Base station antenna

Abstract

To provide a base station antenna.SOLUTION: In a base station antenna, a radiator 30 used for being operated in lower frequency band or higher frequency band, contains two U-character type discharge arms 31 and 32 which are symmetrically distributed to the circumference of a lateral direction center shaft A1. Both of the U-character type discharge arms 31 and 32 are extended along a long direction of the base station antenna. As a result, the radiator 30 generates an electromagnetic emission including an omnidirectional pattern in a direction surface such as a conventional symmetric dipole. A polarization direction of the radiator 30 is the long direction of the base station antenna, and a supply mode is supplied via center connection components 313 and 323 of the U-character type discharge arms 31 and 32. A distance D1 between the two discharge arms 31 and 32 facilitates an assembly of the base station antenna (for example, facilitates a welding connection to a supply construction element of the connection components 313 and 323), and facilitates an impedance matching.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 2021 / 115117662, filed on December 7, 2021, the entire contents of which are incorporated herein by reference as if fully set forth herein.

[0002] The present disclosure relates to communication systems, and more particularly, to base station antennas. [Background technology]

[0003] Wireless base stations are well known in the art and generally include a baseband unit, a radio, an antenna, and other components. The antenna is configured to provide two-way radio frequency (RF) communications with fixed and mobile subscribers (users) located throughout the cell. Typically, the antenna is mounted on a tower or other elevated structure such as a pole, roof, or water tower, and separate baseband and radio units are connected to the antenna.

[0004] FIG. 12A is a schematic structural diagram of a conventional base station 90. The base station 90 includes a base station antenna 95 mountable on a protruding structure 94. The base station 90 also includes base station devices such as a baseband unit 91 and a radio 92. To simplify the drawing, a single baseband unit 91 and a single radio 92 are shown in FIG. 12A . However, it should be understood that multiple baseband units 91 and / or radios 92 may be provided. Furthermore, while the radio 92 is shown co-located with the baseband unit 91 at the bottom of the protruding structure 94, it should be understood that in other cases, the radio 92 may be a remote radio head (RRH) mounted on the convex structure 94 adjacent to the base station antenna 95. The baseband unit 91 can receive data from another source, such as a backhaul network (not shown), process the data, and provide a data stream to the radio 92. The radio 92 may generate RF signals with data encoded therein, amplify these RF signals, and transmit the RF signals to the base station antenna 95 via a radio frequency cable 93 (e.g., a coaxial transmission cable). It should also be understood that the base station 90 of FIG. 12A may typically include various other devices (not shown), such as a power supply, a backup battery, a power bus, an antenna interface signal group (AISG) controller, and the like. Summary of the Invention

[0005] According to a first aspect of the present disclosure, there is provided a base station antenna comprising: a first dielectric substrate extending along a longitudinal direction of the base station antenna; one or more first radiators formed on the first dielectric substrate, each of the first radiators configured to operate in a first frequency band; a plurality of second dielectric substrates extending along a longitudinal direction of the base station antenna; and one or more second radiators formed on each second dielectric substrate, each of the second radiators configured to operate in a second frequency band. and one or more second radiators configured to operate in a frequency range from 1000 kHz to 1000 kHz, wherein a first and second one of the second dielectric substrates are mounted to the first dielectric substrate such that the first and second one of the second dielectric substrates are substantially perpendicular to the first dielectric substrate and a central portion of at least one first radiator of the one or more first radiators is disposed between a second radiator formed on the first one of the second dielectric substrates and a second radiator formed on the second one of the second dielectric substrates.

[0006] According to a second aspect of the present disclosure, there is provided a base station antenna comprising: a plurality of first radiators arranged along a longitudinal direction of the base station antenna, the first radiators operating in a first frequency band and configured to generate electromagnetic radiation having an omnidirectional pattern in an azimuth plane; and a plurality of second radiators arranged along the longitudinal direction of the base station antenna, the second radiators operating in a second frequency band that does not overlap with the first frequency band and configured to generate electromagnetic radiation having an omnidirectional pattern in the azimuth plane, wherein at least one first radiator of the plurality of first radiators is arranged between two adjacent second radiators, and at least one second radiator of the plurality of second radiators is arranged between two adjacent first radiators.

[0007] According to a third aspect of the present disclosure, there is provided a base station antenna comprising: a first array of a plurality of first radiating elements disposed along a longitudinal direction of the base station antenna, the first array configured to generate an antenna beam having an omnidirectional pattern in an azimuth plane for a first frequency band; and a second array of a plurality of second radiating elements disposed along the longitudinal direction of the base station antenna, the second array configured to generate an antenna beam having an omnidirectional pattern in an azimuth plane for a second frequency band, the first array and the second array being interleaved with each other along the longitudinal direction of the base station antenna, and wherein a relative bandwidth of at least one of the first frequency band and the second frequency band is equal to or greater than 25%, 30%, 35%, 40%, or 45%.

[0008] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic front and back plan view of an antenna assembly that may be used to implement a base station antenna, according to one embodiment of the present disclosure. [Figure 2A] FIG. 2A is a schematic plan view of a radiating element in region B of the antenna assembly of FIG. [Figure 2B] FIG. 2B is a schematic diagram of region B of the antenna assembly of FIG. 1, with the frequency selective structures of the radiating elements operating in the low frequency band not shown for simplicity. [Figure 3A-3B] 3A-3B are schematic plan views of components of an antenna assembly that may be used to implement a base station antenna according to further embodiments of the present disclosure. [Figure 4A] FIG. 4A is a schematic plan view of a radiator that may be used to implement a base station antenna according to an embodiment of the present disclosure. [Figure 4B]FIG. 4B is a schematic perspective view of the radiator shown in FIG. 4A formed on a dielectric substrate. [Figures 5A-5C] 5A-5C are schematic structural diagrams of a radiating element that may be used to realize a base station antenna according to an embodiment of the present disclosure, where FIG. 5A is a front view of the radiating element, FIG. 5B is a side view of the radiating element, and FIG. 5C is a perspective view of the radiating element. [Figure 6] FIG. 6 is a schematic perspective view of a radiating element that may be used to implement a base station antenna according to an embodiment of the present disclosure. [Figure 7A-7C] 7A-7C are schematic plan views of radiating elements that may be used to implement a base station antenna according to an embodiment of the present disclosure. [Figure 8A-8B] 8A-8B are graphs of input reflection coefficient as a function of frequency for a radiating element operating in the lower frequency band and a radiating element operating in the higher frequency band, respectively, of the antenna assembly of FIG. [Figure 9A] FIG. 9A is a solid three-dimensional view of the antenna beam generated by the radiating unit of FIG. 2A. [Figure 9B-9C] 9B-9C are antenna beam patterns generated by radiating elements operating in the lower frequency band and the higher frequency band, respectively, in the radiating unit of FIG. 2A in the azimuth plane. [Figures 10A-10B] 10A-10B are a solid three-dimensional view and pattern, respectively, in the azimuth plane of an antenna beam produced by an array of radiating elements operating in the low frequency band in the antenna assembly of FIG. [Figures 11A-11B] 11A-11B are a solid three-dimensional view and pattern, respectively, in the azimuth plane of an antenna beam produced by an array of radiating elements in the antenna assembly of FIG. 1 operating in the high frequency band. [Figure 12A] FIG. 12A is a schematic structural diagram of a conventional base station. [Figure 12B] FIG. 12B is a combination of several views of an antenna beam having an omnidirectional pattern in the azimuth plane.

[0010] It should be noted that in the embodiments described below, the same reference numerals may be used together in different accompanying drawings to indicate the same components or components having the same functions, and the repeated description thereof will be omitted. In some cases, similar labels and letters are used to indicate similar items. Therefore, once an item is defined in one accompanying drawing, there is no need to further discuss it in subsequent accompanying drawings.

[0011] For ease of understanding, the positions, dimensions, and ranges of each structure shown in the accompanying drawings may not represent the actual positions, dimensions, and ranges, and therefore the present disclosure is not limited to the positions, sizes, ranges, and the like disclosed in the accompanying drawings. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure may be embodied in many different ways and is not limited to the embodiments described below. Indeed, the embodiments described below are intended to make the present disclosure more complete and fully explain the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed in the present disclosure may be combined in various ways to provide many additional embodiments.

[0013] It should be understood that the terms used in this specification are used only to describe specific embodiments and are not intended to limit the scope of the present disclosure. All terms (including technical and scientific terms) used in this specification have the meanings commonly understood by those skilled in the art unless otherwise defined. For the sake of brevity and / or clarity, well-known functions or structures may not be further described in detail.

[0014] As used herein, when an element is referred to as being "on," "attached to," "connected to," "coupled to," or "in contact with" another element, the element may be directly on, attached to, connected to, coupled to, or in contact with another element, or intermediate elements may be present. In contrast, when an element is described as being "immediately on," "directly attached to," "directly connected to," "directly coupled to," or "directly in contact with" another element, intermediate elements are not present. As used herein, when one feature is disposed "adjacent" another feature, it may mean that the one feature has a portion that overlaps with the adjacent feature, or a portion that is located above or below the adjacent feature.

[0015] As used herein, reference may be made to elements, nodes, or features that are "coupled" together. Unless expressly stated otherwise, "coupled" means that one element / node / feature is connected to and enables interaction with another element / node / function in a mechanical, electrical, logical, or other direct or indirect manner, even if the two features are not directly connected. That is, "coupled" is intended to include both direct and indirect connection of components or other features, including connections using one or more intermediate components.

[0016] As used herein, spatial relationship terms, such as "top," "bottom," "left," "right," "front," "back," "high," and "low," may describe the relationship between one feature and another feature in a drawing. It should be understood that spatial relationship language also includes the orientation shown in the drawing, as well as different orientations of the device during use or operation. For example, if a device in the accompanying drawings is rotated inverted, a feature may be described as "top" while originally describing the other feature as "bottom." The device may also be oriented by other means (rotated 90 degrees or elsewhere), at which point the relative spatial relationships are described accordingly.

[0017] As used herein, the term "A or B" includes "A and B" and "A or B," but not exclusively "A" or "B," unless otherwise specified.

[0018] As used herein, the term "exemplary" means "serving as an example, instance, or illustration" and not as a "model" to be exactly copied. Any implementation illustratively described herein may not necessarily be construed as preferred or advantageous over other implementations. Furthermore, this disclosure is not limited by any expressed or implied theory presented in the preceding technical field, background, brief summary, or specific embodiments.

[0019] As used herein, the term "essentially" is meant to include any minor variations caused by design or manufacturing defects, device or component tolerances, environmental influences, and / or other factors. The term "essentially" also allows for deviations from perfect or ideal conditions due to parasitic effects, noise, and other practical considerations that may be present in an actual implementation.

[0020] Additionally, terms such as "first," "second," and similar terms may be used herein for reference purposes only and are not intended to be limiting. For example, the terms "first," "second," and other such numerical terms including structures or elements do not imply any sequence or order unless the context clearly dictates otherwise.

[0021] It should also be understood that when the term "comprises" is used in this specification, it indicates the presence of specified features, wholes, steps, operations, units and / or components, but does not exclude the presence or addition of one or more other features, steps, operations, units and / or components, and / or combinations thereof.

[0022] FIG. 12B is a combination of several views of an antenna beam 80 having an omnidirectional pattern in the azimuth plane, which may be generated by a base station antenna 95. In particular, FIG. 12B includes a solid three-dimensional view of the antenna beam 80 (labeled as "3D pattern"), as well as plan views of that pattern in the azimuth plane (labeled as "azimuth pattern") and elevation plane (labeled as "elevation pattern"). The azimuth pattern is generated by cutting a horizontal cross section through the middle of the three-dimensional antenna beam 80, while the elevation pattern is generated by cutting a vertical cross section through the middle of the three-dimensional antenna beam 80. The three-dimensional pattern in FIG. 12B shows the overall shape of the antenna beam 80 generated in three dimensions. As can be seen, the antenna beam 80 extends through a full 360 degrees in the azimuth plane, and the antenna beam 80 may have approximately constant gain in all directions in the azimuth plane. In the elevation plane, antenna beam 80 has high gain in the azimuth plane (i.e., parallel to the horizon), but the gain drops off rapidly both above and below the horizon. Thus, antenna beam 80 is omnidirectional in the azimuth plane and directional in the elevation plane.

[0023] Embodiments of the present disclosure provide a base station antenna operating in two frequency bands (a "dual-band base station antenna") capable of generating an antenna beam that is omnidirectional in the azimuth plane and directional in the elevation plane. The two frequency bands in which the base station antenna operates may be referred to herein as a lower frequency band (hereinafter referred to as LB) and a higher frequency band (hereinafter referred to as HB). The base station antenna may include an array of LB radiating elements that generate an LB antenna beam and an array of HB radiating elements that generate an HB antenna beam. For example, the LB antenna beam may be used to achieve wide-area (long-distance) coverage, and the HB antenna beam may be used for high-speed data services. In some embodiments, the LB radiating element and the HB radiating element are wideband radiating elements, such that the base station antenna can obtain wide bandwidths in both the LB and HB bands. For example, the LB band may be the 718-960 MHz band with a relative bandwidth of 29%, and the HB band may be the 1.7-2.7 GHz band with a relative bandwidth of 45%. In some embodiments, the array of LB radiating elements and the array of HB radiating elements may be disposed along the length of the base station antenna and may be interleaved with each other. This configuration allows each of the LB array and the HB array to utilize the entire length of the antenna, thereby achieving high gain while providing a base station antenna with a compact size. In some embodiments, each LB radiating element may be configured as a dipole radiator with two symmetrical U-shaped radiating arms, and each HB radiating element may be disposed between the two branches of each U-shaped radiating arm. This configuration provides a more compact size for the base station antenna. In some embodiments, each LB radiating element may be configured to be frequency selective so as to be substantially transparent to electromagnetic radiation in the HB, thereby minimizing the effect of the LB radiating element on the electromagnetic radiation emitted by the HB radiating element.

[0024] 4A is a schematic plan view of a radiator 30 that may be used to implement a base station antenna according to an embodiment of the present disclosure. In a base station antenna according to an embodiment of the present disclosure, each radiator used for operation at LB or HB may have the configuration of radiator 30 shown in FIG. 4A.

[0025] The radiator 30 includes two U-shaped radiating arms 31 and 32 symmetrically disposed about the lateral central axis A1 of the radiator 30. The characteristics of the radiator 30 may be similar to those of a conventional symmetric dipole radiator. Compared to a conventional symmetric dipole radiator, the U-shaped radiating arms 31 and 32 of the radiator 30 can be considered as thick (wide) dipole arms to achieve a wider bandwidth. In a base station antenna according to an embodiment of the present disclosure, both radiating arms 31 and 32 extend along the longitudinal direction of the base station antenna. As a result, the radiator 30 can generate electromagnetic radiation with an omnidirectional pattern in the azimuth plane, like a conventional symmetric dipole. As with a conventional symmetric dipole, the polarization direction of the radiator 30 is the same as the extension direction of the radiating arms 31 and 32. In a base station antenna according to an embodiment of the present disclosure, the polarization direction of the radiator 30 is the longitudinal direction of the base station antenna. The feeding mode of the radiator 30 may also be the same as that of a conventional symmetric dipole radiator, for example fed through the central connecting pieces 313 and 323 of the two U-shaped radiating arms 31 and 32. The distance D1 between the two radiating arms 31 and 32 may be configured to facilitate assembly of the base station antenna (e.g., to facilitate welding connection of the connecting pieces 313 and 323 to the feeding components) and to facilitate impedance matching.

[0026] Each of the two U-shaped radiating arms 31 and 32 has two branches. The radiating arm 31 includes branches 311 and 312 and a connecting portion 313 between the two branches 311 and 312 for connecting the two branches 311 and 312. The radiating arm 32 includes branches 321 and 322 and a connecting portion 323 between the two branches 321 and 322 for connecting the two branches 321 and 322. The lengths of the branches 311 and 312 and the lengths of the branches 321 and 322 may be configured so that the radiator 30 resonates at one frequency in its operating band. The distance D2 between the branches 311 and 312 of the radiating arm 31 and between the branches 321 and 322 of the radiating arm 32 may be configured so that the circularity of the electromagnetic radiation pattern of the radiator 30 in the azimuth plane (i.e., the degree to which the antenna beam deviates from a perfectly round omnidirectional pattern in the azimuth plane) meets design requirements.

[0027] The radiator 30 that may be used to implement a base station antenna according to an embodiment of the present disclosure may be manufactured using a variety of processes, such as sheet metal, printed circuit board (PCB), laser direct sintering (LDS), or three-dimensional (3D) printing.

[0028] A radiator 30 having two U-shaped radiating arms 31 and 32 that may be used to realize a base station antenna according to an embodiment of the present disclosure is described above with reference to Figure 4A. Those skilled in the art should understand that other radiators capable of producing electromagnetic radiation in an omnidirectional pattern in the azimuth plane may also be used to realize a base station antenna according to an embodiment of the present disclosure.

[0029] Figure 4B is a schematic perspective view of the radiator 30 shown in Figure 4A formed on a dielectric substrate 10 (or 20). In order to facilitate wiring of the feed assembly, when the radiator 30 is formed on the dielectric substrate 10, the two radiating arms 31 and 32 may be formed on opposite sides of the dielectric substrate 10. In the view direction shown in Figure 4B, the radiating arm 31 of the radiator 30 is formed on the top surface of the dielectric substrate 10, and the radiating arm 32 is formed on the bottom surface of the dielectric substrate 10, so that the feed components of the radiating arm 31 may be disposed on the top surface and / or upper side of the dielectric substrate 10, and the feed components of the radiating arm 32 may be disposed on the bottom surface and / or lower side of the dielectric substrate 10.

[0030] In some embodiments, the LB and / or HB radiating elements that may be used to implement a base station antenna according to embodiments of the present disclosure are wideband radiating elements. For example, radiating elements having a relative bandwidth of 25%, 30%, 35%, 40%, or 45% or greater. Each wideband radiating element includes not only the radiator 30 described above but also a parasitic radiator. Figures 5A-5C are schematic structural diagrams of radiating elements that may be used to implement a base station antenna according to embodiments of the present disclosure, where Figure 5A is a front view of the radiating element, Figure 5B is a side view of the radiating element, and Figure 5C is a perspective view of the radiating element.

[0031] 5A to 5C includes a radiator 30 having two symmetrically U-shaped radiating arms 31 and 32, and parasitic radiators 411, 412, 421, and 422 spaced apart from the radiator 30 (e.g., spaced a first distance from the extension surface of the radiator 30), each symmetrical about a lateral central axis A1 of the radiator 30. The parasitic radiator 411 is positioned on a first side of the extension surface of the radiator 30 (e.g., a first side of a dielectric substrate (not shown), which is the upper side in the viewing direction of FIGS. 5A to 5C), and corresponds to the position of the branch 311 of the radiating arm 31 and the branch 321 of the radiating arm 32 of the radiator 30. The parasitic radiator 412 is positioned on a first side of the extension surface of the radiator 30 and corresponds to the position of the branch 312 of the radiation arm 31 and the branch 322 of the radiation arm 32 of the radiator 30. The parasitic radiator 421 is positioned on a second side of the extension surface of the radiator 30 and corresponds to the position of the branch 311 of the radiation arm 31 and the branch 321 of the radiation arm 32 of the radiator 30. The parasitic radiator 422 is positioned on the second side of the extension surface of the radiator 30 and corresponds to the position of the branch 312 of the radiation arm 31 and the branch 322 of the radiation arm 32 of the radiator 30.

[0032] Each of the parasitic radiators 411, 412, 421 and 422 is parasitic on the radiator 30 in that each parasitic radiator is excited by electromagnetic radiation emitted from the radiator 30. The radiator 30 may be configured to resonate at a first frequency within the operating band of the radiating element, and the parasitic radiators 411, 412, 421 and 422 may be configured (e.g., by configuring the length of the parasitic radiators 411, 412, 421 and 422) to resonate at a second frequency different from the first frequency within the operating band of the radiating element. For example, when a radiating element for a base station antenna operating in the 718-960 MHz band is implemented in the radiating element configuration shown in Figures 5A-5C, radiator 30 may be configured to resonate at a frequency of approximately 750 MHz, and parasitic radiators 411, 412, 421, and 422 may be configured to resonate at a frequency of approximately 910 MHz, such that the radiating element has an input reflection coefficient (S1,1 parameter) as shown in Figure 8A. When a radiating element for a base station antenna operating in the 1.7-2.7 GHz band is implemented in the radiating element configuration shown in Figures 5A-5C, radiator 30 may be configured to resonate at a frequency of approximately 1.9 GHz, and parasitic radiators 411, 412, 421, and 422 may be configured to resonate at a frequency of approximately 2.7 GHz, such that the radiating element has an input reflection coefficient (S1,1 parameter) as shown in Figure 8B.

[0033] Broadband radiating elements that can be used to realize base station antennas according to embodiments of the present disclosure are described above with reference to FIGS. 5A-5C. Those skilled in the art should understand that other broadband radiating elements capable of generating electromagnetic radiation in an omnidirectional pattern in the azimuth plane can also be used to realize base station antennas according to embodiments of the present disclosure. The location and number of parasitic radiators can be configured as needed. FIGS. 7A-7C show schematic plan views of several other radiating elements. In the examples of FIGS. 7A and 7B, the location of the parasitic radiator may not fully or partially correspond to the location of the branch of the radiating arm. Regarding the symmetry of the radiation pattern of the radiating element, the parasitic radiator is located in the middle of the radiator (in the longitudinal direction). For example, in addition to each parasitic radiator being symmetric about the radiator's central lateral axis (e.g., axis A1 of radiator 30), two parasitic radiators (e.g., parasitic radiators 411 and 412) located on the same side of the radiator's extension surface are also symmetric about the radiator's central longitudinal axis. In the embodiment of FIG. 7C, the radiating element may include only one parasitic radiator (e.g., parasitic radiator 41) on each side of the radiator's extension surface. For the symmetry of the radiation pattern of the radiating element, the parasitic radiator is aligned with the radiator's central longitudinal axis and is symmetric about the radiator's central lateral axis. Note that the "lateral" and "longitudinal" directions referred to herein refer to the directions when the base station antenna is installed for use. When the base station antenna is installed for use, the longitudinal direction (also referred to as the length direction of the base station antenna) is a direction substantially perpendicular to a plane defined by the horizon, and the lateral direction is a direction substantially parallel to the plane defined by the horizon. Thus, in the viewing direction of Figures 7A-7C, the extension direction of the lateral central axis of the radiator is the vertical direction of the figure, and the extension direction of the longitudinal central axis of the radiator is the horizontal direction of the figure.

[0034] In some embodiments, to reduce the effect on the electromagnetic radiation emitted by the HB radiating element, each LB radiating element may be configured to have frequency selectivity so as to be substantially transparent to the electromagnetic radiation in the HB. Those skilled in the art should understand that in some embodiments, the HB radiating element may also be configured to have frequency selectivity. FIG. 6 is a schematic perspective view of a frequency-selective LB radiating element. Each radiator in the LB-operated radiating element, including radiator 30 having branches 311, 312, 321, and 322 and respective parasitic radiators 411, 412, 421, and 422, is configured to at least partially attenuate the current in the HB, for example, by at least 50%. In the embodiment shown in FIG. 6, each of branches 311, 312, 321, and 322 of radiator 30 and each of parasitic radiators 411, 412, 421, and 422 includes a resonant circuit formed by coupling an inductive element and a capacitive element in series, and the resonant circuit is configured to attenuate the current in the HB by at least 50%. Those skilled in the art should understand that the frequency selective structure for making the radiating element frequency selective may have other forms. In other embodiments, each of the branches 311, 312, 321 and 322 of the radiator 30 and each of the parasitic radiators 411, 412, 421 and 422 may include at least one inductive element configured to have a high impedance at HB and a low impedance at LB.

[0035] FIG. 1 is a combination of schematic front views of an antenna assembly that may be used to implement a base station antenna according to one embodiment of the present disclosure. The antenna assembly includes a dielectric substrate 10. The left-hand view of FIG. 1 is a plan view of the antenna assembly from a side view of a first surface of the dielectric substrate 10, and the right-hand view of FIG. 1 is a plan view of the antenna assembly from a side view of a second surface of the dielectric substrate 10 opposite the first surface. FIG. 2A is a schematic plan view of a radiating element in region B of the antenna assembly of FIG. 1. FIG. 2B is a schematic view of region B of the antenna assembly of FIG. 1, where the frequency-selective structure of a radiating element operating in a low frequency band is not shown for simplicity.

[0036] The base station antenna includes a first array consisting of a plurality of LB radiating elements arranged along a longitudinal direction and a second array consisting of a plurality of HB radiating elements arranged along a longitudinal direction. Each LB radiating element operates within the LB and generates electromagnetic radiation having an omnidirectional pattern in the azimuth plane, such that the first array generates an antenna beam having an omnidirectional pattern in the azimuth plane of the LB. Each HB radiating element operates within the HB and generates electromagnetic radiation having an omnidirectional pattern in the azimuth plane, such that the second array generates an antenna beam having an omnidirectional pattern in the azimuth plane of the HB. The first array and the second array are interleaved with each other along the longitudinal direction of the base station antenna, such that at least one HB radiating element is disposed between two adjacent LB radiating elements and at least one LB radiating element is disposed between some pairs of two adjacent HB radiating elements. This arrangement allows at least one of the first array and the second array (or both the first array and the second array) to extend along the entire length of the base station antenna, thereby achieving high gain in a base station antenna having a compact size.

[0037] In this particular embodiment, each LB radiating element and each HB radiating element includes a dipole radiator with two symmetrical U-shaped radiating arms to generate electromagnetic radiation with an omnidirectional pattern in the azimuth plane. Such dipole radiators have a space between the two branches of the U-shaped radiating arms that can accommodate other elements (such as other radiators) so that the LB and HB radiating elements can be more easily arranged along the length of the base station antenna. It should be understood by those skilled in the art that in other embodiments, only the larger sized LB radiating element includes a dipole radiator with two symmetrical U-shaped radiating arms, and therefore the HB radiating element can be arranged between the two branches of the U-shaped radiating arms of the LB radiating element even if the HB radiating element is not implemented as a dipole radiator with two symmetrical U-shaped radiating arms.

[0038] In this particular embodiment, each LB radiating element may be implemented as a broadband radiating element having a frequency selective structure as shown in FIG. 6. Referring again to FIGS. 2A and 2B, each LB radiating element includes a dipole radiator having two symmetrical U-shaped radiating arms formed on a dielectric substrate 10 extending along the longitudinal direction of the base station antenna, with the first U-shaped radiating arm formed on a first surface of the dielectric substrate 10 and the second U-shaped radiating arm formed on a second surface of the dielectric substrate 10. The first U-shaped radiating arm includes branches 121 and 122, and the second U-shaped radiating arm includes branches 123 and 124. Each LB radiating element further includes parasitic radiators 131 and 132 located in front of the first surface of the dielectric substrate 10. Parasitic radiator 131 corresponds to the positions of branches 121 and 123, and parasitic radiator 132 corresponds to the positions of branches 122 and 124. Each LB radiating element further includes another pair of parasitic radiators located behind the second surface of the dielectric substrate 10. Each U-shaped radiating arm and each branch of each parasitic radiator may be constructed with a frequency selective structure, so that the LB radiating element is essentially transparent to electromagnetic radiation in the HB.

[0039] Each HB radiating element may be implemented as a broadband radiating element, as shown in FIGS. 5A-5C. Each HB radiating element includes a dipole radiator having two symmetrical U-shaped radiating arms 21 and 22 formed on a dielectric substrate 20 extending along the longitudinal direction of the base station antenna. The U-shaped radiating arm 21 is formed on a first surface of the dielectric substrate 20, and the U-shaped radiating arm 22 is formed on a second surface of the dielectric substrate 20. Note that in this context, a two-part reference number (e.g., dielectric substrate 20-1) may be used when multiple identical or similar elements are provided. These elements may be individually referenced by their complete drawing markers (e.g., dielectric substrate 20-1, dielectric substrate 20-2) or collectively referenced by the first portion of their drawing markers (e.g., dielectric substrate 20) when there is no need to distinguish them from one another. Each HB radiating element further includes one or more parasitic radiators 23 positioned on one side of the first surface of the dielectric substrate 20 and one or more parasitic radiators 24 positioned on one side of the second surface of the dielectric substrate 20.

[0040] The dielectric substrates 20-1 and 20-2 are mounted to the dielectric substrate 10 such that the dielectric substrates 20-1 and 20-2 are substantially perpendicular to the dielectric substrate 10. This can be best seen, for example, in FIG. 2B. The dielectric substrates 20-1 and 20-2 and the dielectric substrate 10 generally intersect along the central longitudinal axis A2 of the base station antenna. As such, a first plane extending from the dipole radiator of the LB radiating element and a second plane extending from the dipole radiator of the HB radiating element are perpendicular to each other, with the first plane located midway between the two branches of the U-shaped radiating arm of the HB radiating element, and the second plane located midway between the two branches of the U-shaped radiating arm of the LB radiating element. This configuration can reduce interference between the electromagnetic radiation emitted by the LB radiating element and the HB radiating element. Furthermore, such a configuration may cause the base station antenna to present a cylindrical appearance, for example, with a cylindrical radome 50 as shown in Figure 2B, or it may have other shapes such as an elliptical column and prisms not shown. Because the dielectric substrates 20 and 10 intersect along the central longitudinal axis A2 of the base station antenna, the diameter of the column may be small and the base station antenna may be of a finer size.

[0041] The dielectric substrate 20-1 is mounted to the dielectric substrate 10 between branches 121 and 122 of the first U-shaped radiating arm of the LB radiating element and is substantially perpendicular to the dielectric substrate 10, so that the HB radiating element, including U-shaped radiating arms 21-1 and 22-1 and parasitic radiators 23-1 and 24-1, is positioned between branches 121 and 122 of the first U-shaped radiating arm. The dielectric substrate 20-2 is mounted to the dielectric substrate 10 between branches 123 and 124 of the second U-shaped radiating arm of the LB radiating element and is substantially perpendicular to the dielectric substrate 10, so that the HB radiating element, including U-shaped radiating arms 21-2 and 22-2 and parasitic radiators 23-2 and 24-2, is positioned between branches 123 and 124 of the second U-shaped radiating arm. Therefore, the longitudinal cross-section of the base station antenna occupied by the LB radiating elements and the longitudinal cross-section of the base station antenna occupied by the HB radiating elements have an overlapping portion. This configuration allows more LB and / or HB radiating elements to be disposed in the base station antenna, thereby achieving higher gain. For example, a 38 mm diameter and 1500 mm long base station antenna having an antenna assembly such as that shown in FIG. 1 can have a gain of over 6 dBi at LB and a gain of over 12 dBi at HB.

[0042] FIG. 9A is a three-dimensional view of the antenna beam of the radiating element of FIG. 2A, where the cookie-like pattern on the LB radiating element represents the equivalent inductance in the frequency-selective structure. FIGS. 9B and 9C are the antenna beam patterns of the radiating element operating in LB and the radiating element operating in HB, respectively, of the radiating unit of FIG. 2A in the azimuth plane. It can be seen that both the LB and HB radiating elements can generate radiation patterns that are omnidirectional in the azimuth plane and directional in the elevation plane. Furthermore, the radiation patterns of the LB and HB radiating elements in the azimuth plane are essentially circular, and their circularity can meet requirements. FIGS. 10A and 10B are the three-dimensional view and pattern, respectively, of the antenna beam generated by a first array of 6 LB radiating elements in the antenna assembly of FIG. 1. FIGS. 11A and 11B are the three-dimensional view and pattern, respectively, of the antenna beam generated by a second array of 14 HB radiating elements in the antenna assembly of FIG. 1. It can be seen that the antenna beams of the first array and the second array are obviously compressed in the elevation plane, so that the antenna beams have higher gain in the azimuth plane. Furthermore, the circularity of the antenna beams of the first array and the second array on the azimuth plane can meet the requirement.

[0043] An antenna assembly that can be used to realize a base station antenna according to an embodiment of the present disclosure is described above with reference to FIG. 1 , in which two HB radiating elements are disposed between each of two adjacent LB radiating elements. Both HB radiating elements are disposed in the space between the two branches of the U-shaped radiating arms of the LB radiating elements. It should be understood by those skilled in the art that an antenna assembly that can be used to realize a base station antenna according to an embodiment of the present disclosure may also have other configurations, and at least one advantage of the present disclosure may be achieved as long as the first array of LB radiating elements and the second array of HB radiating elements are interleaved with each other. For example, only one HB radiating element may be disposed between each of two adjacent LB radiating elements (as shown in FIG. 3A ), three HB radiating elements may be disposed between each of two adjacent LB radiating elements (as shown in FIG. 3B ), or other arrangements may be adopted.

[0044] Although some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and do not limit the scope of the present disclosure. The examples disclosed herein can be arbitrarily combined without departing from the spirit and scope of the present disclosure. Those skilled in the art should also understand that various modifications can be made to the examples without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. 1. A base station antenna, comprising: a first dielectric substrate extending along a longitudinal direction of the base station antenna, and one or more first radiators formed on the first dielectric substrate, each of the first radiators configured to operate in a first frequency band; a plurality of second dielectric substrates extending along the longitudinal direction of the base station antenna, and one or more second radiators formed on each second dielectric substrate, each of the second radiators configured to operate in a second frequency band; the first and second substrate elements of the second dielectric substrate are attached to the first dielectric substrate; the first and second substrate elements of the second dielectric substrate are substantially perpendicular to the first dielectric substrate; and a base station antenna, wherein a central portion of at least one first radiator of the one or more first radiators is mounted to the first dielectric substrate such that the central portion is disposed between a second radiator formed on the first substrate element of the second dielectric substrate and a second radiator formed on the second substrate element of the second dielectric substrate.

2. each of the first radiators is configured to generate electromagnetic radiation having an omnidirectional pattern in an azimuthal plane; The base station antenna of claim 1 , wherein each of the second radiators is configured to generate electromagnetic radiation having an omnidirectional pattern in the azimuth plane.

3. the at least one first radiator includes two first U-shaped radiating arms symmetrical along a lateral central axis of the at least one first radiator, each of the two first U-shaped radiating arms having two branches; 2. The base station antenna of claim 1, wherein the first and second substrate elements of the second dielectric substrate are mounted to the first dielectric substrate such that the second radiator formed on the first substrate element of the second dielectric substrate is between the two branches of a first arm element of the two first U-shaped radiating arms, and the second radiator formed on the second substrate element of the second dielectric substrate is between the two branches of a second arm element of the two first U-shaped radiating arms.

4. 4. The base station antenna of claim 3, wherein the first arm elements of the two first U-shaped radiating arms are formed on a first surface of the first dielectric substrate, and the second arm elements of the two first U-shaped radiating arms are formed on a second surface of the first dielectric substrate opposite the first surface.

5. 4. The base station antenna of claim 3, wherein the first and second substrate elements of the second dielectric substrate and the first dielectric substrate intersect substantially along a central longitudinal axis of the base station antenna.

6. the second radiator formed on the first substrate element of the second dielectric substrate and the second radiator formed on the second substrate element of the second dielectric substrate each include two second U-shaped radiating arms symmetrical along a lateral central axis of the corresponding second radiator, each of the two second U-shaped radiating arms having two branches; 6. The base station antenna according to claim 3, wherein each of the first and second substrate elements of the second dielectric substrate is mounted on the first dielectric substrate such that the first arm elements of the two first U-shaped radiating arms are between two branches of at least one second U-shaped radiating arm of the second radiator formed on the first substrate element of the second dielectric substrate, and the second arm elements of the two first U-shaped radiating arms are between two branches of at least one second U-shaped radiating arm of the second radiator formed on the second substrate element of the second dielectric substrate.

7. the first frequency band is lower than the second frequency band; A base station antenna according to any one of claims 3 to 5, wherein the at least one first radiator is configured to attenuate at least partly currents in the second frequency band.

8. 8. The base station antenna of claim 7, wherein each of the first and second arm elements of the two first U-shaped radiating arms includes a resonant circuit formed by coupling an inductive element and a capacitive element in series, the resonant circuit configured to attenuate the current in the second frequency band by at least 50%.

9. 8. The base station antenna of claim 7, wherein each of the two first U-shaped radiating arms includes at least one inductive element configured to have a high impedance in the second frequency band and a low impedance in the first frequency band.

10. one or more first parasitic radiators parallel to and spaced a first distance from the first dielectric substrate; The base station antenna of claim 1 , wherein each of the one or more first parasitic radiators is configured to be excited by electromagnetic radiation emitted by a corresponding one of the first radiators.

11. each of the one or more first radiators is configured to resonate at a first frequency within the first frequency band; 11. The base station antenna of claim 10, wherein the first parasitic radiator is configured to resonate at a second frequency within the first frequency band that is different from the first frequency.

12. The base station antenna of claim 10 , wherein each of the one or more first parasitic radiators is positioned in the middle of a corresponding first radiator.

13. 11. The base station antenna of claim 10, wherein each of the one or more first parasitic radiators includes a first first parasitic radiator located on a first side of the first dielectric substrate and a second first parasitic radiator located on a second side of the first dielectric substrate opposite the first side.

14. further comprising first to fourth parasitic radiators corresponding to the at least one first radiator and spaced apart from the at least one first radiator, each of the first to fourth parasitic radiators being symmetrical with respect to a lateral central axis of the at least one first radiator; the first parasitic radiator is located on a first side of the first dielectric substrate and corresponds to a position of a first branch of the two branches of each first U-shaped radiation arm; the second parasitic radiator is located on the first side of the first dielectric substrate and corresponds to the position of a second branch of the two branches of each first U-shaped radiation arm; the third parasitic radiator is located on a second side of the first dielectric substrate opposite to the first side, and corresponds to a position of the first branch of the two branches of each first U-shaped radiation arm; 4. The base station antenna of claim 3, wherein the fourth parasitic radiator is located on the second side of the first dielectric substrate and corresponds to the position of the second branch of the two branches of each first U-shaped radiating arm.

15. 1. A base station antenna, comprising: a plurality of first radiators disposed along a length of the base station antenna, the first radiators configured to operate in a first frequency band and to generate electromagnetic radiation having an omnidirectional pattern in an azimuth plane; and a plurality of second radiators disposed along the longitudinal direction of the base station antenna, the second radiators operating in a second frequency band that does not overlap with the first frequency band and configured to generate electromagnetic radiation having an omnidirectional pattern in an azimuth plane; At least one first radiator of the plurality of first radiators is disposed between two adjacent second radiators; a base station antenna, wherein at least one second radiator of the plurality of second radiators is disposed between two adjacent first radiators;

16. the first radiator is formed as a symmetric dipole radiator having two U-shaped radiation arms, 16. The base station antenna of claim 15, wherein at least one second radiator of the plurality of second radiators is disposed between two branches of a U-shaped radiating arm of at least one first radiator of the plurality of first radiators.

17. 16. The base station antenna of claim 15, wherein the second radiator is formed as a symmetric dipole radiator having two U-shaped radiating arms.

18. 17. A base station antenna according to claim 15 or 16, wherein the first frequency band is lower than the second frequency band.

19. At least a portion of the plurality of first radiators extend in a first longitudinal plane; At least a portion of the plurality of second radiators extend in a second longitudinal plane; 17. The base station antenna of claim 16, wherein the first longitudinal plane and the second longitudinal plane are perpendicular to each other.

20. 20. The base station antenna of claim 19, wherein the first longitudinal plane and the second longitudinal plane intersect substantially along a central longitudinal axis of the base station antenna.

21. 17. The base station antenna of claim 16, wherein the first radiator is configured to be frequency selective such that the first radiator is substantially transparent to electromagnetic radiation in the second frequency band.

22. the first radiator is configured to resonate at a first frequency within the first frequency band; the base station antenna also 16. The base station antenna of claim 15, comprising a plurality of first parasitic radiators disposed along the longitudinal direction of the base station antenna, each first parasitic radiator resonating at a second frequency different from the first frequency within the first frequency band and configured to be excited by electromagnetic radiation emitted by a corresponding first radiator.

23. the second radiator is configured to resonate at a first frequency within the second frequency band; the base station antenna also 23. A base station antenna according to claim 15 or 22, comprising a plurality of second parasitic radiators arranged along the longitudinal direction of the base station antenna, the second parasitic radiators resonating at a second frequency different from the first frequency within the second frequency band and configured to be excited by electromagnetic radiation emitted by the second radiators.

24. the first frequency band is lower than the second frequency band; the first radiator is configured to be frequency selective such that the first radiator is substantially transparent to electromagnetic radiation in the second frequency band; 23. The base station antenna of claim 22, wherein the first parasitic radiator is configured to be frequency selective such that the first parasitic radiator is substantially transparent to electromagnetic radiation in the second frequency band.

25. 1. A base station antenna, comprising: a first array of first radiating elements disposed along a length of the base station antenna, the first array configured to generate an antenna beam having an omnidirectional pattern in the azimuth plane for a first frequency band; a second array of second radiating elements disposed along the longitudinal direction of the base station antenna, the second array configured to generate an antenna beam having an omnidirectional pattern in the azimuth plane for a second frequency band; the first array and the second array are interleaved with one another along the longitudinal direction of the base station antenna; A base station antenna, wherein the relative bandwidth of the first frequency band is greater than or equal to 25%, 30%, 35%, 40%, or 45%.

26. 26. The base station antenna of claim 25, wherein a first longitudinal section of the base station antenna occupied by at least one first radiating element of the first array has an overlapping portion with a second longitudinal section of the base station antenna occupied by at least one second radiating element of the second array.

27. 27. The base station antenna of claim 26, wherein the at least one first radiating element is configured to be frequency selective such that the at least one first radiating element is substantially transparent to electromagnetic radiation in the second frequency band.

28. the first radiating element comprises a first radiator formed on a first plane, a first parasitic radiator located on a first side of the first plane, and a second parasitic radiator located on a second side of the first plane; the first radiator is configured to resonate at a first frequency within the first frequency band; 26. The base station antenna of claim 25, wherein the first parasitic radiator and the second parasitic radiator are configured to resonate at a second frequency within the first frequency band that is different from the first frequency.

29. 30. The base station antenna of claim 28, wherein the second radiating element comprises a second radiator formed on a second plane, the first plane and the second plane being perpendicular to one another.

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