width than the unit cell 171 located in the middle portion 170m, shown as having a common height and a larger width (with a larger central space 172).

[0254] Figure 22 The density of unit cells 171 at the middle portion 170m of the grid reflector 170 is greater than that at the unit cells 171 at the right 170r and / or left 170l portions. Figure 22It is also shown that the unit cell 171 located in the right and left portions 170r, 170l may have a larger surface area, height and width (with a larger central space 172) than the unit cell 171 located in the middle portion 170m.

[0255] The mesh reflector 170 can be configured, for example, as an outer 170s extending longitudinally. Figure 15A The right and left sides 214s are incorporated into or attached to the longitudinal extension of the (solid) surface of the main reflector 214 at one or more locations. The grid reflector 170 can be configured to have different unit cell configurations and / or sizes at different locations.

[0256] When configured to allow high-frequency band energy to pass through the grid reflector 170, the thick / wide grid perimeter 173 surrounding the open space 172 of the unit cell 171 should be avoided to reduce obstruction at the slant scan points in the high-frequency band.

[0257] In some embodiments, the grid reflector 170 of the passive antenna assembly 190 can be configured to act as a high-pass filter that substantially allows low-frequency band energy to be completely reflected when the grid is formed of a sheet of metal, while allowing higher-frequency band energy (e.g., about 3.5 GHz or higher) to pass through, typically substantially completely. Therefore, the grid reflector 170 is transparent or invisible to higher-frequency band energy and can achieve a suitable out-of-band rejection response.

[0258] Now go to Figure 23A , 23B Figures 24 and 25 illustrate an exemplary passive antenna assembly 190. A grid reflector 170 may be incorporated into a longitudinally and laterally extending main reflector 214. The main reflector 214 may have a longitudinal length greater than the longitudinal length of the grid reflector 170. The main reflector 214 may have a solid reflective surface for antenna elements located in front of the main reflector 214 and may be positioned above an operating component 314 (e.g., a filter, tilt adjuster, etc.).

[0259] In some embodiments, the grid reflector 170 may be located at a distance ranging from 1 / 8 to 1 / 4 of the operating wavelength behind the low-band dipole 222. The term "operating wavelength" refers to the wavelength corresponding to the center frequency of the operating band of the radiating element (e.g., the low-band radiating element 222). In some embodiments, the grid reflector 170 may be located at a distance ranging from 1 / 10 to 1 / 2 of the operating wavelength in front of the high-band radiating element 1195. For example, in certain specific embodiments, the grid reflector 170 may be located at a physical distance of 0.25 inches and 2 inches from the ground plane behind the mMIMO array of the radiating element 1195 of the active antenna module 110 or from the reflector 1172. Figure 25 ,26A (26B). Other placement locations can be used.

[0260] In some embodiments, the ground plane or reflector 1172 of the active antenna module 110 may be electrically connected to the grid reflector 170 and / or the main reflector 214 of the base station antenna 100, for example, by current connection and / or capacitive connection. In other embodiments, the ground plane or reflector 1172 of the active antenna module 110 is not electrically connected to the grid reflector 170 and / or the main reflector 214.

[0261] refer to Figure 23A The grid reflector 170 may have a longitudinal range "L" and a lateral range "W". The longitudinal range L may extend a distance greater than the lateral range W. The longitudinal range L may be smaller than the lateral range W. The grid reflector 170 has a front side 170f facing the front side 100f of the housing 100h / radome 111f.

[0262] Antenna assembly 190 includes multiple arrays of radiating elements, typically arranged in six columns, wherein the radiating elements extend forward from the front side 170f of reflector 170, and some columns of radiating elements continue to extend in front of main reflector 214. Each array of radiating elements in antenna assembly 190 may include radiating elements 222 configured to operate in a first frequency band and radiating elements 232 configured to operate in a second frequency band. Other arrays of radiating elements may include radiating elements configured to operate in a second or third frequency band. The first, second, and third frequency bands may be different frequency bands (although they may overlap). In some embodiments, a low-frequency band antenna element 222 with dipole arms may be located in front of grid reflector 170, typically along the right and left portions 170s and / or the main reflector side 214s of grid reflector 170.

[0263] Figure 23C The grid reflector 170 is shown to be configured as a reflector body or assembly having a first grid reflector 1701 and a second grid reflector 1702, the first grid reflector and the second grid reflector being longitudinally spaced apart and typically separated by a main reflector 214 having a continuous surface without grid unit cells 171.

[0264] As discussed above, Figure 23C It is also shown that a dielectric cap 271 may be attached to a grid reflector 170 and extend across the unit cell 171. In some embodiments, the dielectric cap 271 may have a dielectric constant of at least 1 and may be in the range of 1-6, such as 1, 2, 3, 4, 5, 6 or any number in the range of 1-6, including the endpoints. In some embodiments, a dielectric material with a higher dielectric constant may be suitable.

[0265] In some embodiments, the grid reflector 170 and the main reflector 214 may be integrally formed as a single (sheet-like) metal body. Alternatively, the grid reflector 170 and the main reflector 214 may be configured as separate components, directly or indirectly attached and electrically connected together to provide a common electrical ground. The grid reflector 170 and the main reflector 214 may both be metal sheets of the same or different thicknesses.

[0266] In some embodiments, the grid reflector 170 may be provided with a substrate different from that of the main reflector 214. In some embodiments, the grid reflector 170 may be provided as a printed circuit board having conductive patches forming an array of unit cells 171. The grid reflector 170 may be provided as a flexible circuit board with conductive patches. The grid reflector 170 may be provided as a non-metallic substrate with metallized patches.

[0267] Some of the radiating elements of antenna 100 (discussed below) may be mounted to extend forward from main reflector 214, and if dipole-based radiating elements are used, the dipole radiators of these radiating elements may be mounted in front of main reflector 214 at approximately ¼ of the wavelength of the operating frequency of each radiating element. Main reflector 214 may serve as a reflector and ground plane for the radiating elements mounted thereon of base station antenna 100.

[0268] Still referencing Figure 23A , 23B 24. The passive antenna assembly 190 of the base station antenna 100 may include one or more arrays 220 of low-frequency band radiating elements 222, one or more arrays 230 of first intermediate frequency band radiating elements 232, one or more arrays 240 of second intermediate frequency band radiating elements 242, and optionally one or more arrays 250 of high-frequency band radiating elements 252. Radiating elements 222, 232, 242, 252, and 1195 may each be a dual-polarized radiating element. Further details of the radiating elements can be found in co-pending WO2019 / 236203 and WO2020 / 072880, the contents of which are incorporated herein by reference as if described in their entirety herein. Some of the high-frequency band radiating elements, such as radiating element 1195, may be provided as mMIMO antenna arrays and may be disposed in the active antenna module 110 instead of in the housing 100h of the base station antenna 100.

[0269] The low-frequency radiating element 222 may be mounted to extend forward from the main or primary reflector 214 and / or the grid reflector 170, and may be mounted in two columns to form two linear arrays 220 of the low-frequency radiating element 222. In some embodiments, each low-frequency linear array 220 may extend along substantially the full length of the antenna 100.

[0270] The low-frequency radiating element 222 may be configured to transmit and receive signals in a first frequency band. In some embodiments, the first frequency band may include a frequency range of 617-960 MHz or a portion thereof (e.g., a 617-896 MHz band, a 696-960 MHz band, etc.). The low-frequency linear array 220 may or may not be used to transmit and receive signals in the same portion of the first frequency band. For example, in some embodiments, the low-frequency radiating element 222 in the first linear array 220 may be used to transmit and receive signals in a 700 MHz band, and the low-frequency radiating element 222 in the second linear array 220 may be used to transmit and receive signals in an 800 MHz band. In other embodiments, the low-frequency radiating element 222 in both the first linear array 220-1 and the second linear array 220-2 may be used to transmit and receive signals in a 700 MHz (or 800 MHz) band.

[0271] The first intermediate frequency (IF) band radiating element 232 may also be mounted to extend forward from the main reflector 214 and / or the grid reflector 170, and may be mounted in two columns to form a linear array 230 of the first IF band radiating elements 232. The linear array 230 of the IF band radiating elements 232 may extend along the respective side edges of the grid reflector 170 and / or the main reflector 214. The first IF band radiating element 232 may be configured to transmit and receive signals in a second frequency band. In some embodiments, the second frequency band may include a frequency range of 1427–2690 MHz or a portion thereof (e.g., the 1710–2200 MHz band, the 2300–2690 MHz band, etc.). In the depicted embodiment, the first IF band radiating element 232 is configured to transmit and receive signals in the lower portion of the second frequency band (e.g., some or all of the 1427–2200 MHz band). The linear array 230 of the first intermediate frequency radiating element 232 can be configured to transmit and receive signals in the same part of the second frequency band or in different parts of the second frequency band.

[0272] The second intermediate frequency (IF) band radiating element 242 can be mounted in columns to form a linear array 240 of the second IF band radiating element 242. The second IF band radiating element 242 can be configured to transmit and receive signals in a second frequency band. In the depicted embodiment, the second IF band radiating element 242 is configured to transmit and receive signals in the upper portion of the second frequency band (e.g., some or all of the 2300-2700 MHz band). In the depicted embodiment, the second IF band radiating element 242 can have a different design than the first IF band radiating element 232.

[0273] The high-frequency radiating elements 252 and / or 1195 may be mounted in columns within the upper inner or central portion of the antenna 100 to form a multi-column (e.g., four- or eight-column) array 250 of the high-frequency radiating elements 252 and / or 1195. The high-frequency radiating element 1195 may be configured to transmit and receive signals in a third frequency band. In some embodiments, the third frequency band may include a frequency range of 3300-4200 MHz or a portion thereof.

[0274] In the depicted embodiment, the array 220 of low-frequency radiating elements 222, the array 230 of the first intermediate-frequency radiating elements 232, and the array 240 of the second intermediate-frequency radiating elements 242 are all part of the passive antenna assembly 190, while the array 250 of the high-frequency radiating elements 1195 is part of the active antenna module 110. It should be understood that in other embodiments, the type of arrays included in the passive antenna assembly 190 and / or the active antenna module 110 may vary.

[0275] It will also be recognized that the number of linear arrays of low-frequency, mid-frequency, and high-frequency radiating elements may differ from that shown in the figures. For example, the number of linear arrays of each type of radiating element may differ from that shown, some types of linear arrays may be omitted and / or other types of arrays may be added, the number of radiating elements in each array may differ from that shown, and / or the arrays may be arranged differently. As a specific example, the two linear arrays 240 of the second mid-frequency radiating element 242 may be replaced by four linear arrays of an ultra-high-frequency radiating element that transmits and receives signals in the 5 GHz band.

[0276] At least some of the low-frequency and mid-frequency radiating elements 222, 232, 242 may be mounted to extend forward from and / or from the grid reflector 170 or the main reflector 214.

[0277] Each array 220 of the low-frequency band radiating elements 222 can be used to form a pair of antenna bundles, i.e., one antenna bundle in each of the two polarizations, where the dual-polarized radiating elements are designed to transmit and receive RF signals. Similarly, each array 232 of the first intermediate-frequency band radiating elements 232 and each array 242 of the second intermediate-frequency band radiating elements 242 can be configured to form a pair of antenna bundles, i.e., one antenna bundle in each of the two polarizations, where the dual-polarized radiating elements are designed to transmit and receive RF signals. Each linear array 220, 230, 240 can be configured to provide service to a sector of the base station. For example, each linear array 220, 230, 240 can be configured to provide approximately 120° of coverage in the azimuth plane, such that the base station antenna 100 can be used as a sector antenna for a three-sector base station. It will be appreciated that the linear arrays can be configured to provide coverage at different azimuth beamwidths. While all radiating elements 222, 232, 242, 252, and 1195 in the depicted embodiments may be dual-polarized radiating elements, it should be recognized that in other embodiments, some or all of the dual-polarized radiating elements may be replaced with single-polarized radiating elements. It should also be recognized that although the radiating elements are shown as dipole radiating elements in the depicted embodiments, other types of radiating elements, such as, for example, patch radiating elements, may be used in other embodiments.

[0278] Some or all of the radiating elements 222, 232, 242, 252, and 1195 may be mounted on a feed board that couples RF signals to and from the respective radiating elements 222, 232, 242, 252, and 1195, wherein one or more radiating elements 222, 232, 242, 252, and 1195 are mounted on each feed board. Cables (not shown) and / or connectors may be used to connect each feed board to other components of antenna 100, such as duplexers, phase shifters, calibration boards, etc.

[0279] An RF connector or "port" 140 may be mounted in the bottom cover 130 for coupling RF signals from an external remote radio unit (not shown) to arrays 220, 230, and 240 of the passive antenna assembly 190. Two RF ports, a first RF port 140 and a second RF port 140, are provided for each array 220, 230, and 240. The first RF port couples a first-polarized RF signal between the remote radio unit and arrays 220, 230, and 240, and the second RF port couples a second-polarized RF signal between the remote radio unit and arrays 220, 230, and 240. Since radiating elements 222, 232, and 242 may be tilted cross-dipole radiating elements, the first and second polarizations may be -45° and +45° polarization, respectively.

[0280] The phase shifter can be connected to a corresponding port in RF port 140. The phase shifter can be implemented as, for example, a brushed arc phase shifter, such as the one disclosed in U.S. Patent No. 7,907,096 to Timofeev, the disclosure of which is incorporated herein by reference in its entirety. A mechanical linkage can be coupled to a RET actuator (not shown). The RET actuator can apply a force to the mechanical linkage, which in turn adjusts movable elements on the phase shifter to electronically adjust the downtilt angle of one or more antenna beams generated by the low-band or mid-band linear arrays 220, 230, 240.

[0281] It should be noted that a multi-connector RF port (also known as a “cluster” connector) can be used instead of a single RF port 140. A suitable cluster connector is disclosed in U.S. Patent Application Serial No. 16 / 375,530, filed April 4, 2019, the entire contents of which are incorporated herein by reference.

[0282] refer to Figure 23A , 23B The feed plate 1200 can be positioned in front of or behind the side section 214s of the main reflector 214. The feed plate 1200 is connected to the feed handle 221 (or 222f) of the radiating element 222 (e.g., a low-frequency band element). The feed handle 221 can be an angled feed handle that projects outward and laterally inward, such that the front end of the feed handle 221 is positioned closer to the center of the reflector 170 than the rear end. The feed plate 1200 can be coupled to and / or connected to the grid reflector 170 or the main reflector 214.

[0283] The radiating element 220 may be a dipole element configured to operate in some or all of the 617-960 MHz frequency band. A feed circuit including a hook-type balun may be disposed on the feed handle 221. Further discussion of exemplary antenna elements including the antenna element (including the feed handle) can be found in U.S. Provisional Patent Application Serials 63 / 087,451 and 62 / 993,925 and / or related utility model patent applications claiming priority thereto, the contents of which are incorporated herein by reference as if described in their entirety herein.

[0284] Some or all of the low-frequency or mid-frequency radiating elements 222, 232 may be mounted on the feed board 1200, and RF signals may be coupled to individual radiating elements 222, 232 and from said individual radiating elements. Cables (not shown) and / or connectors may be used to connect each feed board to other components of the base station antenna 100, such as duplexers, phase shifters, calibration boards, etc.

[0285] Now go to Figure 25An exemplary active antenna module 110 is illustrated. The active antenna module 110 may include an RRU (Remote Radio Unit) unit 1120 with radio circuitry. The active antenna module 110 may also include a filter and calibration printed circuit board assembly 1180, and an antenna assembly 1190 including a reflector or ground plane on a printed circuit board 1172 behind a radiating element 1195. The antenna assembly 1190 may also include a phase shifter 1191, which may alternatively be part of the filter and calibration assembly 1180. The radiating element 1195 may be provided as a massive MIMO array. The RRU unit 1120 is a radio unit that typically includes radio circuitry that converts digital transmissions from a base station into analog RF signals (and vice versa). One or more of the radio unit or RRU unit 1120, the antenna assembly 1190, or the filter and calibration assembly 1180 may be configured as attachable (stackable) individual sub-units. RRU unit 1120 and antenna assembly 1190 can be provided as an integrated unit, optionally also including calibration assembly 1180. When configured as sub-units, different sub-units can be supplied by an OEM or cellular service provider, while still using a common base station antenna housing 100h and its passive antenna assembly 190. Antenna assembly 1190 can be coupled to filter and calibration board assembly 1180 via, for example, a pogo connector 111. Other connector configurations can be used for each connection, such as a 3-piece SMP connector. RRU unit 1120 can also be coupled to filter and calibration board assembly 1180 via pogo connector 111, thereby providing a fully blind-fit connection assembly without the need for cable connections. Alignment of cooperating components within tight tolerances may be required to provide suitable performance. In other embodiments, radio circuitry can be provided together with the antenna assembly as a single integrated unit.

[0286] Antenna module 110 may include radome 119 and optional second radome 1119. In some embodiments, the second radome 1119 covers the first radome 119 for aesthetic purposes and may be removed during installation.

[0287] Figure 26A and 26B An exemplary embodiment of the base station antenna 100 and the active antenna module 110 is shown. Figure 26A The rear portion 100r of the base station antenna 100 is shown to have a flat surface, and the active antenna assembly 1190 can be configured to face the rear portion 100r, with radomes 119, 111r therebetween, and a grid reflector 170 in front of the radiating element 1195. Figure 26B The rear portion 100r of the base station antenna 100 is shown to have a recessed section 102 and is sized to receive the radome 119 of the active antenna element 110, wherein the radiating element 1195 is behind and faces the grid reflector 170.

[0288] Figure 27 This is a simplified cross-sectional view of an exemplary base station antenna 100 having a grid reflector 170 aligned with an active antenna module 110.

[0289] The grid reflector 170 can provide a wide bandpass in the high-frequency band, high suppression in the low-frequency band, and large incident angle support in the notched reflector.

[0290] Now go to Figure 28A The diagram shows a grid reflector 170, in which two linear columns of low-frequency band radiating elements 222 extend in front of it. The linear columns extend above the main reflector 214 and below the grid reflector 170. The grid reflector 170 can be coupled to the right and left segments 214s of the main reflector 214, or it can be held by the body 21 of the grid reflector and coupled to the main reflector 214. Figure 28B An exemplary rear side of the grid reflector 170 and the main reflector 214 is shown.

[0291] Figure 28C A grid reflector 170 is shown attached to the front-facing inner surface of the rear radome 111r and rear portion 100r, which are connected to the housing 100h. The grid reflector 170 may be in a different plane behind the plane of the main reflector 214. The grid reflector 170 may be electrically coupled to the main reflector 214 such that both are at a common ground. The rear radome 111r may cooperate with the grid reflector 170 for its dielectric loading. The term "dielectric loading" means that the rear radome 111r, 100r is configured to cooperate with the grid reflector 170 (e.g., FSS) via spacing and a material having a dielectric constant to reduce or minimize reflections at the frequency band through which the grid reflector and / or FSS are configured to transmit.

[0292] The grid reflector 170 can be configured as a flexible circuit that conformally attaches to the inner surface of the rear (wall) 100r of the radome 111r. Double-sided tape, adhesive, bonding material, or other attachment methods can be used to attach the grid reflector 170 to the rear radome 111r. The rear radome 111r can have a dielectric constant in the range of 1-3.

[0293] In other embodiments, reference is made to... Figure 28D A mesh reflector 170 may be attached to a main reflector 214, shown in this figure as spaced-out right and left segments 214s of the main reflector 214. The main surface 170p of the mesh reflector 170 may be parallel to the main surface 214p of the main reflector 214. The main surface of the mesh reflector 170 may be coplanar with the main surface 214p of the main reflector 214. In other embodiments, the mesh reflector 170 may be located behind the main surface of the main reflector 214 in a different plane.

[0294] Now go to Figure 28E , 28F In 28G, the base station antenna 100 may have at least one matching layer 310, which may be located behind the main surface of the front reflector 214 and in front of the grid reflector 170. The matching layer 310 behind the main surface of the front reflector 214 may be referred to as the "rear" matching layer 310b. In some embodiments, the rear matching layer 310b may be closely spaced from the rear radome 111r and / or the grid reflector 170, typically at a distance ranging from 0.1 mm to 25 mm (e.g., about 10-15 mm), and may be about 10 mm, about 11 mm, and about 12 mm.

[0295] Still referencing Figure 28E , 28F In some embodiments, at least one additional matching layer 310 may also be located in front of the main reflector 214, and at least one matching reflector may be located behind the right front side and left front side 214s of the front reflector 214.

[0296] The main reflector 214 may have spaced-out right and left segments 214s as described above, which may be bent rearward to define a rear segment 214b. A mesh reflector 170 may be attached to the inner surface 111i of the rear segment 214b and / or the rear radome 111r. The mesh reflector 170 may be configured as a multilayer printed circuit board and / or flexible circuitry.

[0297] Now go to Figures 29A-29D The mesh reflector 170 may be provided as a separate component from the main reflector 214. The mesh reflector 170 may be provided as a sheet-like metal mesh reflector. The mesh reflector 170 may have a connecting section 170c for attachment to the main reflector 214. The mesh reflector 170 may be electrically connected to the main reflector 214. The mesh reflector 170 may be coplanar with the main reflector 214.

[0298] Figure 29A It is also shown that the base station antenna 100 may include a plurality of protruding matching layer support posts 300, which can support at least one matching layer 310 (e.g., Figure 28G , Figure 37 ).

[0299] Figure 29B and 29C The connecting segment 170c is shown to include a longitudinally extending and laterally spaced right arm and a left arm. The right arm and left arm can be attached to adjacent segments of the main reflector 214. The mesh reflector 170 can be located behind the main surface 214p of the main reflector 214, closer to the rear radome 111r. In some embodiments, similar to the description of... Figure 28G The printed circuit board configuration of the grid reflector 170 discussed herein, wherein the rear matching layer 310b may be closely spaced from the rear radome 111r and / or the grid reflector 170, typically within a range of 0.1 mm to 25 mm (e.g., about 10-15 mm), and may be about 12 mm.

[0300] refer to Figures 29C-29E The base station antenna 100 may include two matching layers located behind the main surface of the main reflector 214. Figure 29E The layers are designated 310b1 and 310b2. The first back-matching layer 310b1 may be positioned closer to the main surface 214p of the main reflector 214 than the second back-matching layer 310b2. In some embodiments, the first back-matching layer 310b1 and the second back-matching layer 310b2 may be stacked in the front-to-back direction but spaced apart by a distance in the range of 10-100 mm, for example, about 60-70 mm.

[0301] Figures 30-33 The base station antenna 100 is shown to provide an integrated reflector 1214 that provides both the main reflector 214 and the grid reflector 170 in a single (mono) structure.

[0302] Figure 31 The grid reflector 170 is shown to have a three-dimensional body 170b having unit cells 171 extending on a front surface 170f and also on a rearwardly extending wall 170w. The front surface 170f may extend laterally and may be incorporated into the right and left corners connected to the rearwardly extending wall 170w. The rearwardly extending wall 170w may be orthogonal to the front surface 170f. The three-dimensional body 170b may be provided separately from the main reflector 214.

[0303] like Figure 34 and 35 As shown, the three-dimensional body 170b can also be configured to provide an isolation wall 350 that projects rearward from the rearward-facing surface and / or forward from the front-facing surface 170f. The isolation wall 350 can be metallic, metallized, or provided for a frequency-selective surface / substrate reflector configuration. Also as shown, a sidewall 170w can extend in front of and behind the front surface 170f of the grid reflector 170, orthogonally to it. The forward-projecting sections of the sidewall 170 can be metallic, metallized, or provided for a frequency-selective surface / substrate.

[0304] Figure 36 and 37The base station antenna 100 is shown to have a first reflector 1701 and a second reflector 1702. Both the first and second reflectors can be configured as grid reflectors 170 and stacked in a front-to-back orientation, one at least partially in front of the other, inside the base station antenna housing 100h. Multiple linear columns of radiating elements 222 can protrude in front of the first reflector 1701. The second grid reflector 1702 can be positioned closer to the rear 100r of the base station antenna 100 than the first grid reflector 1701.

[0305] The first grid reflector 1701 and the second grid reflector 1702 may have different main substrates and may be tuned to reflect and propagate RF energy in the same or different frequency bands. One of the first grid reflector 1701 or the second grid reflector 1702 may be constructed as a metal grid reflector 170, and the other of the first grid reflector 1701 or the second grid reflector 1702 may be constructed as a non-metallic substrate with metal patches, such as a multilayer circuit board or flexible circuit that can improve low-frequency band reflection.

[0306] The first grid reflector 1701 may include a unit cell 171 configured to transmit RF energy in a second frequency band and absorb and / or reflect at least one of the RF energy in a first frequency band, and optionally also absorb and / or reflect RF energy in a third frequency band. The third frequency band may include frequencies between the first and second frequency bands.

[0307] refer to Figure 37 At least one of the first reflector 1701 and the second reflector 1702 can be configured to mount at least some of the matching layer support posts 300. As shown, at least one matching layer 310 (shown as two matching layers stacked and spaced apart in the front-rear direction) can be located behind the first reflector 1701. The support post 300 for supporting the matching layer 310 can protrude from behind the first reflector 1701 and / or from the front of the second reflector 1702. Alternatively, the support post 300 can protrude inward from the side 100 of the housing 100h to mount the corresponding matching layer 310 (not shown).

[0308] Still referencing Figure 37 The base station antenna 100 may have multiple matching layers 310 in front of the first reflector 1701 and multiple matching layers behind the first grid reflector 1701. As shown, there are four matching layers 3101, 3102, 3103, and 3104, wherein the first and second matching layers 3101 and 3102 are behind the grid reflector 1701, and 3103 and 3104 are in front of the grid reflector.

[0309] It is also envisioned that, for example, by using a low dielectric constant radome material to adjust the spacing of the high-frequency radiating element and the low-frequency radiating element 222 in the active antenna module 110 relative to each other and the front radome 100f and / or the rear radome 100r, the base station antenna 100 may have a grid reflector 170 without any matching layer 310.

[0310] refer to Figure 38A and 38B The grid reflector 170 may have a grid of unit cells 171, the unit cell grid having a first subset 171a of unit cells 171, the first subset being tuned to block and / or reflect RF energy in a first frequency band, while allowing RF energy in a second frequency band to propagate through it. The grid reflector 170 may also have a second subset 171b of unit cells 171, the second subset being tuned to block and / or reflect RF energy in both the first and third frequency bands. The third frequency band includes frequencies between the first and second frequency bands.

[0311] A first subset 171a of unit cells 171 may be located at the upper portion of the base station antenna 100. A second subset 171b of unit cells 171 may include unit cells below and / or to the right and left of the first subset 171a of unit cells 171. The grid reflector 170 may include a region 171r, optionally having a third subset 171c of unit cells 171, which may be tuned to block and / or reflect RF energy in the first, second, and third frequency bands. Region 171r may be a closed metal or metallized surface and does not require unit cells, and may provide increased rigidity / structural support. Some of the unit cells 171 in the second subset 171b of unit cells 171 may be to the left and / or to the right of the first subset of unit cells 171a.

[0312] A first subset 171a of unit cell 171 may be located behind the low-frequency band radiating element 222 and in front of the high-frequency band radiating element 1195 (e.g., an mMIMO array). A second subset 171b of unit cell 171 may be located behind the mid-frequency band radiating element 232. The first frequency band may be a low-frequency band, the second frequency band may be a high-frequency band, and the third frequency band may be a mid-frequency band, having at least some frequencies between the first frequency and the second frequency.

[0313] The reflector 170 can be provided as a three-dimensional structure or body 170b, which includes some of the rear unit cells 171 located in the first subset 171a of the unit cells 171.

[0314] Now go to Figures 39A-39CAs discussed above regarding 28C, the grid reflector 170 may be configured as a printed circuit board reflector, optionally with flexible circuitry, which may be attached or coupled to the rear radome 111r. The base station antenna 100 may also include at least one rear matching layer 310. The at least one matching layer 310 may include at least one rear matching layer 310b located behind the main surface of the main reflector 214 and in front of the grid reflector 170. The at least one rear matching layer 310b may be located at a distance “d” in front of the rear radome 111r and / or the grid reflector 170, where “d” is a distance in the range of 0.1 mm to 25 mm, for example, about 10-15 mm, and may be about 10 mm, about 11 mm, and about 12 mm.

[0315] Figure 40 The base station antenna 100 is shown to include at least four matching layers 3101-3104 stacked in a rear-to-rear direction within the base station antenna housing 100h. As shown, two matching layers 3103 and 3104 may be rear matching layers 310b1 and 310b2. The grid reflector 170 may be coplanar with the main reflector 214 (main surface). The rearmost rear reflector 310b2 may be positioned adjacent to the rear radome 111r, typically at a distance of 1-20 mm from the rear radome 111r. Two center or intermediate matching layers 3102 and 3103 may be disposed on the opposite main surface of the grid reflector 170 and very close to it, for example, within approximately 2-10 mm. The foremost matching layer 3101 and the rearmost matching layer 3104 may be equally spaced at a distance “D” from the grid reflector 170. The first matching layer 3101 and the last matching layer 3104 can be equally spaced at a distance D1 from the corresponding intermediate matching layers 3102 and 3103, respectively.

[0316] The reflector 214 and / or FSS 170 may have rear sections 214b and 170b, which extend behind the main surfaces 214 and 170, respectively, and are positioned adjacent to the rear wall 100r and / or the rear radome 111r.

[0317] Figure 40 It is also shown that the grid reflector 170 may have rearwardly extending sidewalls 170w and may also include an array of apertures forming an FSS and / or grid reflector surface that may be orthogonal to the front radome 100f and / or the front FSS surface 170f. The sidewalls 170w may be curved metal segments that extend rearward of the front surface 170f.

[0318] Figure 41A-41FAn additional exemplary embodiment is shown, in which stacked first and second reflectors 1701, 1702 spaced apart in the front-rear direction of base station antenna 100. An array of radiating elements 1195 may be positioned behind the first reflectors 1701 and the second reflectors 1702, typically in active antenna module 110. The array of radiating elements 1195 may include an mMIMO array of radiating elements as discussed herein.

[0319] refer to Figure 41C , 41D 41E and 41F, the first reflector 1701 may include a plurality of spaced-apart cutouts 1201. A feed plate 1200 may extend across / along these cutouts 1201, and a feed handle 222f may connect a radiating element 222 to the feed plate 1200. In some embodiments, the feed plate 1200 may be located behind the main front surface 170f of the reflector 1701 and may include conductive (e.g., a copper ground plane patterned surface / circuit). The radiating element 222 may be provided in different configurations and is not limited to the configurations shown.

[0320] Figure 41A , 41F Figure 41G shows that at least one of the first reflector 1701 and the second reflector 1702 may have a rearwardly extending portion defining at least a portion of a sidewall 170w. The corresponding sidewall 170w may be metallic or provided as a printed circuit board or a combination thereof. The sidewall 170w may be a curved portion of one or more of the first reflector 1701 and the second reflector 1702. The sidewall 170w may provide structural support for the reflector 170 and / or the radiating element 222 mounted thereon. The sidewall 170w may also, or alternatively, be configured to improve the radiation pattern provided by one or more radiating elements 222 and / or radiating elements 1195 in front of and / or behind the reflectors 1701, 1702.

[0321] The first / front reflector 1701 can be located in the same plane as the main reflector 214 (at the front and rear positions aligned with the main reflector 214).

[0322] One or both of the first reflector 1701 and the second reflector 1702 may be configured such that the grid pattern extends across its entire lateral extent. In other embodiments, the grid pattern may terminate at or be coupled to the feed plate 1200 or a solid metal surface.

[0323] Figure 41B , 41EA first reflector 1701 and a second reflector 1702, which can provide a straight side, are shown. For example, one or both of reflectors 1701 and 1702 can be coupled to an internal mounting structure, such as a lateral extension and / or a longitudinal track, to align them in a suitable position within the base station antenna 100. One or both of the first reflector 1701 and the second reflector 1702 can be coupled to a surface of an radome or housing provided by the base station antenna 100.

[0324] refer to Figure 41A , 41F In 41G, the sidewall 170w may be solid metal (e.g., a solid metal sheet), or may have an aperture 170a or cutout extending between strip segments extending behind and / or in front of the front main surface 170f of the grid reflector 170.

[0325] For example Figure 41G As shown, the sidewall 170w may extend in front of and behind the front surface 170f of the first grid reflector 1701 and / or the second grid reflector 1702, shown as extending in front of and behind the front / first reflector 1701, orthogonal to it. At least a portion of the sidewall 170w may be formed by bending forward and / or backward to form a section of sheet metal of the grid reflector 170.

[0326] At least a portion of the sidewall 170w may be provided by a metal mesh or otherwise configured to provide, for example, a metallic, metallized, or frequency-selective surface / wall or FSS.

[0327] like Figure 41G As shown, the sidewall 170w may have a front section 170wf extending forward in front of the reflector 170f. The sidewall 170w may also have a rear section / rear segment 170wb extending behind the front section, with the front portion of the reflector extending laterally therebetween. The front section 170wf may have a different construction than the rear section 170wb. In some embodiments, the front section 170wf may be solid metal or formed of FSS. The rear section / rear segment 170wb may be solid, having an aperture 170a and / or a grid pattern 171.

[0328] Embodiments of the invention have been described above with reference to the accompanying drawings, in which embodiments of the invention are illustrated. However, the invention may 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. Throughout the text, the same numerals denote the same elements.

[0329] 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 used only to distinguish one element from another. For example, without departing from the scope of the invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0330] It will be understood that when an element is described as being “on” another element, that element may be directly on the other element, or there may be intermediate elements. Conversely, when an element is described as being “directly on” another element, there are no intermediate elements. It will also be understood that when an element is described as being “connected” or “coupled” to another element, that element may be directly connected or coupled to the other element, or there may be intermediate elements. Conversely, when an element is described as being “directly connected” or “directly coupled” to another element, there are no intermediate elements. Other terms used to describe relationships between elements should be interpreted in a similar manner (i.e., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.).

[0331] Relative terms, such as “below” or “above” or “upper” or “lower” or “horizontal” or “vertical”, may be used herein to describe the relationship of one element, layer, or region to another element, layer, or region, as illustrated in the accompanying drawings. It should be understood that these terms are intended to cover different orientations of the device other than those depicted in the drawings.

[0332] The term “approximately” in the context of numbers refers to a change of + / - 10%.

[0333] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will also be understood that the terms “comprising,” “including,” and / or “having” as used herein mean the presence of the stated features, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, operations, elements, components, and / or groups thereof.

[0334] All aspects and elements of the embodiments disclosed above may be combined in any way and / or combined with aspects or elements of other embodiments to provide multiple additional embodiments.

Claims

1. A base station antenna, comprising: First frequency selection surface; The second frequency selection surface is located behind the first frequency selection surface in the front-back direction and is positioned closer to the rear of the base station antenna than the first frequency selection surface, the rear of the base station antenna facing the mounting structure of the base station antenna; as well as An active antenna element located behind the second frequency selection surface in the front-back direction; The first frequency selective surface includes a unit cell grid having a first subset of unit cells tuned to block and / or reflect RF energy in a first frequency band while allowing RF energy in a second frequency band to propagate therethrough. The first frequency selective surface also includes a second subset of the unit cells tuned to block and / or reflect RF energy in the first frequency band and RF energy in a third frequency band, wherein the third frequency band includes frequencies between the first and second frequency bands.

2. The base station antenna according to claim 1, wherein the first frequency selection surface has a first main surface, and the second frequency selection surface has a second main surface, and wherein the first main surface and the second main surface are parallel to each other.

3. The base station antenna according to claim 1 further includes a first plurality of radiating elements located in front of the first frequency selection surface and a second plurality of radiating elements located behind the first frequency selection surface and behind the second frequency selection surface.

4. The base station antenna of claim 3, wherein the first plurality of radiating elements operate in the first frequency band, and the second plurality of radiating elements operate in the second frequency band.

5. The base station antenna of claim 3, wherein the first plurality of radiating elements includes low-frequency band radiating elements configured to operate in the first frequency band, and the second plurality of radiating elements includes higher-frequency band radiating elements configured to operate in the second frequency band, the second frequency band containing frequencies higher than the first frequency band.

6. The base station antenna according to claim 1, wherein at least one of the first frequency selection surface and / or the second frequency selection surface comprises a unit cell pattern in a metal sheet.

7. The base station antenna of claim 1, wherein at least one of the first frequency selection surface and / or the second frequency selection surface comprises a unit cell pattern provided by a conductive patch in or on a dielectric substrate.

8. The base station antenna of claim 1, wherein the second frequency selection surface is attached to the radome.

9. The base station antenna of claim 8, wherein the radome is a rear radome of the base station antenna, wherein the second frequency selective surface is attached to the inward-facing surface of the rear radome, and wherein the rear radome cooperates with the first frequency selective surface for dielectric loading thereon.

10. The base station antenna of claim 1, further comprising a primary reflector coupled to the first frequency selective surface, wherein the primary reflector has a first sub-length and a second sub-length, wherein the second sub-length includes a spaced-apart right side and a left side separated by a laterally extending opening, and wherein the first frequency selective surface extends longitudinally and laterally across the laterally extending opening.

11. The base station antenna of claim 1, further comprising a primary reflector, wherein the first frequency selection surface is parallel to or coplanar with the primary reflector, and the first frequency selection surface has a shorter length than the primary reflector.

12. The base station antenna of claim 1, wherein the first frequency selection surface is attached to the primary reflector.

13. The base station antenna of claim 12, wherein the main reflector and the first frequency selective surface are defined by a single-piece, integral metal sheet body.

14. The base station antenna according to claim 1, wherein the first frequency selection surface has a three-dimensional shape.

15. The base station antenna of claim 14, wherein the first frequency selection surface includes a longitudinally extending, laterally spaced right side portion and a left side portion, wherein the right side portion and the left side portion define a corner having orthogonal wall sections defining portions of the first frequency selection surface.

16. The base station antenna of claim 1, further comprising at least one matching layer behind the first frequency selection surface.

17. The base station antenna of claim 16, further comprising at least one matching layer in front of the first frequency selection surface.

18. The base station antenna of claim 1, wherein the first subset of the unit cells is located at the upper portion of the base station antenna and aligned with the array of radiating elements of the active antenna element, and wherein the second subset of the unit cells includes unit cells to the right of the first subset of the unit cells and also includes unit cells to the left of the first subset of the unit cells.

19. The base station antenna of claim 1, wherein the first frequency selection surface includes a right corner and a left corner, each of the right corner and the left corner having an orthogonal first wall segment and a second wall segment, wherein the first wall segment extends laterally, and wherein the second wall segment extends rearward from the first wall segment in a front-rear direction.

20. The base station antenna of claim 19, wherein some of the unit cells of the unit cell grid of the first frequency selection surface are present on at least one of the first wall segment and the second wall segment.

21. The base station antenna of claim 15, wherein the right-side portion and the left-side portion are located on opposite sides of an open lateral and longitudinal extension space, and wherein the first frequency selection surface includes a front surface extending across at least a portion of the lateral extension space.

22. The base station antenna of claim 1, wherein the second frequency band includes at least a portion of the RF energy in the 3.2-4.1 GHz frequency band.

23. The base station antenna of claim 16, wherein the matching layer behind the first frequency selection surface is arranged as a first matching layer and a second matching layer stacked in the front-to-back direction.

24. The base station antenna according to claim 1, further comprising: The housing includes a front radome, a rear radome, and an internal compartment; The second frequency selection surface is attached to the forward-facing surface of the rear radome.

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