CN118889011A - Base station antenna with integrated radiating elements for different frequency bands - Google Patents

Abstract

The present disclosure provides a base station antenna. The base station antenna includes a plurality of first-band dipole radiating elements and a plurality of second-band dipole radiating elements. A first second-band dipole radiating element in the second-band dipole radiating elements is installed on a first first-band dipole radiating element in the first-band dipole radiating elements and/or different second-band dipole radiating elements in the second-band dipole radiating elements are at different heights.

Description

Base station antenna with integrated radiating elements for different frequency bands

Technical Field

The present disclosure relates to communication systems, and in particular, to base station antennas for cellular communication systems.

Background Art

Cellular communication systems are well known in the art. In a cellular communication system, a geographic area is divided into a series of areas, which are referred to as "cells" and are served by individual base stations. A base station may include one or more base station antennas configured to provide two-way radio frequency ("RF") communications with mobile subscribers within the cell served by the base station. Typically, the base station antenna is mounted on a tower or other elevated structure, and the base station antenna produces a radiation pattern (also referred to herein as an "antenna beam") that is directed outward.

A common base station configuration is a three-sector configuration, in which the cell is divided into three 120° "sectors" in the azimuth (horizontal) plane. A separate base station antenna provides coverage (service) for each sector. Typically, each base station antenna will include multiple vertically extending columns of radiating elements that operate, for example, using second generation ("2G"), third generation ("3G"), or fourth generation ("4G") cellular network protocols. These vertically extending columns of radiating elements are often referred to as "linear arrays" and can be straight columns of radiating elements or columns in which some of the radiating elements are staggered horizontally. Most modern base station antennas include linear arrays of "low-band" radiating elements that support services in part or all of the 617-960 MHz frequency band and linear arrays of "mid-band" radiating elements that support services in part or all of the 1427-2690 MHz frequency band. These linear arrays are typically formed using dual-polarized radiating elements, which allows each array to transmit and receive RF signals at two orthogonal polarizations.

Each of the above linear arrays is coupled to two ports of the radio (one port for each polarization). The RF signal to be transmitted by the linear array is passed from the radio to the antenna, where it is split into a number of sub-components, each of which is fed to a corresponding subset of the radiating elements in the linear array (typically each sub-component is fed to one to three radiating elements). The sub-components of the RF signal are transmitted by the radiating elements to generate an antenna beam that covers a generally fixed coverage area (e.g., a sector of a cell). Typically these linear arrays will have remote electronic tilt ("RET") capability, which allows the cellular operator to change the pointing angle of the generated antenna beam in the elevation (vertical) plane to change the size of the sector served by the linear array. Because the antenna beams produced by the above-mentioned 2G/3G/4G linear arrays produce static antenna beams, they are often referred to as "passive" linear arrays.

Most cellular operators are currently upgrading their networks to support fifth generation (“5G”) cellular services. An important component of 5G cellular services is the use of so-called multi-column “active” beamforming arrays that work in conjunction with beamforming radios to dynamically adjust the size, shape, and pointing direction of antenna beams generated by the active beamforming arrays. These active beamforming arrays are typically formed using “high band” radiating elements that operate in higher frequency bands (e.g., part or all of the 3.3-4.2 GHz and/or 5.1-5.8 GHz bands). Each column in such an active beamforming array is typically coupled to a corresponding port of a beamforming radio. The beamforming radio can be a separate device or can be integrated with an active antenna array. The beamforming radio can adjust the amplitude and phase of the sub-components of the RF signal fed to each port of the radio in order to generate antenna beams with narrowed beamwidths in the azimuth plane and/or elevation plane (and therefore higher antenna gain). These narrowed antenna beams can be steered electronically by properly selecting the amplitude and phase of the subcomponents of the RF signal.

In order to avoid having to increase the number of antennas at the cell site, the above-mentioned 5G antennas generally also include passive linear arrays that support traditional 2G, 3G and/or 4G cellular services. In some cases, both the active beamforming array and the passive linear array can be included in a single base station antenna. Another solution to provide an antenna that supports both 2G/3G/4G and 5G cellular services is to install a 5G active antenna module (i.e., a module including an active beamforming array and an associated beamforming radio) on the rear surface of a passive base station antenna that includes multiple 2G, 3G and/or 4G passive linear arrays. An opening is provided in the reflector of the passive base station antenna so that the antenna beam generated by the active beamforming array can be transmitted through the passive base station antenna. This design is advantageous because the active antenna module can be detachable, so as enhanced 5G capabilities are developed, cellular operators can replace the original active antenna module with an upgraded active antenna module without having to replace the passive base station antenna. Herein, the combination of a passive base station antenna on which an active antenna module is installed is referred to as a "passive/active antenna system".

Summary of the invention

According to an embodiment of the present invention, a base station antenna is provided. The base station antenna comprises: a first antenna array, the first antenna array having a plurality of first-band dipole radiating elements; and a second antenna array, the second antenna array having a plurality of second-band dipole radiating elements. A first second-band dipole radiating element in the second-band dipole radiating elements is installed on a first first-band dipole radiating element in the first-band dipole radiating elements and is installed in front of the first first-band dipole radiating element.

In some embodiments, the first first-band dipole radiating element and the first second-band dipole radiating element share a feeding handle. In some embodiments, the shared feeding handle extends through the first first-band dipole radiating element to be coupled to the first second-band dipole radiating element. In some embodiments, the shared feeding handle comprises a printed circuit board PCB having: a first feed line, the first feed line coupled to the first dipole of the first first-band dipole radiating element; and a second feed line, the second feed line coupled to the first dipole of the first second-band dipole radiating element. In some embodiments, the shared feeding handle is an angled feeding handle, no feeding handle other than the shared feeding handle is coupled to the first first-band dipole radiating element, and no feeding handle other than the shared feeding handle is coupled to the first second-band dipole radiating element.

In some embodiments, the base station antenna further comprises a metal layer extending parallel to the dipole radiator of the first first band dipole radiating element on the feed handle. In some embodiments, the metal layer comprises a frequency selective surface FSS. In some embodiments, the base station antenna may further comprise a third antenna array having a plurality of third band radiating elements mounted behind the FSS. In some embodiments, the FSS is a first FSS and the base station antenna further comprises a second FSS between the third band radiating element and the first FSS. In some embodiments, the first band dipole radiating element is configured to operate in a first frequency band lower than a second frequency band in which the second band dipole radiating element is configured to operate, the second frequency band being lower than a third frequency band in which the third band radiating element is configured to operate, and the FSS is configured to allow RF energy at the third frequency band to pass through and reflect RF energy at the second frequency band. In some embodiments, the FSS is configured not to reflect RF energy at the first frequency band. In some embodiments, the second band radiating element is concealed relative to the RF energy at the third frequency band.

In some embodiments, the first frequency band dipole radiating element is configured to operate in a lower frequency band than the second frequency band dipole radiating element.

In some embodiments, the first band dipole radiating element is configured to operate in all or part of the 617-960 megahertz frequency band and the second band dipole radiating element is configured to operate in all or part of the 1695-2690 megahertz frequency band.

In some embodiments, the base station antenna is a passive base station antenna provided as part of a passive/active antenna system, the passive/active antenna system further comprising an active antenna module on the passive base station antenna.

In some embodiments, the second antenna array is a first antenna array of a plurality of antenna arrays of second frequency band dipole radiating elements, and the second antenna array is mounted further forward than a second antenna array of the plurality of antenna arrays of second frequency band dipole radiating elements. In some embodiments, the base station antenna is configured to provide phase compensation to compensate for the different heights of the second frequency band dipole radiating elements.

In some embodiments, the first second frequency band dipole radiating element is mounted further forward than the second second frequency band dipole radiating element. In some embodiments, the base station antenna is configured to provide phase compensation to compensate for the different heights of the second frequency band dipole radiating elements.

In some embodiments, said first first frequency band dipole radiating element comprises a printed circuit board PCB with an integrated reflector.

According to another embodiment of the present invention, a base station antenna is provided. The base station antenna includes a first antenna array having a plurality of first-band dipole radiating elements and a second antenna array having a plurality of second-band dipole radiating elements. A first second-band dipole radiating element in the second-band dipole radiating elements is fed by the same feeding handle as a first first-band dipole radiating element in the first-band dipole radiating elements, and the first-band dipole radiating element is configured to operate in a lower frequency band than the second-band dipole radiating element.

In some embodiments, the feed shank extends through the first first-band dipole radiating element to couple to the first second-band dipole radiating element.

In some embodiments, the feeding handle includes a printed circuit board PCB having: a first feed line, the first feed line coupled to the first dipole of the first first-band dipole radiating element; and a second feed line coupled to the first dipole of the first second-band dipole radiating element.

In some embodiments, the feeding handle is an angled feeding handle.

According to another embodiment of the present invention, a base station antenna is provided. The base station antenna includes a first antenna array having a plurality of first-band dipole radiating elements and a second antenna array having a plurality of second-band dipole radiating elements. A first second-band dipole radiating element in the second-band dipole radiating elements is completely within an occupied area of a first first-band dipole radiating element in the first-band dipole radiating elements, and the first-band dipole radiating element is configured to operate in a lower frequency band than the second-band dipole radiating element.

In some embodiments, the first first-band dipole radiating element includes a first cross-dipole radiating element, the first second-band dipole radiating element includes a second cross-dipole radiating element, the first dipole of the second cross-dipole radiating element overlaps with the first dipole of the first cross-dipole radiating element in a forward direction, and the second dipole of the second cross-dipole radiating element overlaps with the second dipole of the first cross-dipole radiating element in a forward direction.

In some embodiments, the first dipole of the first cross-dipole radiating element includes two dipole arms, the first dipole of the second cross-dipole radiating element includes two dipole arms that overlap with the two dipole arms of the first dipole of the first cross-dipole radiating element in a forward direction, the second dipole of the first cross-dipole radiating element includes two dipole arms, and the second dipole of the second cross-dipole radiating element includes two dipole arms that overlap with the two dipole arms of the second dipole of the first cross-dipole radiating element in a forward direction.

According to an embodiment of the present invention, a passive/active antenna system including a passive base station antenna and an active antenna module is provided. The passive base station antenna includes a first antenna array having a plurality of first-band dipole radiating elements and a second antenna array having a plurality of second-band dipole radiating elements. The active antenna module is installed behind the passive base station antenna. The first-band dipole radiating element is configured to operate in a lower frequency band than the second-band dipole radiating element, and the first second-band dipole radiating element in the second-band dipole radiating element is installed in the first first-band dipole radiating element in the first-band dipole radiating element and installed in front of the first first-band dipole radiating element.

In some embodiments, the active antenna module includes radio circuitry and a massive MIMO antenna element array.

According to an additional embodiment of the present invention, a base station antenna is provided. The base station antenna includes a reflector, a first antenna array having a plurality of first-band dipole radiating elements on the reflector, and a second antenna array having a plurality of second-band dipole radiating elements. A first second-band dipole radiating element of the second-band dipole radiating elements extends forward farther from the reflector than a second second-band dipole radiating element of the second-band dipole radiating elements, and the first-band dipole radiating element is configured to operate in a lower frequency band than the second-band dipole radiating element.

In some embodiments, the first second-band dipole radiating element is mounted on and in front of a first first-band dipole radiating element among the first-band dipole radiating elements, and the second second-band dipole radiating element is not mounted on any first-band dipole radiating element among the first-band dipole radiating elements.

In some embodiments, the base station antenna is configured to provide phase compensation to compensate for different heights of the second frequency band dipole radiating elements.

According to other embodiments of the present invention, a base station antenna is provided. The base station antenna includes a reflector, a first antenna array having a plurality of first-band dipole radiating elements on the reflector, and a second antenna array and a third antenna array each having a plurality of second-band dipole radiating elements. The second-band dipole radiating elements of the second antenna array extend further forward from the reflector than the second-band dipole radiating elements of the third antenna array, and the first-band dipole radiating elements are configured to operate in a lower frequency band than the second-band dipole radiating elements.

In some embodiments, the second-band dipole radiating elements of the second antenna array are respectively mounted on the first-band dipole radiating elements of the first antenna array and are respectively mounted in front of the first-band dipole radiating elements of the first antenna array, and the second-band dipole radiating elements of the third antenna array are not mounted on any other dipole radiating elements.

In some embodiments, the base station antenna is configured to provide phase compensation to compensate for different heights of the second frequency band dipole radiating elements.

According to other embodiments of the present invention, a base station antenna is provided. The base station antenna includes a first antenna array having a plurality of low-band dipole radiating elements, a metal layer on the rear surface of a first low-band dipole radiating element among the low-band dipole radiating elements, a second antenna array having a plurality of mid-band dipole radiating elements, and a third antenna array having a plurality of high-band dipole radiating elements. A first mid-band dipole radiating element among the mid-band dipole radiating elements is mounted on the first low-band dipole radiating element, the low-band dipole radiating element is configured to operate in a low-frequency band lower than the mid-frequency band in which the mid-band dipole radiating element is configured to operate, and the mid-frequency band is lower than the high-frequency band in which the high-band radiating element is configured to operate.

In some embodiments, the metal layer includes a frequency selective surface FSS. In some embodiments, the high-band radiating element is mounted behind the FSS. In some embodiments, the FSS is configured to allow RF energy at the high-band to pass through and reflect RF energy at the mid-band. In some embodiments, the FSS is configured not to reflect RF energy at the low-band. In some embodiments, the mid-band radiating element is concealed relative to the RF energy at the high-band.

According to another embodiment of the present invention, a base station antenna is provided. The base station antenna comprises: a first antenna array, the first antenna array having a plurality of first-band dipole radiating elements, wherein a first first-band dipole radiating element of the first-band dipole radiating elements comprises a printed circuit board PCB with an integrated reflector; and a second antenna array, the second antenna array having a plurality of second-band dipole radiating elements. A first second-band dipole radiating element of the second-band dipole radiating elements is mounted on the first first-band dipole radiating element, and the first-band dipole radiating element is configured to operate in a lower frequency band than the second-band dipole radiating element.

In some embodiments, the integrated reflector comprises a frequency selective surface FSS. In some embodiments, the base station antenna further comprises a third antenna array having a plurality of third frequency band radiating elements mounted behind the FSS.

In some embodiments, the first frequency band dipole radiating element is configured to operate in a first frequency band that is lower than a second frequency band in which the second frequency band dipole radiating element is configured to operate, the second frequency band is lower than a third frequency band in which the third frequency band radiating element is configured to operate, and the FSS is configured to allow RF energy at the third frequency band to pass and reflect RF energy at the second frequency band.

BRIEF DESCRIPTION OF THE DRAWINGS

1A is a schematic rear perspective view of a passive/active antenna system including a passive base station antenna with an active antenna module mounted thereon according to an embodiment of the present invention.

1B is a schematic perspective view of the passive/active antenna system of FIG. 1A with the radome of the passive base station antenna removed.

1C is a perspective view of an active antenna module of the passive/active antenna system of FIGS. 1A-1B .

2A is an example schematic front view of a low-band array included in the passive/active antenna system of FIG. 1A .

2B is an example schematic front view of a mid-band array included in the passive/active antenna system of FIG. 1A .

2C is an example schematic front view of a high-band array included in the passive/active antenna system of FIG. 1A .

3A is a schematic block diagram of the two radiating elements of FIGS. 2A and 2B sharing a common feed stem.

3B is a schematic block diagram of the mid-band radiating element of FIG. 2B within the footprint of the low-band radiating element of FIG. 2A .

4A is a schematic front view of the mid-band radiating element and the low-band radiating element of FIG. 3B .

4B is a schematic block diagram of the low-band radiating element of FIG. 4A having a metal layer on its rear surface.

5A and 5B are opposing schematic side views of a feed stem shared by the mid-band radiating element and the low-band radiating element of FIG. 4A.

6A is a front view of the top portion of the passive/active antenna system of FIG. 1B with the second frequency selective surface, which was omitted in FIG. 1B , in place.

6B is a front perspective view of a portion of the passive/active antenna system shown in FIG. 6A.

7A is a schematic block diagram illustrating the height of the low-band array and the mid-band array of FIG. 6A .

7B is a schematic block diagram illustrating radiating elements of different heights in the same mid-band array according to other embodiments.

7C is a schematic block diagram illustrating a phase compensation circuit coupled to the mid-band radiating element of FIG. 2B .

DETAILED DESCRIPTION

Although it may be advantageous to place low-frequency band, medium-frequency band and high-frequency band radiating elements in the same base station antenna, the radiating element arrays working in different frequency bands may have a negative impact on each other's RF performance. Therefore, in order to improve the performance of the base station antenna, it may be beneficial to, for example, reduce the impact of the medium-frequency band radiating element on the high-frequency band radiating element. According to an embodiment of the present invention, a base station antenna is provided, and the impact of the medium-frequency band radiating element on the high-frequency band radiating element can be reduced by integrating the medium-frequency band radiating element with the low-frequency band radiating element. For example, the medium-frequency band radiating element can be installed on the low-frequency band radiating element and installed in front of the low-frequency band radiating element. For a base station antenna system that includes a passive base station antenna with a low-frequency and medium-frequency linear array and an active antenna module with one or more multi-column arrays of high-frequency band radiating elements, the integrated radiating element can reduce the degree (for example, by using less metal) of the radiating element of the passive base station antenna shielding the high-frequency band radiating element of the active antenna module, thereby the performance of the active antenna module can be improved. Furthermore, even if the passive base station antenna does not include an associated active antenna module, the integrated radiating elements may reduce the degree of shielding of the radiating elements of the mid-band array by the low-band array, thereby improving the performance of the mid-band array.

In some embodiments, the mid-band radiating element and the low-band radiating element are integrated with each other and can share the same feed handle. By sharing a single feed handle between two radiating elements, costs can be reduced. According to some embodiments, the shared feed handle can be the only feed handle for any radiating element. Therefore, no cross handle (i.e., a feed handle comprising two feed handle printed circuit boards that fit together so that the two printed circuit boards intersect at a 90° angle) is required for any radiating element. Removing the cross handle can reduce unwanted shielding/reflections and can further reduce costs.

Exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1A-1C illustrate a passive/active antenna system 100 including both a passive base station antenna and an active antenna module. In particular, FIG. 1A is a schematic rear perspective view of the passive/active antenna system 100. FIG. 1B is a schematic perspective view of the passive/active antenna system 100 of FIG. 1A , wherein the radome of the passive base station antenna is omitted. FIG. 1C is a perspective view of the active antenna module shown in FIG. 1A . In FIGS. 1A and 1B , the axes show the vertical (V), horizontal (H), and forward (F) directions of the base station antenna system 100.

1A , a passive/active antenna system 100 may be mounted on an antenna tower 102, for example, using mounting hardware 104. The passive/active antenna system 100 includes a passive base station antenna 110 and an active antenna module 150 mounted behind the passive base station antenna 110. The active antenna module 150 may be mounted directly on the rear surface of the passive base station antenna 110, or may be held in place behind the passive base station antenna 110, for example, by mounting hardware 104 used to mount the passive/active antenna system 100 on an antenna tower 102 (or other structure). The front surface of the passive/active antenna system 100 may be opposite the antenna tower 102, facing the coverage area of the passive/active antenna system 100. The passive base station antenna 110 includes a tubular radome 112 that surrounds and protects an antenna assembly mounted within the radome 112. A top end cap 114 covers a top opening in the radome 112, and a bottom end cap 116 covers a bottom opening in the radome 112. A plurality of RF ports 118 extend through the bottom end cap 116 and are used to connect the passive base station antenna 110 to one or more external radios (not shown). The active antenna module 150 may be removably mounted behind the passive base station antenna 110 so that the active antenna module 150 may later be replaced by a different active antenna module, preferably without removing the passive base station antenna 110 from the antenna tower 102.

Referring to FIG. 1B , the passive base station antenna 110 includes a reflector assembly 120 and multiple passive linear arrays of radiating elements extending forward from the passive reflector assembly 120. The reflector assembly 120 may be referred to herein as a "passive reflector assembly" because it is part of the passive base station antenna 110. The linear array may support, for example, 3G and/or 4G cellular services. In the example passive base station antenna 110 shown in FIG. 1A-1B , the linear array includes first and second low-band linear arrays 130-1, 130-2, which are configured to operate in all or part of the 617-960 MHz frequency band. Each low-band linear array 130 includes 132 columns of low-band radiating elements extending vertically. The passive base station antenna 110 also includes first to fourth mid-band linear arrays 140-1 to 140-4, which are configured to operate in all or part of the 1427-2690 MHz frequency band. Each mid-band linear array 140 includes 142 columns of mid-band radiating elements extending vertically. Each of the low-band and mid-band linear arrays 130, 140 can generate relatively static antenna beams (e.g., each antenna beam is configured to cover a sector of a base station) that provide coverage of a predefined coverage area, where the coverage area only changes when the electronic downtilt angle of the generated antenna beam is adjusted (e.g., to change the size of the cell).

Each of the low-band and mid-band radiating elements 132, 142 can be implemented as a dual-polarized radiating element, which includes a first and a second radiator that transmits and receives RF energy with orthogonal polarizations. When using such dual-polarized radiating elements, each of the low-band and mid-band linear arrays 130, 140 can be connected to a pair of RF ports 118. The first RF port 118 is connected between a first port of a radio (e.g., a remote radio head mounted on an antenna tower 102 near a passive base station antenna 110) and a first polarized radiator of a radiating element in the array, and the second RF port 118 is connected between a second port of the radio and a second polarized radiator of a radiating element in the array. The RF signal to be transmitted by a selected one of the linear arrays 130, 140 is passed from the radio to one of the RF ports 118, and from the RF port 118 to a power divider (or, optionally, to a phase shifter assembly including a power divider), which divides the RF signal into a plurality of sub-components, which are fed to corresponding first or second radiators of the radiating elements in the linear array, where the sub-components are radiated into free space.

The passive reflector assembly 120 includes a main reflector 122 and spaced first and second reflector strips 124-1, 124-2, the spaced first and second reflector strips 124-1, 124-2 extending vertically from the respective first and second opposite sides of the main reflector 122. The passive reflector assembly 120 may also include a third reflector strip 124-3 extending in a horizontal direction between the first and second reflector strips 124-1, 124-2. An opening 126 is defined between the first and second reflector strips 124-1, 124-2. For example, the opening 126 may be defined by the top of the main reflector 122, the first and second reflector strips 124-1, 124-2, and the third reflector strip 124-3. Most of the low-band and mid-band radiating elements 132, 142 are mounted to extend forward from the main reflector 122. However, the low-band linear arrays 130-1, 130-2 and the mid-band linear arrays 140-2, 140-3 each extend substantially the entire length of the passive/active antenna system 100 and therefore extend beyond the main reflector 122. The first and second reflector bars 124-1, 124-2 provide mounting locations for the low-band radiating elements 132 positioned above the main reflector 122. The first and second reflector bars 124-1, 124-2 can be integrated with the main reflector 122 so that the first and second reflector bars 124-1, 124-2 and the main reflector 122 will remain at a common ground voltage, which can be important for the performance of the linear arrays 130-1, 130-2, 140-2, 140-3.

Each low-band radiating element 132 may include a tilted -45°/+45° cross-dipole radiating element including a -45° dipole radiator 134-1 and a +45° dipole radiator 134-2 arranged to form a cross when the radiating element 132 is viewed from the front. The dipole radiator 134 may (but is not required to) extend in a plane parallel to the plane defined by the main reflector 122. The dipole radiators 134-1, 134-2 may be mounted on a feeding handle 136 of the radiating element 132. Typically, the cross-dipole radiating element extends forward from the main reflector surface of the reflector assembly, wherein the radiating element feeding handle extends perpendicular to the main reflector surface. The feeding handle may be configured to transfer RF signals between the dipole radiator and an associated feeding network, and may also be used to support the dipole radiator in front of the reflector assembly. The radiating elements 132 extending forward from the main reflector 122 can have a conventional design in which the feeding handle extends perpendicular to the main reflector 122. However, the center of the low-band radiating elements 132 mounted on the first and second reflector bars 124-1, 124-2 is located above the opening 126, so conventional radiating elements are not easy to use. Therefore, the three uppermost low-band radiating elements 132 have so-called "tilted" feeding handles 136, which extend forward from the reflector bars 124-1, 124-2 at an inclined angle. In particular, the base of each feeding handle 136 is mounted on one of the reflector bars 124-1, 124-2, and the feeding handle 136 extends at an angle so that the center of the intersection defined by the dipole radiators 134-1, 134-2 is located above the opening 126. In an exemplary embodiment, the feeding handle 136 can extend at an angle of approximately 30° to 60° relative to the front surface of the reflector bars 124-1, 124-2. In addition, the three uppermost low-band radiating elements 132 also each include a corresponding integrated mid-band radiating element 142 mounted thereon, which will be discussed in further detail below.

Referring to FIGS. 1B and 1C , the active antenna module 150 includes a multi-column beamforming array 160 of radiating elements 162 and a beamforming radio (not visible in the figure). The multi-column beamforming array 160 can be mounted in a front portion of the radome 152 of the active antenna module 150, and the beamforming radio can be mounted behind the multi-column beamforming array 160. The beamforming array 160 can, for example, include a plurality of vertically extending columns of high-band radiating elements 162 configured to operate in all or part of the 3.1-4.2 GHz frequency band. The high-band radiating elements 162 are mounted to extend forward from the reflector 154 (herein referred to as an “active reflector”) of the active antenna module 150. The beamforming radio can electronically adjust the amplitude and/or phase of the sub-components of the RF signal output to different radiating elements 162 of the multi-column beamforming array 160. For example, each port of the beamforming radio can be coupled to a column of radiators of the beamforming array 160, and the amplitude and phase of the subcomponents of the RF signal fed to each column of radiators can be adjusted so that the generated antenna beam is narrowed in the azimuth plane and points in the desired direction in the azimuth plane. The active antenna module 150 may also include other components, such as filters, calibration networks, antenna interface signal group (AISG) controllers, etc.

As shown in FIG1B , the beamforming array 160 of the active antenna module 150 is mounted behind an opening 126 in the passive reflector assembly 114. The beamforming array 160 is visible in FIG1B , where the passive base station antenna 110 and the radomes 112, 152 of the active antenna module 150 are removed in the view of FIG1B . The opening 126 in the passive reflector assembly 120 allows the antenna beam generated by the beamforming array 160 to pass through the passive base station antenna 110 and out the front of the radome 112 of the passive base station antenna 110 to provide service to the coverage area of the passive/active antenna system 100. The opening 126 may be covered by a frequency selective surface, which will be discussed in more detail below.

Fig. 2A is an example schematic front view of two low-band arrays 130-1, 130-2 included in the passive/active antenna system 100 of Fig. 1A-1C. Two low-band arrays 130-1, 130-2 are spaced apart from each other in the horizontal direction H. Each low-band array 130 includes a plurality of low-band radiating elements 132 and can extend from the bottom of the passive/active antenna system 100 to its top in the vertical direction V. Each low-band array 130 can therefore be referred to as a "vertical column". The vertical direction V can be or can be parallel to the longitudinal axis of the passive base station antenna. The vertical direction V can also be perpendicular to the horizontal direction H and the forward direction F. As used herein, the term "vertical" does not necessarily require something to be completely vertical (e.g., the passive/active antenna system 100 can have a small mechanical downtilt).

The low-band arrays 130 are each configured to transmit and/or receive RF signals in one or more frequency bands, such as all or part of the 617-960 MHz frequency band. Although FIG. 2A illustrates two arrays 130-1, 130-2, the passive base station antenna 110 may include more or fewer low-band arrays 130. Furthermore, the number of radiating elements 132 included in each low-band array 130 may be any number from two to twenty or more, with five to nine radiating elements being most typical.

2B is an example schematic front view of four mid-band arrays 140-1 to 140-4 included in the passive base station antenna 110 of FIG1A . The four mid-band arrays 140-1 to 140-4 are spaced apart from each other in a horizontal direction H. Each mid-band array 140 (e.g., a vertical column) includes a plurality of mid-band radiating elements 142 and may extend in a vertical direction V.

The mid-band arrays 140 are each configured to transmit and/or receive RF signals in one or more frequency bands, such as all or part of the 1427-2690 MHz frequency band. Although FIG. 2B illustrates four mid-band arrays 140-1 to 140-4, the passive base station antenna 110 may include more (e.g., five or more) or fewer (e.g., two or three) mid-band arrays 140. Furthermore, the number of radiating elements 142 in each mid-band array 140 may be any number from two to twenty or more.

Fig. 2 C is an example schematic front view of a multi-column array 160 of a high-frequency band radiating element 162 included in the active antenna module 150 of Fig. 1A-1C. High-frequency band array 160 comprises four columns 164-1 to 164-8 of high-frequency band radiating element 162. These four columns 164 are spaced apart from each other in the horizontal direction H. Each column 164 can extend from the bottom of the active antenna module 150 to its top in the vertical direction V.

The high frequency band array 160 is configured to transmit and/or receive RF signals in one or more frequency bands, for example, including one or more frequency bands of 3.1-4.2 GHz (e.g., 3.3-4.2 GHz). Although FIG. 2C illustrates eight columns of high frequency band array 160, the high frequency band array 160 may include more or fewer columns 164 of radiating elements 162. In addition, the number of radiating elements 162 in each column 164 may be any number from two to twenty or more.

To simplify the illustration, the low-band array 130 (FIG. 2A) and the mid-band array 140 (FIG. 2B) are omitted in FIG. 2C. Likewise, the high-band array 160 is omitted in FIG. 2A and 2B, and the low-band and mid-band arrays 130, 140 are omitted from the views of FIG. 2B and 2A, respectively.

FIG. 3A is a schematic block diagram of the first and second radiating elements RE-1, RE-2 (e.g., the low-band radiating element 132 and the mid-band radiating element 142 of FIGS. 2A and 2B ) of a common feeding handle 400. As shown in FIG. 3A , the first-band radiating element RE-1 and the second-band radiating element RE-2 can be mounted on the common feeding handle 400 at different distances in front of the reflector 430 (in the forward direction F), respectively. The common feeding handle 400 can be mounted on the reflector 430 or on a feed board printed circuit board (not shown) mounted on the reflector 430, for example. The common feeding handle 400 extends forward from the reflector 430. As a result, the second-band radiating element RE-2 overlaps with the first-band radiating element RE-1 in the forward direction F (i.e., an axis perpendicular to the reflector 430 extends through both the first-band radiating element RE-1 and the second-band radiating element RE-2). For example, the first frequency band radiation element RE-1 and the second frequency band radiation element RE-2 may be corresponding dipole radiation elements (e.g., corresponding cross-dipole radiation elements), and at least one dipole of the second frequency band radiation element RE-2 may overlap with a corresponding dipole of the first frequency band radiation element RE-1 in the forward direction F.

The common feeding handle 400 is coupled to both the first frequency band radiating element RE-1 and the second frequency band radiating element RE-2. For example, the common feeding handle 400 may extend through the first frequency band radiating element RE-1 to be coupled to the second frequency band radiating element RE-2. In some embodiments, the common feeding handle 400 may be the only feeding handle coupled to the first frequency band radiating element RE-1 and the only feeding handle coupled to the second frequency band radiating element RE-2. Therefore, the first frequency band radiating element RE-1 and the second frequency band radiating element RE-2 may not be coupled to any other feeding handles. The first frequency band radiating element RE-1 and the second frequency band radiating element RE-2 may therefore not be fed by a cross handle, which is different from conventional radiating elements (e.g., conventional mid-band radiating elements).

According to some embodiments, the first band radiating element RE-1 and the second band radiating element RE-2 may be the low band radiating element 132 (FIG. 2A) and the mid-band radiating element 142 (FIG. 2B), respectively. The mid-band radiating element 142 may thus be mounted on the low band radiating element 132 and in front of the low band radiating element 132 (in the forward direction F). In other embodiments, the first band radiating element RE-1 and the second band radiating element RE-2 may be the mid-band radiating element 142 and the low band radiating element 132, respectively, such that the low band radiating element 132 is mounted on the mid-band radiating element 142 and in front of the mid-band radiating element 142. Therefore, the mid-band radiating element 142 may be located between the reflector 430 and the low band radiating element 132 in the forward direction F, or the low band radiating element 132 may be located between the reflector 430 and the mid-band radiating element 142 in the forward direction F. Other embodiments are possible. For example, the second frequency band radiating element RE- 2 may be the high frequency band radiating element 162 , and the first frequency band radiating element RE- 1 may be the low frequency band radiating element 132 or the mid frequency band radiating element 142 .

FIG3B is a schematic block diagram of the mid-band radiating element 142 of FIG2B within the footprint of the low-band radiating element 132 of FIG2A . As shown in FIG3B , the mid-band radiating element 142 does not extend outward beyond the footprint of the low-band radiating element 132 in either the horizontal direction H or the vertical direction V. Therefore, the entire mid-band radiating element 142 can be within the footprint of the low-band radiating element 132.

FIG4A is a schematic front view of the mid-band radiating element 142 and the low-band radiating element 132 of FIG3B. As shown in FIG4A, the mid-band radiating element 142 and the low-band radiating element 132 may be corresponding cross-dipole radiating elements. The low-band radiating element 132 may include a first dipole having first and second dipole arms 401-1, 401-2 and a second dipole having third and fourth dipole arms 401-3, 401-4. The mid-band radiating element 142 may include a first dipole having first and second dipole arms 402-1, 402-2 and a second dipole having third and fourth dipole arms 402-3, 402-4. In an example embodiment, the first to fourth dipole arms 401-1 to 401-4 of the low-band radiating element 132 may share (i.e., may each be located at) a front surface of a PCB 403 of the low-band radiating element 132, and the first to fourth dipole arms 402-1 to 402-4 of the mid-band radiating element 142 may share a front surface of a PCB 404 of the mid-band radiating element 142.

The low-band radiating element 132 and the mid-band radiating element 142 may each be dual-polarized (e.g., a cross-dipole radiating element tilted at -/+45°). As an example, a first dipole of the low-band radiating element 132 and the mid-band radiating element 142 may be a first polarized radiator, and a second dipole of the low-band radiating element 132 and the mid-band radiating element 142 may be a second polarized radiator, wherein the second polarization (e.g., -45°) is different from (e.g., orthogonal to) the first polarization (+45°).

In some embodiments, each dipole of the mid-band radiating element 142 may overlap with a corresponding dipole of the low-band radiating element 132 in the forward direction F. For example, each dipole arm 402 of the mid-band radiating element 142 may overlap with a corresponding dipole arm 401 of the low-band radiating element 132 in the forward direction F. Thus, the first to fourth dipole arms 402-1 to 402-4 of the mid-band radiating element 142 may overlap with the first to fourth dipole arms 401-1 to 401-4 of the low-band radiating element 132, respectively, in the forward direction F. As an example, the first to fourth mid-band dipole arms 402-1 to 402-4 are respectively in front of the first to fourth low-band dipole arms 401-1 to 401-4 at a distance of about a quarter wavelength corresponding to the center frequency of the operating frequency band of the mid-band radiating element 142.

According to some embodiments, the low-band radiating element 132 may have a metal layer 410 on its rear surface, such as on the rear surface 403R (FIG. 4B) of the PCB 403. The metal layer 410 may be, for example, a substantially square sheet of metal and may serve as a reflector for the mid-band radiating element 142. The metal layer 410 may be referred to herein as an "integrated reflector" because it may be integrated with/may be part of the PCB 403 of the low-band radiating element 132 and reflect RF energy at the operating frequency band ("mid-band") of the mid-band radiating element 142. In addition, the metal layer 410 may not be grounded and may therefore be electrically floating in some embodiments (but may also be grounded). In order to simply illustrate the shape and position of the metal layer 410 relative to the shape and position of the dipole arms 401, 402, FIG. 4A depicts the metal layer 410 as visible from the front side of the PCB 403. However, in some embodiments, the metal layer 410 may not be visible from the front side of the PCB 403. For example, PCB 403 may be opaque rather than translucent.

In some embodiments, the metal layer 410 may be a frequency selective surface ("FSS") rather than a continuous metal sheet, which may act as a spatial filter that transmits, or substantially attenuates, and/or reflects RF energy according to the frequency of the RF energy. FSSs are known in the art and typically include a grid pattern of cells, such as a grid pattern of metal patches and/or other metal structures that form a resonant circuit. The metal patches/structures may be arranged in one or more layers. The FSS may be implemented as, for example, a metal plate having a stamped or otherwise formed grid structure therein, or as a dielectric substrate (e.g., a printed circuit board) having one or more metal patterns formed therein. The FSS may be configured to substantially transmit RF energy incident thereon in a first frequency range, while partially or substantially attenuating (e.g., reflecting) RF energy incident thereon in a second frequency range. As an example, the metal layer 410 may be configured to allow RF energy at a high frequency band (the high frequency band radiating element 162 of FIG. 2C operates in this frequency band) to pass through and reflect RF energy at a mid-frequency band (the mid-frequency band radiating element 142 operates in this frequency band). In addition, the metal layer 410 can be configured to reflect RF energy at only one frequency band (e.g., a mid-band) and can therefore be configured to pass (i.e., not reflect or absorb) RF energy at a low frequency band (at which the low-band radiating element 132 operates). The mid-band is lower than the high-band and higher than the low-band. Examples of FSS (including its spatial filtering characteristics) are discussed in U.S. Patent No. 11,482,774 to Hou et al., which is incorporated herein by reference in its entirety.

The passive/active antenna system 100 may also include a second FSS 420 mounted behind the metal layer 410. In some embodiments, the second FSS 420 may be configured to allow RF energy to pass through in the high frequency band and reflect RF energy in the low frequency band. In addition, the second FSS 420 may be configured not to reflect RF energy at the mid-frequency band because the second FSS 420 may reflect only for a single frequency band (e.g., a low frequency band) instead of multiple frequency bands. The second FSS 420 is longer than the metal layer 410 in both the vertical direction V and the horizontal direction H, so the metal layer 410 may be in the occupied area of the second FSS 420. According to some embodiments, the metal layer 410 and the second FSS 420 may be the first FSS and the second FSS, respectively. The high-band radiating element 162 may be mounted behind the second FSS 420, as will be described herein with reference to FIG. 4B, and also described in more detail in U.S. Pat. No. 11,482,774 to Hou et al.

4A also shows that the entirety of each dipole arm 402 of the mid-band radiating element 142 may be within the footprint of the low-band radiating element 132. For example, the entire mid-band radiating element 142 may be within the footprint of the PCB 403 of the low-band radiating element 132 (i.e., may overlap in the forward direction F). In some embodiments, the entire mid-band radiating element 142 may be within the footprint of a metal layer 410 located on the rear surface of the low-band radiating element 132.

According to some embodiments, the mid-band radiating elements 142 may be concealed relative to RF energy at the high frequency band. The dipole radiator of each concealed mid-band radiating element 142 may be substantially transparent to RF energy in the high frequency band. The mid-band radiating elements 142 may thus be "stealth" radiating elements that have a reduced impact (i.e., reduced scattering) on antenna beams generated by closely located radiating elements that transmit and receive signals in other frequency bands. Example concealed radiating elements are discussed in U.S. Patent Application No. 63/431,426 to Wu et al., the disclosure of which is incorporated herein by reference in its entirety.

In some embodiments, the director can be located on the mid-band radiating element 142. For example, the director can be installed in front of the dipole of the mid-band radiating element 142 (for example, using a plastic support structure that is mounted on the PCB 404 or can be mounted on the inner surface of the antenna cover 112 (Figure 1A) facing the mid-band radiating element 142). The director can be a metal structure that acts as a parasitic radiating element, which receives radio waves from the driven radiating element (here, the dipole of the corresponding mid-band radiating element 142) and re-radiates the radio waves with a different phase. The role of the director is to enhance the radiation in a given direction, thereby increasing the gain of the "element antenna beam" generated by the radiating element including the director in that direction. To simplify the description, the director is not shown in Figure 4A.

A variety of techniques may be used to provide directors on the inner surface of the radome 112. For example, the directors may be located on a thin PCB that is attached (e.g., with double-sided tape) to the inner surface of the radome 112. As another example, the directors may be printed onto the inner surface of the radome 112. In a further example, the directors may be implemented as metal sheets suspended from the inner surface of the radome 112. Additionally, the directors may be mounted on the inner surface of the radome 112 using a pick-and-place device, an example of which is discussed in U.S. Pat. No. 10,741,920, the entire contents of which are incorporated herein by reference.

FIG. 4B is a schematic block diagram of the low-band radiation element 132 of FIG. 4A . The low-band radiation element 132 is implemented using a PCB 403, which includes a dielectric substrate 403D, and a front metallization layer and a rear metallization layer are formed on two main surfaces of the dielectric substrate 403D. The dipole arms 401-1 to 401-4 are implemented in the front metallization layer. The rear metallization layer may include a metal layer 410, which may be a continuous or patterned metal layer. The metal layer 410 may face the front (e.g., frontmost) surface of the second FSS 420. A plurality of high-band radiation elements 162 may be mounted (e.g., on a reflector 430) behind the metal layer 410 and behind the second FSS 420. The second FSS 420 may be located between the high-band radiation element 162 and the metal layer 410 in the forward direction F. To simplify the illustration, the common feed stem 400 (FIG. 3A) that feeds both the low-band radiating element 132 and the mid-band radiating element 142 is omitted from the view of FIG. 4B.

Although FIG. 4B shows the dipole arms 401-1 to 401-4 implemented in the front metallization layer and the metal layer 410 implemented in the back metallization layer, in some embodiments (e.g., embodiments where the metal layer 410 is implemented as a FSS), these elements may be reversed so that the metal layer 410 is in front of the dipole arms 401-1 to 401-4. It should also be understood that the metal layer 410 may be separate from the PCB 403 (e.g., a sheet metal layer of another PCB), and the dipole arms 401 need not be implemented using a PCB in other embodiments.

5A and 5B are relative schematic side views of a feed handle 500 shared by the mid-band radiating element 142 and the low-band radiating element 132 of FIG4A. The shared feed handle 500 is an example of the shared feed handle 400 shown in FIG3A. As shown in FIGS5A and 5B, the shared feed handle 500 is a PCB feed handle having a first feed line 510, which is coupled to the first dipole (having the first and second dipole arms 401-1, 401-2 (FIG4A)) of the low-band radiating element 132 via the PCB 403 of the low-band radiating element 132.

The PCB feed handle 500 also has a second feed line 530, a third feed line 520, and a fourth feed line 540, the second feed line 530 being coupled to the first dipole (having the first and second dipole arms 402-1, 402-2 (FIG. 4A)) of the mid-band radiating element 142 via the PCB 404 of the mid-band radiating element 142, the third feed line 520 being coupled to the second dipole (having the third and fourth dipole arms 401-3, 401-4 (FIG. 4A)) of the low-band radiating element 132 via the PCB 403, and the fourth feed line 540 being coupled to the second dipole (having the third and fourth dipole arms 402-3, 402-4 (FIG. 4A)) of the mid-band radiating element 142 via the PCB 404. The first to fourth feed lines 510 to 540 may include conductive (e.g., copper or other metal) traces on the PCB feed handle 500.

5A and 5B show that PCB feeding handle 500 extends through PCB 403 (e.g., through a slot in PCB 403) to couple to PCB 404. In some embodiments, PCB feeding handle 500 is not a cross handle and is the only feeding handle coupled to PCB 403 or PCB 404. In addition, PCB feeding handle 500 can be an angled (e.g., tilted) feeding handle instead of a straight feeding handle, as shown in the angled middle portion (rear of PCB 403) of PCB feeding handle 500 in FIGS. 5A and 5B.

FIG6A is a front view of a portion of the low-band array 130 of FIG2A and a portion of the two mid-band arrays 140 of FIG2B. In some embodiments, the low-band array 130 and the mid-band array 140 may be a portion of the passive base station antenna 110 (FIG. 1A) of the passive/active antenna system 100. Thus, the view shown in FIG6A may be a view of the passive base station antenna 110 with its radome 112 (FIG. 1A) removed (for ease of illustration). In addition, the passive/active antenna system 100 may include at least one active antenna module 150 (FIG. 1B) located on (e.g., attached to) the passive base station antenna 110.

As shown in Fig. 6A, the second and third arrays 140-2, 140-3 of mid-band radiating elements 142 may be mounted to and positioned in front of (in the forward direction F) the first and second arrays 130-1, 130-2 of low-band radiating elements 132, respectively. For example, Fig. 6A shows six mid-band radiating elements 142 integrated with six low-band radiating elements 132, respectively. The integrated radiating elements extend on or above the second FSS 420 located in front of the reflector 430.

In some embodiments, the passive base station antenna 110 may include a low-band radiating element 132 and/or a mid-band radiating element 142 that is not on (or overlaps) the second FSS 420. As an example, FIG. 6A shows two low-band radiating elements 610 and two mid-band radiating elements 620 that are located on a reflector 415 (which corresponds to the main reflector 122 in FIG. 1B ) and do not overlap the second FSS 420 (in the forward direction F). According to some embodiments, the reflector 415 may be at a different level than the reflector 430 in the forward direction F. For example, the reflector 415 may be raised to a level in front of the reflector 430 (and in front of the level of the second FSS 420), so that the low-band radiating element 610 may extend further forward (in the forward direction F) than the low-band radiating element 132 on the second FSS 420. Furthermore, due to space limitations on the low-band radiating element 610 in the forward direction F, the mid-band radiating element 620 may not be mounted on the low-band radiating element 610 .

6A also shows that the second and third arrays 140-2, 140-3 of mid-band radiating elements 142 can be located inside the first and fourth arrays 140-1, 140-4 of mid-band radiating elements 142 in the horizontal direction H. In other embodiments, the second and third mid-band arrays 140-2, 140-3 can be located outside the first and fourth mid-band arrays 140-1, 140-4 in the horizontal direction H. In addition, each mid-band radiating element 142 in the first array 140-1 can be adjacent to and equidistant from (and therefore overlapping with) two low-band radiating elements 132 in the first array 130-1 in the vertical direction V. Similarly, each mid-band radiating element 142 in the fourth array 140-4 can be adjacent to and equidistant from (and therefore overlapping with) two low-band radiating elements 132 in the second array 130-2 in the vertical direction V.

FIG6B is a front perspective view of the low-band array 130 and the mid-band array 140 shown in FIG6A. As shown in FIG6B, each low-band radiating element 132 on the second FSS 420 can be fed by a corresponding common feeding handle 500, which also feeds a corresponding mid-band radiating element 142 mounted on and in front of the low-band radiating element 132. The common feeding handle 500 can be angled inwardly toward the center of the reflector 430 (and therefore away from its outer edge in the horizontal direction H(6A)). The mid-band radiating elements 142 of the second and third arrays 140-2, 140-3 fed by the common feeding handle 500 extend further forward than the mid-band radiating elements 142 of the first and fourth arrays 140-1, 140-4 that do not share the feeding handle with the low-band radiating element 132. 6B shows an elevated reflector 415 and the low-band radiating element 132 thereon, the low-band radiating element 132 thereon extending further forward than the low-band radiating element 132 on the second FSS 420. As shown in FIG.

FIG7A is a schematic block diagram illustrating the height of the low-band array 130 and the mid-band array 140 of FIG6A. As shown in FIG7A, the second and third mid-band arrays 140-2, 140-3 (which are mounted on and placed in front of the first and second low-band arrays 130-1, 130-2) extend further forward than the first and fourth mid-band arrays 140-1, 140-4. For example, the second and third mid-band arrays 140-2, 140-3 may have a second height H2 (in the forward direction F) from the reflector 430, and the second height H2 is higher/longer than the third height H3 (in the forward direction F) of the first and fourth mid-band arrays 140-1, 140-4 from the reflector 430. The first height H1 (along the forward direction F) of the first and second low-band arrays 130-1, 130-2 from the reflector 430 may be higher/longer than the third height H3 and lower/shorter than the second height H2.

For simplicity of explanation, FIG7A shows that the first and fourth mid-band arrays 140-1, 140-4 are horizontally overlapped with the first and second low-band arrays 130-1, 130-2. However, as shown in FIG6A, the first and fourth mid-band arrays 140-1, 140-4 may not overlap with the first and second low-band arrays 130-1, 130-2 in the horizontal direction H. On the contrary, the first and fourth mid-band arrays 140-1, 140-4 may overlap with the first and second low-band arrays 130-1, 130-2 in the vertical direction V, respectively.

FIG7B is a schematic block diagram showing radiating elements 142 of different heights in the same (second) mid-band array 140-2 according to other embodiments. As shown in FIG7B , two radiating elements RE-M in the second mid-band array 140-2 mounted on the corresponding low-band radiating elements 132 have a second height H2, while two radiating elements 142 in the second mid-band array 140-2 not mounted on the low-band radiating elements 132 have a third height H3 that is lower than/shorter than the second height H2. Therefore, some radiating elements 142 of the second mid-band array 140-2 can be installed further forward (in the forward direction F) than other radiating elements 142 in the second mid-band array 140-2. In addition, FIG7B shows that the radiating elements 142 with the third height H3 can be alternated (and co-linear) with the radiating elements 142 with the second height H2 along the vertical direction V.

7C is a schematic block diagram illustrating a phase compensation circuit 710 coupled to the mid-band radiating element 142. The phase compensation circuit 710 may include, for example, one or more phase delay lines (and/or other phase compensation circuits) to compensate for phase differences due to varying heights between the plurality of mid-band radiating elements 142.

In some embodiments, the phase compensation circuit 710 may be part of a feed circuit 700 that couples a radio 742 to a plurality of mid-band radiating elements 142 of a passive base station antenna 110 ( FIG. 1A ). As shown in FIG. 7C , at least one of the mid-band radiating elements 142 may not be coupled to any phase compensation circuit 710. As an example, the two mid-band radiating elements 142 shown in FIG. 7C may include a first mid-band radiating element 142 coupled to the phase compensation circuit 710 and a second mid-band radiating element 142 not coupled to any phase compensation circuit 710, wherein the first and second mid-band radiating elements 142 may have different heights H2, H3, respectively, (or vice versa), as shown in FIG. 7A (or FIG. 7B ). The phase compensation circuit 710 may be configured to provide phase compensation to compensate for the different heights H2, H3. Therefore, referring to Fig. 7A, the phase compensation circuit 710 can be coupled to the second and/or third intermediate frequency band arrays 140-2, 140-3 but not to the first and/or fourth intermediate frequency band arrays 140-1, 140-4, and vice versa. In addition, referring to Fig. 7B, the phase compensation circuit 710 can be coupled to the radiation element 142 having the second height H2 in the second intermediate frequency band array 140-2, but not to the radiation element 142 having the third height H3 in the second intermediate frequency band array 140-2, and vice versa.

The base station antenna 100 (FIG. 1A) according to an embodiment of the present invention can provide many advantages. These advantages include reducing costs by using fewer feed handles, because the common feed handles 400/500 (FIG. 3A, 5A) of the present invention are each coupled to multiple radiating elements (FIG. 3A, 5A) operating in different frequency bands. In addition, RF performance (e.g., massive MIMO performance and/or mid-band performance) can be improved by reducing shielding of the massive MIMO zone and/or mid-band array.

The present invention has been described above with reference to the accompanying drawings. The present invention is not limited to the illustrated embodiments. On the contrary, these embodiments are intended to fully and completely disclose the present invention to those skilled in the art. In the accompanying drawings, like numbers refer to like elements throughout. For clarity, the thickness and size of some components may be exaggerated.

Spatially relative terms, such as "below," "under," "lower," "above," "upper," "top," "bottom," and the like, may be used herein to facilitate description of the relationship of one element or feature to another element or feature as shown in the figures. It should be understood that the spatially relative terms are intended to cover different orientations of the device in use or operation in addition to the orientation shown in the figures. For example, if the device in the figure is turned over, elements described as being "below" or "beneath" other elements or features will be oriented as being "above" the other elements or features. Thus, the example term "below" may include both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein are interpreted accordingly.

Herein, unless otherwise stated, the terms “attached,” “connected,” “interconnected,” “contacting,” “mounted,” “coupled,” and the like may represent a direct or indirect attachment or coupling between elements.

For brevity and/or clarity, well-known functions or constructions may not be described in detail.As used herein, the expression "and/or" includes any and all combinations of one or more of the associated listed items.

The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the present invention. As used herein, the singular forms "a", "an" and "the" are intended to also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include", "comprise", "include" and/or "comprising" when used in this specification specify the presence of 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.

Claims (45)

1. A base station antenna, comprising: a first antenna array having a plurality of first frequency band dipole radiating elements; and a second antenna array, the second antenna array having a plurality of second frequency band dipole radiating elements, The first second-band dipole radiating element in the second-band dipole radiating elements is installed on the first first-band dipole radiating element in the first-band dipole radiating elements and is installed in front of the first first-band dipole radiating element. 2 . The base station antenna of claim 1 , wherein the first first-band dipole radiating element and the first second-band dipole radiating element share a feeding handle. 3. The base station antenna of claim 2, wherein the common feed stem extends through the first first-band dipole radiating element to couple to the first second-band dipole radiating element. 4. The base station antenna according to claim 2, wherein the common feed handle comprises a printed circuit board PCB, wherein the PCB has: a first feed line coupled to a first dipole of said first first frequency band dipole radiating element; and A second feed line is coupled to the first dipole of the first second frequency band dipole radiating element. 5. The base station antenna according to claim 2, wherein the common feeding handle is an angled feeding handle, wherein no feed stem other than the shared feed stem is coupled to the first first frequency band dipole radiating element, and Wherein, no feeding stem other than the shared feeding stem is coupled to the first and second frequency band dipole radiating elements. 6. The base station antenna of claim 1, further comprising a metal layer on the feed stem extending parallel to the dipole radiator of the first first-band dipole radiating element. The base station antenna according to claim 6 , wherein the metal layer comprises a frequency selective surface (FSS). 8. The base station antenna of claim 7, further comprising a third antenna array having a plurality of third frequency band radiating elements mounted behind the FSS. 9. The base station antenna according to claim 8, wherein the FSS is a first FSS, and The base station antenna further includes a second FSS between the third frequency band radiation element and the first FSS. 10. The base station antenna according to claim 8, wherein the first frequency band dipole radiating element is configured to operate in a first frequency band, the first frequency band being lower than the second frequency band in which the second frequency band dipole radiating element is configured to operate, wherein the second frequency band is lower than the third frequency band in which the radiating element is configured to operate, and The FSS is configured to allow RF energy at a third frequency band to pass through and reflect RF energy at a second frequency band. 11. The base station antenna of claim 10, wherein the FSS is configured not to reflect RF energy at a first frequency band. 12. The base station antenna of claim 10, wherein the second frequency band radiating element is covert with respect to RF energy at the third frequency band. 13. The base station antenna of claim 1, wherein the first frequency band dipole radiating element is configured to operate in a lower frequency band than the second frequency band dipole radiating element. 14. The base station antenna according to claim 13, wherein the first band dipole radiating element is configured to operate in all or part of the 617-960 MHz frequency band, and Therein, the second band dipole radiating element is configured to operate in all or part of the 1695-2690 MHz frequency band. 15. The base station antenna according to claim 1, The base station antenna is a passive base station antenna, and the passive base station antenna is provided as a part of a passive/active antenna system, and the passive/active antenna system further includes an active antenna module on the passive base station antenna. 16. The base station antenna of claim 1, wherein the second antenna array is a first antenna array among a plurality of antenna arrays of second frequency band dipole radiating elements, and the second antenna array is installed further forward than a second antenna array among a plurality of antenna arrays of second frequency band dipole radiating elements. 17. The base station antenna of claim 16, wherein the base station antenna is configured to provide phase compensation to compensate for different heights of the second frequency band dipole radiating elements. 18. The base station antenna of claim 1, wherein the first second frequency band dipole radiating element is mounted further forward than the second second frequency band dipole radiating element. 19. The base station antenna of claim 18, wherein the base station antenna is configured to provide phase compensation to compensate for different heights of the second frequency band dipole radiating elements. 20. The base station antenna of claim 1, wherein the first first frequency band dipole radiating element comprises a printed circuit board (PCB) with an integrated reflector. 21. A base station antenna, comprising: a first antenna array having a plurality of first frequency band dipole radiating elements; and a second antenna array, the second antenna array having a plurality of second frequency band dipole radiating elements, wherein a first second-band dipole radiating element of the second-band dipole radiating elements is fed by the same feeding stem as a first first-band dipole radiating element of the first-band dipole radiating elements, and The first frequency band dipole radiating element is configured to operate in a lower frequency band than the second frequency band dipole radiating element. 22. The base station antenna of claim 21, wherein the feed stem extends through the first first-band dipole radiating element to couple to the first second-band dipole radiating element. 23. The base station antenna according to claim 21, wherein the feed handle comprises a printed circuit board PCB, wherein the PCB has: a first feed line coupled to a first dipole of said first first frequency band dipole radiating element; and A second feed line is coupled to the first dipole of the first second frequency band dipole radiating element. 24. The base station antenna of claim 21, wherein the feed stem is an angled feed stem. 25. A base station antenna, comprising: a first antenna array having a plurality of first frequency band dipole radiating elements; and a second antenna array, the second antenna array having a plurality of second frequency band dipole radiating elements, wherein a first one of the second frequency band dipole radiating elements is completely within an occupied area of a first one of the first frequency band dipole radiating elements, and The first frequency band dipole radiating element is configured to operate in a lower frequency band than the second frequency band dipole radiating element. 26. The base station antenna according to claim 25, Wherein, the first first-band dipole radiating element comprises a first cross-dipole radiating element, Wherein, the first and second frequency band dipole radiating elements include a second cross-dipole radiating element, wherein the first dipole of the second cross-dipole radiating element overlaps the first dipole of the first cross-dipole radiating element in a forward direction, and The second dipole of the second cross-dipole radiating element overlaps the second dipole of the first cross-dipole radiating element in the forward direction. 27. The base station antenna according to claim 26, The first dipole of the first cross-dipole radiating element comprises two dipole arms. wherein the first dipole of the second cross-dipole radiating element comprises two dipole arms respectively overlapping with the two dipole arms of the first dipole of the first cross-dipole radiating element in the forward direction, wherein the second dipole of the first cross-dipole radiating element comprises two dipole arms, and The second dipole of the second cross-dipole radiating element includes two dipole arms respectively overlapping with the two dipole arms of the second dipole of the first cross-dipole radiating element in the forward direction. 28. A passive/active antenna system, comprising: A passive base station antenna, the passive base station antenna comprising: a first antenna array having a plurality of first frequency band dipole radiating elements; and a second antenna array, the second antenna array having a plurality of second frequency band dipole radiating elements; and an active antenna module mounted behind the passive base station antenna, wherein the first frequency band dipole radiating element is configured to operate in a lower frequency band than the second frequency band dipole radiating element, and The first second-band dipole radiating element in the second-band dipole radiating elements is installed on the first first-band dipole radiating element in the first-band dipole radiating elements and is installed in front of the first first-band dipole radiating element. 29. The passive/active antenna system of claim 28, wherein the active antenna module comprises a radio circuit and a massive MIMO antenna element array. 30. A base station antenna, comprising: Reflector; a first antenna array having a plurality of first frequency band dipole radiating elements on the reflector; and a second antenna array, the second antenna array having a plurality of second frequency band dipole radiating elements, wherein a first one of the second frequency band dipole radiating elements extends further forward from the reflector than a second one of the second frequency band dipole radiating elements, and The first frequency band dipole radiating element is configured to operate in a lower frequency band than the second frequency band dipole radiating element. 31. The base station antenna according to claim 30, wherein the first second-band dipole radiating element is mounted on the first first-band dipole radiating element in the first-band dipole radiating element and is mounted in front of the first first-band dipole radiating element, and Wherein, the second second-band dipole radiating element is not installed on any first-band dipole radiating element among the first-band dipole radiating elements. 32. The base station antenna of claim 31 , wherein the base station antenna is configured to provide phase compensation to compensate for different heights of the second frequency band dipole radiating elements. 33. A base station antenna, comprising: Reflector; a first antenna array having a plurality of first frequency band dipole radiating elements on the reflector; and a second antenna array and a third antenna array, each of the second antenna array and the third antenna array having a plurality of second frequency band dipole radiating elements, wherein the second frequency band dipole radiating elements of the second antenna array extend further forward from the reflector than the second frequency band dipole radiating elements of the third antenna array, and The first frequency band dipole radiating element is configured to operate in a lower frequency band than the second frequency band dipole radiating element. 34. The base station antenna according to claim 33, The second frequency band dipole radiating elements of the second antenna array are respectively mounted on the first frequency band dipole radiating elements of the first antenna array and are respectively mounted in front of the first frequency band dipole radiating elements of the first antenna array, and The second frequency band dipole radiating element of the third antenna array is not mounted on any other dipole radiating element. 35. The base station antenna of claim 33, wherein the base station antenna is configured to provide phase compensation to compensate for different heights of the second frequency band dipole radiating elements. 36. A base station antenna, comprising: a first antenna array, the first antenna array having a plurality of low-band dipole radiating elements; a metal layer on a rear surface of a first low-band dipole radiating element of the low-band dipole radiating elements; a second antenna array, the second antenna array having a plurality of mid-band dipole radiating elements; and a third antenna array, the third antenna array having a plurality of high-frequency band dipole radiating elements, wherein a first intermediate-frequency band dipole radiating element among the intermediate-frequency band dipole radiating elements is mounted on the first low-frequency band dipole radiating element, wherein the low-band dipole radiating element is configured to operate in a low frequency band that is lower than a mid-band in which the mid-band dipole radiating element is configured to operate, and Therein, the mid-band is lower than the high-band in which the high-band radiating element is configured to operate. The base station antenna according to claim 36 , wherein the metal layer comprises a frequency selective surface (FSS). 38. The base station antenna of claim 37, wherein a high-band radiating element is mounted behind the FSS. 39. The base station antenna of claim 38, wherein the FSS is configured to allow RF energy at a high frequency band to pass through and reflect RF energy at a mid frequency band. 40. The base station antenna of claim 39, wherein the FSS is configured not to reflect RF energy at a low frequency band. 41. The base station antenna of claim 39, wherein the mid-band radiating element is concealed relative to RF energy at the high-band. 42. A base station antenna, comprising: a first antenna array, the first antenna array having a plurality of first frequency band dipole radiating elements, wherein a first of the first frequency band dipole radiating elements comprises a printed circuit board PCB having an integrated reflector; and a second antenna array, the second antenna array having a plurality of second frequency band dipole radiating elements, wherein a first second-band dipole radiating element in the second-band dipole radiating element is mounted on the first first-band dipole radiating element, and The first frequency band dipole radiating element is configured to operate in a lower frequency band than the second frequency band dipole radiating element. 43. The base station antenna of claim 42, wherein the integrated reflector comprises a frequency selective surface (FSS). 44. The base station antenna of claim 43, further comprising a third antenna array having a plurality of third frequency band radiating elements mounted behind the FSS. 45. The base station antenna according to claim 44, wherein the first frequency band dipole radiating element is configured to operate in a first frequency band, the first frequency band being lower than the second frequency band in which the second frequency band dipole radiating element is configured to operate, wherein the second frequency band is lower than the third frequency band in which the radiating element is configured to operate, and The FSS is configured to allow RF energy at a third frequency band to pass through and reflect RF energy at a second frequency band.