Base station antenna with skeletonized radio frequency lens

Abstract

The present disclosure relates to base station antennas with skeletal radio frequency lenses. A lensed base station antenna includes a first array comprising a plurality of radiating elements configured to transmit respective sub-components of a first RF signal, a second array comprising a plurality of radiating elements configured to transmit respective sub-components of a second RF signal, and a skeletal RF lens positioned to receive electromagnetic radiation from a first one of the radiating elements of the first array and from a first one of the radiating elements of the second array. In some embodiments, the skeletal RF lens includes a plurality of layers of dielectric material separated by air gaps.

Description

[0001] This application is a divisional application of the invention patent application filed on April 10, 2020, with application number 202080034195.5 and invention title "Base Station Antenna with Skeleton Radio Frequency Lens".

[0002] Cross-references to related applications

[0003] This application claims priority to U.S. Provisional Patent Application No. 62 / 845,393, filed May 9, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This invention generally relates to radio communications, and more specifically to lensed antennas for cellular communication systems and other communication systems. Background Technology

[0005] Cellular communication systems are well known in the art. In a typical cellular communication system, a geographical area is divided into a series of areas called “cells,” and each cell is served by a base station. A base station may include baseband equipment, a radio, and a base station antenna configured to provide bidirectional radio frequency (“RF”) communication with users located throughout the cell. In many cases, a cell may be divided into multiple “sectors,” and a separate base station antenna provides coverage for each sector. Antennas are typically mounted on towers or other elevated structures, where a radiating beam (“antenna beam”) generated by each antenna is pointed outward to serve the corresponding sector. Typically, a base station antenna comprises one or more phased arrays of radiating elements, wherein, when the antenna is installed and in use, the radiating elements are arranged in one or more vertical columns. Here, “vertical” means a direction perpendicular to a plane defined by the horizon.

[0006] A common base station configuration is a "three-sector" configuration, where the cell is divided into three 120° sectors in the azimuth plane, and the base station includes three base station antennas providing coverage of the three corresponding sectors. The azimuth plane is a horizontal plane that bisects the base station antennas and is parallel to the plane defined by the horizon. In a three-sector configuration, the antenna bundle generated by each base station antenna typically has a half-power beamwidth ("HPBW") in the azimuth plane of approximately 65°, allowing the antenna bundle to provide good coverage of the entire 120° sector. Typically, each base station antenna will include a vertically extending column of radiating elements, commonly referred to as a "linear array." Each radiating element in the linear array can have an HPBW of approximately 65°, such that the antenna bundle generated by the linear array will provide coverage of the 120° sector in the azimuth plane. In many cases, the base station antenna can be what is called a "multi-band" antenna, which includes arrays of two or more radiating elements operating in different frequency bands.

[0007] Sector splitting refers to a technique in which the coverage area of ​​a base station is divided into more than three sectors in the azimuth plane, such as six, nine, or even twelve sectors. A six-sector base station would have six 60° sectors in the azimuth plane. Dividing each 120° sector into multiple smaller sub-sectors increases system capacity because each antenna beam provides coverage to a smaller area, thus providing higher antenna gain and / or allowing frequency reuse within the 120° sector. In sector splitting applications, a single multi-beam antenna is typically used for each 120° sector. The multi-beam antenna generates two or more antenna beams within the same frequency band, thereby dividing the sector into two or more smaller sub-sectors.

[0008] One technique for implementing multi-beam antennas involves mounting two or more linear arrays of radiating elements operating in the same frequency band within antennas pointing at different azimuth angles, such that each linear array covers a predetermined portion of a 120° sector, for example, half of a 120° sector (for a dual-beam antenna) or one-third of a 120° sector (for a three-beam antenna). Since the azimuth beamwidth of a typical radiating element is generally suitable for covering the entire 120° sector, an RF lens can be mounted in front of the linear array of radiating elements. This RF lens reduces the azimuth beamwidth of each antenna beam by an appropriate amount to provide service to the sub-sector. However, unfortunately, the use of RF lenses can increase the size, weight, and cost of the base station antenna, and other problems may arise associated with their use. Summary of the Invention

[0009] According to an embodiment of the present invention, a base station antenna with a lens is provided, comprising: a first array including a plurality of radiating elements configured to transmit respective sub-components of a first RF signal; a second array including a plurality of radiating elements configured to transmit respective sub-components of a second RF signal; and a skeleton RF lens positioned to receive electromagnetic radiation from a first of the radiating elements of the first array and from a first of the radiating elements of the second array. The skeleton RF lens includes a plurality of dielectric material layers separated by air gaps.

[0010] In some embodiments, the plurality of dielectric material layers may include at least one of a plurality of spaced-apart dielectric material sheets and a plurality of concentric dielectric material tubes.

[0011] In some embodiments, the base station antenna may extend along a longitudinal axis, and at least some of the dielectric material layers may have a thickness of at least 6 mm in the depth dimension of the base station antenna.

[0012] In some embodiments, the plurality of dielectric material layers may comprise a plurality of spaced-apart dielectric material sheets that are substantially parallel to each other. The spaced-apart dielectric material sheets may be spaced apart from each other in the depth dimension of the base station antenna.

[0013] In some embodiments, the spaced dielectric sheets arranged substantially parallel to each other may include a first set of spaced dielectric sheets, and the RF lens may also include a second set of dielectric sheets, each of the second set of dielectric sheets extending at a corresponding angle relative to the dielectric sheets in the first set of spaced dielectric sheets.

[0014] In some embodiments, at least some of the spaced dielectric material sheets may have a thickness between 6 mm and 12 mm in the depth dimension of the base station antenna, and at least two adjacent dielectric material sheets may be separated by 15 mm to 40 mm.

[0015] In some embodiments, a plurality of spaced-apart dielectric material sheets arranged substantially parallel to each other may include a proximal dielectric material sheet closest to the first array, a distal dielectric material sheet furthest from the first array, and at least one central dielectric material sheet between the proximal and distal dielectric material sheets. The width of the at least one central dielectric material sheet may exceed the width of both the proximal and distal dielectric material sheets.

[0016] In some embodiments, a plurality of spaced dielectric material sheets arranged substantially parallel to each other may include at least five spaced dielectric material sheets.

[0017] In some embodiments, the plurality of dielectric material layers may include a plurality of spaced-apart dielectric material sheets, and the RF lens may further include a plurality of dielectric fasteners connecting adjacent dielectric material sheets among the spaced-apart dielectric material sheets.

[0018] In some embodiments, the first array and the second array may be configured to form a respective first antenna bundle and a second antenna bundle, and the respective azimuth boresight pointing direction of each of the first antenna bundle and the second antenna bundle may extend through at least four air-filled channels.

[0019] In some embodiments, the RF lens may be substantially metal-free.

[0020] In some embodiments, the mixed dielectric constant of the RF lens along the optic direction of the first array may substantially comprise the average of the dielectric constant of the dielectric material layer and the dielectric constant of air, the average being weighted based on the amount of dielectric material and the amount of air present along the optic direction of the first array.

[0021] In some embodiments, the plurality of dielectric material layers may include a plurality of spaced dielectric material sheets arranged substantially parallel to each other and substantially perpendicular to the azimuth line of sight of the base station antenna.

[0022] In some embodiments, the plurality of dielectric material layers may include a plurality of spaced dielectric material sheets arranged substantially parallel to each other and substantially perpendicular to the azimuth axis pointing direction of the first array.

[0023] In some embodiments, the RF lens may be a cylindrical RF lens.

[0024] According to another embodiment of the present invention, a base station antenna with a lens is provided, comprising: a first array including a plurality of radiating elements configured to transmit respective sub-components of a first RF signal; a second array including a plurality of radiating elements configured to transmit respective sub-components of a second RF signal; and a skeleton RF lens positioned to receive electromagnetic radiation from a first of the radiating elements of the first array and from a first of the radiating elements of the second array. The skeleton RF lens includes a plurality of spaced-apart sheets of dielectric material arranged substantially parallel to each other.

[0025] In some embodiments, the spaced dielectric material sheets may be substantially perpendicular to the azimuth line of the base station antenna.

[0026] In some embodiments, the base station antenna may extend along a longitudinal axis, and at least some of the spaced dielectric material sheets may have a thickness of at least 6 mm in the depth dimension of the base station antenna.

[0027] In some embodiments, the spaced-apart dielectric material sheets may be spaced apart from each other in the depth dimension of the base station antenna.

[0028] In some embodiments, a plurality of spaced dielectric sheets arranged substantially parallel to each other may include a first set of spaced dielectric sheets, and the RF lens may also include a second set of dielectric sheets, each of the second set of dielectric sheets extending at a corresponding angle relative to the dielectric sheets in the first set of spaced dielectric sheets.

[0029] In some embodiments, at least some of the spaced dielectric material sheets may have a thickness between 6 mm and 12 mm in the depth dimension of the base station antenna, and at least two adjacent dielectric material sheets may be separated by 15 mm to 40 mm.

[0030] In some embodiments, a plurality of spaced dielectric material sheets arranged substantially parallel to each other may include at least five spaced dielectric material sheets.

[0031] In some embodiments, the interior of the RF lens may consist essentially of sheets of dielectric material separated by air-filled chambers.

[0032] According to further embodiments of the present invention, a base station antenna with a lens is provided, comprising: a first array including a plurality of radiating elements configured to transmit respective sub-components of a first RF signal; a second array including a plurality of radiating elements configured to transmit respective sub-components of a second RF signal; and a skeleton RF lens positioned to receive electromagnetic radiation from a first of the radiating elements of the first array and from a first of the radiating elements of the second array. A segment of the RF lens extending along the azimuthal line of sight of the first radiating element of the first array includes at least a first to fourth dielectric material region at least 3 mm thick and having a dielectric constant of at least 2.5, wherein each of the first to fourth dielectric material regions is separated by a corresponding first to third air gap.

[0033] In some embodiments, the interior of the RF lens may substantially include a sheet of dielectric material separated by air-filled chambers.

[0034] In some embodiments, the thickness of each of the first to fourth dielectric material regions may be at least 6 millimeters.

[0035] In some embodiments, the first to fourth dielectric material regions may include first to fourth spaced dielectric material sheets arranged substantially parallel to each other.

[0036] In some embodiments, the thickness of each of the first to fourth spaced-apart dielectric material sheets in the depth dimension of the base station antenna may be between 6 mm and 12 mm, and at least two adjacent dielectric material sheets in the first to fourth spaced-apart dielectric material sheets may be separated by 15 mm to 40 mm.

[0037] In some embodiments, the first to fourth spaced-apart dielectric material sheets may be interconnected by a plurality of dielectric fasteners connecting adjacent dielectric material sheets in the spaced-apart dielectric material sheets. Attached Figure Description

[0038] Figure 1AThis is a perspective view of a base station antenna with a lens according to an embodiment of the present invention.

[0039] Figure 1B yes Figure 1A Exploded perspective view of a base station antenna with a lens.

[0040] Figure 1C yes Figure 1B An enlarged perspective view of one of the linear arrays of radiating elements shown.

[0041] Figure 1D yes Figure 1B The perspective view of the RF lens shown.

[0042] Figure 1E yes Figure 1A-1B A cross-sectional view of the base station antenna.

[0043] Figure 1F yes Figure 1A-1B A schematic top view of the base station antenna with the top cover removed shows the antenna bundle formed by the antenna.

[0044] Figure 2 This is a schematic cross-sectional view of a base station antenna with a lens according to another embodiment of the present invention.

[0045] Figures 3A-3C They are shown separately Figure 2 A diagram showing the azimuth of the first to third linear arrays of the base station antenna.

[0046] Figure 4 This is a schematic cross-sectional view of a base station antenna with a lens according to some other embodiments of the present invention.

[0047] Figure 5 This is a schematic cross-sectional view of a base station antenna with a lens according to an additional embodiment of the present invention.

[0048] Figure 6A This is a schematic cross-sectional view of a base station antenna with a lens according to some additional embodiments of the present invention.

[0049] Figure 6B yes Figure 6A An enlarged perspective view of a portion of one of the linear arrays of radiating elements shown.

[0050] Figure 6C yes Figure 6A A schematic cross-sectional view of the RF lens included in the base station antenna with lens, which shows multiple fasteners that can be used to connect the dielectric sheet to the overall structure.

[0051] Figures 7A-7C They are shown separately Figures 6A-6CA diagram showing the azimuth of the first to third linear arrays of the base station antenna.

[0052] Figure 8A This is a schematic perspective view of a dual-beam base station antenna (with its radome omitted) according to an embodiment of the present invention.

[0053] Figure 8B yes Figure 8A A schematic cross-sectional view of a dual-beam antenna, in which the RF lens is also omitted to show the bottom array of radiating elements.

[0054] Figure 8C This is a schematic transverse cross-sectional view of an RF lens according to another embodiment of the present invention.

[0055] Figure 8D This is a schematic transverse cross-sectional view of an RF lens according to some other embodiments of the present invention. Detailed Implementation

[0056] As described above, one method for implementing sector segmentation is to provide a base station antenna with two or more arrays of radiating elements pointing to different portions of a sector, and to use RF lenses to reduce the azimuth beamwidth of the antenna bundle generated by the arrays, such that the antenna bundle is sized to provide coverage to the corresponding portion of the sector or "sub-sector". RF lenses can be formed of dielectric materials, and generally, the higher the dielectric constant of the lens material, the more RF focusing will occur. Prior art lensed base station antennas include RF lenses formed using what are called "artificial" dielectric materials as RF energy focusing materials to reduce the azimuth beamwidth of the antenna bundle. These artificial dielectric materials comprise small metal sheets of composite material dispersed within a dielectric substrate to produce electromagnetic properties similar to those of high-dielectric constant dielectric materials. These artificial dielectric materials can be lightweight and have a relatively high dielectric constant (e.g., between 1.8 and 2.2), sufficient to reduce the azimuth beamwidth by the required amount.

[0057] While RF lenses offer a convenient mechanism for implementing sector segmentation, the artificial dielectric materials used in these lenses can be expensive, and the metal particles included in these materials are a potential source of passive intermodulation (“PIM”) distortion. PIM distortion is particularly concerning in base station antenna applications, as a single source of PIM distortion can significantly degrade the performance of a cellular base station. Furthermore, a portion of the RF energy injected into the RF lens of a lensed base station antenna can be converted into heat within the RF lens. Excessive heating of the RF lens can damage the RF energy focusing material and alter its electromagnetic properties, thereby reducing antenna performance.

[0058] According to embodiments of the present invention, a base station antenna with a lens is provided, comprising a skeleton RF lens formed using inexpensive, readily available dielectric materials such as polyvinyl chloride (“PVC”), acrylonitrile-butadiene-styrene (“ABS”), etc. These RF lenses can be formed, for example, by injection molding, extrusion, and / or by mounting dielectric material sheets within the antenna. An RF lens according to embodiments of the present invention can be a “skeleton” structure comprising spaced-apart dielectric material layers separated by air gaps, such that the RF lens comprises an open-spaced frame. Therefore, the RF lens can be inexpensive and easy to manufacture. An RF lens can be formed by using dielectric material layers having a higher dielectric constant (e.g., 2.5 or greater) separated by air gaps, having a “hybrid” dielectric constant comparable to that of RF lenses formed using artificial dielectric materials, but at a lower cost. Furthermore, an RF lens according to embodiments of the present invention may be metal-free and therefore will not be a potential source of PIM distortion. Furthermore, since the RF lenses according to embodiments of the present invention include air channels between dielectric materials and can be formed of materials that are not easily damaged by heat, they may not require any special heat dissipation elements to dissipate heat from the RF lens. The RF lenses according to embodiments of the present invention can also be lighter than similar prior art RF lenses and can avoid the potential need for antennas including RF absorber materials sometimes used to reduce PIM distortion.

[0059] The spaced dielectric material layers used to form the RF lens according to embodiments of the present invention can have a wide variety of different configurations. Generally, the spaced dielectric material layers can be designed such that for each array of radiating elements mounted behind the RF lens, the RF energy emitted by that array along each azimuth angle in the operating sub-sector of the array will pass through the total thickness of the dielectric material, thereby producing the desired amount of focused RF energy in the azimuth plane for the dielectric constant of the material.

[0060] Typically, RF lenses are filled with a dielectric material (or an artificial dielectric material) having a dielectric constant greater than 1. Therefore, RF energy passing through such an RF lens is focused as it passes through all the different sections of the lens. In stark contrast, the skeleton RF lens according to an embodiment of the invention contains large air channels where RF energy is not focused, such that RF energy alternately passes through relatively thin sections of a relatively high-dielectric-constant material where RF energy is highly focused, and then through thicker air channels where RF energy is not focused. It has been found that this method can achieve the necessary RF energy focusing using RF lens structures that are cheaper and easier to manufacture. Furthermore, the air channels serve as heat dissipation channels, and the RF lens can be formed solely of dielectric material (i.e., without using any metal), thus allowing for a PIM-free RF lens structure.

[0061] According to embodiments of the present invention, a base station antenna can be a multi-beam antenna suitable for sector-segmentation applications. In some embodiments, such multi-beam base station antennas may include at least first and second arrays configured to operate radiating elements in the same frequency band, and RF lenses positioned to receive electromagnetic radiation from the first and second arrays. The RF lens may be a skeleton RF lens. In some embodiments, the skeleton RF lens includes a plurality of dielectric material layers separated by air gaps. In some embodiments, a segment of the RF lens extending along the azimuthal line of sight of a first radiating element of the first array includes at least a first to a fourth dielectric material region at least 3 mm thick and having a dielectric constant of at least 2.5, wherein each of the first to fourth dielectric material regions is separated by a corresponding first to third air gap.

[0062] In some embodiments, the dielectric material layer may include a plurality of parallel, spaced-apart dielectric material sheets and / or a plurality of concentric dielectric material tubes. At least some of the dielectric material layers may have a thickness of at least 6 mm, and at least some layers may be spaced apart from adjacent layers by air gaps having a thickness more than twice that of the dielectric material layer. In one exemplary embodiment, the spaced-apart dielectric material sheets have a thickness between 6 mm and 12 mm in the depth dimension of the antenna, and adjacent dielectric material sheets in the spaced-apart dielectric material sheets have a center-to-center separation between 15 mm and 40 mm.

[0063] Embodiments of the invention will now be discussed in more detail with reference to the accompanying drawings, in which exemplary embodiments are shown.

[0064] Now refer to the appendix Figure 1A-1F This illustrates a lens-equipped multi-beam base station antenna 100 according to an exemplary embodiment of the present invention. Specifically, Figure 1A and 1B These are perspective views and exploded perspective views of the multi-beam base station antenna 100 with a lens. Figure 1C yes Figure 1B An enlarged perspective view of one of the linear arrays of radiating elements shown. Figure 1D yes Figure 1B The perspective view of the RF lens shown. Figure 1E This is a cross-sectional view of the base station antenna 100 taken through the RF lens. Finally, Figure 1F The top cover has been removed. Figure 1A-1B A schematic top view of the base station antenna.

[0065] First refer to Figure 1A-1BThe multi-beam base station antenna 100 with a lens includes a housing 110. In the depicted embodiment, the housing 110 is a multi-piece housing including an radome 112, a tray 114, a top cover 116, and a bottom cover 118. A bracket extends from the rear side of the tray 114 for mounting the antenna 100 on an antenna mounting structure. A plurality of RF ports 120 and a control port 122 may be housed in the bottom cover 118. The RF ports 120 may include RF connectors for receiving coaxial cables providing RF connectivity between the base station antenna 100 and one or more radio devices (not shown). The control ports 122 may include connectors for receiving control cables that can be used to transmit control signals to the antenna 100.

[0066] The radome 112, end caps 116, 118, and tray 114 provide physical support and environmental protection for the antenna 100. The end caps 116, 118, radome 112, and tray 114 can be formed from, for example, extruded plastic and can comprise multiple components or be implemented as a single component. For example, the radome 112 and end cap 116 can be implemented as a single integral element. In some embodiments, an RF absorber (not shown) can be placed between the tray 114 and the radiating element 132 (discussed below). The RF absorber can help reduce potential passive intermodulation (“PIM”) distortion because the metal tray 114 and the metal reflector 140 (discussed below) can form a resonant cavity that generates PIM distortion.

[0067] like Figure 1A As also shown, the base station antenna 100 is an elongated structure extending along the longitudinal axis A1. The azimuth line of sight of the base station antenna 100 refers to the horizontal axis extending from the base station antenna 100 to the center of the sector served by the base station antenna in the azimuth plane. When the base station antenna 100 is installed for normal use, the longitudinal axis A1 will generally extend along the vertical axis, but in some cases, the base station antenna 100 may be tilted a few degrees from the vertical direction to impart a mechanical downward tilt to the antenna bundle formed by the base station antenna 100. Figure 1A The diagram also shows that the base station antenna 100 has a length, depth, and width. The length L of the base station antenna 100 refers to the distance the antenna extends along the longitudinal axis A1. The depth D of the antenna 100 refers to the distance the antenna extends along an axis A2 that is perpendicular to the longitudinal dimension A1 and collinear with the azimuth line of sight of the base station antenna 100. The width W of the base station antenna 100 refers to the distance the antenna extends along an axis A3 that is perpendicular to both axes A1 and A2.

[0068] refer to Figure 1B and 1CThe base station antenna 100 also includes one or more linear arrays 130-1, 130-2, and 130-3 of radiating elements 132. In this document, when multiple identical elements are included in the antenna, these elements may be individually referred to by their complete reference numerals (e.g., linear array 130-3) and collectively by the first part of their reference numerals (e.g., linear array 130). Each linear array 130 includes multiple radiating elements 132. Although... Figure 1B-1C The diagram illustrates the radiating element 132 included in each linear array 130, as a cross-polarized "box-shaped" dipole radiating element 132 having four dipole arms mounted on a feed shank printed circuit board. These four dipole arms form a pair of tilted -45° / +45° dipole radiators that respectively emit RF energy with -45° and +45° polarization. However, it will be appreciated that any suitable radiating element 132 can be used. For example, in other embodiments, a single polarized dipole radiating element or a patch radiating element can be used.

[0069] As will be discussed in more detail below, the base station antenna 100 includes a cylindrical RF lens 150 that reduces the azimuth beamwidth of each linear array 130. Using a cylindrical lens, such as the RF lens 150, can reduce grating lobes (and other far lobes). This reduction in grating lobes can also advantageously allow for an increase in the spacing between adjacent radiating elements 132, potentially allowing a 20-30% reduction in the number of radiating elements 132 included in each linear array 130, as explained in U.S. Patent No. 9,819,094.

[0070] Each linear array 130 may be mounted to extend forward from the reflector 140. In the depicted embodiment, each linear array 130 includes a separate reflector 140, but it will be appreciated that in other embodiments, a monolithic reflector 140 may be used as the reflector for all three linear arrays 130. Each reflector 140 may include a metal sheet that acts as a ground plane for the radiating element 132 and also redirects a large portion of the backward-directed radiation emitted by the radiating element 132 forward. Figure 1C As shown, each linear array 130 may also include an associated phase shifter / distributor 134. The distributor portion of each phase shifter / distributor 134 can divide the RF signal in the transmit path into multiple sub-components (and can combine multiple receive sub-components of the RF signal in the receive path). The phase shifter portion of the phase shifter / distributor 134 can be used to inject phase taper onto the sub-components of the RF signal to change the elevation angle of the resulting antenna beam in a desired manner. One or more phase shifters / distributors 134 may be provided for each linear array 130. Figure 1CAs also shown, two RF connectors 120 can be used to transmit signals between each linear array 130 and a radio device (not shown), i.e., to transmit RF signals in each of two orthogonal polarizations. Although antenna 100 includes three linear arrays 130, it will be appreciated that different numbers of linear arrays 130 can be used. For example, in other embodiments, two or four linear arrays 130 may be used.

[0071] Figure 1B and 1D -1E illustrates an RF lens 150 included in the base station antenna 100. The RF lens 150 can be positioned in front of the linear arrays 130 such that the azimuth line of each linear array 130 points towards the central longitudinal axis of the RF lens 150 (which may be the aforementioned longitudinal axis A1 of the base station antenna 100). In some embodiments, each linear array 130 may have approximately the same length as the RF lens 150. When the antenna 100 is mounted for use, the azimuth plane is generally perpendicular to the central longitudinal axis A1 of the RF lens 150.

[0072] As discussed above, conventional lens-based base station antennas may encounter several problems, including increased cost, PIM distortion, and / or heat dissipation issues, which can negatively impact the electromagnetic properties of the RF energy focusing material of the RF lens. The RF lens according to embodiments of the present invention can avoid these problems associated with conventional RF lenses, as will be explained in further detail herein.

[0073] The RF lens 150 may or may not include an outer dielectric housing 152. The RF lens 150 may be a skeleton lens comprising spaced-apart dielectric material layers 160. These spaced-apart dielectric material layers 160 may define air-filled channels 154, which may have open or closed side surfaces. The top and bottom of the air-filled channels 154 may also be open or closed. The spaced-apart dielectric material layers 160 may define an open-spaced frame. In some embodiments, the spaced-apart dielectric material layers 160 may include a plurality of flat dielectric material sheets 162 spaced apart from each other and defining parallel planes. In some embodiments, one or more additional flat dielectric material sheets 164 (see...) Figure 6A The columnar dielectric material sheet 166, etc., can be connected to the parallel flat dielectric material sheet 162, making the RF lens a monolithic structure. In other embodiments, dielectric spacers 156 and / or dielectric fasteners 158 (e.g., plastic screws) can be provided to space the dielectric material layers 160 apart and optionally to connect the dielectric material layers 160 together, so that the RF lens 150 can be mounted as a single piece in the base station antenna 100.

[0074] The spaced dielectric material layers 160 can be used as RF energy focusing materials. In some embodiments, all dielectric material layers 160 may be formed using the same type of dielectric material, such that the material forming the skeleton lens 150 has a constant dielectric constant. In other embodiments, two or more different dielectric materials may be used to form the skeleton RF lens 150. For example, the spaced dielectric material layers 160 may be formed of a dielectric material having a first dielectric constant, and one or more additional materials having other dielectric constants may be used to form spacers 156 and / or fasteners 158. In still other embodiments, some of the spaced dielectric material layers 160 (e.g., a plurality of parallel flat dielectric material sheets 162) may have a first dielectric constant, while other spaced dielectric material layers 160 (e.g., adding parallel flat dielectric material sheets 162 or other dielectric material sheets 164) may have a second dielectric constant different from the first dielectric constant.

[0075] In some embodiments, some or all of the dielectric material layer 160 forming the RF lens 150 may be conventional, relatively lightweight dielectric materials, such as PVC, ABS, polyetherimide (“PEI”, sold under the brand name Ultem™), polyetheretherketone (“PEEK”), fiberglass, polytetrafluoroethylene, etc. Depending on the specific formulation of the PVC, it may have a dielectric constant, for example, between about 2.8 and 3.5. ABS typically has a dielectric constant of about 3.0, while PEI has a dielectric constant of about 3.1. In some exemplary embodiments, the majority of the solid dielectric material used to form the RF lens according to embodiments of the invention may have a dielectric constant between about 2.5 and 4.0, and in other embodiments between about 2.8 and 3.5. The amount of dielectric material included in the RF lens according to embodiments of the invention may be selected such that, in some embodiments of the invention, the RF lens will have an “effective” dielectric constant of about 1.7–2.3, where the “effective” dielectric constant corresponds to the dielectric constant of an RF lens of the same size formed from a homogeneous dielectric material. In other words, in some embodiments, the RF lens according to an embodiment of the invention can perform substantially the same focusing as a conventional solid RF lens formed of a dielectric material with a dielectric constant in the range of 1.7-2.3.

[0076] Because the base station antenna 100 includes cross-polarized radiating elements 132, each linear array 130 can generate two antenna beams 170, i.e., one antenna beam 170 at each of the two polarizations. Figure 1F The diagram schematically illustrates three antenna bundles 170-1, 170-2, and 170-3 generated by the corresponding linear arrays 130-1, 130-2, and 130-3. Figure 1FOnly three antenna bundles 170 are shown, because two antenna bundles 170 formed by each linear array 130 with orthogonal polarization can have substantially the same shape and pointing direction. The center of the antenna bundle 170 formed by each linear array 130 (i.e., the azimuth line of sight pointing direction of each linear array 130) points to azimuth angles of -40°, 0°, and 40° respectively relative to the azimuth line of sight pointing direction of the base station antenna 100. Therefore, the three linear arrays 130 generate antenna bundles 170, which together provide coverage of a 120° sector in the azimuth plane.

[0077] The RF lens 150 can reduce the 3 dB beamwidth of each antenna beam 170-1, 170-2, and 170-3 in the azimuth plane from approximately 65° to approximately 23°-25°. By reducing the azimuth beamwidth of each antenna beam 170, the RF lens 150 increases the gain of each antenna beam 170 by, for example, approximately 4-5 dB. The higher antenna gain allows the multi-beam base station antenna 100 to support higher data rates with the same quality of service. The multi-beam base station antenna 100 can also reduce the antenna count of the base station.

[0078] For reference Figure 1E and 1F As can be seen, the azimuth line of each of the antenna bundles 170-1, 170-2, and 170-3 extends through a large number of air-filled channels 154 and through a large number of dielectric layers 160.

[0079] Although the RF lens 150 has a generally cylindrical shape, it will be appreciated that the RF lens 150 may have other shapes, including spherical, elliptical, elongated elliptical cylindrical, etc., and in other embodiments of the invention, the antenna 100 may include more than one RF lens 150.

[0080] As described above, the RF lens 150 may be made solely of dielectric material. Therefore, any metal that could potentially serve as a source of PIM distortion may be absent from the RF lens 150. Furthermore, the RF lens 150 may be formed from inexpensive and readily available dielectric materials and can be easily manufactured, for example, from sheet material or through a simple extrusion process. Therefore, the RF lens 150 may be less expensive than prior art RF lenses exhibiting similar performance levels. Additionally, as described above, the RF lens 150 may include a large number of air-filled channels 154. These air-filled channels 154 provide pathways for dissipating heat generated within the RF lens 150 due to the absorption of RF energy, and thus ensure that thermal issues do not degrade the performance of the lens-equipped base station antenna 100.

[0081] Figure 2This is a cross-sectional view of a base station antenna 200 with a lens according to another embodiment of the present invention. The base station antenna 200 with a lens can be the same as the base station 100 with a lens described above, except that the RF lens 150 included in the base station antenna 100 is replaced by the RF lens 250 in the base station antenna 200. Therefore, the following description will focus only on the RF lens 250.

[0082] like Figure 2 As shown, the RF lens 250 is a skeleton lens comprising spaced-apart dielectric material layers 160. The RF lens 250 does not include a separate external dielectric shell 152. The spaced-apart dielectric material layers 160 also define air-filled channels 154 having open side surfaces, such that all channels 154 in the front half of the RF lens 250 communicate with each other, and all channels 154 in the rear half of the RF lens 250 also communicate with each other.

[0083] The RF lens 250 includes seven flat dielectric material sheets 162-1 to 162-7 spaced apart from each other and defining parallel planes, and a columnar dielectric material sheet 166 defining the outer surface of the RF lens 250. The RF lens 250 also includes dielectric spacers 156 and dielectric fasteners 158 for spacing the flat dielectric material sheets 160 apart from each other and interconnecting the seven flat dielectric material sheets 162 into a single unit. The columnar dielectric material sheet 166 is integrally formed with the intermediate flat dielectric material sheet 162-4, such that the entire RF lens 250 is a single unit. The dielectric spacer 156 may include, for example, a hollow cylinder formed of dielectric material. The cylinder may have a closed end with a corresponding opening (e.g., a threaded hole) for receiving the fastener 158. The dielectric fastener 158 may include, for example, a plastic screw. It should be understood that the dielectric spacer 156 and the dielectric fastener 158 can be implemented in a variety of other ways. As another example, the dielectric fastener 158 may include a plastic nut and a bolt, and the dielectric spacer 156 may include a cylinder with a closed end, a smooth bore opening in the cylinder, and openings in the sidewalls of the cylinder. The openings in the sidewalls allow the insertion of a plastic nut therein, and each bolt may pass through an opening in a corresponding one of the flat dielectric material sheets 162, and through a corresponding opening in the end of the dielectric spacer 156, and into its corresponding nut.

[0084] exist Figure 2In the RF lens 250, each flat dielectric material sheet 162 is spaced apart from one or two adjacent flat dielectric material sheets 162 by a distance H2, H3, or H4. The center of the foremost flat dielectric material sheet 162-1 is spaced apart from the columnar dielectric material sheet 166 by a distance H1, and the center of the last flat dielectric material sheet 162-7 is similarly spaced apart from the columnar dielectric sheet 166 by a distance H1. The flat dielectric material sheets 162 are arranged symmetrically in the RF lens 250, but this is not necessary. The flat dielectric material sheets 162 can have different widths. Figure 2 As shown, the flat dielectric material sheet 162-4 located at the center of the RF lens 250 has the largest width, while the flat dielectric material sheets 162-1 and 162-7 at the front and rear of the RF lens 250 have the smallest widths, respectively. The width of the flat dielectric material sheet 162 decreases as the distance from the flat dielectric material sheet 162-4 located at the center of the RF lens 250 increases.

[0085] Each flat dielectric material sheet 162 may have a certain thickness. Figure 2 In the illustrated embodiment, all flat dielectric sheets 162 have the same thickness T1 as the columnar dielectric sheets 166, but the thickness may vary in other embodiments. In some embodiments, the thickness T1 may be between, for example, 5-15 mm. In other embodiments, the thickness T1 may be between 7-12 mm. In still other embodiments, the thickness T1 may be between 8-10 mm. In some embodiments, H1 may be greater than H2, H3, and H4. In some embodiments, H1 may be between, for example, 30-50 mm, and in other embodiments, between 35-45 mm. In some embodiments, H2, H3, and H4 may be between, for example, 15-40 mm. In other embodiments, H2, H3, and H4 may be between 20-35 mm, and in still other embodiments, between 25-30 mm. In some embodiments, each distance H2, H3, H4 may be at least twice the thickness T1 of the dielectric sheets 162 separated by specific air-filled channels 154. In other embodiments, each distance H2, H3, H4 may be at least three times the thickness T1 of the dielectric sheet 162 separated by a specific air-fill channel 154. For example, dielectric sheets 162-5 and 162-6 may each have a thickness T1 and may be separated by an air-fill channel with a depth distance H3. H3 may be at least two or at least three times the thickness T1.

[0086] It should be recognized that the thickness of the dielectric sheet, the dielectric constant of the dielectric sheet, and the size of the gap between adjacent dielectric sheets should be selected to optimize the performance of the RF lens according to embodiments of the present invention. Generally, as the dielectric constant and / or the thickness of the dielectric sheet increases, the gap between adjacent dielectric sheets can also be increased. It will also be recognized that, according to this disclosure, dielectric material sheets spaced apart by air-filled channels differ from a single solid dielectric material block of the same thickness in the way RF energy is focused.

[0087] Figures 3A-3C They are shown separately Figure 2 A diagram showing the azimuth of the first to third linear arrays of the base station antenna. Figures 3A-3C The different curves in each figure represent simulated azimuth diagrams at various frequencies within the 1695-2170 MHz frequency band, which is the operating frequency band of the linear array 130 of radiating elements 132 in the base station antenna 200. Curves are provided illustrating... Figures 3A-3C The diagrams below show the common polarization and cross polarization orientations in each figure. Table I below summarizes the various analog performance parameters of the base station antenna 200.

[0088] Table I

[0089] As shown in Table I, depending on the specific sub-band in which the linear array 130 operates, the 3 dB azimuth beamwidth for each beam is between 24° and 26°. Typically, a 3 dB azimuth beamwidth of approximately 23° is optimal for an antenna providing three beams per sector, and values ​​in the 24°–26° range are acceptable for most (if not all) sector-segmentation applications. The peak azimuth sidelobes are 15 dB below the peak gain of each beam, which is still acceptable performance. Front-to-back ratio and cross-polarization discrimination performance are also within acceptable limits. Therefore, the simulation results shown in Table I indicate that the base station antenna 200 provides acceptable performance for three-sub-sector sector-segmentation applications. This performance is achieved using an RF lens 250, which is likely to be less expensive to manufacture, potentially lighter, and more reliable (as it is less likely to experience degradation due to heat buildup issues), and is not a potential source of PIM distortion.

[0090] Figure 4This is a schematic cross-sectional view of a lens-equipped base station antenna 300 according to some other embodiments of the present invention. The lens-equipped base station antenna 300 can be almost identical to the lens-equipped base station 200 described above, except that the RF lens 150 included in the base station antenna 100 is replaced by the RF lens 350 in the base station antenna 300. Therefore, the following description will focus only on the RF lens 350. The RF lens 350 is very similar to the RF lens 250 included in the base station antenna 200, therefore the following description will focus only on the differences between these two lenses.

[0091] like Figure 4 As shown, the RF lens 350 is also a skeleton lens, comprising spaced dielectric material layers 160 in the form of seven parallel, spaced-apart flat dielectric material sheets 162, and columnar dielectric material sheets 166 defining the outer surface of the RF lens 350 (which are smaller than the corresponding columnar dielectric material sheets 166 included in the base station antenna 200 in the base station antenna 300). In some embodiments, the columnar dielectric material sheets 166 may be omitted. The spaced dielectric material layers 160 also define air-filled channels 154 having open side surfaces. The dielectric spacers 156 and dielectric fasteners 158 included in the RF lens 250 are omitted in the RF lens 350. Instead, the top end cap 116 and bottom end cap 118 of the antenna 300 (see...) Figure 1A The top end cap 116 and bottom end cap 118 may include corresponding internal elongated channels configured to receive the respective top and bottom of the flat dielectric material sheet 162. The top end cap 116 and bottom end cap 118 may also include corresponding internal channels having a circular shape configured to receive the respective top and bottom of the columnar dielectric material sheet 166. Alternatively or additionally, a separate lens support structure (not shown) may be provided for holding the RF lens 350 in proper position within the base station antenna 300. Since the base station antenna 300 may otherwise be substantially the same as the base station 200, further description thereof will be omitted. The base station antenna 300 may have substantially the same performance as the base station antenna 200.

[0092] Figure 5 This is a schematic cross-sectional view of a lens-equipped base station antenna 400 according to an additional embodiment of the present invention. The lens-equipped base station antenna 400 can be almost identical to the lens-equipped base station 300 described above, except that the RF lens 350 included in the base station antenna 300 is replaced by the RF lens 450 in the base station antenna 400. Therefore, the following description will focus on the RF lens 450.

[0093] The RF lens 450 differs from the RF lens 350 in that the RF lens 450 includes a plurality of columnar dielectric material sheets 166-1 to 166-5 and does not include any flat dielectric material sheets. The central columnar dielectric material sheet 166-1 may comprise a solid dielectric material tube (as shown), while the remaining four columnar dielectric material sheets 166-2 to 166-5 may comprise open tubes with annular shapes. Therefore, the RF lens 450 includes a plurality of concentric annular dielectric material tubes surrounding the solid dielectric material tube. While the central dielectric material "sheet" 166-1 is implemented as a solid dielectric material tube in the depicted embodiment, it should be understood that in other embodiments, it may be replaced with a dielectric material tube having an open interior. Typically, the top and bottom of each concentric dielectric tube would be open to simplify the manufacture of the RF lens 450, but this is not necessary.

[0094] The line-of-sight of each of the linear arrays 130 points directly through the relatively thick solid dielectric tube 166-1. Therefore, tube 166-1 can perform significant focusing on the RF energy emitted by each linear array 130. Furthermore, the columnar dielectric sheets 166-2 to 166-4 are positioned relatively close to columnar dielectric sheet 166-1, which increases the amount of dielectric material that the RF energy emitted by each linear array 130 passes through as it traverses the RF lens 450, because the RF energy may pass not only through the “front” and “rear” of each columnar dielectric sheet 166-2 to 166-4, but also through the “side” of the sheet, where a larger amount of dielectric material will pass through. The RF lens 450 can be supported in the base station antenna 400 using appropriately shaped channels in the top end cap 116 and bottom end cap 118 and / or with a separate support structure (not shown) (as in the case of RF lens 350), and / or by using dielectric spacers 156 and dielectric fasteners 158 (as in the case of RF lens 250).

[0095] Figures 6A-6C A base station antenna 500 according to another embodiment of the present invention is shown. Specifically, Figure 6A This is a schematic cross-sectional view of the base station antenna 500. Figure 6B This is an enlarged perspective view of a portion of a linear array 130 of radiating elements 532 included in the base station antenna 500. Figure 6CThis is a more detailed cross-sectional view of the RF lens 550 included in the lens-equipped base station antenna 500. The lens-equipped base station antenna 500 is very similar to the lens-equipped base station 200 described above, except that the radiating element 532 included in the linear array 130 of the base station antenna 500 is different from the radiating element 132, and the RF lens 550 included in the base station antenna 500 includes four angled flat dielectric material sheets 164 that are not present in the RF lens 250 of the base station antenna 200. The following description will focus on the differences between the base station antenna 500 and the base station antenna 200.

[0096] like Figure 6A and 6C As shown, RF lens 550 is a skeleton lens that includes spaced-apart dielectric material layers 160 defining an open-side air-fill channel 154. The spaced-apart dielectric material layers 160 include seven parallel flat dielectric material sheets 162 identical to those included in RF lens 250, and four additional flat dielectric material sheets 164 angled relative to the seven parallel flat dielectric material sheets 162. RF lens 550 may optionally include columnar dielectric material sheets 166 surrounding the flat dielectric material sheets 162, 164 and defining an outer surface of RF lens 550. RF lens 550 also includes dielectric spacers 156 and dielectric fasteners 158 for interconnecting the flat dielectric material sheets 162, 164 into a single-piece structure.

[0097] Four additional flat dielectric material sheets 164 provide additional focusing of the RF energy emitted by the linear array 130 of the radiating element 532. These four flat dielectric material sheets 164 are positioned to primarily focus the RF energy emitted by the linear arrays 130-1 and 130-3. Specifically, the first flat dielectric material sheet 164-1 and the second flat dielectric material sheet 164-2 are positioned directly in front of the linear arrays 130-1 and 130-3 along the rear side of the RF lens 550, respectively, and the third flat dielectric material sheet 164-3 and the fourth flat dielectric material sheet 164-4 are positioned along the front side of the RF lens 550 in the azimuth axis pointing direction of the linear arrays 130-1 and 130-3, respectively. Figure 6AAs is best observed, the RF energy from linear arrays 130-1 and 130-3 can pass through less dielectric material of the seven parallel flat dielectric material sheets 162 because sheets 162-1 and 162-7 have a small width and therefore do not align with the corresponding azimuth line of sight of linear arrays 130-1 and 130-2. Therefore, the RF energy emitted by linear arrays 130-1 and 130-3 may experience less focusing through the seven parallel flat dielectric material sheets 162 compared to the RF energy emitted by linear array 130-2. Adding four flat dielectric material sheets 164-1 to 164-4 can compensate for this reduced focusing, thus sufficiently reducing the azimuth beamwidth of linear arrays 130-1 and 130-3.

[0098] As described above, base station antenna 500 uses radiating elements 532 of a different type than those used in base station antenna 200 to form a linear array 130. Figure 6B Several radiating elements 532 are depicted. Radiating elements 532 are ultra-wideband radiating elements designed to operate across the entire 1695-2690 MHz frequency band. A director 534 is also added to each radiating element 532.

[0099] Figures 7A-7C They are shown separately Figures 6A-6C A diagram showing the azimuth of the first to third linear arrays of the base station antenna. Figures 7A-7C The different curves in each figure represent simulated azimuth diagrams at various frequencies within the 1695-2690 MHz frequency band, which is the operating frequency band of the linear array 130 of radiating elements 532 in the base station antenna 500. Curves are provided illustrating... Figures 7A-7C The diagrams below show the common polarization and cross polarization orientations in each figure. Table II below summarizes the various analog performance parameters of the base station antenna 500.

[0100] Table II

[0101] As shown in Table II, the base station antenna 500 can be designed to operate in four different sub-bands within the 1695–2690 MHz frequency range. The performance of all four sub-bands is highly consistent. For example, depending on the specific sub-band in which the linear array 130 operates, the 3 dB azimuth beamwidth for each beam ranges between 23° and 26.5°. Peak azimuth sidelobes vary between 13 and 15 dB below the peak gain of each antenna beam, indicating acceptable performance. Front-to-back ratio and cross-polarization discrimination performance are also within acceptable limits. Therefore, the simulation results shown in Table II indicate that the base station antenna 500 provides acceptable performance for three-sub-sector sector-segmentation applications across the entire 1695–2690 MHz frequency range.

[0102] The embodiments of the invention discussed above are all three-beam antennas, comprising three linear arrays of radiating elements for dividing a 120° sector into three 40° sub-sectors. However, it should be understood that the embodiments of the invention are not limited thereto.

[0103] For example, Figure 8A This is a schematic perspective view of a dual-beam base station antenna 600 (its radome omitted) according to an embodiment of the present invention. Figure 8B This is a schematic perspective view of a dual-beam antenna 600, in which the RF lens 650 is omitted to show the underlying array of the radiating elements of the base station antenna 600. The RF lens 650 can be implemented, for example, using any RF lens design discussed herein. Furthermore, these RF lens designs can be modified to (1) perform less focusing on the RF energy (since the base station antenna is a dual-beam antenna, it is designed to divide the sector into two 60° sub-sectors in the azimuth plane) and / or (2) arrange the dielectric material more appropriately relative to the two linear arrays of the radiating elements.

[0104] For example, Figure 8C An RF lens 750 is shown, which can be used to implement the RF lens 650 of a base station antenna 600. (See comparison...) Figure 6A and 8C As can be seen, the number of flat dielectric material sheets 162 is reduced from seven in RF lens 550 to five in RF lens 750, and the number of flat dielectric material sheets 164 is reduced from four in RF lens 550 to two in RF lens 750, because the dual-beam antenna 600 requires less focused RF energy. Furthermore, the first and second flat dielectric material sheets 164 are angled slightly differently in RF lens 750, such that they are perpendicular to the azimuth line of sight of linear arrays 630-1 and 630-2, respectively. Figure 8D Another RF lens 850 is shown, which can be used to implement the RF lens 650 in the base station antenna 600. (See diagram below.) Figure 8D As shown, the RF lens 850 includes a plurality of flat dielectric material sheets 162 bent to form V-shaped dielectric material sheets.

[0105] It will also be appreciated that the non-lens portion of the base station antenna according to embodiments of the invention can have any suitable design, including different numbers of linear arrays, different array designs, different types of radiating elements, etc. This is, for example, in Figures 8A-8B The diagram shows a base station antenna 600 comprising an "interlaced" linear array 630-1, 630-2 of radiating elements 632, which is contrary to conventional linear arrays. (See diagram for reference.) Figure 8BAs shown, the base station antenna 600 has a V-shaped reflector, and the radiating elements 632 in the linear array 630 include small "interlacing" such that not all radiating elements 632 in a given array 630 are aligned along a common vertical axis, but some radiating elements 632 are horizontally offset by a small amount from other radiating elements 632. Figures 8A-8B In the specific example shown, all radiating elements 632 in a given array 630 are aligned along one of two vertical axes. As explained in U.S. Provisional Patent Application Serial No. 62 / 722,238, filed August 24, 2018, the entire contents of which are incorporated herein by reference.

[0106] It will also be appreciated that, according to embodiments of the invention, a base station antenna may include more than one RF lens. For example, each of the base station antennas described above includes a single circular cylindrical RF lens extending the entire length of the antenna. However, it will be appreciated that these circular cylindrical antennas can be replaced by a stack of multiple circular cylindrical RF lenses, which may be identical to the RF lenses described above, except that each RF lens may have a shorter height. These shorter RF lenses can be stacked to provide a multi-piece RF lens with the exact same shape as the RF lenses described above. Alternatively, small gaps may be provided between the stacked lenses to further facilitate airflow through the heat sink.

[0107] The RF lens according to an embodiment of the present invention is shown primarily in cross-section in the drawings. It should be understood that the dielectric material sheets used to form the RF lens according to an embodiment of the present invention may extend the entire length of the RF lens in the longitudinal direction. Typically, the length of each dielectric material sheet (i.e., the distance in the longitudinal direction of the base station antenna) will be slightly greater than the length of the radiating element of the base station antenna associated with the RF lens.

[0108] It will be appreciated that this specification describes only a few exemplary embodiments of the invention, and that the techniques described herein have applicability beyond the exemplary embodiments described above. It should also be noted that antennas according to embodiments of the invention can be used in applications other than sector segmentation, such as in venues like stadiums, large gymnasiums, conference centers, etc. In such applications, multi-beam configurations are more typically used to cover 60°–90° sectors.

[0109] 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.

[0110] 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 items listed.

[0111] It will be understood that when an element is described as being "on" another element, the 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 "linked" to another element, the element may be directly connected or linked to the other element, or there may be intermediate elements. Conversely, when an element is described as being "directly connected" or "directly linked" to another element, there are no intermediate elements. Other terms used to describe relationships between elements should be interpreted in a similar manner. Right now "between" is the opposite of "directly between," and "adjacent" is the opposite of "directly adjacent," etc.

[0112] 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, when used herein, the terms “comprises / comprising” and / or “includes / including” specify the presence of the described 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.

[0113] 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 with a lens, comprising: A first array, the first array comprising a plurality of first radiating elements; The second array includes a plurality of second radiating elements; as well as An RF lens, the RF lens being positioned to receive electromagnetic radiation from one or more first radiating elements and one or more second radiating elements. The RF lens comprises a plurality of flat dielectric material sheets separated by gaps, such that RF signals emitted by the first array and the second array alternately pass through the flat dielectric material sheets and then through an air channel, the air channel being thicker than the flat dielectric material sheets. The flat dielectric material sheets are arranged parallel to each other. The RF lens further includes at least one additional dielectric material sheet extending at an angle relative to the flat dielectric material sheet.

2. The base station antenna with lens according to claim 1, wherein the plurality of flat dielectric material sheets comprises at least five flat dielectric material sheets.

3. The base station antenna with lens according to claim 1, wherein the flat dielectric material sheets are spaced apart from each other in the depth dimension of the base station antenna.

4. The base station antenna with lens according to claim 1, wherein at least some of the flat dielectric material sheets are interconnected by a plurality of dielectric fasteners, the plurality of dielectric fasteners connecting adjacent flat dielectric material sheets.

5. The base station antenna with lens according to claim 1, wherein the plurality of flat dielectric material sheets include a proximal flat dielectric material sheet closest to the first array, a distal flat dielectric material sheet furthest from the first array, and at least one central flat dielectric material sheet between the proximal flat dielectric material sheet and the distal flat dielectric material sheet, and wherein the width of the at least one central flat dielectric material sheet exceeds the width of the proximal flat dielectric material sheet and the width of the distal flat dielectric material sheet.

6. The base station antenna with lens according to claim 1, wherein the air channel is configured as a heat dissipation path.

7. The base station antenna with a lens according to claim 1, wherein the RF lens is configured to focus more on the first antenna bundle generated by the first array than on the second antenna bundle generated by the second array.

8. A base station antenna, comprising: A first array, the first array comprising a plurality of first radiating elements; The second array includes a plurality of second radiating elements; as well as An RF lens, the RF lens being positioned to receive electromagnetic radiation from one or more first radiating elements and one or more second radiating elements. The RF lens includes a plurality of spaced-apart flat lens material sheets arranged parallel to each other and a plurality of columnar dielectric material sheets.

9. The base station antenna of claim 8, wherein the flat lens material sheet is perpendicular to the azimuth line pointing direction of the base station antenna, wherein the azimuth line pointing direction of the base station antenna refers to a horizontal axis extending from the base station antenna to the center of the sector served by the base station antenna in the azimuth plane.

10. The base station antenna of claim 8, wherein adjacent flat lens material sheets in the flat lens material sheet are separated by gaps, such that RF signals transmitted by the first array and the second array alternately pass through the flat lens material sheet and then through an air channel, the air channel being thicker than the flat lens material sheet.

11. The base station antenna of claim 10, wherein the air channel is configured as a heat dissipation path.

12. The base station antenna of claim 8, wherein the RF lens further comprises at least one additional lens material sheet extending at an oblique angle relative to the flat lens material sheet.

13. The base station antenna of claim 8, wherein the plurality of spaced-apart flat lens material sheets comprise at least five flat lens material sheets.

14. The base station antenna of claim 8, wherein the flat lens material sheets are spaced apart from each other in the depth dimension of the base station antenna.

15. The base station antenna of claim 8, wherein at least some of the flat lens material sheets are interconnected by a plurality of dielectric fasteners, the plurality of dielectric fasteners connecting adjacent flat lens material sheets.

16. The base station antenna of claim 8, wherein at least some of the flat lens material sheets have different widths.

17. The base station antenna of claim 8, wherein the RF lens is configured to focus more on the first antenna bundle generated by the first array than on the second antenna bundle generated by the second array.

18. A base station antenna, comprising: A first array, the first array comprising a plurality of first radiating elements; The second array includes a plurality of second radiating elements; as well as An RF lens, the RF lens being positioned to receive electromagnetic radiation from one or more first radiating elements and one or more second radiating elements. The RF lens includes a plurality of spaced-apart dielectric material sheets and a plurality of dielectric fasteners, the plurality of dielectric fasteners connecting adjacent dielectric material sheets. At least some of the dielectric material sheets have different widths.

19. The base station antenna of claim 18, wherein the dielectric material sheets are flat dielectric material sheets arranged parallel to each other.

20. The base station antenna of claim 19, wherein adjacent flat dielectric sheets in the flat dielectric sheet are separated by air channels.

21. The base station antenna of claim 18, wherein the dielectric material sheet comprises at least five dielectric material sheets.

22. The base station antenna of claim 18, wherein the RF lens is configured to focus more on the first antenna bundle generated by the first array than on the second antenna bundle generated by the second array.

23. A base station antenna, comprising: A first array, the first array comprising a plurality of first radiating elements; The second array includes a plurality of second radiating elements; as well as An RF lens, the RF lens being positioned to receive electromagnetic radiation from one or more first radiating elements and one or more second radiating elements. The RF lens includes a plurality of spaced-apart flat dielectric sheets, including a proximal flat dielectric sheet closest to the first array, a distal flat dielectric sheet furthest from the first array, and at least one central flat dielectric sheet between the proximal and distal flat dielectric sheets, wherein the width of the at least one central flat dielectric sheet exceeds the width of both the proximal and distal flat dielectric sheets.

24. The base station antenna of claim 23, wherein the flat dielectric material sheets are arranged parallel to each other.

25. The base station antenna of claim 23, wherein at least some of the flat dielectric material sheets are interconnected by a plurality of dielectric fasteners, the plurality of dielectric fasteners connecting adjacent flat dielectric material sheets.

26. The base station antenna of claim 23, wherein the RF lens is configured to focus more on the first antenna bundle generated by the first array than on the second antenna bundle generated by the second array.

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