WO2022028669A1

WO2022028669A1 - A 3d radiating architecture for a smart antenna device

Info

Publication number: WO2022028669A1
Application number: PCT/EP2020/071802
Authority: WO
Inventors: Ignacio Gonzalez; Alejandro Murillo BARRERA; Bruno BISCONTINI
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2020-08-03
Filing date: 2020-08-03
Publication date: 2022-02-10

Abstract

The present disclosure relates to an antenna device. The presented antenna device comprises a three-dimensional (3D) radiating architecture. The antenna device, in particular, the antenna device comprises a first 2D arrangement of radiating elements comprising two or more radiating elements arranged adjacent to each other in a first plane. Further, it comprises a second 2D arrangement of radiating elements comprising two or more radiating elements arranged adjacent to each other in a second plane. The second plane is parallel to but not the same as the first plane. Further, it comprises a plurality of feeding structures for connecting a plurality of clusters of radiating elements to a plurality of radio chains, wherein each feeding structure is configured to connect one of the clusters to one of the radio chains.

Description

A 3D RADIATING ARCHITECTURE FOR A SMART ANTENNA DEVICE

TECHNICAL FIELD

The present disclosure relates to an antenna device. In particular, the disclosure presents an antenna device, which includes two or more two-dimensional (2D) arrangements of radiating elements. Each 2D arrangement comprises multiple radiating elements, and is arranged in a different parallel plane. Accordingly, the antenna device of the disclosure comprises a three-dimensional (3D) radiating architecture. As a consequence, the antenna device enables the construction of smart antenna devices and antennas with improved performance, for instance, a multiple input multiple output (MIMO) antenna.

BACKGROUND

By definition, a communication system based on a massive MIMO (mMIMO) antenna makes use of multiple antenna devices, wherein each antenna device comprises one or more radiating elements (radiators). That is, the mMIMO antenna may comprise multiple of such antenna devices. However, the allowed size of the entire radiating area of the antenna, i.e., the antenna aperture area, in which all the antenna devices and their radiating elements need to be placed, is constrained.

It is further known that increasing the quantity of antenna devices, and thus radiating elements, within the available antenna aperture area beyond a certain density turns out counterproductive. In particular, the antenna devices couple with each other, and their radiation patterns become highly correlated. This results in a poorer antenna performance.

To improve the performance of the antenna, e.g. by introducing a higher flexibility in the radiation pattern control, a greater number of TRx (radio chains) may be used. These TRx should be mapped onto the available radiating elements of the antenna devices. This mapping should furthermore be designed in a way that suits the network environment, such as the coverage requirements and the user distribution. Conventionally, this mapping is done over a plane, normally by distributing the antenna devices and their radiating elements, in clusters, for instance, columns, rows or fractions thereof (e.g. halves, quarters, etc.).

As an example, a MIMO antenna may make use of a planar radiating panel, in which clusters of radiating elements of one or more antenna devices are distributed vertically, horizontally, or both. The MIMO antenna may present different geometries, e.g. square, rectangular, circular, but the radiating elements are always arranged in a plane.

However, the exemplary MIMO antenna still lacks an efficient use of the antenna aperture area.

SUMMARY

In view of the above-mentioned issues, embodiments of the present invention aim to provide an improved antenna, in particular, an improved MIMO antenna. An objective is to provide an antenna with a radiating architecture, which makes better use of the available antenna aperture area. To this end, a new kind of antenna device should be provided. In particular, the antenna device should allow using all three dimensions for arranging and clustering multiple radiating elements. Further, it should be possible to increase the number of clusters of radiating elements compared to conventional antenna devices, without increasing the footprint of the antenna device and/or the aperture area of an antenna including the antenna device. Moreover, the cluster sizes should not be reduced.

The objective is achieved by the embodiments of the invention as described in the enclosed independent claims. Advantageous implementations of the embodiments of the invention are further defined in the dependent claims.

In particular, embodiments of the invention provide an antenna device comprising stacked planes of radiating elements (which may be clustered), thus enabling an increased performance, under the constraint of a given antenna aperture area. From a different perspective, the antenna aperture area could be reduced for a given number of (clusters of) radiating elements, at the expense of increasing the antenna thickness (by stacking more planes). A first aspect of the disclosure provides an antenna device comprising: a first two- dimensional arrangement of radiating elements, the first arrangement comprising two or more radiating elements arranged adjacent to each other in a first plane; a second two- dimensional arrangement of radiating elements, the second arrangement comprising two or more radiating elements arranged adjacent to each other in a second plane, the second plane being parallel to but not the same as the first plane; and a plurality of feeding structures for connecting a plurality of clusters of radiating elements to a plurality of radio chains, wherein each feeding structure is configured to connect one of the clusters to one of the radio chains.

Since the 2D arrangements of radiating elements are arranged in parallel planes, the radiating elements, and also the clusters of radiating elements, may be stacked, for instance, along the z-axis of the antenna device (e.g., a direction perpendicular to the planes, which may extend along the x-axis and the y-axis). For instance, one or more planes (each comprising a 2D arrangements of radiating elements) may be provided above a conventional linear or planar array of radiating elements. “Above” may thereby mean that the planes are distanced from each other along the z-axis. Thus, the number of clusters may be increased without increasing the antenna aperture area. The greater number of clusters is possible due to a higher exploitation the potential degrees of freedom of the antenna aperture area. The greater number of clusters can enhance the antenna performance.

The two or more 2D arrangements form a 3D radiating architecture of the antenna device. The clusters in this 3D architecture can maintain a sufficient level of decorrelation. Further, “upper” 2D arrangements of radiating elements may exhibit enough transparency to the “lower” 2D arrangements of radiating elements, in order to not interfere with their performance due to shadowing. “Upper” and “lower” may refer to the z-axis and whether the 2D arrangement is placed closer (“lower”) to an antenna reflector or further away from (“upper) the antenna reflector of the antenna. The antenna reflector may be configured to reflect radiation from the 2D arrangements along a main radiation direction of the antenna. Specifically, but not exclusively, the antenna device of the first aspect may be applied in a multi-user cellular communication system based on a mMIMO antenna. In an implementation form of the first aspect, the first two-dimensional arrangement is a first layer of radiating elements arranged in the first plane; and the second two-dimensional arrangement is a second layer of radiating elements arranged in the second plane.

More than two layers of radiating elements may be stacked one above the other along the first direction.

In an implementation form of the first aspect, the first plane and the second plane are offset from each other by a determined distance along a first direction that is perpendicular to the planes.

In an implementation form of the first aspect, the first two-dimensional arrangement and the second two-dimensional arrangement are arranged within an antenna aperture area that is parallel to the planes.

In this way, by stacking two or more 2D arrangements, the number of radiating elements and clusters can be increased without increasing the antenna aperture area.

In an implementation form of the first aspect, the first and/or second two-dimensional arrangement is at least partly transparent for radiation generated by the two or more radiating elements in the other two-dimensional arrangement.

Thus, shadowing effects and a consequent performance loss of “lower” 2D arrangements can be avoided.

In an implementation form of the first aspect, the second two-dimensional arrangement is aligned with the first two-dimensional arrangement in a second direction parallel to the planes and/or in a third direction parallel to the planes, wherein the third direction is perpendicular to the second direction.

The alignment of the 2D arrangements allows providing a minimum antenna aperture area.

In an implementation form of the first aspect, the second two-dimensional arrangement is displaced relative to the first two-dimensional arrangement along a second direction parallel to the planes and/or a third direction parallel to the planes, wherein the third direction is perpendicular to the second direction.

The displacement of the 2D arrangements reduces shadowing and may improve performance.

In an implementation form of the first aspect, the antenna device comprises: three or more two-dimensional arrangements of radiating elements, including the first two-dimensional arrangement and the second two-dimensional arrangement, wherein each two-dimensional arrangement comprises two or more radiating elements arranged adjacent to each other in a plane, the planes including the first plane and the second plane, and the planes being parallel to each other but not the same.

Any number of 2D arrangements may in principle be stacked above each other, of course, leading to an increased thickness of the antenna device (particularly z-dimension of the antenna device).

In an implementation form of the first aspect, the radiating elements of the first two- dimensional arrangement form one or more of the clusters; and/or the radiating elements of the second two-dimensional arrangement form one or more of the clusters.

Clusters may thus be formed in each plane of the antenna device.

In an implementation form of the first aspect, the first two-dimensional arrangement and/or the second two-dimensional arrangement comprises one or more rows or columns of radiating elements; and each row or column includes two or more radiating elements arranged one after the other along a second direction parallel to the first and/or second plane.

In an implementation form of the first aspect, the first two-dimensional arrangement and/or the second two-dimensional arrangement comprises two or more rows or columns; and the two or more rows or columns are placed side by side along a third direction perpendicular to the second direction. In an implementation form of the first aspect, the first two-dimensional arrangement comprises four rows or columns; the second two-dimensional arrangement comprises four rows or columns; and each row or column comprises four radiating elements, in particular four dual-polarized radiating elements.

In an implementation form of the first aspect, each row or column corresponds to one of the clusters.

In an implementation form of the first aspect, at least one of the clusters comprises one or more radiating elements of the first two-dimensional arrangement and one or more radiating elements of the second two-dimensional arrangement.

Thus, clusters may be formed which span the z-direction, i.e., are distributed over two or more 2D arrangements of radiation elements, thus, two or more planes.

In an implementation form of the first aspect, at least one of the clusters comprises two or more radiating elements of only the first two-dimensional arrangement or two or more radiating elements of only the second two-dimensional arrangement.

Clusters may thus be formed, which are limited to one 2D arrangements, i.e., they do not span the z-direction.

In an implementation form of the first aspect, the two or more radiating elements in the first two-dimensional arrangement are of the same kind; and/or the two or more radiating elements in the second two-dimensional arrangement are of the same kind.

For instance, a kind of radiating element may be a dipole radiating element, or a patch radiating element, and/or a linear dual -polarized radiating element, and/or a multi-mode radiating element.

In an implementation form of the first aspect, the two or more radiating elements in the first two-dimensional arrangement are of the same kind than the radiating elements in the second two-dimensional arrangement; or the two or more radiating elements in the first two-dimensional arrangement are of a different kind than the radiating elements in the second two-dimensional arrangement.

In an implementation form of the first aspect, the first two-dimensional arrangement comprises two or more different kinds of radiating elements; and/or the second two- dimensional arrangement comprises two or more different kinds of radiating elements.

In an implementation form of the first aspect, the first two-dimensional arrangement and/or the second two-dimensional arrangement comprises two or more dual-polarized radiating elements.

In an implementation form of the first aspect, the first two-dimensional arrangement and/or the second two-dimensional arrangement comprises two or more multi-mode radiating elements.

In an implementation form of the first aspect, the antenna device comprises: one or more multi-layered radiating devices; wherein each multi-layered radiating device comprises a first radiating element and a second radiating element arranged on a common axis, and wherein the first radiating element is a radiating element of the first two-dimensional arrangement and the second radiating element is a radiating element of the second two- dimensional arrangement.

The one or more multi-layered radiating devices may thus form the first 2D arrangement and the second 2D arrangement. For instance, multiple of the multi-layered radiating devices may arranged adjacent to each other and/or in a 2D pattern, to form the 2D arrangements.

A second aspect of the disclosure provides an antenna, in particular a MIMO antenna, wherein the antenna comprises at least one antenna device according to the first aspect or any of its implementation forms.

The performance of the antenna can be improved by using the one or more antenna devices according to the first aspect. In particular an aperture area of the antenna can be more efficiently used to provide radiating element, specifically clusters of radiating elements, since all three dimensions are usable. The antenna may be a smart antenna, in the sense that controlling selectively the feeding of the antenna devices, and also selectively the clusters per antenna device, may shape the radiation pattern of the antenna.

It has to be noted that all devices, elements, units and means described in the present application could be implemented in the software or hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof.

BRIEF DESCRIPTION OF DRAWINGS

The above described aspects and implementation forms will be explained in the following description of specific embodiments in relation to the enclosed drawings, in which

FIG. 1 shows an antenna device according to an embodiment of the invention.

FIGs. 2a-c show several antenna devices according to embodiments of the invention.

FIGs. 3a-c show several antenna devices according to embodiments of the invention.

FIG. 4 shows a multi-layered radiating device for an antenna device according to an embodiment of the invention.

FIG. 5 shows an antenna according to an embodiment of the invention, which comprises at least one antenna device according to an embodiment of the invention. FIGs. 6a-c compares a cell throughput of an antenna comprising an antenna device according to an embodiment of the invention with a conventional antenna.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows an antenna device 100 according to an embodiment of the invention. The antenna device may be used for/in an antenna 500 (see e.g. FIG. 5), in particular, for/in a MIMO antenna or mMIMO antenna. The antenna device 100 comprises a plurality of radiating elements 101, which may be distributed in all three dimensions (x-axis, y-axis, and z-axis) with respect to an antenna aperture area of the antenna 500. Thus, the antenna device 100 may provide a 3D architecture of radiating elements 101.

In particular, the antenna device 100 comprises a first 2D arrangement of radiating elements 101, wherein the first arrangement comprises two or more radiating elements 101 arranged adjacent to each other in a first plane 102. Furthermore, the antenna device 100 comprises a second 2D arrangement of radiating elements 101, wherein the second arrangement comprises two or more radiating elements 101 arranged adjacent to each other in a second plane 103. The second plane 103 is parallel to, but not the same as, the first plane 102. The planes 102, 103 may be offset from each other by a determined distance along a first direction perpendicular to the planes. Specifically, as shown, the planes 102 and 103 may be offset along the z-axis, while the planes 102 and 103 may be spanned by the x-axis and y-axis (of the Cartesian coordinate system indicated). The 2D arrangements of radiating elements 101 may be arranged within the antenna aperture area of the antenna 500, wherein the antenna aperture area may be parallel to the planes 102, 103. Each 2D arrangement may be or comprises a layer of radiating elements 101 arranged in a respective plane 102, 103. The antenna device 100 is not limited to two 2D arrangements in the two planes 102 and 103, but may comprise further 2D arrangements in further planes (as described further below).

The radiating elements 101 may all be of the same kind. Alternatively, the radiating elements 101 in each plane 102, 103 may be of the same kind, but may be of different kind from plane to plane. That is, the two or more radiating elements 101 in the first 2D arrangement may be of the same kind, and/or the two or more radiating elements 101 in the second 2D arrangement may be of the same kind. However, each plane 102, 103 may also contain two or more different kinds of radiating elements 101.

Further, the radiating elements 101 of the first 2D arrangement may form one or more of the clusters 105, and/or the radiating elements 101 of the second 2D arrangement may form one or more of the clusters 105. A cluster 105 may, for instance, be formed completely in the first 2D arrangement (like cluster 105_b shown in FIG. 1) or completely in the second 2D arrangement of radiating elements 101 (like cluster 105_c shown in FIG. 1). However, at least one of the clusters 105, or each of multiple clusters 105, may comprise one or more radiating elements 101 of the first 2D arrangement and one or more radiating elements 101 of the second 2D arrangement. That is, a cluster 105 may also be formed by radiating elements 101 of different two 2D arrangements (like cluster 105_a in FIG. 1). A cluster 105 may even span more than two 2D arrangements arranged in more than two parallel planes.

The antenna device 100 further comprises a plurality of feeding structures 104 for connecting a plurality of clusters 105 of radiating elements 101 to a plurality of radio chains 106. Each of the feeding structures 104 is thereby configured to connect one of the clusters 105 to one of the radio chains 106. Each feeding structure 104 may comprise a feeding line, which is connected to the respective cluster 105 of radiating elements 101, for instance, is connected to each radiating element 101 of said cluster 105.

FIG. 2 shows various examples of antenna devices 100 according to embodiments of the invention, which each builds on the embodiment shown in FIG. 1. Same elements in FIG. 1 and FIG. 2 are labelled with the same reference signs, and may be implemented likewise.

In each of the antenna devices 100 shown in FIG. 2, the first 2D arrangement and/or the second 2D arrangement of radiating elements 101 comprises one or more columns 203 of radiating elements 101. A column 203 may comprises two or more radiating elements 101 arranged one after the other along a certain direction, e.g. along the y-axis. Further, each column 203 may corresponds to one of the clusters 105. Columns 203 and/or clusters 105 may be replicated along the x-axis, and/or may be stacked along the z-axis. Generally, an antenna device 100 according to an embodiment of the invention may comprise three or more 2D arrangements of radiating elements 101, including the first 2D arrangement and the second 2D arrangement. In this case, notably, each 2D arrangement comprises two or more radiating elements 101 arranged adjacent to each other in a plane 102, 103, 201, 202, wherein the planes 102, 103, 201, 202 include the first plane 102 and the second plane 103, and the planes 102, 103, 201, 202 are parallel to each other but not the same. Further, each of the 2D arrangements of radiating elements 101 may comprise one or more columns 203 of radiating elements 101.

FIG. 2(a) shows an antenna device 100, which comprises four 2D arrangements of radiating elements 101, the radiating elements 101 of each 2D arrangement being arranged in a different plane of four parallel planes 102, 103, 201, 202 , which are offset along the z-axis (first direction). Further, FIG. 2(a) shows that each of the four 2D arrangements comprises one column 203 of radiating elements 101, each column 203 extending into the y-direction (second direction, also referred to as “vertical” with respect to how the antenna device 100 may be installed in the antenna 500).

FIG. 2(b) shows an antenna device 100, which has two 2D arrangements of radiating elements 101, the radiating elements 101 of each 2D arrangement being arranged in a different plane of two parallel planes 102, 103, which are offset along the z-axis (first direction). Further, FIG. 2(b) shows that each of the two 2D arrangements comprises four columns 203 of radiating elements 101, wherein the four columns 203 are placed side-by- side along the x-axis (third direction, also referred to as “horizontal” with respect to how the antenna device 100 may be installed in the antenna 500). Further, each column 203 extends along the y-axis (second direction, also referred to as “vertical” with respect to how the antenna device 100 may be installed in the antenna 500). Each column 203 comprises four radiating elements 101, which may be four dual-polarized radiating elements 101. The antenna device 100 of FIG. 2(b) may be a “V4Z2 16T16R” antenna device 100, wherein “V4” stands for each of the four columns 203 having radiating elements 101 arranged along the (“vertical”) y-axis, “Z2” stands for the two planes 102, 103 stacked along the z-axis, and “16T16R” stands for the number of clusters 105 of radiating elements 101 that the antenna device 100 may use for transmitting and receiving (16 clusters 105 in total, up to 16 clusters 105 for transmitting, and/or up to 16 clusters 105 for receiving, wherein each cluster 105 may be versatile and may work for transmitting and/or receiving).

FIG. 2(c) shows an antenna device 100, which has four 2D arrangements of radiating elements 101, the radiating elements 101 of each 2D arrangement being arranged in a different plane of four parallel planes 102, 103, 201, 202, which are offset along the z-axis (first direction). Further, FIG. 2(c) shows that each of the two 2D arrangements comprises four columns 203 of radiating elements 101, wherein the four columns 203 are placed side- by-side along the x-axis (third direction, also referred to as “horizontal” with respect to how the antenna device 100 may be installed in the antenna 500). Further, each column 20 extends along the y-axis (second direction, also referred to as “vertical” with respect to how the antenna device 100 may be installed in the antenna 500). Each column 203 comprises four radiating elements 101, which may be four dual-polarized radiating elements 101. The antenna device 100 of FIG. 2(b) may be a “V4Z4 32T32R” antenna device 100, wherein “V4” stands again for each of the four columns 203 having radiating elements 101 arranged along the (“vertical”) y-axis, “Z4” stands for the four planes 102, 103, 201, 202 stacked along the z-axis, and “32T32R” stands for the number of clusters 105 of radiating elements 101 that the antenna device 100 may use for transmitting and receiving (32 clusters 105 in total, up to 32 clusters 105 for transmitting, and/or up to 32 clusters 105 for receiving).

FIG. 3 shows further examples of possible embodiments of the antenna device 100, wherein the 2D arrangements comprise one or more columns 203 or rows 303 of radiating elements 101. Each column 203 or row 303 may be or comprise a cluster 105. A row 303 of radiating elements 101 may comprises two or more radiating elements 101 arranged one after the other along a certain direction, e.g. along the x-axis. Further, each row 203 may corresponds to one of the clusters 105. Rows 303 and/or clusters 105 may be replicated along the y-axis, and/or may be stacked along the z-axis

In particular, FIG. 3(a) shows (left side) an antenna device 100, which may be a “HZ2 4T4R” antenna device 100, wherein “H” indicates that there is just one row 303 (in other embodiments there could be two or more rows 303 placed side-by-side along the y-axis), wherein the one row 303 has radiating elements 301 arranged along the x-axis (also referred to as “horizontal” with respect to how the antenna device 100 may be installed in the antenna 500), “Z2” means that two rows 303 are stacked along the z-axis, and “4T4R” denotes the number of clusters 105 of radiating elements 101 that the antenna device 100 may use for transmitting and receiving, as explained above. That is, the antenna device 100 has 4 clusters 105 of radiating elements 101, up to 4 for transmitting and/or up to 4 for receiving.

FIG. 3(a) further shows (right side) an antenna device 100, which may be a “HZ4 8T8R” antenna device 100, wherein “Z4” indicates that this antenna device 100 has four 2D arrangements of radiating elements 101 offset along the z-axis (first direction). Each 2D arrangement comprises one row 303 extending along the x-direction (third direction, also referred to as “horizontal” with respect to how the antenna device 100 may be installed in the antenna 500). The antenna device may have 8 clusters 105 of radiating elements 101, up to 8 for transmitting and/or up to 8 for receiving.

Further, FIG. 3(b) shows (left side) an antenna device 100, which may be a “NZ2 4T4R” antenna device 100. This antenna device 100 has accordingly two 2D arrangements of radiating elements 101 offset along the z-axis (first direction), and each 2D arrangement comprises one column 203 extending along the y-direction (second direction, also referred to as “vertical” with respect to how the antenna device 100 may be installed in the antenna 500). The “V” means that only one column 203 per 2D arrangement is arranged along the (“horizontal”) x-axis (in other embodiments there could be two or more columns 203 placed side-by-side along the x-axis). The antenna device may have 4 clusters 105 of radiating elements 101, up to 4 for transmitting and/or up to 4 for receiving.

FIG. 3(b) further shows (right side) an antenna device 100, which may be a “VZ4 8T8R” antenna device 100. This antenna device 100 has four 2D arrangements of radiating elements 101 offset along the z-axis (first direction), and each 2D arrangement comprises one column 203 extending along the y-direction (second direction, also referred to as “vertical” with respect to how the antenna device 100 may be installed in the antenna 500). The antenna device may have 8 clusters 105 of radiating elements 101, up to 8 for transmitting and/or up to 8 for receiving, and is particularly designed in a similar manner than the antenna device 100 shown in FIG. 2(a). FIG. 3(c) shows further conventional planar antenna devices, wherein the radiating elements are arranged in “vertically” or “horizontally” extending clusters, wherein two or more clusters may be arranged side-by-side along the “vertical” or “horizontal” direction, respectively, but the z-axis as possible third dimension is unused.

Notably, specifically with respect to FIG. 2 and FIG. 3, any number of radiating elements 101 may be combined into one cluster 105. For instance, if there are k dual -polarized radiating elements 101 in an antenna device 100, there may be 2*k clusters 105.

In the embodiments of FIG. 1-3, the 2D arrangements in “upper” planes 103, 201, 202 may have a sufficient level of transparency with respect to the “lower” planes 102, 102, 201, respectively. Furthermore, the planes 102, 103, 201, 202 may be either perfectly aligned, or may be placed with a certain offset along the x-axis and/or y-axis, to reduce shadowing. For instance, any 2D arrangement may be aligned with another 2D arrangement in a second direction (y-direction) parallel to the planes 102, 103, 201, 202 and/or in a third direction (x-direction) parallel to the planes 102, 103, 201, 202.

FIG. 4 shows a multi-layered radiating device 400. One or more such multi-layered radiating devices 400 may be used to form an antenna device 100 according to an embodiment of the invention, for instance, as shown in FIG. 1-3. The multi-layered radiating device 400 comprises a first radiating element 101_a and a second radiating element 101_b, which are arranged on a common axis 401 (e.g., a common axis parallel to the z-axis). The first radiating element 101_a may be a radiating element 101 of the first 2D arrangement (e.g., first layer), i.e. may be a radiating element 101 of a first plane 102. The second radiating element 101_b may be a radiating element 101 of the second 2D arrangement (e.g., second layer), i.e. may be a radiating element 101 of a second plane 102. Thus, the first radiating element 101_a and the second radiating element 101_b are offset along the z-axis. The antenna device 100 may comprise multiple such multi-layered radiating devices 400 arranged along the x-axis and/or y-axis. Thus, the first radiating elements 101_a of the multiple devices 400 may form the first 2D arrangement, and the second radiating elements 101_b of the multiple devices 400 may form the second 2D arrangement. The multi-layered radiating device 400 may further comprise a support structure 402 for holding the two 2D arrangements offset along the z-axis. Further, the device 400 may comprise feeding lines 403 of the feeding structure 103, the feeding lines 403 connecting the first and second radiating elements 101_la and 101_b. Further, the device 400 may comprise a base structure 404, on which the support structure 402 is provided. The base structure 404 may be Printed Circuit Board (PCB) that carries at least a part of the feeding structure 104 and/or may comprise a reflector for directing radiation from the first radiating element 101_a and the second radiating element 101_b along a main radiation direction, for instance, with the common axis 401 as center.

FIG. 5 shows schematically an antenna 500, which may be a MIMO antenna. The antenna 500 comprises at least one antenna device 100 according to an embodiment of the invention, e.g., as shown in one of the Fig. 1-3.

The benefits of embodiments of the invention has been checked and validated as shown in the graphs in FIG. 6(a)-(c). In particular, FIG. 6 shows cell throughput of an antenna (exemplarily a MIMO antenna) comprising at least one antenna device 100 according to an embodiment of the invention, compared with a conventional antenna.

It can be seen from these graphs that the antenna with antenna devices 100 according to embodiments of the invention, which comprises two or more planes 102, 103, 201, 202 offset along the z-axis (i.e., “HZ2 4T4R”, “HZ4 8T8R”, “VZ2 4T4R”, “VZ4 8T8R”, “V4Z2 16T16R”, and “V4Z4 32T32R”), show an improved performance, in particular a capacity improvement, compared to the conventional antenna with conventional antenna devices (i.e., “Hl 2T2R”, “VI 2T2R” and “V4 8T8R).

Also analysing the radiation patterns of the resulting antenna devices 100 according to embodiments of the invention showed that two main mechanisms cause the improvement. Firstly, The 2D arrangements and/or clusters 105 arranged offset along the z-direction allows a directivity increase of the radiation of the antenna device 100. Secondly, this allows allocation of a higher number of TRx, while maintaining their high directivity (i.e. not sub-dividing the existing clusters 105). The present disclosure has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed subject matter, from the studies of the drawings, this disclosure and the independent claims. In the claims as well as in the description the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

1. An antenna device (100) comprising: a first two-dimensional arrangement of radiating elements (101), the first arrangement comprising two or more radiating elements (101) arranged adjacent to each other in a first plane (102); a second two-dimensional arrangement of radiating elements (101), the second arrangement comprising two or more radiating elements (101) arranged adjacent to each other in a second plane (103), the second plane (103) being parallel to but not the same as the first plane (102); and a plurality of feeding structures (104) for connecting a plurality of clusters (105) of radiating elements (101) to a plurality of radio chains (106), wherein each feeding structure (104) is configured to connect one of the clusters (105) to one of the radio chains (106).

2. The antenna device (100) according to claim 1, wherein: the first two-dimensional arrangement is a first layer of radiating elements (101) arranged in the first plane (102); and the second two-dimensional arrangement is a second layer of radiating elements (101) arranged in the second plane (103).

3. The antenna device (100) according to claim 1 or 2, wherein: the first plane (102) and the second plane (103) are offset from each other by a determined distance along a first direction that is perpendicular to the planes (102, 103).

4. The antenna device (100) according to one of the claims 1 to 3, wherein: the first two-dimensional arrangement and the second two-dimensional arrangement are arranged within an antenna aperture area that is parallel to the planes (102, 103).

5. The antenna device (100) according to one of the claims 1 to 4, wherein: the first and/or second two-dimensional arrangement is at least partly transparent for radiation generated by the two or more radiating elements (101) in the other two- dimensional arrangement.

6. The antenna device (100) according to one of the claims 1 to 5, wherein: the second two-dimensional arrangement is aligned with the first two-dimensional arrangement in a second direction parallel to the planes (102, 103) and/or in a third direction parallel to the planes (102, 103), wherein the third direction is perpendicular to the second direction.

7. The antenna device (100) according to one of the claims 1 to 5, wherein: the second two-dimensional arrangement is displaced relative to the first two- dimensional arrangement along a second direction parallel to the planes (102, 103) and/or a third direction parallel to the planes (102, 103), wherein the third direction is perpendicular to the second direction.

8. The antenna device (100) according to one of the claims 1 to 7, comprising: three or more two-dimensional arrangements of radiating elements (101), including the first two-dimensional arrangement and the second two-dimensional arrangement, wherein each two-dimensional arrangement comprises two or more radiating elements (101) arranged adjacent to each other in a plane (102, 103, 201, 202), the planes (102, 103, 201, 202) including the first plane (102) and the second plane (103), and the planes (102, 103, 201, 202) being parallel to each other but not the same.

9. The antenna device (100) according to one of the claims 1 to 8, wherein: the radiating elements (101) of the first two-dimensional arrangement form one or more of the clusters (105); and/or the radiating elements (101) of the second two-dimensional arrangement form one or more of the clusters (105).

10. The antenna device (100) according to one of the claims 1 to 9, wherein: the first two-dimensional arrangement and/or the second two-dimensional arrangement comprises one or more rows (303) or columns (203) of radiating elements (101); and each row (303) or column (203) includes two or more radiating elements (101) arranged one after the other along a second direction parallel to the first and/or second plane (102, 103).

11. The antenna device (100) according to claim 10, wherein: the first two-dimensional arrangement and/or the second two-dimensional arrangement comprises two or more rows (303) or columns (203); and the two or more rows (303) or columns (203) are placed side by side along a third direction perpendicular to the second direction.

12. The antenna device (100) according to claim 11, wherein: the first two-dimensional arrangement comprises four rows (303) or columns (203); the second two-dimensional arrangement comprises four rows (303) or columns (203); and each row (303) or column (203) comprises four radiating elements (101), in particular four dual-polarized radiating elements (101).

13. The antenna device (100) according to one of the claims 10 to 12, wherein: each row (303) or column (203) corresponds to one of the clusters (105).

14. The antenna device (100) according to one of the claims 1 to 12, wherein: at least one of the clusters (105) comprises one or more radiating elements (101) of the first two-dimensional arrangement and one or more radiating elements (101) of the second two-dimensional arrangement.

15. The antenna device (100) according to one of the claims 1 to 12 or claim 14, wherein: at least one of the clusters (105) comprises two or more radiating elements (101) of only the first two-dimensional arrangement or two or more radiating elements (101) of only the second two-dimensional arrangement.

16. The antenna device (100) according to one of the claims 1 to 15, wherein:

19 the two or more radiating elements (101) in the first two-dimensional arrangement are of the same kind; and/or the two or more radiating elements (101) in the second two-dimensional arrangement are of the same kind.

17. The antenna device (100) according to claim 16, wherein: the two or more radiating elements (101) in the first two-dimensional arrangement are of the same kind than the radiating elements (101) in the second two-dimensional arrangement; or the two or more radiating elements (101) in the first two-dimensional arrangement are of a different kind than the radiating elements (101) in the second two-dimensional arrangement.

18. The antenna device (100) according to one of the claims 1 to 17, wherein: the first two-dimensional arrangement comprises two or more different kinds of radiating elements (101); and/or the second two-dimensional arrangement comprises two or more different kinds of radiating elements (101).

19. The antenna device (100) according to one of the claims 1 to 18, wherein: the first two-dimensional arrangement and/or the second two-dimensional arrangement comprises two or more dual-polarized radiating elements (101).

20. The antenna device (100) according to one of the claims 1 to 19, wherein: the first two-dimensional arrangement and/or the second two-dimensional arrangement comprises two or more multi-mode radiating elements (101).

21. The antenna device (100) according to one of the claims 1 to 20, comprising: one or more multi-layered radiating devices (400); wherein each multi-layered radiating device (400) comprises a first radiating element (101) and a second radiating element (101) arranged on a common axis, and wherein the first radiating element (101) is a radiating element (101) of the first two- dimensional arrangement and the second radiating element (101) is a radiating element of the second two-dimensional arrangement.

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22. An antenna (500), in particular a multiple input multiple output, MIMO, antenna, wherein the antenna (500) comprises at least one antenna device (100) according to one of the claims 1 to 21.

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