Antenna arrangement

Abstract

The present disclosure relates to an antenna arrangement (1), which comprises a baseplate (2) which is at least partially electrically conductive. Said baseplate has a top face (21) and a bottom face (22). The antenna arrangement (1) further comprises at least one radiator assembly (3), which comprises at least one first vertical section (4), which extends in a first vertical plane (VP1) from a first edge (41), which is at least partially arranged on and in electrical contact with the top face (21) of the baseplate (2), to a second edge (42) and at least one first horizontal section (5), which extends in a horizontal plane (HP) from a first edge (51) to a second edge (52). The first vertical section (4) forms part of a vertically polarized tapered slot antenna (VA) and the first horizontal section (5) forms part of a horizontally polarized tapered slot antenna (TA). The present disclosure further relates to a vehicle comprising such an antenna arrangement (1) as well as a method for transmitting and / or receiving communication signals by using such an antenna arrangement (1).

Description

FIELD OF THE DISCLOSURE

[0001] The present disclosure relates to an antenna arrangement, a vehicle comprising such an antenna arrangement and a method for using such an antenna arrangement, preferably on a vehicle.BACKGROUND OF THE DISCLOSURE

[0002] WO2016008607A1 published on 21.01.2016 on behalf of the applicant relates to an antenna arrangement. The antenna arrangement comprises a baseplate that is at least partially electrically conductive and has a top surface, which defines a top level, and a bottom surface, which defines a bottom level. The antenna arrangement further comprises a first and a second cup-shaped antenna radiating element that both have an apex, which is arranged nearby to the top level of the baseplate. Opposite to the apex, an opening is arranged distally to the top level of the baseplate. The antenna radiating elements are arranged above the baseplate, spaced apart with respect to each other by a spacing, and electrically interconnected to the baseplate. The first antenna radiating element is electrically interconnected in the region of its apex to an inner conductor of a first coaxial cable. Said inner conductor is arranged in the region of the apex above said bottom level. The second antenna radiating element is electrically interconnected in the region of its apex to an inner conductor of a second coaxial cable. Said inner conductor is in the region of the apex arranged above said bottom level. The baseplate further comprises at least one port, which is arranged in the bottom surface of the baseplate.

[0003] WO2021116265A1 published on 17.06.2021 on behalf of the applicant relates to an antenna assembly, which comprises a horizontally polarized Vivaldi-type first antenna. The first antenna comprises a horizontally polarized first radiator which extends in a horizontal plane and has a flower-shaped outline comprising several tapered slots. The tapered slots are arranged distributed around a radiator center. The first radiator extends horizontally with respect to the radiator center in an outward direction. In a vertical direction, the radiator extends by a certain thickness. A base plate is arranged at a certain distance below the radiator and is interconnected to the radiator by at least one post. A power divider and a feeding stub are arranged per tapered slot between the base plate and the first radiator, interconnected to the first radiator for coupling radio signals into the first radiator.SUMMARY OF THE DISCLOSURE

[0004] Train antennas with high current protection and an omnidirectional radiation pattern are known from the prior art. An example of such a solution is given in WO2016008607A1. An alternative solution is shown in WO2021116265A1.

[0005] The therein shown antennas have one or more radiating elements with horizontal or vertical polarization. In some cases, the system is in addition supplemented with a global navigation satellite system (GNSS) antenna, like a GPS antenna. When it comes to omnidirectional radiators, it is common to only have a vertically polarized radiator, since any monopole, which due to its rotational symmetry is omnidirectional, can be used.

[0006] Some of the main benefits associated with omnidirectional antennas is their ability to receive signals from all directions. This is due to their omnidirectional radiation pattern, which allows them to capture signals from multiple directions simultaneously. This makes omnidirectional antennas ideal for mobile communications where one side of a radio link is moving. Omnidirectional antennas allow to keep receiving the signal, no matter where the base station is, the relative position of which changes when the mobile side is moving.

[0007] However, omnidirectional antennas tend to have low gain and poor signal quality, which means they require more power to transmit signals over longer distances. This can become a problem in applications requiring long-distance coverage due to weak signal strengths, interference and noise. This is because omnidirectional antennas dissipate their signal in all directions, while directional antennas can focus a signal in a single direction. This makes directional antennas ideal for long range point-to-point communication, which requires a more powerful transmission range, such as satellite communication and long-distance wireless networking. However, they are generally not suitable for mobile communications.

[0008] Moreover, roof-top antennas, especially for trains, must provide so-called high current protection. This means that in case of a broken catenary line which e.g. touches the antenna, the antenna must be able to short the current to the antenna ground (usually the mounting surface) according to specific requirements defined by the authorities. By way of example, the antenna must withstand the high current for at least 125 ms. During this time, the voltage on the antenna connector must remain below 48 V. In this example, it is assumed that after less than 125 ms the protection circuits will kick-in and the catenary line will be de-energized. This requires that the radiator is appropriately grounded and has sufficient cross-section as well as ground contact, which will be able to carry a current of e.g. up to 40 kA for 125 ms. Another requirement is to withstand 70 kA for 15 ms. This applies for both alternating current (AC) and direct current (DC).

[0009] It is therefore a problem underlying the present disclosure to overcome the above-described shortcomings in the prior art. In particular, it is a problem underlying the present disclosure to provide an improved antenna arrangement, in particular an omnidirectional antenna arrangement, more particularly suitable for railway applications. The antenna arrangement should show an improved behavior, in particular regarding antenna gain. Furthermore, it should typically provide sufficient high current protection. Furthermore, it should ideally be suitable for LTE / 5G applications.

[0010] An antenna arrangement according to the present disclosure typically comprises a baseplate which is at least partially electrically conductive. Said baseplate has a top face and a bottom face. The baseplate may be an essentially flat one-pieced plate, made from a conductive material or at least comprising a conductive coating or layer on the top face and / or the bottom face. Good results can be achieved when the baseplate is in the area of the vertical section even. This leads to a favorable radiation. The baseplate may also be slightly curved, e.g. to be conform to a vehicle (e.g. train) roof curvature. It may only be flat in a central area thereof, although it may also be curved, conformal to the shape of the train roof, in this area. The baseplate may comprise at least one port for routing cabling from outside the antenna arrangement through the baseplate into the antenna arrangement. The baseplate is further typically configured to carry a radome which may be screwed to the baseplate. The radome is typically arranged on the top face or in an at least partially circumferential recess. The radome can protect the antenna arrangement from environmental influences. Therefore, the radome can be mounted to the baseplate with a sealing being arranged between radome and baseplate.

[0011] The antenna arrangement typically further comprises at least one radiator assembly. The radiator assembly is configured to send and / or receive a signal. The radiator assembly may comprise at least one first vertical section. The first vertical section may extend in a first vertical plane from a first edge, which is at least partially arranged on and in electrical contact with the top face of the baseplate, preferably to a second edge. The section may in the simplest case be in the form of a rectangular slab, preferably made from a solid metal sheet. In this case, the first and second edge each extend along a longitudinal line and are essentially parallel to each other, preferably parallel to the top face of the baseplate. More often, the first edge is at least partially inclined or curved, to form a radiating slot together with the baseplate, as will be described below in more detail. Good results can be achieved when the first vertical section together with the baseplate forms an antenna element. The radiating slot can thereby be formed between the top face of the baseplate and the first edge of the first vertical section, preferably in form of a half-mode Vivaldi antenna.

[0012] The antenna arrangement typically further comprises at least one first horizontal section, which extends in a horizontal plane from a first edge to a second edge, with one of the edges being at least partially attached to and in electrical contact with the second edge of the first vertical section. Good results can be achieved when the horizontal plane respectively the first horizontal section extends parallel to the top face of the baseplate. The first horizontal section is typically arranged spaced apart from top face of the baseplate. Analogous to the first vertical section, the first horizontal section may be in form of a rectangular slab, preferably made from a solid metal sheet. In this case, the first and second edge each extend along a longitudinal axis and are essentially parallel to each other. More often, the first and / or the second edge is at least partially inclined or curved to form a radiating slot together with the second edge of the first vertical section or a second horizontal section, as will be also described below in more detail. The radiating slot may be a tapered slot, forming a full mode Vivaldi antenna. The first vertical section typically forms part of a vertically polarized tapered slot antenna and the first horizontal section forms part of a horizontally polarized tapered slot antenna.

[0013] A Vivaldi antenna, also referred to as tapered slot antenna (TSA) is a broadband slot antenna, in which the slot typically widens conically. This antenna was presented by Peter J. Gibson at the 9th European Microwave Conference (EuMic) in 1979 under the name "The Vivaldi Aerial". The antenna comprises a conical slot, which can be a full mode Vivaldi antenna with a two-dimensional exponential horn or a half mode Vivaldi antenna with a one-dimensional exponential horn. The antenna is fed at the narrow side of the slot at a feeding point. The radiation direction of the antenna is the direction in which the conical slot widens. Due to its wide bandwidth, this antenna type is suitable for ultra-wideband applications.

[0014] A Vivaldi antenna or Vivaldi aerial can be made from a solid piece of solid metal sheet, a printed circuit board, or from a dielectric plate metalized on one or both sides. In the context of the present disclosure, the vertically polarized tapered slot antenna is typically formed by the first vertical section and the baseplate. The horizontally polarized tapered slot antenna may be formed by the first horizontal section and the first vertical section or the first horizontal section and a second horizontal section. A tapered slot antenna comprises a radiating slot which can be fed by a feedline, which excites the signal into the open space via the tapered slot. The feedline may be a strip line or coaxial cable. Advantages of Vivaldi antennas are their broadband characteristics, being suitable for ultra-wideband signals, as well as their simple manufacturing, because of their comparatively simple geometry, as they are typically made from essentially planar elements.

[0015] The first edge of the first vertical section may comprise a first segment, which extends at least partially curved away from a feeding point towards the second edge. By having a curved first segment, the radiating slot has a tapered shape and widens up, starting from the feeding point. An essentially rectangular radiating slot may lead to insufficient impedance matching over the required frequency range. A rectangular slot would thus only be suitable for a narrowband radiator. A tapered or flared radiating slot on the other hand improves the performance, in particular bandwidth. The first segment of the first vertical section may therefore extend at least partially curved in a manner, so that the radiating slot, formed between the top face of the baseplate and the first segment of the first vertical section, has a flared and widening cross-section.

[0016] The first vertical section may form together with the top face of the baseplate a vertical half-mode Vivaldi antenna. To obtain good matching, the thickness of the metallic body, which typically needs to be relatively large due to the above stated high current protection requirements, is preferably reduced in the area of the radiating slot. The first segment of the first edge of the first vertical section may be tapered, in particular chamfered, step- or wedge-shaped, preferably in form of a ridge which extends away from the first edge. The ridge may be formed from both sides of the section, e.g. in form of chamfers or steps which are made by milling. Alternatively, only a one-sided ridge is possible, whereby the first edge is only machined from only one side. The ridge may be also arranged off-center. The ridge, which may be a thinner section of the first vertical section, preferably along the first segment along the radiating slot, may improve the matching. The ridge may be made by a material removing process, e.g. milling. A recess can be made which is arranged at the first segment. The recess can be either on one side of the first vertical section or two recesses can be arranged, with one on each side. It can be also off-centered. Instead of using a ridge, a chamfer may be used in the area of first segment. Also the chamfer can be single-sided, double-sided or off-centered.

[0017] The first edge of the first vertical section may comprise a second segment which extends away from the feeding point opposite to the first segment in a hemi-circular manner. This second segment together with the preferably planar top face of the baseplate may form a hemi-circular recess. This recess is foreseen for impedance matching. The first edge of the first vertical section may comprise a third segment which is typically essentially planar and interconnected to the top face of the baseplate. The third segment may have a cross-sectional area which is large enough to discharge an electrical current of up to 40 kA for 125 ms, preferably up to 70 kA for 15 ms.

[0018] To further improve the matching, the at least one radiator assembly may further comprise at least one second vertical section, which can extend in a second vertical plane and comprises a matching structure for the vertically polarized tapered slot antenna and / or the horizontally polarized tapered slot antenna. The first vertical plane and the second vertical plane are typically perpendicular to each other. The matching structure can be a circular, hemi-circular or rectangular recess into which the tapered radiating slot opens. The matching structure may open into the respective tapered radiating slot in the area of the feeding point of the tapered radiating slot.

[0019] The at least one second vertical section may extend from a first edge to a second edge, wherein the second edge is at least partially attached to and in electrical contact with the first horizontal section and / or the second horizontal section. The first edge of the at least one second vertical section may at least partially be arranged on and in electrical contact with the top face of the baseplate. The second vertical section may be in the form of a slab, e.g. in the form of a solid metal sheet which may be milled. The second vertical section can be made integral with the first and / or second horizontal sections and / or the first vertical section.

[0020] The at least one second vertical section may comprise a matching structure for the horizontally polarized tapered slot antenna. Alternatively, the at least one second vertical section may comprise a matching structure for the vertically polarized tapered slot antenna. An edge of the at least one second vertical section may be at least partially attached to and in electrical contact with the first vertical section. The matching structure can be a hemi-circular or rectangular recess formed together with the top face of the baseplate. Good results regarding the matching can be achieved if the matching structure for the vertically polarized tapered slot antenna is a hemi-circular recess formed together with the top face of the baseplate. The matching structure for the horizontally polarized tapered slot antenna may be a circular recess.

[0021] By arranging the matching structure in the second vertical section, the first segment of the first horizontal section and the first segment of the second horizontal section or the first segment of the vertical section can be prolonged by keeping the overall size of the radiator assembly and therefore the overall antenna essentially unchanged. By increasing the length of the first segments, the lowest supported frequency can be shifted towards lower frequencies. In an exemplary embodiment, by increasing the length by a factor of two, the lowest supported frequencies can be lowered from 1.0 - 1.5 GHz to 0.6 - 1.1 GHz. Therefore, an improvement of around 400 MHz could be achieved. This improvement allows to also cover cellular bands below 1 GHz, which can be beneficial for long range applications, e.g. in rural area cellular communication.

[0022] The first vertical section may via a feeding point be electrically connected to an inner conductor of a first coaxial cable. An outer conductor of the first coaxial cable may be electrically connected to the baseplate. Besides a coaxial cable, alternative types of feeding of the sections are possible. By way of example, a strip line, e.g. a strip line printed on a printed circuit board (PCB) with fan-type stubs, is possible. In case of feeding by a PCB, the PCB is typically arranged on one lateral side of the section. In case that the first segment of the first edge of the first vertical section is tapered, in particular chamfered, step- or wedge-shaped, the tapering is preferably arranged on the lateral side of the first edge which is opposite to the PCB.

[0023] A plug can be embedded in the baseplate, which may comprise an inner conductor that in a mounted position extends above the top face of the baseplate into the feeding point of the first vertical section. The plug can comprise a plug housing which is embedded in the baseplate and electrically connected to the outer conductor of the first coaxial cable. Good results, such as minimizing the overall height of an antenna arrangement, can be achieved if the plug is inserted into an opening located in the upper and / or lower face of the baseplate. Such an opening can be a through hole or a blind hole. The plug can optionally be inserted by means of press-fit into the opening arranged in the upper and / or lower face of the baseplate. The baseplate may comprise at least one channel or recess which can be arranged in the top face or the bottom face for receiving the feeding element, e.g. coaxial cable or strip line. The recess or channel can be designed in a manner such that the feeding element is arranged in the recess or channel without extending above the top or bottom face.

[0024] The inner conductor of the plug can be a pin that extends into a socket, e.g. in the form of a bushing arranged within the first vertical section. The design can be also the other way round with the inner conductor of the plug being a bushing and the pin being arranged at the first vertical section. The bushing can be press-fitted into the first vertical section. The bushing may comprise spring clips which are mechanically or electrically connected with a distal end of the pin. Such a mechanical and electrical connection can be achieved by means of contact points in the circumference between the distal end area of the pin and the spring terminals. If desirable the contact points can also be in another area of the pin. Good results can be achieved when an insulator is arranged in the housing of the plug, separating the inner conductor from the plug housing.

[0025] Such an insulator may be made of PTFE, PE, a ceramic material or another material with suitable dielectric and mechanical properties. The plug may comprise a housing that is electrically connected to the outer conductor of the coaxial cable. The plug housing may be formed integrally with the base plate. The plug housing can also comprise a connector port, e.g. an opening in form of a through hole, which is arranged on one side, which does not face the connected section. Such an opening can be used as access to the area in which the inner conductor of a coaxial cable and the inner conductor of the connector are connected, e.g. by soldering and / or welding and / or crimping.

[0026] The at least one radiator assembly may further comprise at least one third vertical section which typically extends in the second vertical plane. The at least one third vertical section and the at least one second vertical section may form a feeding slot between each other. Such a design allows to arrange a plug in the baseplate as described above noted in the context of the first vertical section. The plug may be embedded in the baseplate, which comprises an inner conductor which in a mounted position extends above the top face of the baseplate into a feeding point of the at least one second vertical section or a feeding point of the at least one third vertical section. This allows pre-assembly of a cable assembly, including the plug arranged at a first end of a cable and a connector attached to the opposite end of the cable. By using a plug arranged in the baseplate, the cable assembly can be pre-assembled and arranged in the baseplate independent of the radiator assembly. The cable assembly and the radiator assembly can be arranged independently from each other.

[0027] The feeding slot typically extends from the inner conductor of the plug to the tapered radiating slot of the vertically polarized tapered slot antenna. The at least one third vertical section may extend from a first edge to a second edge, with the second edge being at least partially attached to and in electrical contact with the first horizontal section and / or the second horizontal section. The first edge is typically at least partially arranged on and in electrical contact with the top face of the baseplate. The second edge of the at least one second vertical section and / or the second edge of the at least one third vertical section and a third edge of the first horizontal section and / or a third edge of the second horizontal section may be chamfered. The chamfer typically functions as a tuning structure to allow the signal propagating from a vertical section of the feeding slot to a horizontal section without negatively impacting the signal. An edge of the at least one third vertical section is preferably at least partially attached to and in electrical contact with the first vertical section.

[0028] The first edge of the at least one first horizontal section can comprise a first segment which extends at least partially curved away from a feeding point of the first horizontal section towards the second edge of the first vertical section. The first segment of the first edge of the first horizontal section may be tapered, in particular chamfered, step- or wedge-shaped, preferably in form of a ridge which extends away from the first edge. The first, second and third segments of the first horizontal section can be shaped and function analogous to the above-described first vertical section, except for the polarization, which is rotated by 90°. The at least one first horizontal section typically forms a horizontally polarized Vivaldi radiator with a second horizontal section. The Vivaldi radiator can be a full mode radiator if the at least one first horizontal section interacts with a second horizontal section. The at least one first horizontal section and the second horizontal section are arranged symmetrical with respect to each other, with the first segments of the first and second horizontal section forming a tapered radiating slot between each other, which can be shaped as a two-dimensional exponential horn. Alternatively, the Vivaldi radiator can be a half mode radiator if a curved first segment of the at least one first horizontal section interacts with a second horizontal section, which comprises a straight edge or with the second edge of a first vertical section.

[0029] The radiator assembly can comprise a second horizontal section, which extends in the horizontal plane from a first edge to a second edge. The at least one first horizontal section and the second horizontal section can form a horizontally polarized tapered slot antenna. The second horizontal section may be designed analogous to the horizontal section. The first edge of the at least one first horizontal section and the first edge of the second horizontal section can be arranged opposite each other and together can form a funnel- or conical shaped radiating slot, functioning as a horizontal full-mode Vivaldi antenna. The first and second horizontal section can be made as separate parts or can be made integral, e.g. by milling from a plate. The radiator assembly can be divided into single blocks, including the horizontal and vertical sections, to allow a simple CNC milling fabrication process. An alternative division into blocks is also possible. In case that the first and second horizontal section are made as separate parts, they are usually screwed together.

[0030] The plug may be embedded in one of the two horizontal sections, which plug can comprise an inner conductor which in a mounted position extends into the feeding point of the other of the two horizontal sections, i.e. on the other side of the radiating slot. The feeding may be realized by a coaxial adapter, which creates an interface to the feeding coaxial cable. The coaxial cable can be arranged in a groove inside the first or second horizontal section. The inner conductor of the coaxial cable can be connected to a socket on the other side of the radiating slot, inside the other horizontal section. In this way the antenna may be excited. The plug may comprise a pin, which in a mounted state interacts with a socket, arranged inside the other horizontal section. The pin and socket can be designed above described regarding the pin and socket of the first vertical section.

[0031] The coaxial adapter of the plug may alternatively be arranged in a post. The advantage of arranging the plug in a post instead of inside one of the two horizontal sections is that the coaxial cable does not have to be arranged in a groove inside the horizontal section. This allows to prefabricate the post with the coaxial adapter and results in an easier and faster assembly process. The post may be interconnected the first vertical section by a vertical spacer, which may be made from conductive material, e.g. metal. Alternatively, the first horizontal section or the second horizontal section may comprise a first edge with a second segment with a channel and therefore a modified matching section. The plug can be embedded in the respective horizontal section with the inner conductor extending into the feeding point of the other horizontal section. The plug may be a right angle plug similar to the plug above described in the context of feeding the first vertical section. The matching section can have a hemi-circular shape and the channel may be configured to receive the coaxial cable of the plug. The modified matching section does not significantly influence the antenna matching.

[0032] The first horizontal section and the second horizontal section may be two separate parts, as described above already, with the radiating slot being formed between them and fed using a pressed-in coaxial connector / adapter. The inner conductor of the pressed-in coaxial connector / adapter may engage a socket on the other side of the radiating slot. To press-in the coaxial connector as well as a socket, the first and second horizontal section may be separated and after inserting the coaxial connector as well as a socket joined along a horizontal axis. In such a design the radiator assembly may comprise two horizontally polarized antennas, each comprising a first horizontal section and a second horizontal section as well as two back plates, configured for holding the two horizontally polarized antenna sections together to form a horizontally polarized antenna.

[0033] Alternatively, the first and second horizontal section may be made integral with each other. To be able to assemble the feeding port, a plug may be press-fitted in the sections from above. The feeding can be realized by pre-assembled parts - for each horizontal radiator there being a plug section and a socket section. Those sections may be assembled with plugs, coaxial cables and sockets which are later pressed-in into radiator plates. Alternatively, the plug section and a socket section can be in form of inserts which are inserted into a recess in the respective horizontal section and e.g. screwed to the respective horizontal section. In this case, the section with coaxial cable connector and socket section are screwed to the common metallic body of two horizontal radiators.

[0034] The at least one first horizontal section and / or the at least one first vertical section may comprise an isolation slot which extends parallel to the vertically and / or horizontally polarized tapered slot antenna. Such an isolation slot can be added to improve the isolation between radiators and reduce coupling. Different slot geometries are possible. For example, isolation slots can be arranged in the first horizontal and the first vertical sections in a single design. The isolation slots can extend along an axis parallel to the radiating slot and be in the form of a rectangular recess. Alternatively or in addition, L-shaped isolation slots can be added for longer current paths. Also e.g. T-shaped, curved or meandering isolation slots are possible.

[0035] The first edges of the at least two horizontal sections may form half-mode Vivaldi antennas together with a horizontal spacer element, which is preferably in form of a slab. The spacer element may be arranged between two first horizontal sections, which each form of half-mode slot antenna together with the slab. Compared to a design with in total four horizontal sections, the radiator assembly with two first horizontal sections and a slab is slimmer in width. The width of the spacer element can depend on the number of radiator assemblies and the frequency bands. The wider the two first horizontal sections are spaced apart the lower the interference, but therefore the bigger the radiator assembly becomes. A good compromise can be found if the width of the spacer element is between 0.25 times to 2 times the width of the horizontal section between first and second edge, preferably the width of the spacer element is equal to the width of the first horizontal section.

[0036] The edges of the spacer element facing the first horizontal sections may be tapered, in particular chamfered, step- or wedge-shaped. They may comprise a staggered design, preferably in form of a ridge which extends away from the first edge. The ridge may be formed from both sides of a spacer element, e.g. in form of chamfers or steps which are made by milling. Also only a one-sided ridge is possible, whereby the first edge is only machined from only one side. The ridge may be also arranged off-center.

[0037] A radiator assembly may comprise at least two first vertical sections and at least two horizontal sections. In such a variation, the radiator assembly comprises two horizontally polarized antennas and two vertically polarized antennas. The radiator assembly can comprise at least four horizontal sections with two pairs of first horizontal sections and second horizontal sections forming horizontal full-mode Vivaldi antennas with each other. Good results can be achieved if the radiator assembly comprises four horizontal sections with two pairs of first and second horizontal sections forming horizontal full-mode Vivaldi antennas with each other and in addition two first vertical antenna sections. Such a design allows to use each of the radiator assemblies for 4x4-MIMO-5G / LTE applications.

[0038] To be able to assemble the at least one radiator assembly comprising two horizontally polarized antennas and two vertically polarized antennas poses challenges regarding the stability. The radiator assembly should be mechanically stable to also withstand dynamic loads like vibrations, mechanical shocks as well as high currents. Nevertheless, the radiator assembly should be at the same time designed to not negatively influence the directional characteristic. Therefore, the at least two second horizontal sections of the two horizontally polarized antennas can be interconnected to the baseplate by at least one support. The at least one support can be designed as a V or W-shaped post. The at least one support can be made by injection molding. Good results can be made from materials like polycarbonate (PC), polyoxymethylene (POM), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), high density polypropylene (HDPP).

[0039] The antenna arrangement may comprise at least three radiator assemblies which are with respect to a center point of the baseplate arranged radially spaced with respect to each other, preferably offset by 120 degrees or less to each other. Such a sectorial principle has several advantages over known omnidirectional arrangements. Firstly, the gain of omnidirectional radiators is limited, as these radiators have no focusing in one direction. Secondly, omnidirectional radiators are prone to interference / noise from different sources, like different base stations at a time. In comparison, a sectorial antenna arrangement with several distinctly directed radiator assemblies can communicate with only one base station at a time, and has distinct handover points, being certain points at which the communication with a base station is switched from one radiator assembly to another radiator assembly. While in case of three radiator assemblies, the radiator assemblies are with respect to each other spaced by 120°, the opening angle of each radiator assembly is typically exceeding 120°, leading to an overlap. Typically, the switch from one radiator assembly to the neighboring radiator assembly is done when the signal strength falls below half of the original signal strength. This leads to a better signal quality and allows to serve more base stations at a time in parallel without noise. The throughput of a sectorial radiator assembly can thereby be improved compared to an omnidirectional radiator by a factor of about two or even three.

[0040] The radiator assemblies can be split in two halves, which are arranged staggered with respect to each other. For obtaining a more compact and therefore space-saving design, the radiator assemblies can be arranged displaced with respect to each other. Preferably one split radiator assembly is arranged in one sector, which is split in two halves and preferably arranged staggered and displaced with respect to each other.

[0041] In addition to the at least three radiator assemblies, the antenna arrangement may comprise additional radiators, antennas or a GNSS module. The GNSS module may be arranged centered with respect to the antenna arrangement or off-center next to one of the at least three radiator assemblies.

[0042] A further aspect of the present disclosure relates to a vehicle, preferably a train or a bus, comprising an antenna arrangement according to the present disclosure.

[0043] Another aspect of the present disclosure relates to a method for transmitting and / or receiving communication signals by using an antenna arrangement according to the present disclosure, preferably in a vehicle according to the previous paragraph.

[0044] It is to be understood that both the foregoing general description and the following detailed description present embodiments and are intended to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments, and together with the description serve to explain the principles and operation of the concepts disclosed.BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The herein described disclosure will be more fully understood from the detailed description given herein below and the accompanying drawings which should not be considered limiting to the disclosure described in the appended claims. The drawings are showing: Fig. 1a perspective view of a first embodiment of the antenna arrangement from the top with a partial cut-out; Fig. 2a perspective view of the embodiment of the antenna arrangement according to Figure 1 from the top with removed radome; Fig. 3a partially exploded perspective view of the embodiment of the antenna arrangement according to Figure 2; Fig. 4a detail perspective view of the embodiment of the antenna arrangement according to Figure 3; Fig. 5a perspective view of the embodiment of the antenna arrangement according to Figure 2 with a partial cut-out; Fig. 6a detail perspective sectional view of the embodiment of the antenna arrangement according to Figure 5; Fig. 7a top view on a second embodiment of the antenna arrangement; Fig. 8a detail top view of the embodiment of the antenna arrangement according to Figure 7; Fig. 9a perspective view of a third embodiment of the antenna arrangement from the top with removed radome; Fig. 10a detail perspective view of the embodiment of the antenna arrangement according to Figure 9; Fig. 11a perspective view of a fourth embodiment of the antenna arrangement from the top with removed radome; Fig. 12a perspective view of a fifth embodiment of the antenna arrangement from the top with removed radome; Fig. 13a detail perspective view of the embodiment of the antenna arrangement according to Figure 12; Fig. 14a perspective view of a sixth embodiment of the antenna arrangement from the top with removed radome; Fig. 15a perspective view of a seventh embodiment of the antenna arrangement from the top with removed radome; Fig. 16a perspective view of an eighth embodiment of the antenna arrangement from the top with removed radome; Fig. 17a perspective view of a ninth embodiment of the antenna arrangement from the top with removed radome; Fig. 18a perspective view of a tenth embodiment of the antenna arrangement from the top with removed radome; Fig. 19a perspective and partially exploded view of a first embodiment of a radiator assembly with a feeding post; Fig. 20a perspective and partially exploded view of a second embodiment of a radiator assembly with a feeding post; Fig. 21a perspective view of a third embodiment of a radiator assembly; Fig. 22a detailed view of the radiator assembly according to Fig. 21 with visible hidden edges of the plug; Fig. 23a perspective view from the front on a third embodiment of a radiator assembly with a vertical matching section; Fig. 24a perspective view from the back on the third embodiment of a radiator assembly according to Fig. 21; Fig. 25a first plot with test results of the scattering parameters of two exemplary radiator assemblies according to the present disclosure; Fig. 26an expanded view of a part of the plot according to Figure 23 Fig. 27a perspective view of an eleventh embodiment of the antenna arrangement from the top with removed radome; Fig. 28a perspective and partially exploded view of the eleventh embodiment of the antenna arrangement according to Figure 27; Fig. 29a perspective view from the back on a fourth embodiment of a radiator assembly with a vertical matching section; Fig. 30a perspective and partially exploded view from the back on the fourth embodiment of the radiator assembly according to Figure 29. DESCRIPTION OF THE EMBODIMENTS

[0046] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts.

[0047] Figures 1 to 6 show a first embodiment of the antenna arrangement 1. Figure 1 shows the antenna arrangement 1 comprising a baseplate 2, which is at least partially electrically conductive. The baseplate 2 has a top face 21 and a bottom face 22. The shown baseplate 2 is an essentially flat one-pieced plate, made from a conductive material. A radome 12 is mounted on the baseplate 2 to protect the thereon arranged radiator assemblies. The radome 12 is screwed to the baseplate 2. In the shown embodiment the radome 12 is arranged on the top face 21 of the baseplate 2. The radome 12 protects the antenna arrangement 1 from environmental influences. Therefore, the radome 12 is mounted to the baseplate 2 with a seal 13, which is arranged between the radome 12 and the baseplate 2, protecting the radiator assemblies 3 arranged inside the radome 12 on the top face 21 of the baseplate 2.

[0048] As can be obtained from Figure 2, the shown antenna arrangement 1 is a sectorial antenna and comprises three radiator assemblies 3. The radiator assemblies 3 are configured to send and / or receive a signal. Each radiator assembly 3 comprises two first vertical sections 4. The first vertical sections 4 each extend in a first vertical plane VP1 from a first edge 41, which is partially arranged on and in electrical contact with the top face 21 of the baseplate 2, to a second edge 42. The shown first vertical 4 and first and second horizontal sections 5, 8 are made from a rectangular slab by milling. The second edges 42 of the first vertical sections 4 each extend along a longitudinal axis and are arranged parallel to the top face 21 of the baseplate 2. The first edges 41 are at least partially inclined or curved and form a radiating slot RS together with the baseplate.

[0049] As can be obtained from Figure 3, each radiator assembly 3 of the shown antenna arrangement 1 further comprises two first horizontal sections 5 and two second horizontal sections 8, which all extend in a common horizontal plane HP. Each of the two first horizontal sections 5 and the two second horizontal sections 8 extend from a first edge 51 to a second edge 52 with one of the edges being partially attached to and in electrical contact with a second edge 42 of a first vertical section 4. The common horizontal plane HP respectively the first and second horizontal sections 5, 8 extend parallel to the top face 21 of the baseplate 2. The first and second horizontal sections 5, 8 are arranged spaced apart from the top face 21 of the baseplate 2. The first vertical sections 4 each form a vertically polarized tapered slot antenna VA together with the baseplate 2 and each pair of two first and second horizontal sections 5, 8 form part of a horizontally polarized tapered slot antenna HA. Each tapered slot antenna VA, HA comprises a radiating slot RS, which is fed by a coaxial cable.

[0050] In the shown embodiment, the first vertical sections 4 form together with the top face 21 of the baseplate 2 a vertical half-mode Vivaldi antenna and each pair of first and second horizontal sections 5, 8 forms a full-mode Vivaldi antenna. The first edge 41 of the at least one first vertical section 4 may comprise a first segment 43, which extends at least partially curved away from a feeding point 44 towards the second edge 42. By having a curved first segment 43, the radiating slot RS has a tapered shape and widens up, starting from the feeding point 44. A tapered or flared radiating slot RS as shown improves the performance. The first segment 43 may therefore extend at least partially curved in a manner, so that the radiating slot RS, formed between the top face 21 of the baseplate 2 and the first segment 43, has a flared and widening cross-section. The first segment 43 of the first edge 41 is tapered, in the shown variation step-shaped in form of a ridge 46 which extends away from the first edge 41. The shown first edge 41 of the first vertical section 4 further comprises a second segment 45, which extends away from the feeding point 44, opposite to the first segment 43, in a hemi-circular manner for impedance matching. The first segments 53, 83 of the horizontal sections 5, 8 are tapered and comprise a ridge 55, 85 which is more narrow than the main body of the section 5, 8 and extends away from the first edge 51, 81.

[0051] As can be obtained from Figure 4, the first segments 53, 83 of the first and second horizontal sections 5, 8 are tapered and each comprise a ridge 55, 85 which extends away from the first edge 51, 81. To obtain good matching, the thickness of the metallic body, which typically needs to be relatively large due to high current protection requirements, is reduced in the area of the radiating slots. The ridges 55, 85 which are thinner sections of the first segments 53, 83 of the first and second horizontal sections 5, 8 improve the matching. The shown ridges 55, 85 are made by a subtractive manufacturing process, e.g. milling. Specifically, the shown ridges 55, 85 are created by milling a recess on both sides of the first and second horizontal sections 5, 8, with one being on each side.

[0052] The first edges 51, 81 each comprise a second segment 56, 86 which both extend away from the feeding point 54, 84 opposite to the first segments 53, 83 in a hemi-circular manner. These second segments 56, 86 together form a circular recess. This recess is foreseen for impedance matching. The first edges 51, 81 of the horizontal sections 5, 8 each comprise a third segment 57, 87, which are essentially planar and interconnected to each other. The second edge 52 of the horizontal section is interconnected to a second edge 42 of a first vertical section 4 and the second edge 82 of the second horizontal section 8 is connected to a spacer 17. The spacer 17 of the shown embodiment is merely a mechanical support and can therefore be also made from a dielectric material.

[0053] As can be obtained from Figures 5 and 6, the first vertical sections 4 are via a feeding point 44 electrically connected to an inner conductor of a first coaxial cable 6. Recesses 24 are designed such that the coaxial cables 6 are arranged therein, without extending above the top face 21 of the baseplate 2. An outer conductor 62 of the first coaxial cable 6 is electrically connected to the baseplate 2. A plug 7 is embedded in the baseplate 2, which comprises an inner conductor 71, which in the shown mounted position extends above the top face 21 of the baseplate 2 into the feeding point 44 of the first vertical section 4.

[0054] The shown plug 7 is inserted into an opening 23 located in the top face 21 of the baseplate 2. The opening 23 is in form of a blind hole. The plug 7 is inserted by means of press-fit into the opening 23. The plug 7 comprises a plug housing 72, which is embedded in the baseplate 2 and electrically connected to the outer conductor of the coaxial cable. The inner conductor 71 of the shown plug 7 is a pin, which extends into a socket in form of a bushing 73 arranged within the first vertical section 4. The bushing 73 is press-fitted into the first vertical section 4. The bushing 73 comprises spring clips, which are mechanically or electrically connected with a distal end of the pin. An insulator 74 is arranged in the housing 72 of the plug 7, separating the inner conductor 71 from the plug housing 72. The insulator 74 can be made of PTFE, PE, a ceramic material or another material with suitable dielectric and mechanical properties.

[0055] Figures 7 and 8 show a second embodiment of the antenna arrangement 1. The shown embodiment of the antenna arrangement 1 also comprises three radiator assemblies 3, which are with respect to a center point CP of the baseplate 2 arranged radially spaced with respect to each other, offset by 120 degrees. This sectorial antenna arrangement 1 with three distinctly directed radiator assemblies 3 can communicate with one or more base stations at a time, and has distinct handover points, being certain points at which the communication with a base station is switched from one radiator to another radiator. For obtaining a more compact and therefore space-saving design, the radiator assemblies 3 are split into halves, which are arranged displaced with respect to each other.

[0056] The radiator assemblies 3 in two sectors are split in two halves and the two horizontally polarized tapered slot antennas HA are arranged in a staggered design with respect to each other. In the shown embodiment, two radiator assemblies 3 are arranged in one sector. The shown baseplate 2 comprises a port 14 in the form of a through hole for routing cabling from outside the antenna arrangement 1 through the baseplate 2 into the antenna arrangement. The baseplate 2 further comprises recesses 24 in the top face 21 for receiving the coaxial cables 6. The recesses 24 are designed such that the coaxial cables 6 are arranged in the recesses 24 without extending above the top face 21. The recess 24 can be designed just wide and deep enough as to accommodate the coaxial cable 6. This ensures that the performance of the section interacting with the base plate 2 will not be disturbed and provides additional high current protection for the feeding coaxial cables 6.

[0057] As can be obtained from Figure 8, the first edges 51, 81 of the shown two first and second horizontal sections 5, 8 comprise first segment 53, 83 which extend at least partially curved away from a feeding point 54, 84 of the horizontal sections 5, 8 towards the second edges 42 of the first vertical section 4. The first edges 51, 81 of both horizontal sections 5, 8 are tapered and comprise a ridge 55, 85 which extends away from the first edge 51, 81. The ridges 55, 85 of the first and second horizontal section 5, 8 are arranged opposite each other and together form a funnel-shaped horizontal full-mode Vivaldi antenna HA.

[0058] The shown first 5 and second 8 horizontal sections are made as separate parts which are screwed together. The radiating slot RS is fed using a pressed-in coaxial connector / adapter 10. The inner conductor 101 of the pressed-in coaxial connector / adapter 10 engages a socket 102 on the other side of the radiating slot RS. To press-in the inner conductor 101 as well as the socket 102, the first 5 and second 8 horizontal sections are joined along a horizontal central plane. In other words, the horizontal radiator is split into two parts to be able to press-fit both inner conductor 101 and socket 102.

[0059] Figures 9 and 10 show a third embodiment of the antenna arrangement 1. While the basic design is like that of the first embodiment, the shown antenna arrangement 1 differs in that the first 5 and second 8 horizontal sections are made integral with each other. To be able to assemble the feeding point, a plug 10 is press-fitted in the sections 5, 8 from above. The feeding is realized by pre-assembled parts. For each horizontally polarized tapered slot antenna HA, a plug section with inner conductor 101 and a plug section with socket 102 are pre-assembled and pressed into the first and second horizontal sections 5, 8. The sections 101, 102 are pre-assembled with the coaxial cables 9 and pressed in the radiator elements 5, 8 altogether.

[0060] The coaxial cable is arranged in a recess 88 inside the second horizontal section 8. The inner conductor 91 of the coaxial cable 9 is connected to a socket 102 of the plug part 10b on the other side of the radiating slot RS, inside the first horizontal section 5. In this way the horizontally polarized antenna is excited. The plug part 10a comprises a pin 101, which in a mounted state interacts with a socket 102, arranged inside the first horizontal section 5. The pin 101 and socket 102 are designed analogous to the above described pin and socket of the first vertical section as shown by Figures 5 and 6.

[0061] Figure 11 shows a fourth embodiment of the antenna arrangement 1. The basic design is like that of the third embodiment. In addition, the first and second horizontal sections 5, 8 comprise isolation slots 15, which extend parallel to the horizontally polarized tapered slot antennas HA. The isolation slots 15 are added to improve the isolation between the first vertical section 4 and the first and second horizontal sections 5, 8 and reduce coupling. Different slot geometries are possible. The shown isolation slots 15 extend along an axis parallel to the radiating slots RS and are in form of L-shaped slots.

[0062] Figures 12 and 13 show a fifth embodiment of the antenna arrangement 1. While the basic design is like that of the third embodiment, the shown antenna arrangement 1 differs in that the feeding point 54 is realized differently. Instead of press-fitting a plug in the first and second horizontal section 5, 8 from above, the feeding is realized by inserts 16. As can be obtained from Figure 13, for each horizontal radiator element, a plug section with an inner conductor 101 and a socket section 102 are pre-assembled and inserted into the first and second horizontal section 5, 8. The inserts 16a and 16b are pre-assembled with the coaxial cable 9 (insert 16a) and socket 102 (insert 16b) and inserted in the first and second horizontal section 5, 8 all together into a recess 58, 88 in the respective first and second horizontal section 5, 8 and e.g. screwed to the respective horizontal section 5, 8.

[0063] Figures 14 and 15 show a sixth and seventh embodiment of the antenna arrangement 1. The shown embodiments are both optimized in terms of space consumption to achieve miniaturized antenna assemblies. Figure 14 shows an antenna arrangement 1 with three radiator assemblies 3, wherein the first edges 51, 51' of the at least two first horizontal sections 5, 5' form half-mode Vivaldi antennas HA together with a horizontal spacer element 11, which is in form of a slab. The spacer element 11 is arranged between two first horizontal sections 5, 5' which each form of half-mode slot antenna together with the spacer 11. Compared to a design with in total four horizontal sections, the radiator assembly with two horizontal sections and a spacer 11 is slimmer in width.

[0064] Figure 15 shows an embodiment with three radiator assemblies 3, which each comprise two first vertical sections 4, 4' and two first horizontal sections 5, 5', which are made integral with each other. The shown radiator assemblies 3 comprise four half-mode Vivaldi antennas HA, VA. In the shown embodiment the respective first edge 51, 51' of the horizontal sections 5, 5' is attached via the third segment 57 to the second edge 42 of the respective first vertical section 4. The second edges 52, 52' of the first horizontal sections 5, 5' are made integral with each other and meet at a virtual parting line (dotted line).

[0065] Figure 16 shows an eighth embodiment of the antenna arrangement 1 from the top with removed radome. The shown antenna arrangement 1 comprises three radiator assemblies 3, each of which comprising two first vertical sections 4, 4' and two first horizontal sections 5, 5', as well as two second horizontal sections 8, 8'. The three radiator assemblies 3 are with respect to a center point CP of the baseplate 2 arranged radially spaced with respect to each other, offset by 120 degrees. For obtaining a more compact and therefore space-saving design, two of the three radiator assemblies 3 are split into halves, which are arranged displaced with respect to each other. The horizontally polarized tapered slot antennas HA of the radiator assemblies 3 which are split into two halves are arranged in a staggered design with respect to each other.

[0066] In the shown embodiment, two radiator assemblies 3 are arranged in one sector. The shown baseplate 2 comprises a port 14 for routing cabling from outside the antenna arrangement 1 through the baseplate 2 into the antenna arrangement. The baseplate 2 further comprises recesses 24 in the top face 21 for receiving the coaxial cables 6. The recesses 24 are designed such that the coaxial cables 6 are arranged in the recesses 24 without extending above the top face 21. The recess 24 can be designed just wide and deep enough to accommodate the coaxial cable 6. This ensures that the performance of the section interacting with the base plate 2 will not be disturbed and provides additional high current protection for the feeding coaxial cables 6. In addition to the three radiator assemblies 3, the antenna arrangement 1 comprises a GNSS module 210. The GNSS module 210 is arranged centered with respect to the antenna arrangement.

[0067] The horizontal full-mode Vivaldi antennas HA each comprise a second vertical section 18, which comprises a matching structure 181 in form of a circular recess 184 and extends in a second vertical plane VP2 from a first edge 182 to a second edge 183. The first edge 182 is partially arranged on and in electrical contact with the top face 21 of the baseplate 2 and the second edge 183 is attached to and in electrical contact with the respective first horizontal section 5 and the respective second horizontal section 8. The shown second vertical sections 18 are each arranged perpendicular to the respective horizontal section 5 and the respective first vertical section 4 and the respective second vertical plane VP2 is perpendicular to the respective first vertical plane VP1 of the first vertical section 4.

[0068] The shown second vertical sections 18 are each interconnected to the respective first horizontal section 5 and the respective second horizontal section 8. The second vertical sections 18 each comprise a matching structure 181, which has a circular shape. A plug 10 is embedded in the respective first horizontal section 5, which plug 10 comprises an inner conductor, which in a mounted position extends into the feeding point 83 of the second horizontal section. The circular matching structure 181 of the second vertical section 18 is interconnected to the two horizontal sections via the feeding points 54, 83 of the two first and second horizontal sections 5, 8.

[0069] The first horizontal section 5 and the second horizontal section 8 of each of the radiator assemblies 3 of the embodiment of Figure 16 are interconnected to the baseplate 2 by a support 19. The support 19 of the shown embodiment is designed as a V-shaped post. The embodiments shown by Figures 17 and 18 are similar to the one of Figure 16, except for the design of the support 19. Figure 17 shows a perspective view of a ninth embodiment of the antenna arrangement 1 from the top with removed radome. The support 19 shown by Figure 17 is a V-shaped post which is turned upside down. Figure 18 shows a perspective view of a tenth embodiment of the antenna arrangement 1 from the top with removed radome. The support 19 shown by Figure 18 is a W-shaped post.

[0070] Figures 19 and 20 show a first embodiment and second embodiment of a radiator assembly 3 with a feeding post 20. The advantage of arranging the plug 10 in a post 20 instead of inside one of the two horizontal sections 5, 8 is that the coaxial cable does not have to be arranged in a groove inside one of the horizontal sections 5, 8. The shown plug 10 is a right-angled plug, as the plug 7 used to feed the first vertical section 4 as shown by Figures 5 and 6. This allows to prefabricate the post 20 with the coaxial adapter and results in an easier and faster assembly process. The feeding post 20 can be in form of a beam, which is arranged on the top face of the baseplate as shown by Figure 19 or as a vertical slab which is interconnected to a first vertical section 4 as shown by Figure 20. In this case the feeding post 20 is interconnected by a vertical spacer 17 to the first vertical section 4, made out of conductive material, e.g. metal. The plug 10 is arranged at a top end of the post 20 and comprises an inner conductor, which in a mounted position extends into the feeding point 54, 83 of the other of the two horizontal sections 5, 8.

[0071] Figure 21 shows a third embodiment of a radiator assembly 3 and Figure 22 shows a detailed view of the radiator assembly 3 according to Figure 21 with visible hidden edges of the plug 10. The shown radiator assembly 3 comprises a first horizontal section 5 and a second horizontal section 8, wherein the first edge 51 of the first horizontal section 5 comprises a modified second segment 56 and therefore a modified matching section. A plug 10 is embedded in the first horizontal section 5, which plug 10 comprises an inner conductor 101, which in a mounted position extends into the feeding point 83 of the second horizontal section 8. The shown plug 10 is right angled, as the plug 7 used for feeding the first vertical section 4 as shown by Figures 5 and 6. The matching section of the first horizontal section 5 has a hemi-circular shape and the second segment 56 comprises a channel 561 which is configured to receive the coaxial cable of the plug 10. The modified matching section does not significantly influence the antenna matching.

[0072] Figures 23 and 24 show perspective views from the front and back on a third embodiment of a radiator assembly 3 with a second vertical section 18. The horizontal full-mode Vivaldi antenna of the shown radiator assembly 3 comprises a second vertical section 18, which extends in a second vertical plane VP2 from a first edge 182 to a second edge 183, which is perpendicular to the first vertical plane VP1. The first edge 182 is partially arranged on and in electrical contact with the top face 21 of the baseplate 2 and the second edge 183 is attached to and in electrical contact with the first horizontal section 5 and the second horizontal section 8. The second vertical section 18 is arranged perpendicular to the first horizontal section 5 and the second horizontal section 8 as well as the first vertical section 4. The second vertical section 18 comprises a matching structure 181 in form of a circular recess 184. A plug 10 is embedded in the first horizontal section 5, which plug 10 comprises an inner conductor which in a mounted position extends into the feeding point 83 of the second horizontal section 8.

[0073] Figures 25 and 26 show test results for the scattering parameter (S-parameter) of two radiator assemblies, measured with a Vector Network Analyzer (VNA). The dotted line depicts the test result of a radiator assembly of the type as shown by Figures 1 to 6. The solid line depicts the test result of a radiator assembly as shown in Figure 16 (non-staggered radiator). The plots both show the energy reflected (y-axis) over the frequency (x-axis). Plotted is the ratio of power fed into one radiator assembly via a plug and being reflected back, therefore the energy not being radiated. A good performance, in terms of a low scattering parameter is most crucial in the highlighted frequency bands. These are standard cellular (GSM, UMTS, LTE, 5G) and WiFi bands. The frequency range below 1 GHz are cellular frequency bands, frequencies between 1.3 and 3.8 GHz are cellular bands (except 2.4-2.5 GHz band which is the WiFi band), frequencies above 4.2 GHz are WiFi frequency bands. The radiator assembly according to Figures 1 to 6 (dotted line) has a significantly higher loss of energy by reflection. At 0.75 GHz, the loss is about -4 dB which corresponds to a loss of energy of ca. 40 %. The radiator assembly according to Figure 16 (full line) has a loss of about -14 dB at 0.75 GHz, which corresponds to a loss of energy of about 4 %, therefore 4 % of energy being reflected and about 96 % being radiated.

[0074] Figures 27 and 28 show an eleventh embodiment of the antenna arrangement 1 from the top with removed radome. The shown antenna arrangement 1 comprises three radiator assemblies 3, each of which comprising two first vertical sections 4, 4' and two first horizontal sections 5, 5', as well as two second horizontal sections 8, 8' like the antenna arrangements shown by Figures 16 to 18.

[0075] The shown baseplate 2 comprises a port 14 for routing cabling in the form of a cable assembly from outside the antenna arrangement 1 through the baseplate 2 into the antenna arrangement. The baseplate 2 further comprises recesses 24 in the top face 21 for receiving coaxial cables 6. The recesses 24 are designed such that the coaxial cables 6 are arranged in the recesses 24 without extending above the top face 21. The recesses 24 can be designed just wide and deep enough to accommodate the coaxial cable 6. In addition to the three radiator assemblies 3, the antenna arrangement 1 comprises a GNSS module 210. The GNSS module 210 is arranged centered with respect to the antenna arrangement.

[0076] As can be seen best in partially exploded Figure 28 each radiator assembly 3 of the shown antenna arrangement 1 comprises a second vertical section 18 which extends in a second vertical plane and comprises a matching structure 181 for the horizontally polarized tapered slot antenna. Each radiator assembly 3 further comprises a third vertical section 220 which also extends in the second vertical plane. The first vertical plane and the second vertical plane are perpendicular to each other.

[0077] Figures 29 and 30 show a fourth embodiment of a radiator assembly 3. The shown radiator assembly 3 of the antenna arrangement according to Figures 27 and 28 comprises a second vertical section 18 with a matching structure 181 for the horizontally polarized tapered slot antenna HA. The shown second vertical section 18 comprises a hemi-circular matching structure 181. The hemi-circular matching structure 181 is formed together with the top face 21 of the baseplate 2. The second vertical section 18 extends from a first edge 182 to a second edge 183 with the second edge 183 being partially attached to and in electrical contact with the second horizontal section 8. The first edge 182 is at least partially arranged on and in electrical contact with the top face 21 of the baseplate 2.

[0078] The radiator assembly 3 further comprises a third vertical section 220, with the second vertical section 18 and the third vertical section 220 extending in the second vertical plane VP2 which is arranged perpendicular to the first vertical plane VP1. The shown third vertical section 220 and the second vertical section 18 form a feeding slot 223 between each other. A plug 7 is embedded in the baseplate 2, which comprises an inner conductor 71 which in a mounted position extends above the top face 21 of the baseplate 2 into a feeding point 185 of the second vertical section 18. The feeding slot 223 extends from the inner conductor 71 of the plug 7 to the tapered radiating slot RS of the horizontally polarized tapered slot antenna HA.

[0079] The shown third vertical section 220 extends from a first edge 221 to a second edge 222, with the second edge 222 being attached to and in electrical contact with the first horizontal section 5. The first edge 221 is at least partially arranged on and in electrical contact with the top face 21 of the baseplate 2. The third edge 59 of the first horizontal section 5 and the third edge 89 of the second horizontal section 8 are chamfered. An edge of third vertical section 220 is attached to and in electrical contact with the first vertical section 4.Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the Spirit and scope of the disclosure.

[0080] Further aspects of the present disclosure become apparent from the following clauses: 1. An antenna arrangement 1 comprising a. a baseplate 2 which is at least partially electrically conductive, said baseplate having a top face 21 and a bottom face 22; and b. at least one radiator assembly 3 comprising i. at least one first vertical section 4, which extends in a first vertical plane VP1 from a first edge 41, which is at least partially arranged on and in electrical contact with the top face 21 of the baseplate 2, to a second edge 42; ii. at least one first horizontal section 5, which extends in a horizontal plane HP from a first edge 51 to a second edge 52, and wherein the first vertical section 4 forms part of a vertically polarized tapered slot antenna VA and the first horizontal section 5 forms part of a horizontally polarized tapered slot antenna HA. 2. The antenna arrangement 1 according to clause 1, wherein one of the edges 51, 52 of the at least one first horizontal section 5 is at least partially attached to and in electrical contact with the second edge 42 of the first vertical section 4. 3. The antenna arrangement 1 according to clause 1 or 2, wherein the first edge 41 of the at least one first vertical section 4 comprises a first segment 43 which extends at least partially curved away from a feeding point 44 toward the second edge 42. 4. The antenna arrangement 1 according to clause 3, wherein the first segment 43 of the first edge 41 of the first vertical section 4 is tapered, in particular chamfered, step- or wedge-shaped, preferably in form of a ridge 46 which extends away from the first edge 41. 5. The antenna arrangement 1 according to any of clauses 2 to 4, wherein the first vertical section 4 is via the feeding point 44 electrically connected to an inner conductor of a first coaxial cable 6. 6. The antenna arrangement 1 according to clause 5, wherein an outer conductor 62 of the first coaxial cable 6 is electrically connected to the baseplate 2. 7. The antenna arrangement 1 according to clause 5 or 6, wherein a plug 7 is embedded in the baseplate 2, which comprises an inner conductor 71 which in a mounted position extends above the top face 21 of the baseplate 2 into the feeding point 44 of the first vertical section 4. 8. The antenna arrangement 1 according to clause 7, wherein the plug 7 comprises a plug housing 72 which is embedded in the baseplate 2 and electrically connected to the outer conductor 62 of the first coaxial cable 6. 9. The antenna arrangement 1 according to any of the preceding clauses, wherein the first vertical section 4 forms together with the top face 21 of the baseplate 2 a vertical half-mode Vivaldi antenna. 10. The antenna arrangement 1 according to any of the preceding clauses, wherein the first edge 51 of the at least one first horizontal section 5 comprises a first segment 53 which extends at least partially curved away from a feeding point 54 of the first horizontal section 5 towards the second edge 42 of the first vertical section 4. 11. The antenna arrangement 1 according to clause 10, wherein the first segment 53 of the first edge 51 of the at least one first horizontal section 5 is tapered, in particular chamfered, step- or wedge-shaped, prefer-ably in form of a ridge 55, 85 which extends away from the first edge 51. 12. The antenna arrangement 1 according to any of the preceding clauses, wherein the radiator assembly 3 comprises a second horizontal section 8, which extends in the horizontal plane HP from a first edge 81 to a second edge 82 and forms part of a horizontally polarized tapered slot antenna HA. 13. The antenna arrangement 1 according to clause 12, wherein the first edge 51 of the at least one first horizontal section 5 and the first edge 81 of the second horizontal section 8 are arranged opposite each other and together form a funnel- or conical shaped horizontal full-mode Vivaldi antenna. 14. The antenna arrangement 1 according to clause 13, wherein a plug 10 is embedded in one of the first or second horizontal section 5, 8, which plug 10 comprises an inner conductor 101 which in a mounted position extends into the feeding point 54, 83 of the other of the two horizontal sections 5, 8. 15. The antenna arrangement 1 according to any of the preceding clauses, wherein the at least one first horizontal section 5 and / or the at least one first vertical section 4 comprises an isolation slot 15 which extends parallel to the vertically VA and / or horizontally HA polarized tapered slot antenna. 16. The antenna arrangement 1 according to one of clauses 12 to 15, wherein the at least one radiator assembly 3 comprises at least two first vertical sections 4 and at least two horizontal sections 5. 17. The antenna arrangement 1 according to one of clauses 12 to 16, wherein the radiator assembly 3 comprises at least four horizontal sections 5, 8 with two pairs of first and second horizontal sections 5, 8 forming horizontal full-mode Vivaldi antennas with each other. 18. The antenna arrangement 1 according to one of clauses 12 to 17, wherein the first edges 51 of the at least two horizontal sections 5 form half-mode Vivaldi antennas together with a horizontal spacer element 11, which is preferably in form of a slab. 19. The antenna arrangement 1 according to any of the preceding clauses, wherein the antenna arrangement 1 comprises at least three radiator assemblies 3 being with respect to a center point CP of the baseplate 2 arranged radially spaced with respect to each other, preferably offset by 120 degrees or less. 20. The antenna arrangement 1 according to clause 19, wherein each radiator assembly 3 is split into two halves which are arranged staggered with respect to each other. 21. The antenna arrangement 1 according to one of clauses 1 to 20, wherein the at least one radiator assembly 3 further comprises iii. at least one second vertical section 18 which extends in a second vertical plane VP2 and comprises a matching structure 181 for the vertically polarized tapered slot antenna VA and / or the horizontally polarized tapered slot antenna HA. 22. The antenna arrangement 1 according to clause 21, wherein the first vertical plane VP1 and the second vertical plane VP2 are perpendicular to each other. 23. The antenna arrangement 1 according to one of clauses 21 or 22, wherein the matching structure 181 is a circular, hemi-circular or rectangular recess into which the tapered radiating slot RS opens. 24. The antenna arrangement 1 according to one of clauses 21 to 23, wherein the at least one second vertical section 18 comprises a matching structure 181 for the horizontally polarized tapered slot antenna HA. 25. The antenna arrangement 1 according to clause 24, wherein the at least one second vertical section 18 extends from a first edge 182 to a second edge 183, wherein the second edge 183 is at least partially attached to and in electrical contact with the first horizontal section 5 and / or the second horizontal section 8. 26. The antenna arrangement 1 according to clause 25, wherein the first edge 182 is at least partially arranged on and in electrical contact with the top face 21 of the baseplate 2. 27. The antenna arrangement 1 according to one of clauses 1 to 26, wherein the first edge 41 of the first vertical section 4 comprises a matching structure in form of a second segment 45 which extends away from the feeding point 44 opposite to the first segment 43 in a hemi circular manner. 28. The antenna arrangement 1 according to one of clauses 21 to 23, wherein the at least one second vertical section 18 comprises a matching structure 181 for the vertically polarized tapered slot antenna VA. 29. The antenna arrangement 1 according to clause 28, wherein an edge of the at least one second vertical section 18 is at least partially attached to and in electrical contact with the first vertical section 4. 30. The antenna arrangement 1 according to one of clauses 28 or 29, wherein the matching structure 181 is a hemi-circular or rectangular recess formed together with the top face 21 of the baseplate 2. 31. The antenna arrangement 1 according to one of clauses 21 to 30, in particular clause 24, wherein the at least one radiator assembly 3 further comprises at least one third vertical section 220 which extends in the second vertical plane VP2. 32. The antenna arrangement 1 according to one of clause 31, wherein the at least one third vertical section 220 and the at least one second vertical section 18 form a feeding slot 223 between each other. 33. The antenna arrangement 1 according to one of clauses 31 or 32, wherein a plug 7 is embedded in the baseplate 2, which comprises an inner conductor 71 which in a mounted position extends above the top face 21 of the baseplate 2 into a feeding point 185 of the at least one second vertical section 18 or a feeding point of the at least one third vertical section 220. 34. The antenna arrangement 1 according to clause 33, wherein the feeding slot 223 extends from the inner conductor 71 of the plug 7 to the tapered radiating slot RS of the horizontally polarized tapered slot antenna HA. 35. The antenna arrangement 1 according to one of clauses 31 to 34, wherein the at least one third vertical section 220 extends from a first edge 221 to a second edge 222, with the second edge 222 being at least partially attached to and in electrical contact with the first horizontal section 5 and / or the second horizontal section 8. 36. The antenna arrangement 1 according to clause 35, wherein the first edge 221 is at least partially arranged on and in electrical contact with the top face 21 of the baseplate 2. 37. The antenna arrangement 1 according to one of clauses 35 or 36, wherein the second edge 183 of the at least one second vertical section 18 and / or the second edge 222 of the at least one third vertical section 220 and a third edge 59 of the first horizontal section 5 and / or a third edge 89 of the second horizontal section 8 are chamfered. 38. The antenna arrangement 1 according to clause 37, wherein an edge of the at least one third vertical section 220 is at least partially attached to and in electrical contact with the first vertical section 4. 39. A vehicle, preferably a train or a bus, comprising an antenna arrangement 1 according to any one of clauses 1 to 38. 40. A method for transmitting and / or receiving communication signals by using an antenna arrangement 1 according to any one of clauses 1 to 38, preferably in a vehicle according to clause 39. LIST OF DESIGNATIONS

[0081] 1Antenna arrangement 2Baseplate 21Top face 22Bottom face 23Opening 24Recess 3Radiator assembly 4First vertical section 41First edge 42Second edge 43First segment 44Feeding point 45Second segment 46Ridge 5First horizontal section 51First edge 52Second edge 53First segment 54Feeding point 55Ridge 56Second segment 561Channel 57Third segment 58Recess 59Third edge 6First coaxial cable 62Outer conductor 7Plug 71Inner conductor 72Plug housing 73Socket 74Insulator 8Second horizontal section 81First edge 82Second edge 83First segment 84Feeding point 85Ridge 86Second segment 87Third segment 88Recess 89Third edge 9Second coaxial cable 91Inner conductor 10Plug 101Inner conductor 102Socket 11Horizontal spacer element 12Radome 13Seal 14Port 15Isolation slot 16Insert 17Spacer 18Second vertical section 181Matching structure 182First edge 183Second edge 184Recess 19Support 20Post 210GNSS module 220Third vertical section 221First edge 222Second edge 223Feeding slot VP1First vertical plane VP2Second vertical plane HPHorizontal plane CPCenter point VAVertically polarized tapered slot antenna HAHorizontally polarized tapered slot antenna RSRadiating slot

Claims

1. An antenna arrangement (1) comprising a. a baseplate (2) which is at least partially electrically conductive, said baseplate having a top face (21) and a bottom face (22); and b. at least one radiator assembly (3) comprising i. at least one first vertical section (4), which extends in a first vertical plane (VP1) from a first edge (41), which is at least partially arranged on and in electrical contact with the top face (21) of the baseplate (2), to a second edge (42); ii. at least one first horizontal section (5), which extends in a horizontal plane (HP) from a first edge (51) to a second edge (52), and wherein the first vertical section (4) forms part of a vertically polarized tapered slot antenna (VA) and the first horizontal section (5) forms part of a horizontally polarized tapered slot antenna (HA).

2. The antenna arrangement (1) according to claim 1, wherein one of the edges (51, 52) of the at least one first horizontal section (5) is at least partially attached to and in electrical contact with the second edge (42) of the first vertical section (4).

3. The antenna arrangement (1) according to claim 1 or 2, wherein the first edge (41) of the at least one first vertical section (4) comprises a first segment (43) which extends at least partially curved away from a feeding point (44) toward the second edge (42).

4. The antenna arrangement (1) according to any of claims 2 or 3, wherein the first vertical section (4) is via the feeding point (44) electrically connected to an inner conductor of a first coaxial cable (6), wherein preferably an outer conductor (62) of the first coaxial cable (6) is electrically connected to the baseplate (2).

5. The antenna arrangement (1) according to claim 4, wherein a plug (7) is embedded in the baseplate (2), which comprises an inner conductor (71) which in a mounted position extends above the top face (21) of the baseplate (2) into the feeding point (44) of the first vertical section (4), wherein preferably the plug (7) comprises a plug housing (72) which is embedded in the baseplate (2) and electrically connected to the outer conductor (62) of the first coaxial cable (6).

6. The antenna arrangement (1) according to any of the preceding claims, wherein the first vertical section (4) forms together with the top face (21) of the baseplate (2) a vertical half-mode Vivaldi antenna.

7. The antenna arrangement (1) according to any of the preceding claims, wherein the first edge (51) of the at least one first horizontal section (5) comprises a first segment (53) which extends at least partially curved away from a feeding point (54) of the first horizontal section (5) towards the second edge (42) of the first vertical section (4).

8. The antenna arrangement (1) according to any of the preceding claims, wherein the radiator assembly (3) comprises a second horizontal section (8), which extends in the horizontal plane (HP) from a first edge (81) to a second edge (82) and forms part of a horizontally polarized tapered slot antenna (HA), wherein preferably the first edge (51) of the at least one first horizontal section (5) and the first edge (81) of the second horizontal section (8) are arranged opposite each other and together form a funnel- or conical shaped horizontal full-mode Vivaldi antenna.

9. The antenna arrangement (1) according to claim 8, wherein the at least one radiator assembly (3) comprises at least two first vertical sections (4) and at least two horizontal sections (5).

10. The antenna arrangement (1) according to one of claims 8 or 9, wherein the radiator assembly (3) comprises at least four horizontal sections (5, 8) with two pairs of first and second horizontal sections (5, 8) forming horizontal full-mode Vivaldi antennas with each other.

11. The antenna arrangement (1) according to any of the preceding claims, wherein the antenna arrangement (1) comprises at least three radiator assemblies (3) being with respect to a center point (CP) of the baseplate (2) arranged radially spaced with respect to each other, preferably offset by 120 degrees or less, wherein preferably each radiator assembly (3) is split into two halves which are arranged staggered with respect to each other.

12. The antenna arrangement (1) according to one of claims 1 to 11, wherein the at least one radiator assembly (3) further comprises iii. at least one second vertical section (18) which extends in a second vertical plane (VP2) and comprises a matching structure (181) for the vertically polarized tapered slot antenna (VA) and / or the horizontally polarized tapered slot antenna (HA), wherein preferably the matching structure (181) is a circular, hemi-circular or rectangular recess into which the tapered radiating slot (RS) opens.

13. The antenna arrangement (1) according to claim 12, wherein the at least one second vertical section (18) comprises a matching structure (181) for the horizontally polarized tapered slot antenna (HA), wherein preferably the at least one second vertical section (18) extends from a first edge (182) to a second edge (183), wherein the second edge (183) is at least partially attached to and in electrical contact with the first horizontal section (5) and / or the second horizontal section (8), wherein more preferably the first edge (182) is at least partially arranged on and in electrical contact with the top face (21) of the baseplate (2).

14. The antenna arrangement (1) according to one of claims 1 to 13, wherein the first edge (41) of the first vertical section (4) comprises a matching structure in form of a second segment (45) which extends away from the feeding point (44) opposite to the first segment (43) in a hemi circular manner.

15. The antenna arrangement (1) according to one of claims 12 to 14, wherein the at least one second vertical section (18) comprises a matching structure (181) for the vertically polarized tapered slot antenna (VA), wherein preferably an edge of the at least one second vertical section (18) is at least partially attached to and in electrical contact with the first vertical section (4) and / or the matching structure (181) is a hemi-circular or rectangular recess formed together with the top face (21) of the baseplate (2).

16. The antenna arrangement (1) according to one of claims 12 to 15, wherein the at least one radiator assembly (3) further comprises at least one third vertical section (220) which extends in the second vertical plane (VP2), wherein preferably the at least one third vertical section (220) and the at least one second vertical section (18) form a feeding slot (223) between each other.

17. The antenna arrangement (1) according to one of claims 15 or 16, wherein a plug (7) is embedded in the baseplate (2), which comprises an inner conductor (71) which in a mounted position extends above the top face (21) of the baseplate (2) into a feeding point (185) of the at least one second vertical section (18) or a feeding point of the at least one third vertical section (220), wherein preferably the feeding slot (223) extends from the inner conductor (71) of the plug (7) to the tapered radiating slot (RS) of the horizontally polarized tapered slot antenna (HA).

18. The antenna arrangement (1) according to one of claims 15 to 17, wherein the at least one third vertical section (220) extends from a first edge (221) to a second edge (222), with the second edge (222) being at least partially attached to and in electrical contact with the first horizontal section (5) and / or the second horizontal section (8), wherein preferably the first edge (221) is at least partially arranged on and in electrical contact with the top face (21) of the baseplate (2).

19. A vehicle, preferably a train or a bus, comprising an antenna arrangement (1) according to any one of claims 1 to 18.

20. A method for transmitting and / or receiving communication signals by using an antenna arrangement (1) according to any one of claims 1 to 18, preferably in a vehicle according to claim 19.

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