CN212182533U

CN212182533U - Base station antenna and multiband base station antenna

Info

Publication number: CN212182533U
Application number: CN202021054390.8U
Authority: CN
Inventors: 郭鹏斐; 李昀喆; 倪佳嘉; 滕超
Original assignee: Commscope Technologies LLC
Current assignee: Commscope Technologies LLC
Priority date: 2020-06-10
Filing date: 2020-06-10
Publication date: 2020-12-18
Anticipated expiration: 2030-06-10

Abstract

The present disclosure relates to a base station antenna and a multiband base station antenna. There is provided a base station antenna extending in a longitudinal direction, the base station antenna comprising: a plurality of first radiating element columns configured to operate in a first operating frequency band, each first radiating element column comprising a plurality of first radiating elements arranged in a longitudinal direction; and a separation wall positioned between adjacent columns of first radiating elements and extending in the longitudinal direction, wherein the separation wall includes a frequency selective surface configured such that electromagnetic waves within the first operating frequency band are substantially blocked by the separation wall.

Description

Base station antenna and multiband base station antenna

Technical Field

The present disclosure relates generally to the field of antennas, and more particularly, to base station antennas having frequency selective surfaces.

Background

With the development of wireless communication technology, the requirements for integration and miniaturization of antennas are higher and higher, which results in the number of radiation element columns included in the antennas being larger and the distance between adjacent radiation element columns being correspondingly smaller. This may result in enhanced mutual coupling between adjacent columns of radiating elements, which may make it challenging for the antenna to maintain high performance while increasing integration and miniaturization. For example, in some multi-band antenna applications, the low band may be in the frequency range of 600-960MHz, while the high band may be in the frequency range of 1400-2700MHz, or may be in the frequency range of 3000-5000MHz for 5G. In the limited space inside the antenna, the large size of the low-band radiating elements compared to the high-band radiating elements results in more severe mutual coupling phenomena between the columns of low-band radiating elements, which may result in poor inter-band isolation performance between the columns of low-band radiating elements.

SUMMERY OF THE UTILITY MODEL

According to an aspect of the present disclosure, there is provided a base station antenna extending in a longitudinal direction, the base station antenna including: a plurality of first radiating element columns configured to operate in a first operating frequency band, each first radiating element column comprising a plurality of first radiating elements arranged in a longitudinal direction; and a separation wall positioned between adjacent columns of first radiating elements and extending in the longitudinal direction, wherein the separation wall includes a frequency selective surface configured such that electromagnetic waves within the first operating frequency band are substantially blocked by the separation wall.

In some embodiments, the frequency selective surface is configured to reflect electromagnetic waves within a first operational frequency band.

In some embodiments, the base station antenna further comprises a plurality of second radiating element columns configured to operate in a second operating frequency band different from and non-overlapping with the first operating frequency band, each second radiating element column comprising a plurality of second radiating elements arranged in the longitudinal direction, wherein the frequency selective surface is further configured to enable electromagnetic waves within the second operating frequency band to propagate through the separation wall.

In some embodiments, the second operating frequency band is higher than the first operating frequency band.

In some embodiments, the isolation wall includes a frequency selective surface on the printed circuit board.

In some embodiments, the separation wall includes a dielectric plate having opposing first and second sides facing the respective first columns of radiating elements, each of the first and second sides being formed with a periodic conductive structure forming a frequency selective surface.

In some embodiments, the partition wall includes a plurality of partition units arranged periodically, each partition unit including a first unit structure forming the periodic conductive structure of the first side of the dielectric plate and a second unit structure forming the periodic conductive structure of the second side of the dielectric plate, a position of the first unit structure included in each partition unit on the first side of the dielectric plate corresponding to a position of the second unit structure included in the partition unit on the second side of the dielectric plate.

In some embodiments, the periodic conductive structure of the first side of the dielectric plate comprises a grid array structure, the first unit structure comprises a grid as a repeating unit in the grid array structure, and the periodic conductive structure of the second side of the dielectric plate comprises a patch array structure, the second unit structure comprises a patch as a repeating unit in the patch array structure.

In some embodiments, the first unit structure further comprises an extension extending from an angle to a center of the mesh and/or an extension extending from a midpoint of an edge of the mesh to the center.

In some embodiments, the extension is strip-shaped or cross-shaped, the cross-shape comprising two strips perpendicular to each other.

In some embodiments, the first cell structure comprises a square grid and the second cell structure comprises a square patch.

In some embodiments, the first unit structure further includes bar-shaped protruding portions protruding from four corners to a center of the square lattice.

In some embodiments, the first unit structure further comprises a cross-shaped extension extending from four corners to a center of the square lattice, and a bar-shaped extension extending from a midpoint of four sides of the square lattice to the center, the cross-shaped extension comprising two bar-shaped portions perpendicular to each other.

In some embodiments, the periodic conductive structures of the first and second sides of the dielectric plate are formed of a metal.

In some embodiments, the base station antenna includes a plurality of separation walls, each separation wall disposed at a different row of radiating elements between adjacent first columns of radiating elements.

In some embodiments, the base station antenna further comprises a parasitic element disposed on top of the isolation wall.

In some embodiments, the plurality of first radiating elements are masked radiating elements.

In some embodiments, the separation wall is a first separation wall, and the base station antenna further comprises a second separation wall positioned between adjacent columns of second radiating elements and extending in the longitudinal direction, the second separation wall comprising a frequency selective surface configured such that electromagnetic waves within the second operating frequency band are substantially blocked by the second separation wall.

In some embodiments, a first separation wall is also positioned between adjacent second columns of radiating elements, and a second separation wall is also positioned between adjacent first columns of radiating elements.

In some embodiments, the first partition wall and the second partition wall are integrally formed of a multilayer printed circuit board.

In some embodiments, the base station antenna includes a plurality of first partition walls and a plurality of second partition walls alternately arranged in one column, wherein each first partition wall is disposed at a different row of radiating elements between adjacent first columns of radiating elements, and each second partition wall is disposed at a different row of radiating elements between adjacent second columns of radiating elements.

In some embodiments, the height of the separation wall is greater than the height of a first radiating element of the plurality of first radiating elements.

In some embodiments, the separation wall is implemented as a multilayer printed circuit board, one or more layers of which are formed with a frequency selective surface configured such that electromagnetic waves within a predetermined frequency range cannot propagate through the separation wall, and wherein a combination of the predetermined frequency ranges associated with the one or more layers of the multilayer printed circuit board covers the first operating frequency band.

According to another aspect of the present disclosure, there is provided a multi-band base station antenna including: a plurality of low-band radiating element columns configured to operate in a low band, each low-band radiating element column comprising a plurality of low-band radiating elements arranged in a longitudinal direction; a plurality of high-band radiating element columns configured to operate in a high-band that is higher than and non-overlapping with the low-band, each high-band radiating element column including a plurality of high-band radiating elements arranged in a longitudinal direction; and a separation wall positioned between adjacent columns of low-band radiating elements and extending in the longitudinal direction, wherein the separation wall includes a frequency selective surface configured to reflect electromagnetic waves in a low-band while enabling the electromagnetic waves in a high-band to propagate through the separation wall.

Other features of the present disclosure and advantages thereof will become more apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The foregoing and other features and advantages of the disclosure will become apparent from the following description of the embodiments of the disclosure, as illustrated in the accompanying drawings. The accompanying drawings, which are incorporated herein and form a part of the specification, further serve to explain the principles of the disclosure and to enable a person skilled in the pertinent art to make and use the disclosure. Wherein:

fig. 1 is a front view schematically illustrating an example of a base station antenna, in accordance with some embodiments of the present disclosure;

fig. 2 is a front view schematically illustrating an example of a base station antenna, in accordance with some embodiments of the present disclosure;

fig. 3 is a front view schematically illustrating an example of a base station antenna, in accordance with some embodiments of the present disclosure;

fig. 4 is a front view schematically illustrating an example of a base station antenna, in accordance with some embodiments of the present disclosure;

fig. 5 is a schematic enlarged perspective view of a portion surrounded by a dashed-line frame in the base station antenna of fig. 4;

fig. 6 is a front view schematically illustrating an example of a base station antenna, in accordance with some embodiments of the present disclosure;

fig. 7 is a front view schematically illustrating an example of a base station antenna, in accordance with some embodiments of the present disclosure;

figure 8A illustrates a periodic conductive structure of a frequency selective surface of a partition wall of a base station antenna according to some embodiments of the present disclosure;

FIG. 8B shows an isolation unit including isolation walls having frequency selective surfaces with the periodic conductive structure shown in FIG. 8A;

FIG. 8C depicts the variation of S-parameter with frequency for a partition wall comprising a frequency selective surface with periodic conductive structures as shown in FIG. 8A;

figure 9A illustrates a periodic conductive structure of a frequency selective surface of a partition wall of a base station antenna according to some embodiments of the present disclosure;

FIG. 9B shows an isolation unit including isolation walls having frequency selective surfaces with the periodic conductive structure shown in FIG. 9A;

FIG. 9C depicts the variation of S-parameter with frequency for a partition wall comprising a frequency selective surface with periodic conductive structures as shown in FIG. 9A;

figure 10A illustrates a periodic conductive structure of a frequency selective surface of a partition wall of a base station antenna according to some embodiments of the present disclosure;

FIG. 10B shows an isolation unit including isolation walls having frequency selective surfaces with the periodic conductive structure shown in FIG. 10A;

FIG. 10C depicts the variation of S-parameter with frequency for a partition wall comprising a frequency selective surface with periodic conductive structures as shown in FIG. 10A; and

fig. 11 is a series of graphs depicting the mutual coupling strengths between the dipole arms of two low-band radiating elements with and without a separating wall between the adjacent two low-band radiating elements.

Note that in the embodiments described below, the same reference numerals are used in common between different drawings to denote the same portions or portions having the same functions, and a repetitive description thereof will be omitted. In some cases, similar reference numbers and letters are used to denote similar items, and thus, once an item is defined in one figure, it need not be discussed further in subsequent figures.

For convenience of understanding, the positions, sizes, ranges, and the like of the respective structures shown in the drawings and the like do not sometimes indicate actual positions, sizes, ranges, and the like. Therefore, the present disclosure is not limited to the positions, dimensions, ranges, and the like disclosed in the drawings and the like.

Detailed Description

Various exemplary embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. That is, the structures and methods herein are shown by way of example to illustrate different embodiments of the structures and methods of the present disclosure. Those skilled in the art will understand, however, that they are merely illustrative of exemplary ways in which the disclosure may be practiced and not exhaustive. Furthermore, the figures are not necessarily to scale, some features may be exaggerated to show details of particular components.

Additionally, techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification as appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

As discussed above, as the requirements for integration and miniaturization of antennas have increased, the development of techniques for reducing mutual coupling between different columns of radiating elements in the same frequency band and improving the performance of inter-band isolation has become an important aspect in the design of base station antennas. Due to the large size of the low-band radiating elements, it is generally more difficult to significantly reduce coupling between columns of low-band (low-band) radiating elements (such as 600-960MHz, etc.) than to achieve decoupling between columns of high-band (high-band) radiating elements (such as 1400-2700MHz, 3000-5000MHz, etc.). For example, in an antenna having a width of 430mm that includes two columns of low-band radiating elements and four columns of high-band radiating elements, the distance between two adjacent columns of low-band radiating elements may only be about 215mm due to the small width of the antenna. In such a compact arrangement, strong mutual coupling between the columns of low-band radiating elements can result in poor inter-band isolation performance.

A frequency selective surface (frequency selective surface) may filter electromagnetic waves in space. By periodically arranging a plurality of frequency selective surface units on a two-dimensional plane, a metamaterial having a specific reflection/transmission phase distribution can be formed. When an electromagnetic wave is incident on the frequency selective surface, the frequency selective surface can selectively pass/block electromagnetic waves of different frequencies.

An aspect of the present disclosure provides a base station antenna extending in a longitudinal direction, the base station antenna comprising a plurality of first radiating element columns configured for operation in a first operating frequency band, each first radiating element column comprising a plurality of first radiating elements arranged in the longitudinal direction of the base station antenna. The base station antenna also includes a separation wall positioned between adjacent columns of first radiating elements and extending in the longitudinal direction, wherein the separation wall includes a frequency selective surface configured such that electromagnetic waves within the first operating frequency band are substantially prevented from passing through the separation wall. The base station antenna according to the present disclosure can effectively improve the inter-band isolation performance between the same-band radiating element columns without affecting the beam pattern performance of other operating bands.

An example base station antenna 100 according to some embodiments of the present disclosure will now be described in detail in connection with fig. 1. It should be noted that other components may be present in an actual base station antenna and are not shown in the figures and are not discussed herein in order to avoid obscuring the point of the present disclosure. It should also be noted that fig. 1 schematically shows the relative positional relationship of the respective components, and the specific structure of the respective components is not particularly limited.

As shown in fig. 1, the base station antenna 100 may include a plurality of first columns of radiating elements 110-1, 110-2 (hereinafter, may also be collectively referred to as first columns of radiating elements 110) configured for operation in a first operating frequency band. Each first radiation element column 110 includes a plurality of first radiation elements 111 arranged in a longitudinal direction (as indicated by an arrow L in fig. 1). As shown in fig. 1, column 110-1 includes first radiating elements 111-1, 111-2, 111-3, and 111-4, and column 110-2 includes first radiating elements 111-5, 111-6, 111-7, and 111-8, wherein first radiating elements 111-1 and 111-5, first radiating elements 111-2 and 111-6, first radiating elements 111-3 and 111-7, and first radiating elements 111-4 and 111-8 are arranged in respective first through fourth rows of radiating elements. Although fig. 1 illustrates the base station antenna 100 as having two columns of first radiating elements and each column of first radiating elements including four first radiating elements, it will be understood that the base station antenna 100 may include additional columns of radiating elements operating in the same or different operating frequency bands, and that each column of radiating elements may include more or fewer radiating elements. In some embodiments, the first radiating element may be a low band radiating element and the first operating frequency band may be a low frequency band. In other embodiments, the first radiating element may be a high-band radiating element and the first operating frequency band may be a high-band. As used herein, "low band" refers to a lower frequency band such as, for example, a 600-960MHz band or portion thereof, and "high band" as used herein refers to a higher frequency band such as, for example, a 1400-2700MHz band or portion thereof. The present disclosure is not limited to these particular frequency bands and may be used in any other frequency band within the operating frequency range of the base station antenna. In some embodiments, the first radiating element may be a masked radiating element, such as first radiating elements 111-2, 111-6 as depicted in fig. 5.

The base station antenna 100 further comprises a partition wall 130. The partition wall 130 is positioned between adjacent first radiating element columns (i.e., between the first radiating element columns 110-1 and 110-2) and extends in the longitudinal direction (as indicated by arrow L in fig. 1) of the base station antenna 100. The partition wall 130 comprises a frequency selective surface configured such that electromagnetic waves within the first operational frequency band are substantially blocked by the partition wall. For example, the partition wall may reflect and/or absorb electromagnetic waves within the first operational frequency band. Embodiments in which the frequency selective surface is configured to reflect electromagnetic waves within the first operational frequency band may have lower losses than embodiments in which the frequency selective surface absorbs electromagnetic waves within the first operational frequency band. Generally, the separation wall 130 is not in physical contact with any of the first radiating elements.

In some embodiments, a separation wall 130 is positioned in the middle of the first columns of radiating elements 110-1 and 110-2. In some embodiments, the separation wall 130 may extend farther forward from the reflector than the first radiating element 111, for example as shown in fig. 5. Herein, referring to fig. 5, the distance that the partition wall 130 or the first radiating element 111 extends forward from the reflector may be considered as the "height" of the partition wall 130 or the first radiating element 111. As shown in fig. 5, the height of the partition wall 130 is greater than the height of the first radiation element 111. When the factors such as installation conflict are not considered, the farther the partition wall extends forwards, the better the decoupling effect is.

As shown in fig. 1, the partition wall 130 extends longitudinally across all of the first radiating elements 111 in the first radiating element column 110. The partition walls 130 may have other arrangements. In some embodiments, the base station antenna may include a plurality of partition walls, each partition wall being disposed at a different row of radiating elements between adjacent first columns of radiating elements, i.e., between radiating elements in different rows of radiating elements. For example, in some embodiments, two or more adjacent rows of radiating elements in adjacent first columns of radiating elements may share a dividing wall. In some embodiments, each partition wall may extend across one or more rows of radiating elements between adjacent columns of first radiating elements.

For example, as shown in fig. 2, another example of a base station antenna 100' according to the present disclosure includes two separation walls 130-1, 130-2, where the separation wall 130-1 is between the first radiating elements in the upper two first radiating element rows (i.e., the separation wall 130-1 is between the first radiating elements 111-1 and 111-2 and the first radiating elements 111-5 and 111-6), and the separation wall 130-2 is between the first radiating elements in the lower two first radiating element rows (i.e., the separation wall 130-2 is between the first radiating elements 111-3 and 111-4 and the first radiating elements 111-7 and 111-8). The partition walls 130-1, 130-2 may be connected to each other or separated from each other. The divider walls 130-1, 130-2 may be aligned with each other, may be angled with respect to each other, or may be offset parallel to each other. The particular arrangement and the three-dimensional size of the separation walls may depend on the degree of decoupling between the radiating element columns required for a particular application scenario for the base station antenna. The frequency selective surfaces of the separating walls 130-1, 130-2 need not be identical, as long as the electromagnetic waves in the first operating frequency band are reduced and/or prevented from propagating through the separating walls, i.e., the pass band and the stop band of the frequency selective surfaces of the separating walls 130-1, 130-2 need not be identical, as long as the stop band covers the first operating frequency band. It is to be understood that while the separation walls 130-1, 130-2 are shown in fig. 2 as extending across the same number of rows of radiating elements, in other embodiments the separation walls may extend across a different number of rows of radiating elements.

In some embodiments, the base station antenna may include one or more separation walls extending across only some of the rows of radiating elements in adjacent first columns of radiating elements. For example, as shown in fig. 3, another example 100 "of a base station antenna according to the present disclosure includes two separation walls 130-1 ', 130-2', where separation wall 130-1 'is between first radiating elements 111-1 and 111-5, and separation wall 130-2' is between first radiating elements 111-3 and 111-7, and there is no separation wall between first radiating elements 111-2 and 111-6, 111-4 and 111-8. One or more separation walls may be selectively placed at some locations between adjacent columns of radiating elements depending on the degree of decoupling between the columns of radiating elements required by the base station antenna for a particular application scenario.

In some embodiments, the base station antenna may further comprise a parasitic element mounted on or adjacent to the front surface of some or all of the partition walls. For example, as shown in fig. 5, the parasitic element 150 is mounted on the front surface of the partition wall 130 (disposed on the top of the partition wall 130). In some embodiments, these parasitic elements may be masked parasitic elements. In some embodiments, the parasitic element may extend parallel to the partition wall. In other embodiments, the parasitic element may be rotated 90 degrees with respect to the dividing wall.

In some embodiments, the base station antenna may further comprise a plurality of second columns of radiating elements configured to operate in a second operating frequency band different from and non-overlapping with the first operating frequency band. Each second radiating element column may include a plurality of second radiating elements arranged in a longitudinal direction, and the frequency selective surface may be configured to enable electromagnetic waves within a second operational frequency band to propagate through the separation wall.

Referring now to fig. 4, a base station antenna 200 according to further embodiments of the present disclosure is described. The base station antenna 200 further includes a plurality of second radiation element columns 120-1, 120-2, 120-3, and 120-4 (hereinafter, may also be collectively referred to as second radiation element columns 120) in comparison with the base station antenna 100, and each second radiation element column 120 includes a plurality of second radiation elements 121 arranged in the longitudinal direction of the base station antenna. The second radiating element 121 is configured to operate in a second operating frequency band different from and non-overlapping with the first operating frequency band. Generally, the partition wall 130 does not contact any of the second radiation elements 121.

In some embodiments, the second operating frequency band may be higher than the first operating frequency band. In some embodiments, the first radiating element may be a low band radiating element and the first operating band may be a low band, and the second radiating element may be a high band radiating element and the second operating band may be a high band. In other embodiments, the first radiating element may be a high-band radiating element and the first operating band may be a high-band, and the second radiating element may be a low-band radiating element and the second operating band may be a low-band.

Although the base station antenna 200 is shown in fig. 4 as including two columns of first radiating elements and four columns of first radiating elements each, and four columns of second radiating elements and eight second radiating elements each, it will be appreciated that the base station antenna 200 may also include more or fewer columns of first and/or second radiating elements, may additionally include columns of radiating elements operating in other operating frequency bands, and may include more or fewer radiating elements each.

Furthermore, the frequency selective surface of the partition wall 130 of the base station antenna 200 is also configured to enable electromagnetic waves within the second operating frequency band to propagate through the partition wall 130. That is, the partition wall 130 may substantially reduce and/or prevent propagation of electromagnetic waves within the first operational frequency band without substantially affecting propagation of electromagnetic waves within the second operational frequency band. Therefore, the partition wall 130 can reduce mutual coupling between the first radiation element columns without affecting the performance of the second radiation element columns. Furthermore, the present disclosure is also not limited to dual-band base station antennas. For example, a base station antenna according to the present disclosure may be a multi-band base station antenna, and the first and second operating frequency bands may be any two operating frequency bands of the multi-band base station antenna, and further the multi-band base station antenna may further include at least a third operating frequency band that is different from and non-overlapping with the first and second operating frequency bands, and the frequency selection surface may be further configured to allow electromagnetic waves within the third operating frequency band to pass through the partition wall, so that the partition wall may not affect the performance of the columns of radiating elements corresponding to the other operating frequency bands while reducing mutual coupling between the columns of radiating elements corresponding to the first operating frequency band.

In embodiments where the first radiating element is a low-band radiating element and the second radiating element is a high-band radiating element, the inter-band isolation performance is more affected by the mutual coupling between the same frequency band (lower frequency band such as 600-960MHz) columns due to the larger size of the low-band radiating element compared to the high-band radiating element, but the separation wall 130 of the base station antenna 200 may effectively reduce the mutual coupling between the low-band radiating element columns and thus improve the inter-band isolation performance. The arrangement of the partition walls 130 of the base station antenna 200 is also applicable to all the discussion above regarding the arrangement of the partition walls 130 and will not be described in detail here.

In some embodiments, the base station antenna may further comprise a second separation wall positioned between adjacent second columns of radiating elements and extending in the longitudinal direction, the second separation wall comprising a frequency selective surface configured such that electromagnetic waves within the second operating frequency band are substantially blocked by the second separation wall.

For example, as shown in fig. 6, another example 200' of a base station antenna according to an embodiment of the present disclosure further includes a separation wall 140, the separation wall 140 including a frequency selective surface configured such that electromagnetic waves within the second operational frequency band substantially cannot pass through the separation wall 140. The frequency selectivity of the partition wall 140 to the first operating frequency band is not particularly limited. In some embodiments, the separation wall 140 may allow electromagnetic waves within the first operational frequency band to pass through. In some embodiments, the separation wall 140 may not allow electromagnetic waves within the first operational frequency band to pass through. In some embodiments, the separation wall 140 may extend farther forward than the second radiating element 121. When the factors such as installation conflict are not considered, the higher the height of the partition wall is, the better the decoupling effect is. In some embodiments, the height of the partition wall 140 may be the same as the height of the partition wall 130.

As shown in fig. 6, the separation walls 140 may be positioned adjacent to the separation walls 130 and may each extend the entire length of the column of radiating elements. It is understood that the partition wall 140 may be spaced apart from the partition wall 130. Also, as discussed above, a plurality of such combinations of the partition walls 140 and the partition walls 130 may be respectively disposed at different rows of the radiating elements, and will not be described herein again. In some embodiments, the partition wall 140 and the partition wall 130 may be integrally formed using a multi-layer printed circuit board.

In some embodiments, the base station antenna may further include a plurality of first partition walls (e.g., the plurality of partition walls 130) and a plurality of second partition walls (e.g., the plurality of partition walls 140) alternately arranged in one column, wherein each first partition wall is disposed at a different radiation element row between adjacent first radiation element columns, i.e., between radiation elements in a different radiation element row, and each second partition wall is disposed at a different radiation element row between adjacent second radiation element columns, i.e., between radiation elements in a different radiation element row. For example, fig. 7 shows an additional arrangement of the

partition walls

130 and 140. The base station antenna 200 "shown in fig. 7 includes two partition walls 130-1, 130-2 and two partition walls 140-1, 140-2, and the partition walls are alternately arranged in a column in the order of 130-1, 140-1, 130-2, 140-2. It is to be understood that the arrangement of the partition walls shown in the figures is merely exemplary and not limiting, and the order, number, three-dimensional size, etc. of the arrangement of the

partition walls

130, 140 may be set according to the respective interband separation requirements for the first and second columns of radiating elements. As discussed above, the frequency selective surfaces of the plurality of first partition walls need not be identical, so long as the passage of electromagnetic waves within the first operational frequency band can be substantially reduced and/or prevented, and the frequency selective surfaces of the plurality of second partition walls need not be identical, so long as the passage of electromagnetic waves within the second operational frequency band can be substantially reduced and/or prevented.

In the examples of fig. 6 and 7, the separation walls 130, 130-1, 130-2 are positioned between adjacent second columns of radiating elements (e.g., 120-2, 120-3) and the separation walls 140, 140-1, 140-2 are positioned between adjacent first columns of radiating elements (e.g., 110-1, 110-2), but this is exemplary and not intended to limit the present disclosure. For example, the partition wall 130 does not necessarily need to be adjacent to the partition wall 140. For antennas including multiple first columns of radiating elements and/or multiple second columns of radiating elements, the separation wall 130 may be positioned between any two adjacent first columns of radiating elements regardless of the position of the second columns of radiating elements, and the separation wall 140 may be positioned between any two adjacent second columns of radiating elements regardless of the position of the first columns of radiating elements. Where space permits, and as the case may be, a partition wall 130 may be provided between every two adjacent first radiation element columns, and/or a partition wall 140 may be provided between every two adjacent second radiation element columns.

The frequency selective surface is a metamaterial, wherein the term "metamaterial" refers to a synthetic Electromagnetic (EM) material. The metamaterial may include a subwavelength periodic microstructure. The partition wall of a base station antenna according to the present disclosure selectively rejects some frequency bands from passing and allows other frequency bands to pass by including a frequency selective surface to operate as a "spatial filter".

In some embodiments, the

isolation walls

130, 140 may be implemented by forming a frequency selective surface on a printed circuit board. In some embodiments, the isolation wall may include a frequency selective surface on a printed circuit board. In some embodiments, the separation wall may be implemented as a multilayer printed circuit board, one or more layers of the multilayer printed circuit board formed with a frequency selective surface configured such that electromagnetic waves within a predetermined frequency range cannot propagate through the separation wall, and wherein a combination of the predetermined frequency ranges associated with the one or more layers of the multilayer printed circuit board covers the first operational frequency band. In some embodiments, the combination of predetermined frequency ranges associated with one or more layers in the multilayer printed circuit board does not cover the second operating frequency band. The predetermined frequency ranges associated with one or more layers in the multilayer printed circuit board may be different from one another. In some embodiments, the predetermined frequency ranges associated with one or more layers in the multilayer printed circuit board may not overlap with each other. In some embodiments, the predetermined frequency ranges associated with one or more layers in the multilayer printed circuit board may at least partially overlap one another. In such embodiments, each layer of the multilayer printed circuit board in which the frequency selective surface is formed corresponds to one "spatial filter," and the entire multilayer printed circuit board equivalently includes a cascade of multiple "spatial filters," wherein each "spatial filter" blocks (i.e., substantially attenuates and/or reflects) a portion of the first operating frequency band, thereby collectively substantially preventing electromagnetic waves within the first operating frequency band from passing through the partition wall. Thus, it is possible to simplify the design of the frequency selective surface of each layer of the multilayer printed circuit board while ensuring that electromagnetic waves in the first operating frequency band are substantially blocked by the partition wall.

In some embodiments, the separation wall may include a dielectric plate having opposing first and second sides facing the respective columns of first radiating elements, wherein each side includes a periodic conductive structure forming a frequency selective surface. For example, referring back to fig. 1, the separation wall 130 may include a dielectric plate (or dielectric layer) having a first side 131 and a second side 132, wherein the first side 131 faces the first radiation element column 110-1, the second side 132 faces the first radiation element column 110-2, and the first side 131 and the second side 132 are each formed with a periodic conductive structure. The periodic conductive structures of the first side 131 and the second side 132 form a frequency selective surface that substantially prevents electromagnetic waves in the first operational frequency band from passing through the partition wall while allowing electromagnetic waves in the second operational frequency band to pass through the partition wall.

In some embodiments, the isolation wall may include a plurality of isolation cells arranged periodically, wherein each isolation cell may include a first cell structure forming the periodic conductive structure of the first side of the dielectric plate and a second cell structure forming the periodic conductive structure of the second side of the dielectric plate. The position of the first unit structure included in each of the isolation units on the first side of the dielectric plate may correspond to the position of the second unit structure included in the isolation unit on the second side of the dielectric plate. In some embodiments, each first unit structure coincides with a center of a corresponding second unit structure as viewed from a direction perpendicular to the first and second sides.

The first unit structure may be equivalent to an inductor and the second unit structure may be equivalent to a capacitor, whereby the isolation unit including the first unit structure and the second unit structure disposed correspondingly may be equivalent to an LC resonance circuit. In some embodiments, the isolation unit may be configured to be equivalent to a parallel LC resonant circuit. By designing the equivalent inductance value of the first unit structure and the equivalent inductance value of the second unit structure, the frequency range allowed to pass by the frequency selection surface can be adjusted to a desired frequency range.

In some embodiments, the periodic conductive structure of the first side of the dielectric plate comprises a grid array structure, the first unit structure comprises a grid as a repeating unit in the grid array structure, and the periodic conductive structure of the second side of the dielectric plate comprises a patch array structure, the second unit structure comprises a patch as a repeating unit in the patch array structure. For example, the mesh of the first unit structure may have a regular polygonal shape such as a square, and the patch of the second unit structure may also have a regular polygonal shape such as a square.

The first unit structure may further include an additional structure on the basis of the grid. In some embodiments, the first unit structure may further include an extension extending from an angle to a center of the mesh and/or an extension extending from a midpoint of an edge of the mesh to the center. The shape of the protruding portion may be strip-shaped or substantially strip-shaped, cross-shaped or substantially cross-shaped, or may be other suitable shapes. The cross shape described herein includes two strips that are perpendicular to each other. The extensions may not meet each other.

Several exemplary configurations of frequency selective surfaces of the partition walls of the base station antenna according to embodiments of the present disclosure are described in detail below in conjunction with fig. 8A to 10C.

For example, as shown in fig. 8A, the first unit structure of the periodic conductive structure of the first side 131 is a square grid, and the second unit structure of the periodic conductive structure of the second side 132 is a square patch.

Fig. 8B shows an isolation unit including an isolation wall having a frequency selective surface with a periodic conductive structure as shown in fig. 8A, the isolation unit including a square grid (first unit structure) and square patches (second unit structure) at corresponding positions on both sides of a dielectric plate (i.e., the dielectric plate is omitted in fig. 8B). The square grid coincides with the center of the square patch as seen in a direction perpendicular to the first and second sides. Such an isolation unit may be configured to be equivalent to a parallel resonant circuit formed by an inductor (square grid) and a capacitor (square patch). The size of the inductance of the inductor and the size of the capacitance of the capacitor of the equivalent parallel resonant circuit, and thus the size of the square grid and the square patches, may be determined according to the frequency selective properties of the desired frequency selective surface. In the example of fig. 8A, the partition wall is shown to include three rows and eight columns of partition units, but it is to be understood that this is a non-limiting example and the arrangement of the partition units may be determined according to the height and length of the desired partition wall and the size of the desired unit structure.

Fig. 8C shows the variation of S-parameter with frequency of a partition wall including a periodic conductive structure having the periodic conductive structure shown in fig. 8A and designed for a pass band covering a band of 1695 to 2690MHz, wherein the size of a unit structure of the periodic conductive structure of the frequency selective surface of the partition wall is 28mm × 28 mm. In fig. 8C, the S11 parameter represents the reflection of the partition wall for different frequencies, and the S21 parameter represents the transmission of the partition wall for different frequencies. It can be seen from fig. 8C that the S21 parameter of the partition wall is not less than-0.86 dB over the frequency range of 1.70-2.69GHz, which appears as a "transparent window" for the 1695-2690MHz band (i.e., the insertion loss of the partition wall is less than 1dB for the 1695-2690MHz band). In addition, the S11 parameter of the divider in the frequency range below 1.00GHz is greater than-2.00 dB, i.e., a significant portion of the electromagnetic waves in the low frequency band (such as 600-960MHz) used herein are reflected by the divider. Such a partition wall thus effectively reduces the mutual coupling between the columns of low band radiating elements and thus improves the inter-band isolation performance of the columns of low band radiating elements, while not affecting the performance of the columns of higher band (such as 1695-2690MHz) radiating elements.

In some embodiments, the first unit structure includes a square grid, the second unit structure includes square patches, and the first unit structure further includes bar-shaped protruding portions protruding from four corners to a center of the square grid. In some examples, the strip-shaped protruding portions of the first unit structures are at an angle of about 45 degrees with respect to the sides of the square lattice. In some examples, the respective bar-shaped protruding portions of the first unit structures are equal in size to each other. In some examples, the respective strip-shaped projections of the first unit structures do not intersect.

For example, as shown in fig. 9A, the first unit structure of the periodic conductive structure of the first side 131 includes a square grid and bar-shaped protrusions protruding from four corners to a center of the square grid, each of the bar-shaped protrusions forming an angle of 45 degrees with respect to a side of the square grid and not intersecting with each other, and the second unit structure of the periodic conductive structure of the second side 132 includes a square patch. Fig. 9B shows an isolation unit including an isolation wall having a frequency selective surface with the periodic conductive structure shown in fig. 9A, the isolation unit including a first unit structure and a second unit structure at corresponding positions on both sides of a dielectric plate. The first unit structure coincides with the center of the second unit structure as viewed from a direction perpendicular to the first side and the second side. Such an isolation unit may be equivalent to a parallel resonance circuit formed by an inductor (first unit structure) and a capacitor (second unit structure). The size of the inductance of the inductor and the size of the capacitance of the capacitor of the equivalent parallel resonant circuit, and thus the size of the first and second unit structures, may be determined according to the frequency selective performance of the desired frequency selective surface. In the example of fig. 9A, the partition wall is shown as including four rows and thirteen columns of the partition units, but it is understood that this is a non-limiting example, and the arrangement of the partition units may be determined according to the height and length of the desired partition wall and the size of the desired unit structure.

Fig. 9C shows the variation of S parameter with frequency of a partition wall including a periodic conductive structure having the periodic conductive structure as shown in fig. 9A and designed for a pass band covering a band of 1400-2700MHz, in which the size of a unit structure of the periodic conductive structure of the frequency selective surface of the partition wall is 16mm × 16 mm. In fig. 9C, the S11 parameter indicates the reflection of the partition wall at different frequencies, and the S21 parameter indicates the transmission of the partition wall at different frequencies. As can be seen from FIG. 9C, the S21 parameter of the partition wall is not less than-0.98 dB in the frequency range of 1.42-2.70GHz, which appears as a "transparent window" for the 1400-2700MHz band. In addition, the S11 parameter of the partition wall is greater than-3 dB in the frequency range of 0.50-1.00GHz, i.e., most of the electromagnetic waves in the low frequency band (such as 600-960MHz) can be reflected by the partition wall. Such a partition can therefore effectively reduce the mutual coupling between the columns of low band radiating elements and thereby improve the inter-band isolation performance of the columns of low band radiating elements, while not affecting the performance of the columns of high band (e.g., 1400-2700MHz) radiating elements. Since the pass band of the frequency selective surface of the partition wall in fig. 9C covers the entire 1400-2700MHz band, it can ensure that the high-band radiating elements are less affected by the partition wall while reducing mutual coupling between the low-band radiating element columns, as compared with the example of fig. 8C.

In some embodiments, the first unit structure includes a square grid, the second unit structure includes a square patch, and the first unit structure further includes a cross-shaped extension extending from four corners of the square grid toward a center, and a bar-shaped extension extending from a midpoint of four sides of the square grid toward the center, the cross-shaped extension including two bar-shaped portions perpendicular to each other. In some examples, the bar-shaped protruding portions included in the first unit structure extend perpendicular to respective sides of the square lattice included in the first unit structure. In some examples, a longitudinal axis of the cruciform extension included in the first cell structure is at an angle of 45 degrees with respect to a side of the square lattice included in the first cell structure. In some examples, the sizes of the bar-shaped protruding portions included in the first unit structure are the same as each other. In some examples, the sizes of the cross-shaped protruding portions included in the first unit structures are the same as each other. In some examples, the respective strip-shaped protruding portions and the respective cross-shaped protruding portions of the first unit structures do not intersect.

For example, as shown in fig. 10A, the first cell structure of the periodic conductive structure of the first side 131 includes a square grid, cross-shaped extensions extending from four corners of the square grid toward the center, and strip-shaped extensions extending from midpoints of four sides of the square grid toward the center. Each of the cross-shaped extensions includes two strip-shaped portions perpendicular to each other and a longitudinal axis of each of the cross-shaped extensions is at an angle of 45 degrees with respect to a side of the square lattice included in the first unit structure. The strip-shaped extensions extend perpendicular to the respective sides of the square grid. The respective strip-shaped projections and the respective cross-shaped projections do not intersect with each other. The second cell structure of the periodic conductive structure of the second side 132 comprises a square patch. Fig. 10B shows an isolation unit including an isolation wall having a frequency selective surface with the periodic conductive structure shown in fig. 10A, the isolation unit including a first unit structure and a second unit structure at corresponding positions on both sides of a dielectric plate. The first unit structure coincides with the center of the second unit structure as viewed from a direction perpendicular to the first side and the second side. Such an isolation unit may be equivalent to a parallel resonance circuit formed by an inductor (first unit structure) and a capacitor (second unit structure). The size of the inductance of the inductor and the size of the capacitance of the capacitor of the equivalent parallel resonant circuit, and thus the size of the first and second unit structures, may be determined according to the frequency selective performance of the desired frequency selective surface. In the example of fig. 10A, the partition wall is shown to include four rows and twelve columns of partition cells, but it is to be understood that this is a non-limiting example and the arrangement of the partition cells may be determined according to the height and length of the desired partition wall and the size of the desired cell structure.

Fig. 10C shows the variation of the S parameter with frequency of a partition wall including a periodic conductive structure having the periodic conductive structure as shown in fig. 10A and designed for a pass band covering a band of 1400-2700MHz, in which the size of the unit structure of the periodic conductive structure of the frequency selective surface of the partition wall is 12mm × 12 mm. In fig. 10C, the S11 parameter indicates the reflection of the partition wall at different frequencies, and the S21 parameter indicates the transmission of the partition wall at different frequencies. As can be seen from FIG. 10C, the S21 parameter of the partition wall is not less than-1.00 dB in the frequency range of 1.41-2.73GHz, which appears as a "transparent window" for the 1400-2700MHz band. In addition, the S11 parameter of the divider in the frequency range of 0.50-0.96GHz is not less than-2.92 dB, i.e., most of the electromagnetic waves in the low frequency band (such as 600-960MHz) used herein can be reflected by the divider. Thus, the isolation walls can effectively reduce the mutual coupling between the low band columns of radiating elements and thereby improve the inter-band isolation performance of the low band columns of radiating elements without affecting the performance of the high band (such as 1400-2700MHz) columns of radiating elements. Since the pass band of the frequency selective surface of the partition wall in fig. 10C covers the entire 1400-2700MHz band, it can ensure that the high-band radiating element columns are less affected by the partition wall while reducing mutual coupling between the low-band radiating element columns, as compared with the example of fig. 8C. Although the passband of the frequency selective surface of the partition wall in fig. 10C is similar to the passband of the frequency selective surface of the partition wall in fig. 9C, the cell structure of the partition wall in fig. 10C is smaller than that of the example in fig. 9C, and the partition wall in fig. 10C can have more periodically arranged cell structures under the condition that the overall size of the partition wall is the same, and the macroscopically equivalent frequency selective characteristic is more remarkable when the period is more.

In the example patterns shown in fig. 8A, 9A, and 10A, the black lines and black squares have conductive material at their locations, and the white squares have no conductive material at their locations. The periodic conductive structure may be formed to achieve a frequency selective surface by depositing a conductive material on both sides of a dielectric plate and then forming a corresponding pattern by an etching technique such as photolithography. Any other suitable method known in the art or later developed may also be employed to form the desired periodic conductive structure on the dielectric plate. The periodic conductive structures may be formed using any suitable conductive material, typically a metal such as copper, silver, aluminum, and the like. The dielectric plate may be, for example, a printed circuit board. Parameters such as thickness, permittivity and permeability of the dielectric plate affect the coupling strength between the same-band radiating element columns on both sides, and can be determined depending on the desired inter-band isolation performance.

Although in the examples shown in fig. 8A-10C, the frequency selective surface of the partition wall is configured such that electromagnetic waves in the first operational frequency band (such as the 600-960MHz frequency band) are substantially reflected by the partition wall, it will be appreciated that the frequency selective surface of the partition wall may also be configured such that electromagnetic waves in the first operational frequency band (such as the 600-960MHz frequency band) are substantially absorbed by the partition wall.

Compared with a conventional separation wall (such as a metal separation wall) comprising a wave-absorbing material, the separation wall disclosed by the invention has frequency selectivity, can effectively reduce mutual coupling between low-band radiating elements, and meanwhile, does not remarkably influence the performance of high-band radiating elements and does not influence the radiation patterns generated by the low-band radiating elements and the high-band radiating elements. Moreover, the partition wall according to the present disclosure may have lower losses and/or lower costs.

Another aspect of the present disclosure also provides a multi-band base station antenna, including: a plurality of low-band radiating element columns configured to operate in a low band, each low-band radiating element column comprising a plurality of low-band radiating elements arranged in a longitudinal direction; a plurality of high-band radiating element columns configured to operate in a high-band that is higher than and non-overlapping with the low-band, each high-band radiating element column including a plurality of high-band radiating elements arranged in a longitudinal direction; and a separation wall positioned between adjacent columns of low-band radiating elements and extending in the longitudinal direction, wherein the separation wall includes a frequency selective surface configured to reflect electromagnetic waves in a low-band while enabling the electromagnetic waves in a high-band to propagate through the separation wall. As described herein, "low band" refers to a lower frequency band such as 600-960MHz, and "high band" refers to a higher frequency band such as 1400-2700 MHz. The present disclosure is not limited to these particular frequency bands and may be used in other multi-band configurations.

Some of the multi-band base station antennas according to the present disclosure may be described with reference to fig. 4. The multi-band base station antenna of fig. 4 includes a plurality of low-band radiating element columns 110-1, 110-2 configured for operation in a low frequency band (such as 600-960MHz), each low-band radiating element column 110-1, 110-2 including a plurality of low-band radiating elements 111 arranged along a longitudinal direction. The multi-band base station antenna also includes a plurality of high-band radiating element columns 120-1, 120-2, 120-3, 120-4 configured to operate in a high frequency band (such as 1400-2700MHz) that is higher than and non-overlapping with the low frequency band, each high-band radiating element column 120-1, 120-2, 120-3, 120-4 including a plurality of high-band radiating elements 121 arranged in a longitudinal direction. The multi-band base station antenna further includes a separation wall 130 positioned between adjacent columns of low-band radiating elements 110-1, 110-2 and extending in a longitudinal direction, wherein the separation wall 130 includes a frequency selective surface configured to reflect electromagnetic waves in a low frequency band while enabling the electromagnetic waves in a high frequency band to propagate through the separation wall. It will be appreciated that in addition to the illustrated configuration, the multi-band base station antenna may include more or fewer columns of low-band radiating elements and/or columns of high-band radiating elements, may additionally include columns of radiating elements operating in other operating frequency bands, and each column of radiating elements may include more or fewer radiating elements.

Fig. 11 depicts mutual coupling strengths between dipole arms of two low-band radiating elements with and without a partition wall between the adjacent two low-band radiating elements, the partition wall having a periodic conductive structure as shown in fig. 8A and having reflection characteristics and transmission characteristics as shown in fig. 8C. Referring to fig. 5, P1 and P2 are the positive polarized dipole arm and the negative polarized dipole arm, respectively, of the low-band radiating element 111-2, and P3 and P4 are the positive polarized dipole arm and the negative polarized dipole arm, respectively, of the low-band radiating element 111-6. As can be seen from fig. 11, after the partition wall 130 is disposed between the adjacent two low-band radiating elements 111-2 and 111-6, the mutual coupling strength between P1 and P3, the mutual coupling strength between P1 and P4, the mutual coupling strength between P2 and P3, and the mutual coupling strength between P2 and P4 are all reduced, compared to the case without the partition wall. Thus, the isolation wall 130 can effectively reduce mutual coupling between the low-band radiating element rows, thereby improving the inter-band isolation performance of the low-band radiating element rows.

The multi-band base station antenna according to the present disclosure may be applied to the above-discussed embodiments with respect to the base station antenna including the plurality of first radiating element columns and the plurality of second radiating element columns, which are not described herein again.

A multi-band base station antenna according to embodiments of the present disclosure may have improved inter-band isolation performance between low-band radiating element columns while the performance of high-band radiating element columns is not affected by the dividing wall and the radiation patterns generated by the low-band radiating elements and the high-band radiating elements are not affected by the dividing wall.

The terms "left," "right," "front," "back," "top," "bottom," "over," "under," "upper," "lower," and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the disclosure described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. For example, features described originally as "above" other features may be described as "below" other features when the device in the figures is inverted. The device may also be otherwise oriented (rotated 90 degrees or at other orientations) and the relative spatial relationships may be interpreted accordingly.

In the description and claims, an element being "on," attached to, "connected to," coupled to, "or contacting" another element, etc., may be directly on, attached to, connected to, coupled to or contacting the other element, or one or more intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly attached to," directly connected to, "directly coupled to," or "directly contacting" another element, there are no intervening elements present. In the description and claims, one feature may be "adjacent" another feature, and may mean that one feature has a portion that overlaps with or is above or below the adjacent feature.

As used herein, the word "exemplary" means "serving as an example, instance, or illustration," and not as a "model" that is to be replicated accurately. Any implementation exemplarily described herein is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, the disclosure is not limited by any expressed or implied theory presented in the technical field, background, utility model content, or the detailed description.

As used herein, the term "substantially" is intended to encompass any minor variation resulting from design or manufacturing imperfections, device or component tolerances, environmental influences, and/or other factors. The word "substantially" also allows for differences from a perfect or ideal situation due to parasitics, noise, and other practical considerations that may exist in a practical implementation.

In addition, "first," "second," and like terms may also be used herein for reference purposes only, and thus are not intended to be limiting. For example, the terms "first," "second," and other such numerical terms referring to structures or elements do not imply a sequence or order unless clearly indicated by the context.

It will be further understood that the terms "comprises/comprising," "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In the present disclosure, the term "providing" is used broadly to encompass all ways of obtaining an object, and thus "providing an object" includes, but is not limited to, "purchasing," "preparing/manufacturing," "arranging/setting," "installing/assembling," and/or "ordering" the object, and the like.

As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Those skilled in the art will appreciate that the boundaries between the above described operations merely illustrative. Multiple operations may be combined into a single operation, single operations may be distributed in additional operations, and operations may be performed at least partially overlapping in time. Moreover, alternative embodiments may include multiple instances of a particular operation, and the order of operations may be altered in various other embodiments. However, other modifications, variations, and alternatives are also possible. The aspects and elements of all embodiments disclosed above may be combined in any manner and/or in combination with aspects or elements of other embodiments to provide multiple additional embodiments. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.

The present disclosure may also include the following examples:

1. a base station antenna extending in a longitudinal direction, the base station antenna comprising:

a plurality of first radiating element columns configured for operation in a first operating frequency band, each first radiating element column comprising a plurality of first radiating elements arranged along the longitudinal direction; and

a separation wall positioned between adjacent columns of first radiating elements and extending along the longitudinal direction, wherein the separation wall includes a frequency selective surface configured such that electromagnetic waves within the first operating frequency band are substantially blocked by the separation wall.

2. The base station antenna of example 1, wherein the frequency selective surface is configured to reflect electromagnetic waves within the first operational frequency band.

3. The base station antenna of example 1, further comprising a plurality of second radiating element columns configured to operate in a second operating frequency band different from and non-overlapping with the first operating frequency band, each second radiating element column comprising a plurality of second radiating elements arranged in a longitudinal direction, wherein the frequency selective surface is further configured to enable electromagnetic waves within the second operating frequency band to propagate through the separation wall.

4. The base station antenna of example 3, wherein the second operating frequency band is higher than the first operating frequency band.

5. The base station antenna of any of examples 1 to 4, wherein the separation wall comprises a frequency selective surface on a printed circuit board.

6. The base station antenna according to any one of examples 1 to 4, wherein the partition wall includes a dielectric plate having first and second opposite sides facing the respective first columns of radiating elements, the first and second sides each being formed with a periodic conductive structure forming the frequency selective surface.

7. The base station antenna according to example 6, wherein the isolation wall includes a plurality of isolation units that are periodically arranged, each isolation unit including a first unit structure that forms a periodic conductive structure of a first side of the dielectric plate and a second unit structure that forms a periodic conductive structure of a second side of the dielectric plate, a position of the first unit structure included in each isolation unit on the first side of the dielectric plate corresponding to a position of the second unit structure included in the isolation unit on the second side of the dielectric plate.

8. The base station antenna of example 7, wherein the periodic conductive structure of the first side of the dielectric plate comprises a grid array structure, the first unit structure comprises a grid as a repeating unit in the grid array structure, and the periodic conductive structure of the second side of the dielectric plate comprises a patch array structure, the second unit structure comprises a patch as a repeating unit in the patch array structure.

9. The base station antenna of example 8, wherein the first unit structure further comprises an extension extending from an angle to a center of the mesh and/or an extension extending from a midpoint of an edge of the mesh to the center.

10. The base station antenna according to example 9, wherein the protruding portion is a bar shape or a cross shape including two bar shapes perpendicular to each other.

11. The base station antenna of example 8, wherein the first cell structure comprises a square grid and the second cell structure comprises a square patch.

12. The base station antenna according to example 11, wherein the first unit structure further includes strip-shaped protruding portions protruding from four corners to a center of the square grid.

13. The base station antenna according to example 11, wherein the first unit structure further includes a cross-shaped extension portion extending from four corners to a center of the square grid, and a strip-shaped extension portion extending from a midpoint of four sides of the square grid to the center, the cross-shaped extension portion including two strip-shaped portions perpendicular to each other.

14. The base station antenna according to any one of examples 7 to 13, wherein the periodic conductive structures of the first and second sides of the dielectric plate are formed of a metal.

15. The base station antenna of example 1, comprising a plurality of the separation walls, each separation wall disposed at a different row of radiating elements between the adjacent first columns of radiating elements.

16. The base station antenna of example 1, further comprising a parasitic element disposed on top of the isolation wall.

17. The base station antenna of example 4, wherein the plurality of first radiating elements are masked radiating elements.

18. The base station antenna of example 4, wherein the separation wall is a first separation wall, and further comprising a second separation wall positioned between adjacent second columns of radiating elements and extending along the longitudinal direction, the second separation wall comprising a frequency selective surface configured such that electromagnetic waves within the second operational frequency band are substantially blocked by the second separation wall.

19. The base station antenna of example 18, wherein the first separation wall is also positioned between the adjacent second columns of radiating elements and the second separation wall is also positioned between the adjacent first columns of radiating elements.

20. The base station antenna of example 19, wherein the first and second isolation walls are integrally formed from a multilayer printed circuit board.

21. The base station antenna of example 19, comprising a plurality of the first separation walls and a plurality of the second separation walls alternately arranged in a column, wherein each first separation wall is disposed at a different row of radiating elements between the adjacent first columns of radiating elements, and each second separation wall is disposed at a different row of radiating elements between the adjacent second columns of radiating elements.

22. The base station antenna of example 1, wherein a height of the separation wall is greater than a height of a first radiating element of the plurality of first radiating elements.

23. The base station antenna of example 5, wherein the separation wall is implemented as a multilayer printed circuit board, one or more layers of the multilayer printed circuit board formed with a frequency selective surface configured such that electromagnetic waves within a predetermined frequency range cannot propagate through the separation wall, and wherein a combination of predetermined frequency ranges associated with the one or more layers of the multilayer printed circuit board covers the first operating frequency band.

24. A multi-band base station antenna comprising:

a plurality of low-band radiating element columns configured to operate in a low band, each low-band radiating element column comprising a plurality of low-band radiating elements arranged in a longitudinal direction;

a plurality of high-band radiating element columns configured to operate in a high-band that is higher than and non-overlapping with the low-band, each high-band radiating element column including a plurality of high-band radiating elements arranged in a longitudinal direction; and

a separation wall positioned between adjacent columns of low band radiating elements and extending in the longitudinal direction, wherein the separation wall includes a frequency selective surface configured to reflect electromagnetic waves within the low band while enabling the electromagnetic waves within the high band to propagate through the separation wall.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. The various embodiments disclosed herein may be combined in any combination without departing from the spirit and scope of the present disclosure. It will also be appreciated by those skilled in the art that various modifications may be made to the embodiments without departing from the scope and spirit of the disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A base station antenna, wherein the base station antenna extends in a longitudinal direction, the base station antenna comprising:

2. The base station antenna of claim 1, wherein the frequency selective surface is configured to reflect electromagnetic waves within the first operational frequency band.

3. The base station antenna of claim 1, further comprising a plurality of second radiating element columns configured for operation in a second operating frequency band different from and non-overlapping with the first operating frequency band, each second radiating element column comprising a plurality of second radiating elements arranged along a longitudinal direction, wherein the frequency selective surface is further configured to enable electromagnetic waves within the second operating frequency band to propagate through the separation wall.

4. The base station antenna of claim 3, wherein the second operating frequency band is higher than the first operating frequency band.

5. The base station antenna of any of claims 1 to 4, wherein the separation wall comprises a frequency selective surface on a printed circuit board.

6. The base station antenna according to any one of claims 1 to 4, wherein the partition wall comprises a dielectric plate having first and second opposing sides facing the respective first columns of radiating elements, the first and second sides each being formed with a periodic conductive structure forming the frequency selective surface.

7. The base station antenna according to claim 6, wherein the partition wall includes a plurality of partition units arranged periodically, each partition unit including a first unit structure of the periodic conductive structure forming a first side of the dielectric plate and a second unit structure of the periodic conductive structure forming a second side of the dielectric plate, a position of the first unit structure included in each partition unit on the first side of the dielectric plate corresponding to a position of the second unit structure included in the partition unit on the second side of the dielectric plate.

8. The base station antenna of claim 7, wherein the periodic conductive structure of the first side of the dielectric plate comprises a grid array structure, the first unit structure comprises a grid as a repeating unit in the grid array structure, and the periodic conductive structure of the second side of the dielectric plate comprises a patch array structure, the second unit structure comprises a patch as a repeating unit in the patch array structure.

9. The base station antenna according to claim 8, wherein the first unit structure further comprises an extension extending from an angle to a center of the mesh and/or an extension extending from a midpoint of an edge of the mesh to the center.

10. The base station antenna according to claim 9, wherein the extension is a strip or a cross, the cross comprising two strips perpendicular to each other.

11. The base station antenna of claim 8, wherein the first cell structure comprises a square grid and the second cell structure comprises a square patch.

12. The base station antenna according to claim 11, wherein the first unit structure further comprises strip-shaped protruding portions protruding from four corners to a center of the square grid.

13. The base station antenna according to claim 11, wherein the first unit structure further comprises a cross-shaped extension portion extending from four corners to a center of the square grid, and a strip-shaped extension portion extending from a midpoint of four sides of the square grid to the center, the cross-shaped extension portion comprising two strip-shaped portions perpendicular to each other.

14. The base station antenna according to any one of claims 7 to 13, wherein the periodic conductive structures of the first and second sides of the dielectric plate are formed of a metal.

15. The base station antenna of claim 1, wherein the base station antenna comprises a plurality of the separation walls, each separation wall being disposed at a different row of radiating elements between the adjacent first columns of radiating elements.

16. The base station antenna of claim 1, further comprising a parasitic element disposed on top of the isolation wall.

17. The base station antenna of claim 4, wherein the plurality of first radiating elements are masked radiating elements.

18. The base station antenna of claim 4, wherein the separation wall is a first separation wall, and further comprising a second separation wall positioned between adjacent columns of second radiating elements and extending along the longitudinal direction, the second separation wall comprising a frequency selective surface configured such that electromagnetic waves within the second operating frequency band are substantially blocked by the second separation wall.

19. The base station antenna of claim 18, wherein the first separation wall is also positioned between the adjacent second columns of radiating elements and the second separation wall is also positioned between the adjacent first columns of radiating elements.

20. The base station antenna according to claim 19, wherein the first partition wall and the second partition wall are integrally formed by a multilayer printed circuit board.

21. The base station antenna according to claim 19, wherein the base station antenna comprises a plurality of the first partition walls and a plurality of the second partition walls alternately arranged in one column, wherein each first partition wall is provided at a different radiation element row between the adjacent first radiation element columns, and each second partition wall is provided at a different radiation element row between the adjacent second radiation element columns.

22. The base station antenna of claim 1, wherein a height of the separation wall is greater than a height of a first radiating element of the plurality of first radiating elements.

23. The base station antenna of claim 5, wherein the separation wall is implemented as a multilayer printed circuit board, one or more layers of the multilayer printed circuit board being formed with a frequency selective surface configured such that electromagnetic waves within a predetermined frequency range cannot propagate through the separation wall, and wherein a combination of predetermined frequency ranges associated with the one or more layers of the multilayer printed circuit board covers the first operating frequency band.

24. A multi-band base station antenna, comprising: