Device for current return and / or electromagnetic shielding and a radio equipment comprising the device

Abstract

A device is provided. The device (110) is for current return and / or electromagnetic shielding, for use in a radio equipment. The device is electrically conductive, made of a metallic sheet which is tubular shaped and extends along an axis. The device comprises a first rim defining a first opening, and a second rim, defining a second opening. The device further comprises a flection area arranged between the first rim and the second rim. The first rim and / or the second rim are continuous, and the flection area is adapted to flex when the device is axially compressed. The second opening is to be attached to a circuit board to be seamless sealed to the circuit board. The first opening will, during said compression towards a metallic connection part of an electrical connection, provide current return and / or electromagnetic shielding between the first opening and the metallic connection part.

Description

[0001] DEVICE FOR CURRENT RETURN AND / OR ELECTROMAGNETIC SHIELDING AND A RADIO EQUIPMENT COMPRISING THE DEVICE.

[0002] TECHNICAL FIELD

[0003] Embodiments herein relate to a device and a radio equipment. In some aspects, device the device is for current return and / or electromagnetic shielding for use in a radio equipment.

[0004] BACKGROUND

[0005] In a typical wireless communication network comprising radio equipment, wireless devices, also known as wireless communication devices, mobile stations, stations (ST A) and / or User Equipment (UE), communicate via a Wide Area Network or a Local Area Network such as a Wi-Fi network or a cellular network comprising a Radio Access Network (RAN) part and a Core Network (CN) part. The RAN covers a geographical area which is divided into service areas or cell areas, which may also be referred to as a beam or a beam group, with each service area or cell area being served by a radio network node such as a radio access node e.g., a Wi-Fi access point, a Base Station (BS) or a radio base station (RBS), which in some networks may also be denoted, for example, a Base Station (BS), a NodeB, eNodeB (eNB), or gNodeB (gNB) as denoted in Fifth Generation (5G) communications. A service area or cell area is a geographical area where radio coverage is provided by the radio network node. The radio network node communicates over an air interface operating on a radio frequency with the wireless devices within the range of the radio network node.

[0006] 3rd Generation Partnership Project (3GPP) is the standardization body for specifying the standards for the cellular system evolution, e.g., including 3G, 4G, 5G and the future evolutions. Specifications for Evolved Universal Terrestrial Radio Access (E- UTRA) and Evolved Packet System (EPS) have been completed within the 3GPP. In 4G also called a Fourth Generation (4G) network, EPS is core network and E-UTRA is radio access network. In 5G, 5GC is core network, NR is radio access network. As a continued network evolution, the new release of 3GPP specifies a 5G network also referred to as 5G New Radio (NR) and 5G Core (5GC).

[0007] Frequency bands for 5G NR are being separated into two different frequency ranges, Frequency Range 1 (FR1) and Frequency Range 2 (FR2). FR1 comprises sub-6 GHz frequency bands. Some of these bands are bands traditionally used by legacy standards but have been extended to cover potential new spectrum offerings from 410 MHz to 7125 MHz. FR2 comprises frequency bands from 24.25 GHz to 52.6 GHz. Bands in this millimeter wave range have shorter range but higher available bandwidth than bands in the FR1.

[0008] Multi-antenna techniques may significantly increase the data rates and reliability of a wireless communication system. For a wireless connection between a single user, such as UE, and a base station (BS), the performance is in particular improved if both the transmitter and the receiver are equipped with radio equipment such as multiple antennas, which results in a Multiple-Input Multiple-Output (MIMO) communication channel. This may be referred to as Single-User (SU)-MIMO. In the scenario where MIMO techniques is used for the wireless connection between multiple users and the base station, MIMO enables the users to communicate with the base station simultaneously using the same time-frequency resources by spatially separating the users, which increases further the cell capacity. This may be referred to as Multi-User (MU)-MIMO. Note that MU-MIMO may benefit when each UE only has one antenna. The cell capacity can be increased linearly with respect to the number of antennas at the BS side. Due to that, more and more antennas are employed in BS. Such systems and / or related techniques are commonly referred to as massive MIMO.

[0009] Signal or Radio Frequency (RF) transmission is between a centre conductor and a current return conductor. Basically, a current return conductor is typically the thin metallic tube around a centre pin, in which current flows outside of centre pin and inside of the metallic tube. An improper current return conductor will result in a significantly deteriorated signal quality and cause Electromagnetic Interference (EMI) leakage, especially for RF transmissions. A current return conductor may serve many purposes in electronic design, including e.g., a physical connection to the return path, a reference point in a circuit for measuring voltages, and a common return path for signals and power. An electromagnetic field will penetrate the wall of the current return conductor and leakage through the hole or slit of return conductor. As the frequency increases, the leakage level will be significantly increased. Therefore, a seamless tubular is perfect as current return, also as a shield. Due to skin effect of high frequency of the electromagnetic field, even a very thin wall in tens micrometre will give significant high shielding effectiveness only if it is seamless. Otherwise, several layers of current return path have to be implemented in RF applications. Printed Circuit Boards (PCB)s are used in electronic devices to provide a platform for mounting and interconnecting various electronic components. At PCB board level, PCB shielding typically comes in the form of metallic enclosures or cans designed to surround and protect sensitive circuitry. A right level shielding especially on a component will reduce burden for the system level shielding. However in an Advanced Antenna Systems (AAS) structure, a good shielding is a must because a complete shielding is not possible to achieve.

[0010] An RF interconnector is typically designed as a center pin and a current return conductor together to form a coaxial structure, typically a 360 degrees surrounding metallic wall around the center conductor. The electromagnetic field is located between the center conductor and the surrounding metallic wall. However, the field will penetrate through the slit and bad connection to interface, which is causing leakage. In some designs, especially board to board with compressed PCB distance, the center pin and the current return conductor structure can be separated from mechanical purpose. The current return conductor structure in such case may be called disc type to form coaxial structure around center pin. In such case, a disc needs to be more flexible and seamless in 360 degree as current return and prevent the leakage through slit and interconnect interface imperfection.

[0011] SUMMARY

[0012] An object of embodiments herein is to provide a device with improved current return and / or electromagnetic shielding in a radio equipment.

[0013] According to an aspect of embodiments herein, the object is achieved by a device for current return and / or electromagnetic shielding, for use in a radio equipment. The device is electrically conductive, made of a metallic sheet which is tubular shaped and extends along an axis.

[0014] The device comprises a first rim defining a first opening, and a second rim, defining a second opening. The device further comprises a flection area arranged between the first rim and the second rim. The first rim and / or the second rim are continuous, and the flection area is adapted to flex when the device is axially compressed.

[0015] The second opening is to be attached to a circuit board to be seamless sealed to the circuit board. The first opening will, during said compression towards a metallic connection part of an electrical connection, provide current return and / or electromagnetic shielding between the first opening and the metallic connection part.

[0016] According to another aspect of embodiments herein, the object is achieved a radio equipment comprising the device, a circuit board, and a metallic connection part of an electrical cable. The device is located between the circuit board and a metallic connection part of the electrical cable. The circuit board and the metallic connection part are connected, so that a flection area of the device flexes and thereby current return and / or electromagnetic shielding is maintained when subjected to movements.

[0017] Advantages of embodiments herein are e.g. that they provide:

[0018] - 360 degree shielding for higher frequencies such as e.g., over 1 GHz.

[0019] - Lower compression force, also referred to as contact force is needed for 5 N.

[0020] - Easy production and low cost.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Examples of embodiments herein are described in more detail with reference to attached drawings in which:

[0023] Figures 1 a and b schematically illustrate devices according to prior art.

[0024] Figure 2 is a schematic block diagram illustrating embodiments of a wireless communications network.

[0025] Figures 3 a, b and c are schematic diagrams illustrating embodiments of a device. Figures 4 a and b are schematic diagrams illustrating embodiments of a device. Figures 5 a and b are schematic diagrams illustrating embodiments of a device. Figures 6 a b, and c are schematic diagrams illustrating embodiments of a device. Figures 7 a and b are schematic diagrams illustrating embodiments of devices.

[0026] DETAILED DESCRIPTION

[0027] As a part of developing embodiments herein a problem was identified by the inventors and will first be discussed. Compressed PCB to PCB connection or PCB to filter connection become more preferable technical solutions because of the assembly reflexibility, and tolerance requirement from structure. The individual compressed force needs to be limited to a certain level in cases with strong compress force for multiple channels. Therefore a compression force for individual channels needs to be limited to a low level to be able to be used for multiple channel compression.

[0028] Even disc type grounding is a simple component, but requirements are very strict on many aspects, such as mechanical reliability through its lifetime, thermal impact and shielding effectiveness. The deterioration of any performance will significantly impact radio performance. Different systems have different level of shielding, such as -80dB for a radio product, and frequency has to be up to working frequency or multiple resonance. Especially now, when sub 15 or RF frequency reaches 16 GHz, classic shielding method becomes inefficient. Sub 15 is frequency is a content for radio equipment from 3GPP.

[0029] Normally, metallic material such as copper beryllium without hole and slits may easily be used as shielding. However since shielding need to be 360 degree, the flexibility of the shielding material becomes an issue. Furthermore, some elastic material may be used as shielding too. However due to object movement in thermal environment, the contact force between shielded material and interface deteriorates as time or thermal cycling. Any material deterioration and interface imperfection due to thermal effect, aging and mechanical micromovement will significantly deteriorate the shielding effectiveness level.

[0030] Typical disc type shielding structure, either used as current return or shielding, may e.g., be as follows. 360 degree covered by metallic, and good contact force between top and bottom interface. Furthermore, the disc has to be elastic to deal the tolerance from top and bottom interfaces, and even the micromovement due to thermal expansions from system. The contact to interface needs to be electrically low conductive. Otherwise the shielding will deteriorate, which is typical failure for an aged shielding solutions.

[0031] Current solutions are divided into two categories, elastic rubber disc type, and metallic disc type.

[0032] Elastic rubber gaskets are commonly used disc type shielding in. A conductive filler inside the elastic material gives a property of conductivity and gives shielding property when it is new. Elastic material needs strong contact force to an interface to cause low resistivity between an interface and the elastic material, which is part of the shielding properties. Therefore, the elastic material requires consistent good electrical contact between the interface and the elastic material. Normally the elastic rubber gasket failures after some time of field application.

[0033] A metallic coil spring is also to be found very efficient for shielding purpose, especially when it deals with uneven interface. Due to its elastic property of thin metallic steel, it shows great property for good contact electric property to the interfaces, insensitive to micromovement of interfaces. However due to limited turns in the coil spring, there are too many openings, e.g., slits, that will cause high frequency leakage. Therefore, it cannot work at very high frequency, such as e.g. 4 Giga Hertz (GHzZ), but low frequency RF such as under 3GHz. An example of a coil spring compressed in uneven surfaces is shown in Figure 1a.

[0034] Finger type of grounding easy keeps the elastic property for the metallic, therefore it is also quite used in the industry. Since it is metallic, it will be much less issues for the interface contact compared with the above-mentioned gasket. However since there are many fingers needed in 360 degrees around, to keep good contact to interface, it has to sacrifice the higher frequency too. It cannot be used for high shielding effectiveness like 60dB at high frequency above 3GHz. An example of a finger type ring is shown in Figure 1b.

[0035] A Form-In-Place (FIP) gasket is created by dispensing a liquid gasket onto a metal or plastic part before assembly. Because it is dispensed as a liquid, it fits precisely to the part's form, regardless of housing imperfections. This results in a reliable seal and durable finished product. FIP gaskets are widely used, but they count the same as the elastic gaskets mentioned above. In a test it shows unstable contact interface contact resistance even one interface is guaranteed to have good contact.

[0036] A meshed disk comprises thin meshed wires to create elastic property. However it cannot deal with mechanical tolerance very well and strong contact force is needed to ensure the interface contact.

[0037] As mentioned above, the object of embodiments herein is to provide a device with improved current return and / or electromagnetic shielding in a radio equipment.

[0038] Figure 2 is a schematic overview depicting a wireless communications network 100, such as e.g. a wireless communications network, comprising radio equipment 101 wherein embodiments herein may be implemented. The wireless communications network 100 comprises one or more RANs and one or more CNs. The wireless communications network 100 may use 5G NR but may further use a number of other different technologies, such as, 6G, Wi-Fi, (LTE), LTE-Advanced, Wideband Code Division Multiple Access (WCDMA), Global System for Mobile communications / enhanced Data rate for GSM Evolution (GSM / EDGE), or Ultra Mobile Broadband (UMB), just to mention a few possible implementations.

[0039] Radio equipment, such as a radio equipment 101 operates in the wireless communications network 100. The radio equipment 101 may e.g. be comprised in a base station 103, such as a radio unit or a base band unit, an antenna tower, an antenna pole, an antenna, a UE 120 and / or any other radio equipment. The radio equipment 101 e.g. comprises a circuit board 122, also referred to as board herein, to which a device 110 suitable for current return and / or electromagnetic shielding, according to embodiments herein is to be attached. The device 110 may also be referred to as gasket, a connection device ground disc or disc. The device 110 is for connecting a metallic connection part of an electrical cable such e.g., a coaxial cable to the circuit board 122 of the radio equipment 101. The device 110 may be used in radio equipment 101 , e.g. comprising, RRU, AAS and testbed Tx Rx port shielding e.g. in the base station 103 and / or the UE 120. The device 110 will be described more in detail below.

[0040] The radio equipment 101 is e.g. in some embodiments comprised in the base station 103 or comprised in a base station, an antenna system, a transmission and reception point e.g. a radio access network node such as a base station, a radio base station, a NodeB, an evolved Node B (eNB, eNodeB, eNode B), an NR / g Node B (gNB), a part of an Indoor Radio Unit (IRU), an Open RAN (ORAN) node, a base transceiver station, a radio remote unit, an Access Point Base Station, a base station router, a transmission arrangement of a radio base station, a stand-alone access point, a Wireless Local Area Network (WLAN) access point, an Access Point Station (AP STA), an access controller, a UE acting as an access point or a peer in a Device to Device (D2D) communication, or any other network unit capable of communicating with a UE served by the network node 110 depending e.g. on the radio access technology and terminology used.

[0041] The radio equipment 101 is e.g. in some embodiments comprised in a UEs such as e.g. a UE 120, operating in the wireless communications network 100. The UE 120 may e.g. be an NR device, a mobile station, a wireless terminal, an loT device, an loS device, an enhanced Machine Type Communication (eMTC) device, an NR RedCap device, a CAT-M device, a Vehicle-to-everything (V2X) device, Vehicle-to-Vehicle (V2V) device, a Vehicle-to-Pedestrian (V2P) device, a Vehicle-to-lnfrastructure (V2I) device, a Vehicle-to- Network (V2N) device, a Wi-Fi device, an LTE device, a non-access point (non-AP) STA, a STA, that communicates via a base station such as e.g. the network node 110, and one or more Access Networks (AN), e.g. RAN, to one or more core networks (CN). It should be understood by the skilled in the art that the term UE relates to a non-limiting term which means any UE, terminal, wireless communication terminal, user equipment, (D2D) terminal, or node e.g. smart phone, laptop, mobile phone, sensor, relay, mobile tablets or even a small base station communicating within a cell.

[0042] A number of embodiments will now be described, some of which may be seen as alternatives, while some may be used in combination.

[0043] An example embodiment of a side view of the device 110 is depicted in Figure 3a. The device 110 is suitable for current return and / or electromagnetic shielding. The current return and / or electromagnetic shielding may be related to a sealing of the electric connection between a circuit board 122 and the metallic connection part 121 , e.g., of an electrical cable. (See Figure 3b.)

[0044] Thus the device 110 may be used for sealing towards current return such as e.g. RF current return, for shielding or for both RF current return and shielding at the same time. The device 110 may also be referred to as gasket, disc and ground disc herein.

[0045] RF current return e.g., means return current from a center pin. The shielding according to embodiments herein e.g., provides that return current is returned, and no leakage current through a thin wall of the device 110 or through slit or bad interconnection. The shielding provided by the device 110 may work in high frequencies, e.g., up to 50GHz.

[0046] The device 110 is for use in the radio equipment 101 , e.g. in the UE 120 or in the base station 101. The device 110 is electrically conductive. This means that return current will be within the device 110. E.g., this results from the metallic property to form 360 degree coaxial structure around the centre pin.

[0047] The device 110 is made of a metallic sheet which is tubular shaped and extends along an axis 114. The metallic sheet may be thin, e.g., the thickness may be between 0,04 and 0,06 mm, or even below. This an advantage since a low thickness will reduce the force needed to deflect the sheet down on connecting part 121 . The metallic sheet may e.g., be made of a copper beryllium, or any other metal sheet with a good elastic property. To use a copper beryllium sheet is advantageous since its elastic property. Further, it has good mechanical properties, enabling it to withstand the compression forces without plastically deforming thus maintaining its desired shape to effectively shield the electric field inside.

[0048] And thin metallic sheet has property of skin effect, the electrical field will not penetrate through the completely sheet, (compared to much more critical on slit on holes as used in prior art).

[0049] Referring again to Figure 3a. The device 110 comprises a first rim 116 defining a first opening 111 , and a second rim 117 defining a second opening 112. The first and second openings 111 , 112 may be ring-shaped since the device 110 is tubular shaped.

[0050] Tubular shaped when used herein e.g. means that the device 110 is circular around the axis, e.g. like cone or a cylinder. Wherein the high, along the axis is relatively short. Meaning that the device 110 in some embodiments is disclike. Two example embodiments of tubular shapes of the device 110 are depicted in respective Figure 4 a and Figure 4b. The top pictures of each of the Figure 4a and 4b show a sideview, and the corresponding lower pictures show a Three Dimensional (3D) view.

[0051] In some embodiments, the tubular shape comprises a bowl-shape. Examples of bowl-shapes are shown in Figure 5a. In some alternative embodiments, the tubular shape may be cylindric or conic and / or disc shaped.

[0052] Referring again to Figure 3a. The device 110 further comprises a flection area 124 arranged between the first rim 116 and the second rim 117. The flection area 124 is flexible meaning that it will deform elastically during compression and thus keep its elastic mechanical properties, i.e., no plastic deformation occurs. The flection area 124 is made flexible by its shape. From mechanical property, the shape is easily to be deflected.

[0053] The bowl-shape of the device 110 may comprise a bottleneck shape 133 between the first opening 111 and the second opening 112. This is shown both in Figure 5b. An advantage with this is that the shape is easily deflected. This bottleneck shape is desirable since it makes the perpendicular length of the flection area 124 as long as possible, which helps with lowering the force needed to axially compress device 110. The first rim 116 and / or the second 117 rim are continuous. The flection area 124 is adapted to flex when the device 110 is axially compressed. The flection area 124 is made flexible by its shape. The shape is easily to be deflected. This may be accomplished by making the flection area 124 as perpendicular to the compression direction as possible. This will result in bending of the flection area 124 instead of compressing it. This lowers the compression force needed and lowers the stress in the part. This may be to increase the tolerance between board to board distance. “Board to board” or “board to filter” when used herein e.g., refers to “circuit board 122 to metallic connection part 121”

[0054] The second opening 112 is to be attached to a circuit board 122, e.g., a Printed Circuit Board (PCB) to be seamless to the circuit board 122 to provides the sealing, such as 360 degrees sealing.

[0055] The first opening 111 , will, during said compression towards the metallic connection part 121 of an electrical connection, provide current return and / or electromagnetic shielding between the first opening 111 and the metallic connection part 121 .

[0056] The compression performed here is used to have correct board to board or board to filter distance during an assembly process.

[0057] The electrical connection may comprise an electric connection between the circuit board 122 and an electrical cable pin.

[0058] The device 110 is open in the top and the bottom and therefore comprises two openings, a first opening 111 and a second opening 112. Both openings 111 , 112 may be ring shaped.

[0059] The first opening 111 defines a first area, and the second opening 112 defines a second area. The second area may be smaller than the first area. This is an advantage since the greater the diameter distance between the two openings is, the longer and / or wider the horizontal part of flection area 124 can be, which helps with the compression as previously described in the sections of flection area 124 and bottleneck 133.

[0060] The first opening 111 is to be compressed towards a metallic connection part 121. The metallic connection part 121 , may e.g. be a connection part of an electrically conductive interface.

[0061] An example embodiment of a side view of the device 110 when comprised in the radio equipment 101 is depicted in Figure 3b and a 3D view of the device 110 when comprised in the radio equipment 101 is depicted in Figure 3c. The radio equipment 101 comprises the device 110, the circuit board 122, and the metallic connection part 121 of an electrical cable.

[0062] The device 110 is located between the circuit board 122 and the metallic connection part 121 of the electrical cable. The circuit board 122 and the metallic connection part 121 are connected, so that the flection area 124 of the device 101 flexes and thereby current return and / or electromagnetic shielding is maintained when subjected to movements. Example of movement scenarios may e.g. comprise the movement of the device 110 in the axis 114 direction reduced for the flection area 124, resulting in that the first opening 111 will be become enlarged

[0063] The second opening 112 may be attached to the circuit board 122 by being soldered to the circuit board 122.

[0064] In some embodiments, the metallic connection part 121 may comprise a metallic surface. In some other embodiments, the metallic connection part 121 may comprise a metallic slits 131, in which the first rim 116 may be entered and fit in. The metallic connection part 121 , or e.g. the electrical cable may further comprise a center pin 132 to provide RF current return when reaching the PCB 112 through the device 110. Different views and examples of embodiments using the center pin 132 in Figures 6a, 6b and 6c. Figure 6a, 6b, and 6c depict cross-section examples used as an out-ground combination with the center pin 132. This e.g., means that the center pin 132 will be completely surrounded by the thin metallic sheet, e.g. the bowl shaped thin metallic sheet. In such a way, coaxial structure for RF signal is formed. The impedance of this coaxial structure shall preferably be optimized based on the center pin 132 dimension, first opening 111 and second opening 112 dimensions, and the distance between 111 and 112.

[0065] Embodiments herein such as the embodiments mentioned above will now be further described and exemplified. The text below is applicable to and may be combined with any suitable embodiment described above.

[0066] In a manufacturing of the device 110, a thin metallic sheet may be stamped to achieve the tubular shape, such as e.g., elastic bowl-shape. As mentioned above, the metallic sheet may be very thin, e.g., only about 0.05 mm thick. Due to the tubular shape, such as e.g., the bowl-shape, the device 110 is capable to be compressed for example to 0.5mm with about 4N when board to board or board to filter distance is reached. Since its metallic material property, it will create a good contact resistive to the metallic connection part 121 too. And furthermore, the second opening 112 according to embodiments herein may be soldered to the circuit board 122 to be seamless with the circuit board 122. In this way a true 360 degrees shielding is created. The first opening 111 will be compressed to the metallic connection part 121 such as e.g., to a metallic surface or within metallic slit. During its compression it e.g., performs true 360 degrees shielding, and no leakage slit like other finger or coil spring type disc in prior art when compressed.

[0067] Embodiments herein will reduce the cost for shielding solutions, and it may be widely used in e.g. RRU, AAS and testbed Tx Rx port shielding.

[0068] The device 110 e.g., comprises a typical shielding structure, either used as current return or shielding, may e.g., be a disc as follows. 360 degree covered by metallic, and good contact force between top interface, such as the circuit board 122, and bottom interface, such as the metallic connection part 121. Furthermore, the device 110 is elastic, this is to deal with the tolerance from top and bottom interfaces, and even the micromovement due to thermal expansions from system.

[0069] The device 110 may preferably provide electrically low conductive contact to the interfaces. This is to overcome that the shielding may deteriorate, which is typical failure for an aged shielding solutions.

[0070] Figure 7a depicts the device 110 in a position with no compression. The second opening 112 is attached to the circuit board 122.

[0071] Figure 7b depicts the device 110 under compression. The second opening 112 is attached to the circuit board 122. The Metallic connection part 121 is compressed towards the first opening 111 , this can be seen from the arrow 700.

[0072] It can be seen from Figure 7b how the second opening 112, attached to the circuit board 122, is pressed down inside the lower part of the device 110 towards the first opening 111 and, in this way, becomes deformed, when the metallic connection part 121 is compressed towards 700 the first opening 111. This is possible because of the elastic tubular shape.

[0073] The device 110 e.g., provide the following:

[0074] With a shielding with true 360 degrees, it works very high frequency up to above

[0075] 50GHz. With a compressed force that is only 4N, it may be compressed up to 0.5mm, used as elastic e.g., in the AAS or board to board, board to filter system.

[0076] It may be used in combination with the center pin 132 as RF current return or shielding at the same time.

[0077] It may be used with the first opening 111 in the form of a ring, as only an extra shielding for higher frequency.

[0078] It may be used as a low board to board connection distance to form RF interconnection. A low board to board connection may mean a board 121 to board 122 distance less than 10 mm.

[0079] Since the device 110 may be soldered to the circuit board 122, an assembly of the center pin 132, the metallic connection part 121 (e.g., upper PCB 121), the circuit board 122 (e.g., lower PCB 122) or the metallic connection part 121 (e.g., the metallic body 121) may be easily achieved, especially for multiple channels.

[0080] It is easy to produce, also referred to as manufacture, the device 110.

[0081] It is easy to assemble devices 110 for multiple channels use. This is since a single channel has compress force is 4N and no very strict tolerance on x-y because a relatively bigger pad in PCB 121 can be produced.

[0082] The device 110 size may preferably be determined by simulation to get an e.g., 50- ohm impedance for a transmission line. This is since a system requirement to have maximum power transmission through interconnect. This may be based on the metallic connection part 121 dimension and shape, circuit board 122, filter structure and center pin 132 size. The transmission line may be defined from the metallic connection part 121 , the circuit board 122, the filter structure and the center pin 132 size, e.g., the upper PCB, center pin, lower PCB bowel shape.

[0083] When using the word "comprise" or “comprising” it shall be interpreted as nonlimiting, i.e. meaning "consist at least of'.

[0084] The embodiments herein are not limited to the preferred embodiments described above. Various alternatives, modifications and equivalents may be used.

Claims

CLAIMS1 . A device (110) for current return and / or electromagnetic shielding, for use in a radio equipment (101), which device (110) is electrically conductive, made of a metallic sheet which is tubular shaped and extends along an axis (114), a first rim (116) defining a first opening (111), a second rim (117), defining a second opening (112), a flection area (124) arranged between the first rim (116) and the second rim (117), wherein the first rim (116) and / or the second (117) rim are continuous, and the flection area (124) is adapted to flex when the device (110) is axially compressed, and wherein the device (110) is characterized in that: the second opening (112) is to be attached to a circuit board (122) to be seamless sealed to the circuit board (122), wherein the first opening (111), during said compression towards (700) a metallic connection part (121) of an electrical connection, will provide current return and / or electromagnetic shielding between the first opening (111) and the metallic connection part (121).

2. The device (110) according to claim 1 , wherein the metallic sheet is below a thickness between 0,04 and 0,06 mm.

3. The device (110) according to any of the claims 1-2, wherein the tubular shape comprises a bowl-shape.

4. The device (110) according to any of the claims 1 -3, wherein the second opening (112) is to be attached to a circuit board (122) to be seamless to the circuit board (122) to provide 360 degrees sealing.

5. The device (110) according to claims 4, wherein the electrical connection comprises electric connection between the circuit board (122) and the electrical metallic connection part (121).

6. The device (110) according to claim 5, wherein current return and / or electromagnetic shielding is related to sealing the electric connection, between the circuit board (122) and the metallic connection part (121).

7. The device (110) according to any of claims 1 -6, wherein the metallic sheet is made of copper beryllium.

8. A radio equipment (101) comprising a device (110) according to any of the claims 1-7, a circuit board (122), and a metallic connection part (121) of an electrical cable, wherein the radio equipment (101) is characterized in that: the device (110) is located between the circuit board (122) and the metallic connection part (121) of the electrical cable, wherein the circuit board (122) and the metallic connection part (121) are connected, so that a flection area (124) of the device (101) flexes and thereby current return and / or electromagnetic shielding is maintained when subjected to movements.

9. The radio equipment (101) according to claim 8, wherein the second opening (112) is to be attached to the circuit board (122) by being soldered to the circuit board (122).

10. The radio equipment (101) according to any of claims 8-9, wherein the metallic connection part (121) comprises a metallic surface or metallic slits.

11. The radio equipment (101) according to any of claims 8-10, wherein the shielding works in high frequency up to 50GHz.

12. The radio equipment (101) according to any of claims 8-11 , wherein the electrical connection comprises a centre pin (132).

13. The radio equipment (101) according to any of the claims 8-12, wherein the radio equipment (101) is comprised in a base station (103) and / or a User Equipment, UE (120).

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