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). Figures 1 a and 1 b illustrate a conventional dipole 100 comprising a sheet metal body 101 , plastic supports and a printed circuit board (PCB) 1 1 1 (figure 1 b shows a more detailed view of a portion shown in figure 1 a). For manufacturing the dipole 100 several conductive connections have to be provided, such as conductive connections between the sheet metal body 101 , in particular metal pins 102 of the sheet metal body 101 and the PCB 1 1 1 , between the PCB 1 1 1 and metallized plastic parts and/or between different metal portions of the dipole 100. Usually, these conductive connections are provided by a soldering process. However, for providing a soldered conductive connection between different parts of the dipole 100 generally high temperatures of the order of 200 °C and above are required, which will heat at least portions of the respective parts of the dipole 100 being soldered to comparable temperatures. Thus, the respective parts of the dipole 100 being soldered have to be made from materials that can withstand these high temperatures. However, for reducing the costs and increasing the automation of the dipole manufacturing process it would be desirable to provide more components of the dipole as plastic parts, such as plastic foils covered with metal signal lines and ground lines.

However, only very few and, thus, expensive plastic materials can withstand the high temperatures associated with the soldering process.

Thus, there is a need for an improved manufacturing method for providing dipoles, i.e. antenna elements. SUMMARY

It is an object of the invention to provide an improved manufacturing method for providing dipoles, i.e. antenna elements.

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 for transmitting or receiving a RF signal. The method comprises: providing a metallized electrical conduction line on a non-conductive surface of a first support element, wherein the metallized electrical conduction line extends into a contact portion of the surface of the first support element; providing a metallized electrical conduction line on a non-conducting surface of a second support element, wherein the metallized electrical conduction line extends into a contact portion of the surface of the second support element; bringing the contact portion of the first support element at least partially into contact with the contact portion of the second support element; and applying a conductive adhesive to the contact portion of the first support element and/or the contact portion of the second support element for fastening the first support element to the second support element and conductively connecting the metallized electrical conduction line on the surface of the first support element to the metallized electrical conduction line on the surface of the second support element.

Thus, advantageously, the present invention allows providing a PIM free conductive connection between metallized electrical conduction lines on dipole support elements with a process, which includes applying a conductive adhesive/glue and uses smaller temperatures, such as temperatures of about 150 °C, than conventional soldering processes. According to embodiments the conductive adhesive/glue is filled with metal particles.

In a further possible implementation form of the first aspect, the first support element further comprises a radiator element, wherein the metallized electrical conduction line on the surface of the first support element conductively connects to the radiator element and wherein the radiator element is configured to transmit a RF signal, when supplied with an electric current via the metallized electrical conduction line on the surface of the first support element.

In a further possible implementation form of the first aspect, the radiator element is a metallized patch located on the surface of the first support element. Thereby, the radiator element can be provided by a simple cost-efficient manufacturing process.

In a further possible implementation form of the first aspect, the second support element comprises one or more solderable connection pins for connecting the antenna element to a power source, wherein the metallized electrical conduction line on the surface of the second support element is conductively connected to the one or more solderable connection pins and wherein the power source is configured to supply an electric current to the metallized electrical conduction line on the surface of the second support element. Thereby, the antenna element can be easily connected to further components of an antenna or antenna array.

In a further possible implementation form of the first aspect, the method further comprises the step of curing the conductive adhesive.

In a further possible implementation form of the first aspect, the step of curing the conductive adhesive comprises the step of heating the conductive adhesive to a temperature of about 150° Celsius. Thereby, conductive connections can be provided with temperatures much less than the temperatures required for conventional soldering processes.

In a further possible implementation form of the first aspect, the contact portion of the second support element comprises one or more projections, in particular studs, and the contact portion of the first support element comprises one or more recesses, in particular holes, wherein the step of bringing the contact portion of the first support element into contact with the contact portion of the second support element comprises inserting the one or more projections of the contact portion of the second support element into the one or more recesses of the contact portion of the first support element. In another possible implementation form the one or more projections may be defined by the contact portion of the first support element, while the one or more corresponding recesses are defined by the contact portion of the second support element. Thereby, the contact portions of the first and second support element can be brought easily into contact. In a further possible implementation form of the first aspect, the first support element and/or the second support element comprise or consist of a metallized plastic foil.

Thereby, the first and/or second support element can be provided by a cost-efficient manufacturing process.

In a further possible implementation form of the first aspect, the first support element and/or the second support element are a metallized solid plastic part. Thereby, the first and/or second support element can be provided by a cost-efficient manufacturing process.

In a further possible implementation form of the first aspect, the second support element is a printed circuit board. Thereby, the second support element can be provided by a cost- efficient manufacturing process.

In a further possible implementation form of the first aspect, the step of applying the conductive adhesive to the contact portion of the first support element and/or the contact portion of the second support element precedes the step of bringing the contact portion of the first support element into contact with the contact portion of the second support element.

In a further possible implementation form of the first aspect, the step of bringing the contact portion of the first support element into contact with the contact portion of the second support element precedes the step of applying the conductive adhesive to the contact portion of the first support element and/or the contact portion of the second support element.

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 an example of conventional antenna element;

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

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

Figs. 4a and b are perspective views of an example of an antenna element manufactured using 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-d show perspective views of an antenna element 200 manufactured according to a manufacturing method according to a first embodiment of the invention. The 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 in Figure 2a one or more metallized electrical conduction lines 203 are provided on a non-conductive surface of a first support element 201 in such a way that the one or more metallized electrical conduction lines 203 extend into a contact portion of the surface of the first support element 201. Likewise, one or more further metallized electrical conduction lines 213 are provided on a non conducting surface of a separate second support element 21 1 in such a way that the one or more metallized electrical conduction lines 213 extend into a contact portion of the surface of the second support element 21 1. According to an embodiment, the first support element 201 can comprise or consist of a non-solderable plastic material, such as polyoxymethylene (POM), polystyrene (PS), polypropylene (PP) or polycarbonate (PC). According to an embodiment, the second support element 21 1 can comprise or consist of a solderable plastic material, such as liquid cristal polymers (LCP), polyphenylene sulfide (PPS), polyimide or polyether ether ketone, and/or a solderable metal material, such as tin, silver, copper or gold. According to an embodiment, the first support element 201 and the second support element 21 1 may be provided by different manufacturing processes. For instance, the first support element 201 may be provided by an injection moulding process, while the second support element 21 1 may be provided by a deep-drawing process. According to an embodiment, the first support element 201 and/or the second support element 21 1 comprise or consist of a metallized plastic foil. According to an embodiment, the first support element 201 and/or the second support element 21 1 are a metallized solid plastic part. According to an embodiment, the second support element 21 1 is a printed circuit board (PCB).

According to an embodiment, the one or more metallized electrical conduction lines 203 on the non-conducive surface of the first support element 201 can be provided by one or more of the following processes: plasma coating, jet printing, or applying a conductive ink or paste to the surface of the first support element 201. Likewise, the one or more metallized electrical conduction lines 213 on the non-conducive surface of the second support element 21 1 can be provided by one or more of the following processes: plasma coating, jet printing, or applying a conductive ink or paste to the surface of the second support element 21 1.

In a second stage of the manufacturing method the contact portion of the first support element 201 is brought at least partially into contact with the contact portion of the second support element 21 1. In the embodiment shown in figures 2a-d the contact portion of the first support element 201 comprises one or more recesses, in particular holes 201 a and the contact portion of the second support element 21 1 comprises one or more projections, in particular studs 21 1 a. As can be taken from figure 2b, in this embodiment the contact portion of the first support element 201 is brought into contact with the contact portion of the second support element 21 1 by inserting the one or more studs 21 1 a of the contact portion of the second support element 21 1 into the one or more holes 201 a defined by the contact portion of the first support element 201. According to a variant, the one or more projections may be defined by the contact portion of the first support element 201 , while the one or more corresponding recesses are defined by the contact portion of the second support element 21 1.

In a third final stage of the manufacturing method illustrated in figures 2c and 2d (which is a more detailed view of a portion of figure 2c) a conductive adhesive or glue 209 is applied to the contact portion of the first support element 201 and/or the contact portion of the second support element in such a way that the conductive adhesive 209 fastens the first support element 201 to the second support element 21 1 and conductively connects the one or more metallized electrical conduction lines 203 on the surface of the first support element 201 to the one or more metallized electrical conduction lines 213 on the surface of the second support element 21 1. After applying the conductive adhesive 209, this can comprise the further step of curing the conductive adhesive 209, for instance, by heating the conductive adhesive 209 to a temperature of about 150° Celsius for about 15 minutes.

Thus, the conductive adhesive 209, which is preferably filled with metal particles, allows providing a PIM free conductive connection between the metallized electrical conduction lines 203, 213 of the first and second support element 201 , 21 1 using smaller

temperatures, such as temperatures of about 150 °C, than conventional soldering processes.

According to an embodiment, the first support element 201 may further comprise a radiator element, wherein the one or more metallized electrical conduction lines 203 on the surface of the first support element 201 conductively connect to the radiator element and wherein the radiator element is configured to transmit a RF signal, when supplied with an electric current via the one or more metallized electrical conduction lines 203 on the surface of the first support element 201 . The radiator element may be a metallized patch located on the surface of the first support element 201.

According to an embodiment, the second support element 21 1 may comprise one or more solderable connection pins for connecting the antenna element 200 to a power source or other components of an antenna or antenna array, wherein the one or more metallized electrical conduction lines 213 on the surface of the second support element 21 1 are conductively connected to the one or more solderable connection pins and wherein the power source is configured to supply an electric current to the one or more metallized electrical conduction lines on the surface of the second support element 21 1.

Figure 3 is a flow diagram illustrating the steps of a method 300 for manufacturing the antenna element 200 configured to transmit and/or receive a RF signal. The method 300 comprises the steps of: providing 301 the one or more metallized electrical conduction lines 203 on the non-conductive surface of the first support element 201 , wherein the one or more metallized electrical conduction lines 203 extend into a contact portion of the surface of the first support element 201 ; providing 303 the one or more metallized electrical conduction lines 213 on the non-conducting surface of the second support element 21 1 , wherein the one or more metallized electrical conduction lines 213 extend into a contact portion of the surface of the second support element 21 1 ; bringing 305 the contact portion of the first support element 201 at least partially into contact with the contact portion of the second support element 21 1 ; and applying 307 a conductive adhesive 209 to the contact portion of the first support element 201 and/or the contact portion of the second support element 21 1 for fastening the first support element 201 to the second support element 21 1 and conductively connecting the one or more metallized electrical conduction lines 203 on the surface of the first support element 201 with the one or more metallized electrical conduction lines 213 on the surface of the second support element 21 1.

As will be appreciated, in the embodiment of the method 300 illustrated in the context of figures 2a-d the step of bringing the contact portion of the first support element 201 into contact with the contact portion of the second support element 21 1 precedes the step of applying the conductive adhesive 209 to the contact portion of the first support element 201 and/or the contact portion of the second support element 21 1.

According to a further embodiment of the method 300, the step of applying the conductive adhesive 209 to the contact portion of the first support element 201 and/or the contact portion of the second support element 21 1 may precede the step of bringing the contact portion of the first support element 201 into contact with the contact portion of the second support element 21 1 , as illustrated by the embodiment shown in figures 4a and 4b. In the embodiment shown in figures 4a and 4b, both the first support element 201 and the second support element 21 1 are a metallized plastic foil, i.e. a plastic foil with the respective electrical conduction line 203, 213 metallized thereon. In the embodiment shown in figures 4a and 4b, the adhesive glue 209 is applied, by way of example, to the contact portion of the second support element 21 1 , before the first support element 201 and the second support element 21 1 are brought into contact.

Thus, embodiments of the invention allow conductively connecting metallized conduction lines, such as signal lines or ground lines of metallized foils, PCBs, flexible PCBs, metallized plastic parts and metal sheets/foils in all combinations.

In the 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.