METHOD FOR MANUFACTURING AN ANTENNA ELEMENT

TECHNICAL FIELD

The present disclosure relates to equipment for wireless communication systems. More specifically, the disclosure relates to a method for manufacturing an antenna element of an antenna for a base station for wireless communication in a communication network, in particular a 5G communication network.

BACKGROUND

Antennas for base stations used in mobile communication networks are often array antennas, comprising several antenna elements in the form of dipoles (also referred to as radiators). The radiators may be arranged, for example, in a cross configuration in order to generate a +45°and -45° polarization. There are various techniques for manufacturing such radiators. It is known, for instance, to use die casted radiators in combination with additional plastic parts. Furthermore, it is known to use etched planar radiators which consist of several planar substrates (PCBs) and additional plastic parts (sometimes, although less often injection moulded plastic parts with metallized lines thereon).

Usually, the manufacturing process of radiators, i.e. dipoles for antennas for wireless communication in a communication network consists of several often time-consuming manufacturing steps. These manufacturing steps comprise, for instance, alignment of the different radiator parts, soldering the different radiator parts together for providing electrical contact and adding, i.e. attaching additional plastic parts for providing better mechanical stability or electrical performance (also known as matching and pattern correction).

As a radiator for an antenna for wireless communication in a communication network usually is made up from several parts, the costs for assembling the radiator make a substantial contribution to the overall manufacturing costs for an antenna. Moreover, the reliability of an antenna in the field can be negatively impacted by a complex structure of the antenna and/or a complex manufacturing process of the antenna. In order to provide a light-weight dipole with as few parts as possible in a cost-efficient manner, a dipole is often made of one or more plastic support bodies having complex 3D shapes, wherein the radiator lines and feed lines are metallized structures on the one or more plastic support bodies. Figures 1 a and 1 b show perspective views of a dipole 100 comprising a plastic support body 101 with a plurality of metallized lines 103 provided on a surface thereof.

Manufacturing 3D printed plastic parts for an antenna element is, however, often very expensive. This is because in order to be solderable usually the whole part has to be made of a solderable plastic material, which compared to a common non-solderable plastic material is very expensive.

Moreover, using 3D printing for manufacturing plastic parts for an antenna element is limited with respect to creating complex dipole shapes because of the limitations of plating processes and limitations of creating plastic parts with injection moulding or deep drawing. Under these circumstances special applications are usually necessary, such as bonding different plastic parts and then plating over different materials. Further limitations are due to areas of the dipole, which cannot be accessed by metallizing equipment.

Thus, there is a need for an improved manufacturing method for providing antenna elements having a complex shape.

SUMMARY

It is an object of the invention to provide an improved manufacturing method for providing antenna elements having a complex shape.

The foregoing and other objects are achieved by the subject matter of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.

According to a first aspect the invention relates to a method for manufacturing an antenna element having a desired shape, wherein the antenna element is configured to transmit and/or receive an RF signal. The method comprises the steps of: providing a pliable substrate, wherein the pliable substrate has a conductive structure formed thereon; folding the pliable substrate into a folded configuration; and fastening the pliable substrate in the folded configuration to a rigid support for providing the antenna element having the desired shape.

Thus, an improved manufacturing method for providing antenna elements having a desired possibly complex shape is provided. Advantageously, the rigid support provides both shape and stability to the pliable substrate to keep it in the desired shape and, furthermore, can act as a dielectric, if desired.

In a further possible implementation form of the first aspect, the conductive structure comprises one or more feed lines and/or one or more radiators. Each radiator may comprise a dipole. In an operational state of the antenna, the one or more feed lines may be connected to a transmitter or receiver.

In a further possible implementation form of the first aspect, prior to being folded the pliable substrate and the conductive structure together have a flat shape. Thereby, the pliable substrate can be provided using a cost-efficient manufacturing process.

In a further possible implementation form of the first aspect, prior to being folded the pliable substrate has a planar surface on which the conductive structure is arranged.

In a further possible implementation form of the first aspect, the method comprises forming the conductive structure on the substrate by one or more of the following processes: plasma coating, jet printing, applying a conductive ink, applying a conductive paste.

In a further possible implementation form of the first aspect, the method comprises forming the conductive structure on the pliable substrate by placing a metal foil on the substrate and by removing parts of the metal foil, for instance, by etching or punching. Thereby, the conductive structure can be provided on the pliable substrate using a cost- efficient manufacturing process.

In a further possible implementation form of the first aspect, the pliable substrate is or comprises a pliable sheet. Thereby, the pliable substrate can be provided using a cost- efficient manufacturing process. In a further possible implementation form of the first aspect, the pliable substrate consists of or comprises a pliable dielectric material, e.g. a pliable plastic. Thereby, the pliable substrate can act as a dielectric within the antenna element having the desired shape.

In a further possible implementation form of the first aspect, the rigid support comprises or consists of a rigid dielectric material, e.g. a rigid plastic. Thereby, the rigid support can act as a dielectric within the antenna element having the desired shape.

In a further possible implementation form of the first aspect, folding the pliable substrate comprises folding the pliable substrate around at least a portion of the rigid support. Thus, the rigid support may be located at least partially between different planar portions of the folded substrate. The rigid support located between different planar portions of the substrate can act as a dielectric between the different planar portions of the substrate.

In a further possible implementation form of the first aspect, fastening the pliable substrate in the folded configuration to the rigid support comprises a bonding process or a form closure process.

In a further possible implementation form of the first aspect, the pliable substrate is a first pliable substrate and the method comprises the further steps of: providing a second pliable substrate, the second pliable substrate having a conductive structure formed thereon; folding the second pliable substrate into a folded configuration; and fastening the second pliable substrate in the folded configuration to the rigid support. By using a first and a second pliable substrate antenna elements having very complex shapes can be provided.

According to a second aspect the invention relates to an antenna element provided by a manufacturing method according to the first aspect of the invention.

According to a third aspect the invention relates to an antenna comprising a plurality of antenna elements, wherein each antenna element of the antenna is provided by a manufacturing method according to the first aspect of the invention.

Details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

In the following embodiments of the invention are described in more detail with reference to the attached figures and drawings, in which:

Figs. 1 a and 1 b are perspective views of a conventional antenna element;

Figs. 2a-d are perspective views of an antenna element being manufactured according to a manufacturing method according to an embodiment of the invention;

Fig. 3 is a flow diagram illustrating steps of a method for manufacturing an antenna element according to an embodiment of the invention; and

Figs. 4a-e are perspective views of an antenna element being manufactured according to a manufacturing method according to a further embodiment of the invention.

In the following identical reference signs refer to identical or at least functionally equivalent features.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following description, reference is made to the accompanying figures, which form part of the disclosure, and which show, by way of examples, specific aspects of embodiments of the invention or specific aspects in which embodiments of the invention may be used. It is understood that embodiments of the invention may be used in other aspects and comprise structural or logical changes not depicted in the figures. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined by the appended claims.

For instance, it is to be understood that a disclosure in connection with a described method may also hold true for a corresponding device or system configured to perform the method and vice versa. For example, if one or a plurality of specific method steps are described, a corresponding device may include one or a plurality of units, e.g. functional units, to perform the described one or plurality of method steps (e.g. one unit performing the one or plurality of steps, or a plurality of units each performing one or more of the plurality of steps), even if such one or more units are not explicitly described or illustrated in the figures. On the other hand, for example, if a specific apparatus is described based on one or a plurality of units, e.g. functional units, a corresponding method may include one step to perform the functionality of the one or plurality of units (e.g. one step performing the functionality of the one or plurality of units, or a plurality of steps each performing the functionality of one or more of the plurality of units), even if such one or plurality of steps are not explicitly described or illustrated in the figures. Further, it is understood that the features of the various exemplary embodiments and/or aspects described herein may be combined with each other, unless specifically noted otherwise.

Figures 2a-e show perspective views of an antenna element 200 (or components thereof) being manufactured according to a manufacturing method according to an embodiment of the invention. The manufactured antenna element 200, which can be a component of a larger antenna or antenna array, is configured to transmit and/or receive an RF signal.

In a first stage of the manufacturing method illustrated by figures 2a-e a pliable substrate 201 is provided with a conductive structure formed thereon. As illustrated in figure 2a, the conductive structure may comprise one or more feed lines 203a and one or more radiators 203b. Each radiator 203b may comprise or define a dipole. In an operational state of the antenna element 200, the one or more feed lines 203a may be connected to a transmitter or receiver circuitry.

As can be taken from figure 2a, in its original state the pliable substrate 201 and the conductive structure, e.g. the one or more feed lines 203a and/or the one or more radiators 203b, may both have a substantially flat shape. In the embodiment illustrated in figure 2a, the pliable substrate 201 is a pliable sheet and defines a planar surface on which the conductive structure, e.g. the one or more feed lines 203a and/or the one or more radiators 203b, is arranged. According to an embodiment, the substrate 201 may consist of or comprise a pliable dielectric material, such as a pliable dielectric plastic material.

According to an embodiment, the one or more feed lines 203a and/or the one or more radiators 203b can be formed on the pliable substrate 201 by one or more of the following processes: plasma coating, jet printing, applying a conductive ink and/or applying a conductive paste. Alternatively or additionally, the one or more feed lines 203a and/or the one or more radiators 203b can be formed on the pliable substrate 201 by arranging a metal foil on the substrate 201 and removing parts of the metal foil, e.g., by means of an etching or punching process.

In a second stage of the manufacturing method illustrated by figures 2a-e the pliable substrate 201 is folded into a folded configuration having a desired shape. An

intermediate stage of this process of folding the pliable substrate 201 into the desired shape is illustrated in figure 2b. As can be taken from figure 2c the folding of the pliable substrate 201 into the desired shape can comprise folding the substrate 201 around a rigid support. In an embodiment, the rigid support can be a single part or comprise at least two rigid support elements. By way of example, a support having two such rigid support elements 21 1 a,b is illustrated in figure 2c. However, also more than two or only one rigid support element can provide the rigid support. As illustrated in figure 2c and figure 2d (which shows the completely folded configuration), the rigid support elements 21 1 a,b are located at least partially between different planar portions of the folded substrate 201 and can act as a dielectric between the different planar portions of the substrate 201 . Thus, according to an embodiment the support or support elements 21 1 a-c can comprise or consists of a rigid dielectric material, e.g. a rigid plastic material.

In a third stage of the manufacturing method illustrated by figures 2a-e the pliable substrate 201 is fastened in the folded configuration to the rigid support elements 21 1 a,b for providing the antenna element 200 having a desired shape and the required stability, as illustrated in figure 2d. According to an embodiment, fastening the pliable substrate 201 in the folded configuration to the rigid support elements 21 1 a,b can comprises a bonding process or a form closure. For instance, one or more holes 202 may be provided in the pliable substrate 201 , as illustrated in figures 2a-c, wherein the holes 202 are

dimensioned and arranged to receive corresponding alignment pins 212 of the rigid support elements 21 1 a,b. For instance, in the folded configuration the hole 202 illustrated in figure 2c is dimensioned and arranged to receive the alignment pin 212 provided on the edge of the rigid support element 21 1 a.

Figure 3 is a flow diagram illustrating the steps of a method 300 for manufacturing the antenna element 200 according to an embodiment of the invention. The method 300 comprises the steps of: providing 301 the pliable substrate 201 , wherein the pliable substrate 201 has the conductive structure 203a, b formed thereon; folding 303 the pliable substrate 201 into a folded configuration; and fastening 305 the pliable substrate 201 in the folded configuration to the rigid support 21 1 a-c for providing the antenna element 200 having the desired shape.

Figures 4a-e show perspective views of an antenna element 200 (or components thereof) being manufactured according to a manufacturing method according to a further embodiment of the invention. As the different stages of the manufacturing method illustrated in figures 4a-e are mostly identical or very similar to the stages of the manufacturing method illustrated in figures 2a-e, in the following only the differences between the embodiments shown in figures 2a-e and figures 4a-e will be described in more detail.

The main difference between the embodiment shown in figures 4a-e and the embodiment shown in figures 2a-e is that in the embodiment shown in figures 4a-e the antenna element 200 comprises a first pliable substrate 201 having a conductive structure, in particular one or more feed lines 203a and/or one or more radiators 203b, formed thereon and a second pliable substrate 401 having a conductive structure 403, in particular one or more feed lines 403 formed thereon. In the embodiment shown in figures 4a-e both the first pliable substrate 201 and the second pliable substrate 401 are folded into a folded configuration and fastened in the folded configuration to the rigid support for providing the antenna element 200 with the desired shape and stability. More specifically, the first pliable substrate 201 is fastened in the folded configuration to the support element 21 1 a and the second pliable substrate 401 is fastened in the folded configuration to the support elements 21 1 b and 21 1 c. In the embodiments shown in figures 4a-e the support elements 21 1 b are provided by planar dielectric plastic parts and the support element 21 1 c can define a ground potential.

Thus, embodiments of the invention allow providing antenna elements with dipoles or dipole configurations and/or all kind of reflector/director configurations in a 3D structure by folding a pliable 2D substrate with a metallized conduction structure thereon into the desired shape. According to embodiments of the invention a dipole may be built with more and different layers of foils. According to embodiments of the invention the pliable substrate may be adhesively bonded to the support elements. According to embodiments of the invention, a radiator, i.e. dipole head, signal lines and the connection to the antenna can be provided in one part. According to embodiments of the invention, dipole groups comprising radiators, signal lines and/or connections may be realised using a single substrate foil. In several embodiments provided in the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiment is merely exemplary. For example, the unit division is merely logical function division and may be other division in actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or

communication connections may be implemented by using some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In addition, functional units in the embodiments of the invention may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units are integrated into one unit.