Assembly for drag reduction of antenna systems

Abstract

The present disclosure relates to antenna design and, more specifically, to an assembly for reducing wind load on base station antennas. The disclosure proposes an assembly for reducing wind load on an antenna mounted on an antenna mast, wherein the assembly comprises: one or more mounting elements configured to mount the assembly to the antenna or the antenna mast; and a wind reduction structure configured to surround the antenna, when the assembly is mounted on the antenna or the antenna mast, wherein the wind reduction structure has a shape that has a first drag coefficient on a first side of the wind reduction structure, wherein the first drag coefficient is lower than any drag coefficient on any other side of the wind reduction structure. This disclosure further proposes an antenna assembly including one or more antennas and the proposed assembly.

Description

[0001] ASSEMBLY FOR DRAG REDUCTION OF ANTENNA SYSTEMS

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to antenna design and, more specifically, to an assembly for reducing wind load on base station antennas. The assembly is adaptable to different environmental conditions and is designed to optimize the aerodynamic profile of antennas to minimize wind load, thereby addressing challenges associated with the design, deployment, and operational costs of large antennas in exposed areas.

[0004] BACKGROUND

[0005] Base station antennas are critical components of telecommunications infrastructure, but their design and installation are challenged by various factors, including wind load. Wind load significantly affects the structural integrity and stability of antennas, and consequently impacts operational costs and safety. Operators require antennas to have a low wind load to ensure successful performance and durability, especially as future antennas are projected to increase in size to dimensions of 1400mm x 700mm or larger.

[0006] Traditionally, the optimization of wind load has focused on altering the shape of the antenna or its protective enclosure, known as a radome. Existing solutions disclose various approaches for shape optimization of the radome to achieve a lower drag coefficient (CD), which reduces the wind load.

[0007] However, these solutions have disadvantages. The shapes provided by current technologies are permanent and cannot adapt to changing wind conditions, which limits their effectiveness. These fixed shapes are typically optimized only for a specific wind direction, and thus their drag-reducing efficiency is reduced under variable wind conditions. The need to increase the depth of the antenna or radome to optimize aerodynamics leads to undesirable consequences, such as increased visual bulk and higher transportation volumes, which are impractical and cost-inefficient. Furthermore, while existing solutions attempt to reduce wind load, they often do so ineffectively for larger antennas or in highly exposed areas where high wind loads are common. SUMMARY

[0008] In view of the above-discussed, this disclosure aims to propose an innovative solution that provides a dynamic, adjustable approach to optimizing antenna designs for varying wind conditions without compromising the practical aspects of antenna deployment and operation.

[0009] These and other objectives are achieved by the solution of the present disclosure as provided in the enclosed independent claims. Advantageous implementations are further defined in the dependent claims.

[0010] A first aspect of the disclosure provides an assembly for reducing wind load on an antenna mounted on an antenna mast, wherein the assembly comprises: one or more mounting elements configured to mount the assembly to the antenna or the antenna mast; and a wind reduction structure configured to surround the antenna, when the assembly is mounted on the antenna or the antenna mast, wherein the wind reduction structure has a shape that has a first drag coefficient on a first side of the wind reduction structure, wherein the first drag coefficient is lower than a drag coefficient of another side of the wind reduction structure.

[0011] This disclosure proposes to separate the assembly from the antenna for maintaining its independent movement. The proposed assembly design or radome provides a shape having a drag coefficient, CD, in one direction. With the ability to move the assembly around the antenna or a pole, the wind load is moving the assembly in the wind direction to maintain the low CD of the cover shape.

[0012] In an implementation form of the first aspect, the wind reduction structure has a rounded front side leading to a tapered rear, wherein the rounded front side is the first side. Optionally, the wind reduction structure may be teardrop-shaped.

[0013] In an implementation form of the first aspect, the wind reduction structure comprises a fin extending from the tapered rear. An additional element may be added to align the assembly directly with the wind. This element may have the shape of a fin.

[0014] In an implementation form of the first aspect, the one or more mounting elements comprise one or more rotatable elements configured to mount the assembly to the antenna or the antenna mast, to permit rotation of the wind reduction structure, when the assembly is mounted on the antenna or the antenna mast, to a desired orientation. The assembly is mounted movable to the antenna mast, separated from the fixed antenna, or mounted movable to the antenna.

[0015] In an implementation form of the first aspect, the one or more mounting elements further comprise: one or more brackets configured to fix the assembly to the antenna mast; and one or more additional poles configured to fix the wind reduction structure to the antenna, wherein the one or more rotatable elements are configured to mount the assembly to the antenna by attaching to the one or more additional poles. To mount the assembly movable to the antenna, additional poles are required.

[0016] In an implementation form of the first aspect, the one or more mounting elements further comprise one or more fixation elements configured to fix the wind reduction structure to the one or more rotatable elements. The fixation elements can be a semi-circular frame, which can be affixed to the rounded front side of the wind reduction structure at multiple points along its curvature, ensuring a stable and secure connection. The semi-circular frame can be engaged with the rotatable elements via its central axle acting as the pivotal axis for rotation.

[0017] In an implementation form of the first aspect, the assembly further comprises one or two protection covers configured to attach to the wind reduction structure, such that the antenna is enclosed by the wind reduction structure and the one or two protection covers when the assembly is mounted on the antenna. Optionally, the assembly can be closed on top and bottom by a protection cover, or namely an endcap, with a flexible sealing to the pole to achieve an even better drag reduction.

[0018] In an implementation form of the first aspect, each protection cover is formed with a hole to allow the antenna mast or the additional pole to pass through.

[0019] In an implementation form of the first aspect, the assembly is configured to be pivotally mounted on the antenna or the antenna mast, to allow adjustment of the first side to directly face the wind.

[0020] The movement or orientation of the wind reduction structure can be controlled by the natural flow of wind. This means the structure has the ability to automatically adjust its position or orientation in response to changes in wind direction and speed, without requiring external power sources or mechanical input.

[0021] In an implementation form of the first aspect, when multiple antennas are mounted on the antenna mast, the wind reduction structure is configured to surround the multiple antennas when the assembly is mounted on the antenna mast. Optionally, the proposed assembly design can cover one antenna only or a complete sector arrangement of antennas.

[0022] A second aspect of the disclosure provides an antenna assembly, comprising one or more antennas, and an assembly according to the assembly of the first aspect or any of its implementation forms.

[0023] A third aspect of the disclosure provides a wind reduction structure for an antenna, wherein the wind reduction structure is configured to encase the antenna and to be mounted pivotable on the antenna or an antenna mast, wherein the wind reduction structure has a shape providing a first drag coefficient on a first side of the wind reduction structure, wherein the first drag coefficient is lower than a drag coefficient of another side of the wind reduction structure.

[0024] Implementation forms of the antenna assembly of the second and third aspect may correspond to the implementation forms of the assembly of the first aspect described above. The antenna assembly of the second and third aspect and its implementation forms achieve the same advantages and effects as described above for the assembly of the first aspect and its implementation forms.

[0025] It has to be noted that all devices, elements, units, and means described in the present application could be implemented in 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 that 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

[0026] The above-described aspects and implementation forms of the present disclosure will be explained in the following description of specific embodiments in relation to the enclosed drawings, in which:

[0027] FIG. 1 (a) shows an assembly according to an embodiment of this disclosure; (b) shows an assembly according to another embodiment of this disclosure;

[0028] FIG. 2 shows a design procedure according to an embodiment of this disclosure;

[0029] FIG. 3 shows an assembly according to an embodiment of this disclosure;

[0030] FIG. 4 shows an assembly according to an embodiment of this disclosure;

[0031] FIG. 5 shows an assembly according to an embodiment of this disclosure;

[0032] FIG. 6 shows an assembly according to an embodiment of this disclosure; and

[0033] FIG. 7 shows two user cases according to embodiments of this disclosure.

[0034] DETAILED DESCRIPTION OF EMBODIMENTS

[0035] Illustrative embodiments of an assembly and an antenna assembly for reducing wind load are described in the following with reference to the figures. Although this description provides a detailed example of possible implementations, it should be noted that the details are intended to be exemplary and in no way limit the scope of the application.

[0036] Moreover, an embodiment or example may refer to other embodiments or examples. For example, any description including but not limited to terminology, element, process, explanation, and / or technical advantage mentioned in one embodiment or example may also apply to the other embodiments or examples.

[0037] FIG. 1(a) illustrates an assembly 10 for reducing wind load on an antenna 1 mounted on an antenna mast 2, according to an embodiment of the disclosure. The assembly 10 comprises: one or more mounting elements 11 configured to mount the assembly 10 to the antenna mast 2; and a wind reduction structure 12 configured to surround the antenna 1 when the assembly 10 is mounted on the antenna mast 2. In particular, the wind reduction structure 12 has a shape providing a first drag coefficient on a first side (12-1) of the wind reduction structure 12, wherein the first drag coefficient is lower than a drag coefficient of another side of the wind reduction structure 12. The first side (12-1) is not shown explicitely in FIG. 1(a). For better understanding, FIG 1(a) shows the antenna (1) uncovered. However, it is apparent that the wind reduction structure 12 surrounds the antenna 1.

[0038] FIG. 1(b) illustrates an assembly 10 for reducing wind load on an antenna 1 (antenna 1 is not shown in this figure as it is covered by the assembly 10) mounted on an antenna mast 2, according to an embodiment of the disclosure. The assembly 10 comprises: one or more mounting elements 11 configured to mount the assembly 10 to the antenna 1; and a wind reduction structure 12 configured to surround the antenna 1 when the assembly 10 is mounted on the antenna 1. The wind reduction structure 12 has a shape providing a first drag coefficient on a first side (12-1) of the wind reduction structure 12, wherein the first drag coefficient is lower than a drag coefficient of another side of the wind reduction structure 12.

[0039] Optionally, for all described embodiments, the wind reduction structure 12 comprises a fin 12- 2 extending from the tapered rear. This is shown in FIG. 1(a) as dashed line.

[0040] In the embodiment shown in FIG. 1(a), the assembly 10 is mounted on the antenna mast 2, while in the embodiment shown in FIG. 1(b), the assembly 10 is mounted on the antenna 1.

[0041] FIG. 2 depicts design considerations for the assembly aimed at safeguarding the antenna against substantial wind loads. The figure on the left illustrates a top-down perspective of the antenna subjected to windy conditions. In order to minimize the impact of wind load, the present disclosure proposes to surround the antenna with a shaped cover that has a low CD in one direction and a high CD in other directions.

[0042] The drag coefficient CD is a dimensionless number that quantifies the drag or resistance of an object in a fluid environment, such as air. It depends on the shape of the object and how it interacts with the flowing air.

[0043] Optionally, in any of the above-mentioned embodiments, the wind reduction structure 12 may have a rounded front side leading to a tapered rear, wherein the rounded front side is the first side with the low CD. The assembly is mounted movable to the antenna mast, separated from the fixed antenna, or mounted movable to the antenna itself.

[0044] It should be noted that the movement or orientation of the wind reduction structure can be controlled by the natural flow of wind. This means the structure automatically adjusts its position or orientation in response to changes in wind direction and speed, without requiring external power sources or mechanical input. That is, the structure does not rely on motors, hydraulics, or other mechanical systems to change its orientation or position. Instead, it harnesses the kinetic energy of the wind itself to achieve optimal positioning to minimize wind load.

[0045] By eliminating the need for active mechanical components to adjust the position of the assembly, the design can be simpler and potentially more reliable. Fewer moving parts reduce the risk of mechanical failure and maintenance requirements. Utilizing the wind for movement avoids the need for additional energy expenditure and complex control systems, making the assembly more efficient and cost-effective to operate.

[0046] Optionally, in any of these two embodiments, the wind reduction structure 12 may have a rounded front side leading to a tapered rear, wherein the rounded front side is the first side.

[0047] In a particular embodiment, the wind reduction structure 12 further comprises a fin extending from the tapered rear.

[0048] Usually, a radome covering an antenna is fixed (as in prior art). As can be seen on the left side of FIG. 2, the drag coefficient DI, ..., D3 differs with wind direction. Accordingly, the drag forces FDI, FD2, FD3, on the radome are different. When the assembly of the present disclosure (middle part of FIG. 2) is mounted to the antenna or the antenna mast but with the wind reduction structure 12 fixed (“fixed cover”) drag coefficients CD are low and highly dependent of the side of the wind reduction structure 12.

[0049] On the right side of FIG. 2 the wind reduction structure 12 is movable or pivotable mounted on the antenna or antenna mast (for better understanding the antenna is shown inside the wind reduction structure 12). Accordingly, the wind is moving the wind reduction structure 12 in wind direction, so that the low drag coefficient CD of the wind reduction structure 12 is maintained. The movement is thus maintained by the wind direction only and no other forced movement is necessary. The overall drag is reduced and the drag force FD4, is independent of the wind direction.

[0050] As mentioned above, an additional element, for example a fin 12-2 extending from the tapered rear of the wind reduction structure 12, can be added. Such element improves alignment of the wind reduction structure 12 into the wind.

[0051] FIG. 3 shows, as exploded view, an assembly 10 mounted on an antenna mast 2 (i.e., a pole) to surround an antenna 1, according to an embodiment of this disclosure. Possibly, antenna 1 is an antenna with or without a protection cover. The embodiment of FIG. 3 is based on the structure of the embodiment shown in FIG. 1(a).

[0052] The assembly 10 of this embodiment comprises one or more mounting elements 11 configured to mount the assembly 10 to the antenna mast 2; and a wind reduction structure 12 configured to surround the antenna 1 when the assembly 10 is mounted on the antenna mast 2, and one or two protection covers 112 configured to attach to the wind reduction structure 12, such that the antenna 1 is enclosed by the wind reduction structure 12 and the one or two protection covers 112 when the assembly 10 is mounted.

[0053] The one or more mounting elements 11 comprise one or more rotatable elements 111 configured to mount the assembly 10 to the antenna mast 2, to permit rotation of the wind reduction structure 12 to a desired orientation.

[0054] Possibly, each protection cover 112 is formed with a hole to allow the antenna mast 2 to pass through.

[0055] FIG. 4 shows an assembly 10 mounted on an antenna mast 2 (i.e., a pole) to surround an antenna 1, according to an embodiment of this disclosure. Possibly, antenna 1 is an antenna with a protection cover. The embodiment of FIG. 4 is based on the structure of the embodiment shown in FIG. 1(a).

[0056] The assembly 10 of this embodiment comprises a wind reduction structure 12 configured to surround the antenna 1 when the assembly 10 is mounted on the antenna mast 2, one or more rotatable elements 111 configured to mount the assembly 10 to the antenna mast 2, to permit rotation of the wind reduction structure 12, and one or more fixation elements 113 configured to fix the wind reduction structure 12 to engage with the one or more rotatable elements 111.

[0057] The fixation element 113 comprise a semi-circular frame, which can be affixed to the rounded front side of the wind reduction structure 12 at multiple points along its curvature, ensuring a stable and secure connection. The semi-circular frame can be engaged with the rotatable elements 111 via its central axle acting as the pivotal axis for rotation.

[0058] FIG. 5 shows an assembly 10 mounted on antenna 1 to surround the antenna, according to an embodiment of this disclosure. Possibly, antenna 1 is an antenna with or without a protection cover. The embodiment of FIG. 5 is based on the structure of the embodiment shown in FIG. 1(b)-

[0059] The assembly 10 of this embodiment comprises one or more mounting elements 11 configured to mount the assembly 10 to the antenna 1; and a wind reduction structure 12 configured to surround the antenna 1 when the assembly 10 is mounted, and one or two protection covers 112 configured to attach to the wind reduction structure 12, such that the antenna 1 is enclosed by the wind reduction structure 12 and the one or two protection covers 112 when the assembly 10 is mounted.

[0060] In particular, the one or more mounting elements 11 further comprise: one or more additional poles 115 configured to fix the wind reduction structure 12 to the antenna 1, one or more rotatable elements 111 configured to mount the assembly 10 to the antenna 1 by attaching to the one or more additional poles 115, to permit rotation of the wind reduction structure 12 to a desired orientation, and one or more brackets 114 configured to fix the wind reduction structure 12 to the antenna mast 2.

[0061] Optionally, each protection cover 112 is formed with a hole to allow the additional pole 115 to pass through.

[0062] FIG. 6 shows an assembly 10 mounted on antenna 1 to surround the antenna, according to an embodiment of this disclosure. Possibly, antenna 1 is an antenna with a protection cover. The embodiment of FIG. 6 is based on the structure of the embodiment shown in FIG. 1(b). The assembly 10 of this embodiment comprises one or more mounting elements 11 configured to mount the assembly 10 to the antenna 1, and a wind reduction structure 12 configured to surround the antenna 1 when the assembly 10 is mounted on the antenna 1.

[0063] The one or more mounting elements 11 further comprise: one or more additional poles 115 configured to fix the wind reduction structure 12 to the antenna 1, one or more rotatable elements 111 configured to mount the assembly 10 to the antenna 1 by attaching to the one or more additional poles 115, to permit rotation of the wind reduction structure 12 to a desired orientation, one or more fixation elements 113 configured to fix the wind reduction structure 12 to engage with the one or more rotatable elements 111, and one or more brackets 114 configured to fix the wind reduction structure 12 to the antenna mast 2.

[0064] Possibly, the fixation element 113 may comprise a semi-circular frame, which can be affixed to the rounded front side of the wind reduction structure 12 at multiple points along its curvature, ensuring a stable and secure connection. The semi-circular frame can be engaged with the rotatable elements 111 via its central axle acting as the pivotal axis for rotation.

[0065] It may be understood that for the previous embodiments, the assembly 10 may be configured to be pivotally mounted on the antenna 1 or the antenna mast 2, to allow adjustment of the first side to directly face the wind.

[0066] It should be noted that the movement or orientation of the wind reduction structure can be controlled by the natural flow of wind. This means the structure automatically adjusts its position or orientation in response to changes in wind direction and speed, without requiring external power sources or mechanical input.

[0067] In another possible embodiment, when multiple antennas 1 are mounted on the antenna mast 2, the wind reduction structure 12 may be configured to surround the multiple antennas (1) when the assembly 10 is mounted on the antenna mast 2. That is, the proposed assembly design can cover one antenna only or a complete sector arrangement of antennas, to protect them from the heavy wind situation. As previously discussed, future antennas may have a projected size of 1400mm x 700mm or more. For example, considering an antenna with such size, the force of drag FD can be calculated using FD = CD*H*W*P*V2 / 2, where CD is the drag coefficient, H is the height of the object that is exposed to the wind, W is the width of the object exposed to the wind, p is the air density, which can vary with altitude and temperature, and v is the wind velocity. It may be understood that the force of drag is the wind load on a stationary object caused by the wind flow.

[0068] The wind load on antennas with size of 1400mm x 700mm, can be calculated as: FD _front= 1252 N, and FD side = 204 N. FD front is the force experienced when the wind is head-on, typically the maximum drag force because the effective area facing the wind is at its greatest. FD side is the force experienced when the wind comes from the side, which is usually less due to a smaller effective area being exposed to the wind and possibly a more streamlined shape from that angle.

[0069] FIG. 7 shows two user cases according to the embodiments of this disclosure: first user case (Var 1) where the drag force is FD var i = 477 N; second user case (Var 2) where the drag force is FD Var 2=262 N.

[0070] For an assembly mounted on pole (shown in FIG. 7 (a)) with the size H = 1600 mm, W = 1400 mm, L = 2800 mm, and CD = 0.2 mm, the drag force FD front can be reduced by 62%. For an assembly mounted on antenna (shown in FIG. 7 (b)) with the size H = 1600 mm, W = 7700 mm, L = 1540 mm, and CD = 0.2 mm, the drag force FD front can be reduced by 79%. The proposed solution thus reduces worst cases and improves the overall drag reduction.

[0071] The calculations presented herein, including the values for the drag coefficient, area, and wind velocity, are intended purely as examples to illustrate the principles of the invention. They are not meant to limit the scope of this application to any particular antenna size or configuration. The concept of this disclosure is applicable to a wide range of dimensions and environmental conditions, and the specific figures can be adjusted accordingly to apply the formula to different scenarios.

[0072] 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 embodiments of the disclosure, 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 mutually different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

CLAIMS1. An assembly (10) for reducing wind load on an antenna (1) mounted to an antenna mast (2), the assembly (10) comprising: one or more mounting elements (11) configured to mount the assembly (10) on the antenna (1) or the antenna mast (2); and a wind reduction structure (12) configured to surround the antenna (1), when the assembly (10) is mounted on the antenna (1) or the antenna mast (2), wherein the wind reduction structure (12) has a shape that has a first drag coefficient on a first side (12-1) of the wind reduction structure (12), wherein the first drag coefficient is lower than a drag coefficient of another side of the wind reduction structure (12).

2. The assembly (10) according to claim 1, wherein the wind reduction structure (12) has a rounded front side leading to a tapered rear, wherein the rounded front side is the first side (12-1).

3. The assembly (10) according to claim 2, wherein the wind reduction structure (12) comprises a fin (12-2) extending from the tapered rear.

4. The assembly (10) according to one of the claims 1 to 3, wherein the one or more mounting elements (11) comprise one or more rotatable elements (111) configured to mount the assembly (10) to the antenna (1) or the antenna mast (2), to permit rotation of the wind reduction structure (12), when the assembly (10) is mounted on the antenna (1) or the antenna mast (2), to a desired orientation.

5. The assembly (10) according to claim 4, wherein the one or more mounting elements (11) further comprise: one or more brackets (114) configured to fix the wind reduction structure (12) to the antenna mast (2); and one or more additional poles (115) configured to fix the wind reduction structure (12) to the antenna (1), wherein the one or more rotatable elements (111) are configured to mount the assembly (10) to the antenna (1) by attaching to the one or more additional poles (115).

6. The assembly (10) according to claim 4 or 5, wherein the one or more mounting elements (11) further comprise one or more fixation elements (113) configured to fix the wind reduction structure (12) to the one or more rotatable elements (111).

7. The assembly (10) according to one of the claims 1 to 6, further comprising: one or two protection covers (112) configured to attach to the wind reduction structure (12), such that the antenna (1) is enclosed by the wind reduction structure (12) and the one or two protection covers (112) when the assembly (10) is mounted on the antenna (1).

8. The assembly (10) according to claim 7, wherein each protection cover (112) is formed with a hole to allow the antenna mast (2) or the additional pole to pass through.

9. The assembly (10) according to one of the claims 1 to 8, wherein the assembly (10) is configured to be pivotally mounted on the antenna (1) or the antenna mast (2), to allow adjustment of the first side to directly face the wind.

10. The assembly (10) according to one of the claims 1 to 9, wherein when multiple antennas (1, 1’) are mounted on the antenna mast (2), the wind reduction structure (12) is configured to surround the multiple antennas (1, 1’) when the assembly (10) is mounted on the antenna mast (2).

11. An antenna assembly (100), comprising: one or more antennas (1, 1’), and an assembly (10) according to one of the claims 1 to 10.

12. A wind reduction structure (12) for an antenna (1), wherein the wind reduction structure (12) is configured to surround the antenna (1) and be mounted pivotable on the antenna or an antenna mast, wherein the wind reduction structure (12) has a shape providing a first drag coefficient on a first side of the wind reduction structure (12), wherein the first drag coefficient is lower than a drag coefficient of another side of the wind reduction structure (12).

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