A SUBARRAY ANTENNA ADAPTED TO BE MOUNTED TO OTHER SUBARRAY ANTENNAS, AND AN ARRAY ANTENNA FORMED BY SUCH SUBARRAY ANTENNAS

Abstract

The present disclosure relates to a sub array antenna (101a, 101b, 101c) adapted to be mounted to at least one other sub array antenna (101a, 101b, 101c) along at least one extension (E1, E2) to form an array antenna (100). The sub array antenna (101a, 101b, 101c) comprises an electrically conducting ground plane (102a, 102b, 102c) and at least one edge part (104a, 105a; 104b, 105b; 104c, 105c) that is adapted to face an edge part of an adjacent sub array antenna. The edge part (104a, 105a; 104b, 105b; 104c, 105c) at least partly comprises a locking structure comprising an outer lock part (103a, 103b) and an indent (106a, 106b) that is positioned between the outer lock part (103a, 103b) and the ground plane (102a, 102b, 102c) in a direction of the extension (E1, E2). The indent (106a, 106b) is adapted to receive an adjacent outer lock part (103b, 103a) of an adjacent sub array antenna (101b, 101a), and the outer lock part (103b, 103a) is adapted to engage an indent (106b, 106a) of an adjacent sub array antenna (101b, 101a). The outer lock part (103b, 103a) and the indent (106a, 106b) are electrically conducting and electrically connected to the ground plane (102a, 102b).

Description

TECHNICAL FIELD

The present disclosure relates to subarray antennas adapted to be mounted to each other, and an array antenna formed by such subarray antennas. Each subarray antenna comprises an electrically conducting ground plane and at least one edge part that is adapted to face an edge part of an adjacent subarray antenna.

BACKGROUND

There is a general demand in increased data capacity in the digital communication networks globally. Today many 5G networks use phased arrays, but there are also solutions for 4G. The trend is that the arrays are getting bigger and bigger with an increased number of antenna elements; for future 6G networks there are discussions about arrays with more than 1000 antenna elements. Due to lack of bandwidth there is also a desire to use higher and higher frequencies. 5G is already today using for example 28 GHz and 39 GHz, and 47 GHz and possibly higher bands are considered as well. For 6G, frequencies around and above 100 GHz are considered.

To limit the number of antennas in the networks, a relative high beam steering is considered. Beam steering in azimuth ±60° is likely. This will require a small element-to-element distance to avoid so called grating lobes, and with ±60° beam steering in azimuth, an element distance of about a half wavelength is needed. In elevation, however, the beam steering is limited to +/- 15° in many use cases, thus relaxing the element-to-element distance somewhat.

There is a desire to lower the cost, resulting in that it becomes more and more common to integrate the antenna elements into packages and other types of subarray antennas that are combined to bigger arrays.

Similar challenges exist in the backhaul network and to some degree even worse, as traditional backhaul frequencies are moved to 5G and 6G applications, leading to increased backhaul frequencies. Higher frequencies in backhaul generally results in narrower antenna lobes which will make it more challenging to install the antenna and to keep the antenna steady. Most likely some type of beam tracking will be needed in the future for high gain high frequency backhaul networks. By having a small array feeding a parabolic antenna, some beam adjustment could be done during installation as well as during operation.

When designing a larger total array antenna using smaller subarray antennas, there will be discontinuities in the antenna ground that could cause major problems with the antenna performance.

Some problems are due to resonances on multiplies of half wave length.

• These could radiate.
• These could create notches in the frequency plan.
• The distance between the slots are relative long, several half wavelengths, therefore these could generate grating lobes.
• Keeping good cross polarization becomes more difficult.
• Parallel plate modes can occur which distribute RF power between antenna elements in an unpredictable manner.

Other problems are due to that the antenna elements also will excite the edge parts, and that there is no control of the grounding of the common antenna ground plane, and the related ground currents, between the subarray antennas.

A further problem when using multiple subarray antennas to build a larger total array antenna is that the alignment between the subarray antennas needs to be good, otherwise there will be a detrimental impact on the antenna patterns and the polarization purity. For example, when soldering subarray antenna components, there can be a small misalignment, and many of these misalignments can add together to a total undesired error over the total array antenna. There could also be a misalignment in height, resulting in that the ground plane level of the total array antenna can be different for the different subarray antennas. This misalignment may affect the radiation pattern and also excite the ground plan edge parts.

Even relatively small offsets between adjacent subarray antennas can result in a relatively large difference in the electrical environment. All of sudden, there can be pointwise ground connections, and as these connections will be unpredictable, they can have a major impact on antenna patterns etc.

There can also be a misalignment in height, so the ground plan level could be different for the different subarray antennas in the total array antenna. It is therefore desired to counteract these problems.

SUMMARY

It is an object of the present disclosure to provide means for mounting subarray antennas to each other while maintaining a continuous and leveled ground plane for the formed array antenna.

This object is obtained by means of a subarray antenna adapted to be mounted to at least one other subarray antenna along at least one extension to form an array antenna. The subarray antenna comprises an electrically conducting ground plane and at least one edge part that is adapted to face an edge part of an adjacent subarray antenna. The edge part at least partly comprises a locking structure comprising an outer lock part and an indent that is positioned between the outer lock part and the ground plane in a direction of the extension. The indent is adapted to receive an adjacent outer lock part of an adjacent subarray antenna, and the outer lock part is adapted to engage an indent of an adjacent subarray antenna. The outer lock part and the indent are electrically conducting and electrically connected to the ground plane.

In this way, discontinuation in the antenna ground plan in an array that consists of a number of subarray antennas is mitigated. This will reduce the risk for uncontrolled radiation from an array antenna since the risk for exciting the edges of the subarray antennas is eliminated. Thereto, the alignment of the subarray antennas will be improved. These features will also help to improve the antenna radiation pattern. Especially for higher frequencies, such as for example 100 GHz, this is advantageous since the sensitivity for ground plane discontinuations increases with increasing frequency and may limit the array performance a lot.

According to some aspects, the subarray antenna comprises a first type edge part and a second type edge part, where the first type edge part comprises a first type locking structure that is adapted to engage a second type locking structure that is comprised in the second type edge part.

In this way, a secure mounting is provided.

According to some aspects, the outer lock part comprises a slanted side that faces the indent.

In this way, movement in a direction that is perpendicular to the at least one extension is prevented, perpendicular to the extension of the ground plane. This results in that the mounting of subarray antenna even more surely will result in an even ground plane that runs in a common level.

According to some aspects, each edge part comprises at least one protrusion that extends away from the edge part and at least one notch that extends in the opposite direction, each protrusion being adapted to engage a corresponding notch in an adjacent subarray antenna and each notch being adapted to engage a corresponding protrusion in an adjacent subarray antenna.

In this way, a secure mounting that provides a continuous ground plane is provided.

According to some aspects, the ground plane is formed in a piece of metal, and the edge part is formed in the same piece of metal. Alternatively, according to some aspects, the ground plane is in the form of a metallization on a dielectric material where the edge part is formed in the dielectric material and at least partly comprises a metallization.

This means that the mounting arrangement according to the present disclosure is applicable for many different types of antenna types.

This object is also obtained by means of an array antenna and a method which are associated with the above advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will now be described more in detail with reference to the appended drawings, where:

FIG. 1 schematically shows a cut-open side view of an array antenna according to a first example with horn antennas;

FIG. 2A schematically shows a first type of locking structure for the array antenna according to the first example;

FIG. 2B schematically shows a second type of locking structure for the array antenna according to the first example;

FIG. 3 schematically shows a front view of a first type of the array antenna according to the first example;

FIG. 4A schematically shows a front view of a second type of the array antenna according to the first example, having co-operating protrusions and notches along the edges;

FIG. 4B schematically shows a detail of FIG. 4A, illustrating co-operating protrusions and notches;

FIG. 5 schematically shows a cut-open side view of an array antenna according to a second example with microstrip patch antennas;

FIG. 6A schematically shows a first type of locking structure for the array antenna according to the second example;

FIG. 6B schematically shows a second type of locking structure for the array antenna according to the second example;

FIG. 7 schematically shows a front view of a first type of the array antenna according to the second example;

FIG. 8A schematically shows a front view of a second type of the array antenna according to the first example, having co-operating protrusions and notches along the edges;

FIG. 8B schematically shows a detail of FIG. 8A, illustrating co-operating protrusions and notches; and

FIG. 9 shows a flowchart for methods according to the present disclosure.

DETAILED DESCRIPTION

Aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings. The different devices, systems, computer programs and methods disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein. Like numbers in the drawings refer to like elements throughout.

The terminology used herein is for describing aspects of the disclosure only and is not intended to limit the invention. 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.

With reference to FIG. 1 that schematically shows a cut-open side view of a first example of an array antenna 100, the array antenna 100 is constituted by a number of subarray antennas 101a, 101b, 101c. In FIG. 1, three subarray antennas 101a, 101b, 101c are shown; a first subarray 101a, a second subarray antenna 101b and a third subarray antenna 101c which are mounted to each other along a first extension E1. In practice there are normally more subarray antennas which the form rows and columns. With reference to also FIG. 3, the subarray antennas 101a, 101b, 101c; 101d, 101e, 101f form two rows 310, 320 along a second extension E2 with three subarray antennas 101a, 101b, 101c; 101d, 101e, 101f in each row 310, 320.

Only being described for a first subarray antenna 101a in FIG. 1, but being applicable for all subarray antennas 101a, 101b, 101c; 101d, 101e, 101f, according to some aspects, each subarray antenna 101a, 101b, 101 is an active subarray antenna that comprises one or more antenna elements 109 where each antenna element 109 is fed by a feeding arrangement 110, which in turn is connected to a radio circuit 111 mounted to a heat-sink 112 in a radio arrangement 113. The radio arrangement 113 is mounted to a printed circuit board (PCB) 114, and electrically connected to conductors in the PCB 114. In this way, each subarray antenna 101a, 101b, 101c; 101d, 101e, 101f can DC current supply and both receive and send control signaling and signal data by means of the PCB conductors (not shown). The PCB conductors are connected to other suitable circuitry in a well, known manner such that a radio unit may be formed. The subarray antennas 101a, 101b, 101c; 101d, 101e, 101f are suitable mounted to the PCB 114 by means of pick-and place techniques and a reflow process in a previously well-known manner.

Here, the antenna elements 109 are in the form of horn antennas formed in a piece of metal 102a, 102b, 102c forming a ground plane. It is desired to connect each subarray antenna 101a, 101b, 101c; 101d, 101e, 101f to an adjacent subarray antenna in such a way that a coherent total ground plane 130 is formed, without slots that form discontinuations in the total ground plane 130. Such slots can for example be due to non-linear mounting as well as variations of ground plane level for each subarray antenna, which in turn can be due to errors in the assembly and reflow processes. Even what could seem like a small offset of a subarray could be a big difference in the electrical environmental. All of sudden there could be only pointwise ground connections between the ground planes 102a, 102b, 102c. As these connections will be unpredictable they could be of major impact for antenna patterns etc.

Each subarray antenna 101a, 101b, 101 comprises least one edge part 104a, 105a; 104b, 105b; 104c, 105c that is adapted to face an edge part of an adjacent subarray antenna. According to the present disclosure, the edge part 104a, 105a; 104b, 105b; 104c, 105c at least partly comprises a locking structure that is shown in more detail in FIG. 2A that illustrates adjacent edge parts 105a, 104b between the first subarray antenna 101a and the second subarray antenna 101b, where a first edge part 105a is formed in a first ground plane 102a of the first subarray antenna 101a, and where a second edge part 105b is formed in a second ground plane 102b of the second subarray antenna 101b.

Each locking structure comprises an outer lock part 103a, 103b and an indent 106a, 106b that is positioned between the outer lock part 103a, 103b and the ground plane 102a, 102b, 102c in a direction of the extension E1. As illustrated in FIG. 2A, an indent 106a of the first ground plane 102a is adapted to receive an adjacent outer lock part 103b of the second ground plane, and an indent 106b of the second ground plane 102b is adapted to receive an adjacent outer lock part 103a of the first ground plane 102. More generally, an indent 106a, 106b is adapted to receive an adjacent outer lock part 103b, 103a of an adjacent subarray antenna 101b, 101a, and the outer lock part 103b, 103a being adapted to engage an indent 106b, 106a of an adjacent subarray antenna 101b, 101a. Also, in general, the outer lock part 103b, 103a and the indent 106a, 106b are electrically conducting and electrically connected to the ground plane 102a, 102b.

According to some aspects and as illustrated in FIG. 1, each subarray antenna 101a, 101b, 101c comprises a first type edge part 104a, 104b, 104c and second type edge part 105a, 105b, 105c where, as illustrated for the first subarray antenna 101a and the second subarray antenna 101b in FIG. 2B, the first type edge part 104b comprises a first type locking structure 103b, 106b that is adapted to engage a second type locking structure 103a, 106a that is comprised in the second type edge part 105c.

According to some aspects, the first type locking structure 103b, 106b comprises an indent 106b that is facing away from the PCB 114 when the subarray antenna 101a, 101b, 101c is mounted to the PCB 114, and the second type locking structure 103a, 106a comprises an indent 106a that is facing towards the PCB 114 when the subarray antenna 101a, 101b, 101c is mounted to the PCB 114. According to some aspects, each locking structure 103a, 106a; 103b, 106b is hook-shaped.

According to some aspects, with reference to FIG. 2B, the edge parts 105′a, 104′b comprises lock parts 103′b, 103′a where each outer lock part 103′b, 103′a comprises a slanted side 201a, 201b that faces the indent 106′a, 106′b such that a width of the outer lock part 103′b, 103′a increases away from the indent 106′a, 106′b. This means that when two locking structure 103b, 106b are connected to each other, the slanted sides 201a, 201b of the outer lock parts 103b, 103a engage each other such then when mounted, movement in a direction N that is perpendicular to the extensions E1, E2, and to the total ground plane 130 is prevented. This results in that the mounting of subarray antenna 101a, 101b, 101c even more surely will result in an even ground plane that runs in a common level.

As mentioned initially, FIG. 3 shows six subarray antennas 101a, 101b, 101c; 101d, 101e, 101f that form two rows 310, 320 along a second extension E2 with three subarray antennas 101a, 101b, 101c; 101d, 101e, 101f in each row 310, 320. Everywhere where there are adjacent edges, edge part are connected to each other by means of the locking structures. More in detail, in each row 310, 320, the edge parts 105a, 104b; 105b, 104c; 105d 104e; 105e, 104f are connected, and the rows 310, 320 are connected to each other by means of corresponding edge parts 304a, 315d; 304b, 315e; 304c, 315f. Especially in the case of the locking structures being of the kind according to FIG. 2B, the edge parts are suitably slid together. For this purpose, according to some aspects, longitudinally running edge parts of rows and columns that form the array antenna 100 have locking parts of the same type such that sliding is admitted.

According to some aspects, with reference to FIG. 4A that mainly corresponds to FIG. 3, there is an alternative array antenna 400. Six subarray antennas 401a, 401b, 401c; 401d, 401e, 401f that form two rows 410, 420 along the second extension E2 with three subarray antennas 401a, 401b, 401c; 401d, 401e, 401f in each row 410, 420. In each row 410, 420, the edge parts 405a, 404b; 405b, 404c; 405d, 404e; 405e, 404f are connected, and the rows 410, 420 are connected to each other by means of corresponding edge parts 404a, 415d; 404b, 415e; 404c, 415f. In the following, the edge parts 405a, 404b that connect the first subarray antenna 401a to the second subarray antenna 401b will be discussed, but of course the same arrangement is applicable for all edge parts.

With reference also to FIG. 4B, showing a detail of FIG. 4A, according to some aspects, the first edge part 405a comprises one protrusion 407a that extends away from the edge part and one notch 408a that extends in the opposite direction. In the same manner, the second edge part 404b comprises one protrusion 407b that extends away from the edge part and one notch 408b that extends in the opposite direction. When the edge parts are mounted to each other, the protrusions 407a, 407b are positioned opposite a notch 408a, 408b of the opposing edge part such that each protrusion 407a, 407b is adapted to engage a corresponding notch 408a, 408b in the adjacent subarray antenna, and each notch 408a, 408b is adapted to engage a corresponding protrusion 407a, 407b in the adjacent subarray antenna.

This prevents movements along the first extension E1 and the second extension E2 since the protrusions 407a, 407b and notches 408a, 408b locally take the place of the locking structures 103a, 103b; 106a, 106b along the edge parts 405a, 404b and engage each other in an interleaving manner in a direction that is perpendicular to the extension of the edge parts 405a, 404b.

In the above, a first example of an active array antenna has been described with antenna elements formed as horn antennas in metal where the edge parts 104a, 105a; 104b, 105b; 104c, 105c are formed in the same piece of metal. A metalized non-conducting material can of course be used instead. The present disclosure is generally intended for all types of ground planes that are to be connected in a coherent manner, and in the following a second example of an array antenna will be described with reference to FIG. 5 that schematically shows a cut-open side view of a second example of an array antenna 500.

The array antenna 500 is constituted by a number of subarray antennas 501a, 501b, 501c. In FIG. 5, three subarray antennas are shown; a first subarray 501a, a second subarray antenna 5501b and a third subarray antenna 501c which are mounted to each other along a first extension E1. In practice there are normally more subarray antennas which the form rows and columns. With reference to also FIG. 7, the subarray antennas 501a, 501b, 501c; 501d, 501e, 501f form two rows 710, 720 along a second extension E2 with three subarray antennas 501a, 501b, 501c; 501d, 501e, 501f in each row 710, 720.

Here each subarray antenna 501a, 501b, 501c comprises a plurality of antenna elements 509 in the form of patch elements that are formed as metallizations on a dielectric material 512a, 512b, 512c. Each subarray antenna 501a, 501b, 501c comprises a ground plane 502a, 502b, 502c that is in the form of a metallization on the dielectric material 512a, 512b, 512c, where the ground plane 502a, 502b, 502c is formed on an opposite side of the dielectric material 512a, 512b, 512c relative the antenna elements 509.

Each subarray antenna 501a, 501b, 501 comprises least one edge part 504a, 505a; 504b, 505b; 504c, 505c that is adapted to face an edge part of an adjacent subarray antenna. In accordance with the present disclosure, in the same way as for the first example, the edge part 504a, 505a; 504b, 505b; 504c, 505c at least partly comprises a locking structure that is shown in more detail in FIG. 6A that illustrates adjacent edge parts 505a, 504b between the first subarray antenna 501a and the second subarray antenna 501b, where, for the first subarray antenna 501a, a first edge part 505a is formed in the dielectric material 512a and at least partly comprises a metallization 513. For the second subarray antenna 501b, a second edge part 504b is formed in the dielectric material 512b and at least partly comprises a metallization 514.

The locking structure comprises outer lock parts 503a, 503b and indents 506a, 506b that are configured in the same way as in the first example. This means that the indents 506a, 506b and the adjacent outer lock parts 503b, 503a are adapted to receive each other in a locking configuration, where the outer lock parts 503b, 503a and the indents 506a, 506b are electrically conducting and electrically connected to the ground plane 502a, 502b by means of the metallizations 513, 514.

In the following, features similar to the ones described for the first example will be described, but in a less detailed manner.

According to some aspects and as illustrated in FIG. 5, each subarray antenna 501a, 501b, 501c comprises a first type edge part 504a, 504b, 504c and second type edge part 505a, 505b, 505c in the same way as described for the first example.

According to some aspects, with reference to FIG. 6B, the edge parts 505′a, 504′b comprises lock parts 503′b, 503′a where each outer lock part 503′b, 503′a comprises a slanted side 601a, 601b that faces the indent 506′a, 506′b such that a width of the outer lock part 103′b, 103′a increases away from the indent 106′a, 106′b in the same way as described for the first example.

As mentioned initially, FIG. 7 shows six subarray antennas 501a, 501b, 501c; 501d, 501e, 501f that form two rows 710, 720 along a second extension E2 with three subarray antennas 501a, 501b, 501c; 501d, 501e, 501f in each row 710, 720. Everywhere where there are adjacent edges, edge parts are connected to each other by means of the locking structures. More in detail, in each row 710, 720, the edge parts 505a, 504b; 505b, 504c; 505d 504e; 505e, 504f are connected, and the rows 710, 720 are connected to each other by means of corresponding edge parts 704a, 715d; 704b, 715e; 704c, 715f. Especially in the case of the locking structures being of the kind according to FIG. 6B, the edge parts are suitably slid together. For this purpose, according to some aspects, longitudinally running edge parts of rows and columns that form the array antenna 100 have locking parts of the same type such that sliding is admitted.

According to some aspects, with reference to FIG. 8A that mainly corresponds to FIG. 7, there is an alternative array antenna 800. Six subarray antennas 801a, 801b, 801c; 801d, 801e, 801f that form two rows 810, 820 along the second extension E2 with three subarray antennas 801a, 801b, 801c; 801d, 801e, 801f in each row 810, 820. In each row 810, 820, the edge parts 805a, 804b; 805b, 804c; 805d, 804e; 805e, 804f are connected, and the rows 810, 820 are connected to each other by means of corresponding edge parts 804a, 815d; 804b, 815e; 804c, 815f. In the following, the edge parts 805a, 804b that connect the first subarray antenna 801a to the second subarray antenna 801b will be discussed, but of course the same arrangement is applicable for all edge parts.

With reference also to FIG. 8B, showing a detail of FIG. 8A, according to some aspects, the first edge part 805a comprises one protrusion 807a that extends away from the edge part and one notch 808a that extends in the opposite direction. In the same manner, the second edge part 404b comprises one protrusion 807b that extends away from the edge part and one notch 808b that extends in the opposite direction. The protrusion 807a, 807b and notches 808a, 808b are adapted to engage each other in the same manner as in the first example, preventing movements along the first extension E1 and the second extension E2 since the protrusions 807a, 807b and notches 808a, 808b locally take the place of the locking structures 503a, 503b; 506a, 506b along the edge parts 805a, 804b and engage each other in an interleaving manner in a direction that is perpendicular to the extension of the edge parts 805a, 804b.

With reference to FIG. 9, the present disclosure also relates to a method for assembling an array antenna 100, where the method comprises providing S100 a first subarray antenna 101a and a second subarray antennas 101b, each subarray antenna 101a, 101b comprising a corresponding electrically conducting ground plane 102a, 102b and connecting S200 a first edge part 105a of the first subarray antenna 101a to a second edge part 104b of the second subarray antenna 101b along a first extension E1. Each edge part 105a; 104b at least partly comprises a locking structure with an outer lock part 103a, 103b and an indent 106a, 106b that is positioned between the outer lock part 103a, 103b and the ground plane 102a, 102b in a direction of the extension E1. The indent 106a of the first edge part 105a is used for receiving the outer lock part 103b of the second edge part 105a, and the outer lock part 103a of the first edge part 105a is used for engaging the indent 106b of the second edge part 105a. Each outer lock part 103b, 103a and each indent 106a, 106b is electrically conducting and electrically connected to the ground plane 102a, 102b.

According to some aspects, the method comprises forming S300 a first row 310 of subarray antennas 101a, 101b, 10c by mounting subarray antennas 101a, 101b, 10c to each other along the first extension E1 and forming S400 a second row 320 of subarray antennas 101d, 101e, 10f by mounting subarray antennas 101d, 101e, 10f to each other along the first extension E1. The method further comprises mounting S500 the rows 310, 320 to each other along a second extension E that is perpendicular the first extension E1 by connecting edge parts 304a, 304b, 304c of the first row 310 and edge parts 305d, 305e, 305f of the second row 320 to each other, where each edge part 1304a, 304b, 304c; 305d, 305e, 305f at least partly comprises the locking structure 103a, 106a; 103b, 106b.

By forming the rows first, and then mounting the rows to each other, certain edge parts are easier to connect to each other.

The present disclosure is not limited to the above, but may vary freely within the scope the appended claims. For example, according to some aspects, the subarray antennas comprising edge parts and the a locking structure according to the present disclosure, may be any kind of subarray antenna that comprises a ground plane, where the at ground plane can have any form and position, and where the subarray antenna can comprise one or more antenna element of any suitable kind such as the described horn antennas, patch antennas, dipoles, stacked antenna structures, slot antennas etc. A subarray antenna can either be passive or active, and can generally be regarded as a subarray antenna arrangement. A subarray antenna can be adapted to be connected to active circuitry, but can in itself constitute a passive subarray antenna. The subarray antennas 101a, 11b, 101c according to the first example have been regarded as comprising active circuitry in a radio arrangement 113, but could of course be regarded as passive subarray antennas instead, without the radio arrangement 113.

Different types of edge parts can be combined, for example the edge parts described with reference to FIGS. 2B and 6B can be combined with the edge parts described with reference to FIGS. 4A, 4B, 8A and 8B at different edge part at the same subarray antenna. A subarray antenna can have different types of edge parts, for example there can be one or more protrusions and notches at one or more edge parts.

The can also be one or more protrusion and one or more notch at each edge part that is equipped with these elements.

According to some aspects, notches and protrusions can have other geometrical shapes than the rectangular shape shown.

According to some aspects, each locking structure 103a, 106a; 103b, 106b; 103′a, 106′a; 103′b, 106′b; 503a, 506a; 503b, 506b; 503′a, 506′a; 503′b, 506′b is hook-shaped.

In particular in the case where protrusion and notches are used, preventing mutual lateral movement of the subarray antennas, when the array antenna 400, 800 is mounted, it can be lifted without falling apart or changing the subarray antennas position by sliding away. Depending of the exact arrangement chosen for an array antenna 100, 400, 500, 800, it can lifted in a SMD machine or with a suction picking tool. The array antenna 100, 400, 500, 800 can be assembled on a standard PCB.

By means of the locking structure, the risk for abrupt height differences in a total array antenna ground plane is mitigated. The total ground plane 130, 530 will be continuous and smooth. In addition, there could be a guiding functionality built into the subarray antennas and/or in the PCB to ensure the alignment of the array antenna 100 becomes perfect versus the PCB 114. This alignment could be done with guiding pins, brackets in the corners or other technics.

By means of the present disclosure, the risk for uncontrolled radiation from an array antenna is reduced since the risk for exciting the edges of the subarray antennas is eliminated. Thereto, the alignment of the subarray antennas will be improved. These features will also help to improve the array antenna radiation pattern. Especially for higher frequencies, the sensitivity for ground plane discontinuations increases and may limit array antenna performance a lot if not taken care of.

Generally, the present disclosure relates to a subarray antenna 101a, 101b, 101c adapted to be mounted to at least one other subarray antenna 101a, 101b, 101c along at least one extension E1, E2 to form an array antenna 100. The subarray antenna 101a, 101b, 101c comprises an electrically conducting ground plane 102a, 102b, 102c and at least one edge part 104a, 105a; 104b, 105b; 104c, 105c that is adapted to face an edge part of an adjacent subarray antenna. The edge part 104a, 105a; 104b, 105b; 104c, 105c at least partly comprises a locking structure comprising an outer lock part 103a, 103b and an indent 106a, 106b that is positioned between the outer lock part 103a, 103b and the ground plane 102a, 102b, 102c in a direction of the extension E1, E2 .The indent 106a, 106b is adapted to receive an adjacent outer lock part 103b, 103a of an adjacent subarray antenna 101b, 101a, and the outer lock part 103b, 103a is adapted to engage an indent 106b, 106a of an adjacent subarray antenna 101b, 101a. The outer lock part 103b, 103a and the indent 106a, 106b are electrically conducting and electrically connected to the ground plane 102a, 102b.

According to some aspects, the subarray antenna 101a, 101b, 101c comprises a first type edge part 104a, 104b, 104c and a second type edge part 105a, 105b, 105c, where the first type edge part 104a, 104b, 104c comprises a first type locking structure 103b, 106b that is adapted to engage a second type locking structure 103a, 106a that is comprised in the second type edge part 105a, 105b, 105c.

According to some aspects, the outer lock part 103′b, 103′a comprises a slanted side 201a, 201b that faces the indent 106′a, 106′b.

According to some aspects, each edge part 405a, 404b comprises at least one protrusion 407a, 407b that extends away from the edge part 405a, 04b and at least one notch 408a, 408b that extends in the opposite direction. Each protrusion 407a, 407b is adapted to engage a corresponding notch 408a, 408b in an adjacent subarray antenna and each notch 408a, 408b being adapted to engage a corresponding protrusion 407a, 407b in an adjacent subarray antenna.

According to some aspects, the ground plane is formed in a piece of metal 102a, 102b, 102c, and where the edge part 104a, 105a; 104b, 105b; 104c, 105c is formed in the same piece of metal.

According to some aspects, the ground plane 502a, 502b, 502c is in the form of a metallization on a dielectric material 512a, 512b, 512c, and where the edge part 504a, 505a; 504b, 505b; 504c, 505c is formed in the dielectric material 512a, 512b, 512c and at least partly comprises a metallization 513, 514′; 513, 514′.

According to some aspects, the subarray antenna 101a, 101b, 101c; 501a, 501b, 501c comprises a plurality of antenna elements 109, 509.

Generally, the present disclosure also relates to an array antenna 100 comprising at least two subarray antennas 101a, 101b, 101c; 101d, 101e, 101f mounted to each other along at least one extension E1, E2. Each subarray antenna 101a comprises an electrically conducting ground plane 102a and at least one edge part 104a, 105a that is adapted to face an edge part 104a, 105a of an adjacent subarray antenna 101b. Each edge part 104a, 105a; 104b, 105b; 104c, 105c at least partly comprises a locking structure comprising an outer lock part 103a, 103b and an indent 106a, 106b that is positioned between the outer lock part 103a, 103b and the ground plane 102a, 102b in a direction of the extension E1, E2. The indent 106a, 106b is adapted to receive an adjacent outer lock part 103b, 103a of an adjacent subarray antenna 101b, 101a, and the outer lock part 103b, 103a is adapted to engage an indent 106b, 106a of an adjacent subarray antenna 101b, 101a. The outer lock part 103b, 103a and the indent 106a, 106b are electrically conducting and electrically connected to the ground plane 102a, 102b.

According to some aspects, each subarray antenna 101a, 101b, 101c comprises a first type edge part 104a, 104b, 104c and a second type edge part 105a, 105b, 105c, where the first type edge part 104a, 104b, 104c comprises a first type locking structure 103a, 106a that is adapted to engage a second type locking structure 103b, 106b that is comprised in the second type edge part 104a, 104b, 104c.

According to some aspects, each outer lock part 103b, 103a comprises a slanted side 201a, 201b that faces the indent 106a, 106b, enabling adjacent subarray antennas 101a, 101b, 101c to be locked to each other in a direction N that is normal to an antenna aperture of the array antenna 100.

According to some aspects, each edge part 405a, 404b comprises at least one protrusion 407a, 407b that extends away from the edge part 405a, 04b and at least one notch 408a, 408b that extends in the opposite direction. Each protrusion 407a, 407b is adapted to engage a corresponding notch 408a, 408b in an adjacent subarray antenna and each notch 408a, 408b is adapted to engage a corresponding protrusion 407a, 407b in an adjacent subarray antenna, enabling adjacent subarray antennas 101a, 101b, 101c to be locked to each other in a direction along the edge parts 405a, 404b.

According to some aspects, the ground plane is formed in a piece of metal 102a, 102b, 102c, and where the edge part 104a, 105a; 104b, 105b; 104c, 105c is formed in the same piece of metal.

According to some aspects, the ground plane 502a, 502b, 502c is in the form on a metallization on a dielectric material 512a, 512b, 512c, and where the edge part 504a, 505a; 504b, 505b; 504c, 505c is formed in the dielectric material 512a, 512b, 512c and at least partly comprises a metallization 513, 514; 513′, 514′.

According to some aspects, the subarray antenna 101a, 101b, 101c; 501a, 501b, 501c comprises a plurality of antenna elements 109, 509.

Claims

1. A subarray antenna adapted to be mounted to at least one other subarray antenna along at least one extension to form an array antenna, the subarray antenna comprising an electrically conducting ground plane and at least one edge part that is adapted to face an edge part of an adjacent subarray antenna, wherein the edge part at least partly comprises a locking structure comprising an outer lock part and an indent that is positioned between the outer lock part and the ground plane in a direction of the extension, the indent being adapted to receive an adjacent outer lock part of an adjacent subarray antenna, and the outer lock part being adapted to engage an indent of an adjacent subarray antenna, the outer lock part and the indent being electrically conducting and electrically connected to the ground plane.

2. The subarray antenna of claim 1, wherein the subarray antenna comprises a first type edge part and a second type edge part, where the first type edge part comprises a first type locking structure that is adapted to engage a second type locking structure that is comprised in the second type edge part .

3. The subarray antenna of claim 1, wherein the outer lock part comprises a slanted side that faces the indent.

4. The subarray antenna of claim 1, wherein each edge part comprises at least one protrusion that extends away from the edge part and at least one notch that extends in the opposite direction, each protrusion being adapted to engage a corresponding notch in an adjacent subarray antenna and each notch being adapted to engage a corresponding protrusion in an adjacent subarray antenna.

5. The subarray antenna of claim 1, wherein the ground plane is formed in a piece of metal, and where the edge part is formed in the same piece of metal.

6. The subarray antenna of claim 1, wherein the ground plane is in the form of a metallization on a dielectric material, and where the edge part is formed in the dielectric material and at least partly comprises a metallization.

7. The subarray antenna of claim 1, wherein the subarray antenna comprises a plurality of antenna elements.

8. An array antenna comprising at least two subarray antennas ) mounted to each other along at least one extension, each subarray antenna comprising an electrically conducting ground plane and at least one edge part that is adapted to face an edge part of an adjacent subarray antenna, wherein each edge part at least partly comprises a locking structure comprising an outer lock part and an indent that is positioned between the outer lock part and the ground plane in a direction of the extension, the indent being adapted to receive an adjacent outer lock part of an adjacent subarray antenna, and the outer lock part being adapted to engage an indent of an adjacent subarray antenna, the outer lock part and the indent being electrically conducting and electrically connected to the ground plane.

9. The array antenna of claim 8, wherein each subarray antenna comprises a first type edge part and a second type edge part, where the first type edge part comprises a first type locking structure that is adapted to engage a second type locking structure that is comprised in the second type edge part .

10. The array antenna of claim 8, wherein each outer lock part comprises a slanted side that faces the indent, enabling adjacent subarray antennas to be locked to each other in a direction that is normal to an antenna aperture of the array antenna.

11. The array antenna of claim 8, wherein each edge part comprises at least one protrusion that extends away from the edge part and at least one notch that extends in the opposite direction, each protrusion being adapted to engage a corresponding notch in an adjacent subarray antenna and each notch being adapted to engage a corresponding protrusion in an adjacent subarray antenna, enabling adjacent subarray antennas to be locked to each other in a direction along the edge parts .

12. The array antenna of claim 8, wherein the ground plane is formed in a piece of metal, and where the edge part is formed in the same piece of metal.

13. The array antenna of claim 8, wherein the ground plane is in the form on a metallization on a dielectric material, and where the edge part is formed in the dielectric material and at least partly comprises a metallization.

14. The array antenna of claim 8, wherein the subarray antenna comprises a plurality of antenna elements.

15. A method for assembling an array antenna, where the method comprises: providing a first subarray antenna and a second subarray antennas, each subarray antenna comprising a corresponding electrically conducting ground plane;connecting a first edge part of the first subarray antenna to a second edge part of the second subarray antenna along a first extension;wherein each edge part at least partly comprises a locking structure with an outer lock part and an indent that is positioned between the outer lock part and the ground plane in a direction of the extension, the indent of the first edge part being used for receiving the outer lock part of the second edge part, and the outer lock part of the first edge part being used for engaging the indent of the second edge part, each outer lock part and each indent being electrically conducting and electrically connected to the ground plane.

16. The method of claim 15, where in the method comprises: forming a first row of subarray antennas by mounting subarray antennas to each other along the first extension;forming a second row of subarray antennas by mounting subarray antennas to each other along the first extension;mounting the rows to each other along a second extension that is perpendicular the first extension by connecting edge parts of the first row and edge parts of the second row to each other, where each edge part at least partly comprises the locking structure .