Vehicle antenna

Abstract

Vehicle antenna (20), comprising - a support element (21) made of dielectric material with an antenna structure (22) arranged on it, as well as - a holder (23) made of electrically conductive material, which is attached to the support element (21) by means of fastening elements (231), wherein the holder (23) has a recess (24) and a screw connection with an electrically conductive screw (30) at an end region facing away from the antenna structure (22), which is guided through the recess to a rear side of the holder (23) in such a way that the vehicle antenna (20) can be connected to an electrically conductive area of ​​a vehicle body (1), wherein the holder (23) has an anti-rotation device (25) at an end region facing away from the antenna structure and beyond the recess (24), characterized in that the anti-rotation device (25) is designed as a bracket.

Description

[0001] Vehicle antennas are located inside or outside the vehicle and serve to provide wireless communication links, e.g., for V2X communication, i.e., communication between the vehicle and its environment, such as other vehicles, base stations, or external devices like traffic lights or roadside units. They can also provide cellular communication and wireless (near-field) communication links within the vehicle, e.g., to connect vehicle occupants to the entertainment system.

[0002] To provide different communication channels, a wide variety of standards are available, e.g. near field communication via Bluetooth or WLAN, but also transmission standards from the mobile communications sector, e.g. LTE or 5G.

[0003] Mobile phone antennas, in particular, are usually mounted outside the vehicle, on the roof as roof antennas. Antennas can also be attached to the side mirrors or spoilers. For this purpose, they are either glued in place or attached using a clip-on system.

[0004] Such vehicle antennas are known, for example, from DE 10 2015 012 888 A1, EP 3139440 A1, or DE 10 2014 209 702 A1. Vehicle antennas are also known from WO 2019 / 073691A1 and the associated DE 11 2018 004 509 B4, as well as CN 104466349 A or DE 10 2017 213 376 A1.

[0005] The integration of antenna structures into cavities or onto the vehicle body is usually limited by aesthetic or design criteria, as well as by performance requirements. Furthermore, space is needed for integration, but this is a limited resource. For these reasons, modern antenna designs, which rely on multiple antenna elements to provide diversity and spatial multiplexing, strive for a small volume and low profile while maintaining comparable functionality, in order to be integrated into the vehicle body or on add-on parts, ideally within cavities.

[0006] A disadvantage of known integrations of vehicle antennas within cavities on a vehicle, e.g. within spoilers, is that due to the assembly process, e.g. gluing, elaborate preparations and cleaning of the surfaces to be glued or e.g. clicking / snapping, several assembly steps or additional components such as screws for fixing are required, or process safety must be ensured in a complex manner.

[0007] Due to the disadvantages of known vehicle antennas described above, it is an object of this invention to provide a vehicle antenna that can be more easily integrated into a free installation space in the vehicle body or an add-on part. This object is achieved according to the invention by the features of the independent claims. Advantageous embodiments are the subject of the dependent claims.

[0008] A vehicle antenna is proposed, comprising a support element made of dielectric material with an antenna structure mounted on it, and a holder made of electrically conductive material, which is attached to the support element by means of fastening elements. The holder has a recess and a screw connection with an electrically conductive screw at one end facing away from the antenna structure. This screw is guided through the recess to the back of the holder in such a way that the vehicle antenna can be connected to an electrically conductive area of ​​a vehicle body.

[0009] Since the vehicle antenna is a monopole antenna, the electrically conductive area acts as the base plate or counter pole of the vehicle antenna.

[0010] The vehicle antenna can be mounted on any area of ​​a vehicle body made of electrically conductive material, such as aluminum, steel, or CFRP (carbon fiber reinforced plastic). It is advantageous to integrate it into a free space within the body or an add-on part, so that it is not visible from the outside. When the vehicle antenna is attached to an add-on part, the mounting is carried out using and integrating standard fasteners and standard mounting tools, taking into account the existing thermal and manufacturing tolerances of the add-on part.

[0011] Furthermore, the screw connection is designed to have a spring washer located on the back of the holder, through which the screw is guided and securely fixed.

[0012] The screw connection creates an electrically conductive connection to the electrically conductive area of ​​the vehicle body that serves as the base plate for the antenna. The spring washer also ensures that the screw is not lost during transport, installation, and tightening of the antenna. This allows the antenna, including its mounting hardware, to be pre-assembled as a separate component, saving assembly steps. Furthermore, after installation, the screw is secured and allows for tolerance compensation due to thermal expansion of body panels and components attached to the antenna, as well as manufacturing tolerances.

[0013] Furthermore, depending on certain requirements and the available space and design of the insertion point, the screw may be a self-tapping screw to destroy a protective layer in the press-fit nut, or a thread-cutting screw. Alternatively, the screw may have a thread that corresponds to a press-fit nut already present in the vehicle body. Since the screw must establish a galvanic connection to the electrically conductive area of ​​the body, it is self-tapping if, for example, it is to be inserted directly into the body, which already has a protective layer. Alternatively, a thread, such as a press-fit nut, may already be present in the body, establishing an electrically conductive connection, so the screw only needs to have a corresponding thread.

[0014] Furthermore, according to the invention, the holder has an anti-rotation device at its end region facing away from the antenna structure and beyond the recess. This anti-rotation device is formed as a bracket. The anti-rotation device guarantees the precise alignment of the antenna, taking into account the respective installation space requirements, such as minimum distances to surrounding components, considering distortion and manufacturing tolerances of the components, as well as the tightening torques.

[0015] Furthermore, the section of the bracket containing the recess is positioned at an angle to the section of the bracket connected to the support element. This angle is chosen so that the recessed section lies as flush as possible against the bodywork and any attached component, to facilitate screwing. The anti-rotation device is also located in the angled section of the bracket and is designed, for example, as a bracket that rests against a protrusion on the bodywork or any attached component.

[0016] Furthermore, a direct-contact connector or a cable tail with a connector is provided at the vehicle antenna for electrical connection to a specified control unit. Depending on the vehicle antenna's location on the vehicle, it is necessary to make the electrical connection to the control unit suitable for wet environments, i.e., to protect it from moisture. For example, the cables can be routed through a waterproof cable outlet.

[0017] The vehicle antenna establishes a connection between the telematics control unit (TCU) and other road users and infrastructure components for V2X communication. For mobile communication applications, a connection is established to a base station. The vehicle antenna can be used for mobile communication, V2X communication, or near-field communication, encompassing at least Bluetooth, UWB (Ultra-Wideband), and WLAN. Bluetooth and WLAN can connect the TCU to vehicle occupants, for example, via their smartphones, or establish a connection to charging infrastructure. Bluetooth and UWB can also be used for vehicle access.

[0018] Furthermore, a vehicle is proposed featuring a body with an electrically conductive area for attaching the vehicle antenna using a screw. A screw hole is provided in this area to accommodate the screw in the case of direct fastening with a self-tapping screw. Alternatively, a screw hole with a press-fit nut inserted into it is provided for receiving the vehicle antenna screw in the electrically conductive area. The screw can also be a self-tapping screw if the press-fit nut has a protective coating.

[0019] Furthermore, it is stipulated that the electrically conductive area is a free installation space in the bodywork in which at least one vehicle antenna is mounted in a manner that is not visible from the outside.

[0020] Furthermore, an add-on part for a vehicle is proposed, comprising a cavity and through-holes corresponding to screw holes in the bodywork. At least one vehicle antenna is invisibly attached within the cavity by means of a screw connection such that the screw connection fastens the add-on part to the bodywork via a corresponding through-hole. This means that the add-on part is fastened between the vehicle antenna and the bodywork via the screw. For this purpose, the through-hole of the add-on part is designed so that, after (partial) assembly of the add-on part, it aligns with the screw hole in the bodywork. This allows the screw of the vehicle antenna to pass through both holes, and the vehicle antenna can additionally serve as a fastening element for the add-on part.

[0021] If more than one vehicle antenna is provided, there is one screw hole and one through-hole for each vehicle antenna.

[0022] The attachment is advantageously made of electrically non-conductive material in order to avoid creating shielding and shading.

[0023] Furthermore, the add-on component can be a rear spoiler for the vehicle, with the vehicle antenna integrated into the spoiler's lower shell. The rear spoiler has an internal cavity in which at least one vehicle antenna can be housed, thus concealing it from view. Its high mounting position on the vehicle also improves the antenna's transmission and reception characteristics, as well as its omnidirectional radiation pattern.

[0024] Integrating a vehicle antenna with the proposed mounting system into a free installation space on the vehicle or into an aerodynamic add-on such as a rear spoiler saves both assembly steps and installation space. In particular, existing mounting elements can be used to integrate a vehicle antenna into a free installation space on the vehicle or body. For example, mounting elements of an aerodynamic add-on such as a rear spoiler can be used, allowing existing mounting tools to be utilized.

[0025] Further features and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, with reference to the figures in the drawing, which shows details of the invention, and from the claims. The individual features can be implemented individually or in any combination in a variant of the invention.

[0026] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawing. Fig. Figure 1 shows a schematic representation of vehicle antennas arranged in a cavity of an add-on part of a vehicle in the final installation position (left) and transport or pre-assembly position (right) according to an embodiment of the present invention. Fig. Figure 2 shows a sectional view of a vehicle antenna according to an embodiment of the present invention.

[0027] The basic concept of the invention is to provide a vehicle antenna 20 with a mounting for attaching the vehicle antenna 20 to an electrically conductive area of ​​the vehicle body 1. The electrically conductive area then serves as the counterpart of the vehicle antenna 20. The electrically conductive area of ​​the body 1 also has a screw hole 2 or a press-fit nut 2 into which the screw 30 can be screwed. The screw 30 can be self-tapping to scrape off any coating that may be present on the body 1 when screwed into the screw hole 2, thus ensuring the electrical connection between the vehicle antenna 20 and the body 1. Alternatively, the electrical connection to the body 1 is already ensured by the press-fit nut 2, so that the screw 30 only needs to have a suitable thread to be screwed into the press-fit nut 2.

[0028] The vehicle antenna 20 is in Fig. Figure 2 shows a sectional view. It comprises a support element 21 made of dielectric material with an antenna structure 22 mounted on it and a holder 23 made of electrically conductive material, which is attached to the support element 21 by means of fastening elements 231. The fastening elements 231 can be screws, rivets, or other suitable fasteners 231. The support element 21 made of dielectric material can be a printed circuit board, but also a film or other component that can support the antenna structure 22. The shape of the support element 21 can be either flat or curved, depending on which support element 21 is used. In this way, the support element 21 can be adapted to the available installation space.

[0029] The holder 23 has a recess 24 and a screw connection with an electrically conductive screw 30 at one end region facing away from the antenna structure 22. The screw 30 is guided through the recess to a rear side of the holder 23 in such a way that the vehicle antenna 20 can be connected to an electrically conductive area of ​​a vehicle body 1.

[0030] The screw 30 can be designed to be screwed into a thread in a counterpart, e.g., a press-fit nut 2, or it can be self-tapping or self-scraping. It is important that an electrical connection to the bodywork 1 is established, even if it is already coated or painted.

[0031] Additionally, an attachment 10 made of electrically non-conductive material can be arranged as an intermediate element between the body 1 and the vehicle antenna 20 and is attached to the body 1 by the vehicle antenna 20, as shown in Fig. 1 shown.

[0032] If the vehicle antenna 20 is screwed to the body 1 via an attachment 10, a spring washer 40 is advantageously provided on the back of the holder 23. If the vehicle antenna 20 is screwed directly to the body 1, a spring washer 40 is not strictly necessary. The spring washer 40 holds the screw 30 in place on the holder 23 during transport, preventing the screw 30 from being lost while still allowing it to be tightened. Furthermore, the spring washer 40 compensates for tolerances, particularly manufacturing tolerances or expansion due to thermal stress, e.g., of the attachment 10. Additionally, it acts as a locking mechanism, preventing the screw 30 from loosening after being tightened in the screw hole 2 or the press-fit nut 2 of the body 1.

[0033] Ideally, the vehicle antenna 20 is advantageously installed in a free space or cavity so that it is not visible from the outside. The cavity is a cavity in an aerodynamic add-on component 10, such as a spoiler lower shell, which is attached to the body 1 by the vehicle antenna 20. The add-on component 10 should be made of an electrically non-conductive material to avoid shielding the radiation.

[0034] The vehicle antenna 20 can be positioned in any orientation within the cavity and thus fits into many installation spaces. A cavity located high up on the vehicle is advantageous, as the performance of the vehicle antenna 20 is best there. Therefore, a rear spoiler located at the upper rear of the vehicle, specifically the spoiler lower shell 10, is suitable for integration. Care must be taken to ensure that the propagation of the electromagnetic waves is not impaired, for example, by metallic objects near the antenna structures 22.

[0035] Each vehicle antenna 20 is connected to a control unit, e.g., a telematics unit, of the vehicle via an electrical connection, e.g., a direct-contact connector or a cable tail with connector or a cable outlet 50, using appropriate cables, e.g., coaxial cables. The cables can also be routed within the cavity in which the vehicle antenna 20 is located. Depending on the arrangement, it is also necessary that the direct-contact connector or the cable tail be made watertight to the support element 21. For this purpose, they can be routed in the wet area within a cable tail or cable outlet 50 up to the transition to the dry area where the telematics unit is located. A grommet is advantageously provided at the transition to ensure a tight seal against the dry area of ​​the vehicle.

[0036] The fastening of the vehicle antenna 20 using the screw connection has the advantage that existing structural elements, such as parts of the body 1 and parts of the attachment 10, e.g., the spoiler lower shell, and screw holes 2 or through holes, can be used. This reduces the assembly complexity and allows the use of existing assembly tools.

[0037] Furthermore, the vehicle antenna 20 can be pre-assembled into a holder provided in the cavity by inserting the screw 30 and, if necessary, a spring washer 40, so that it assumes a transport position. Fig. 1 shown on the right. This is particularly advantageous when the vehicle antenna 20 is arranged in an attachment 10. Thus, the screw 30 protruding through the recess 24 to the rear cannot scratch the bodywork 1 during the installation of the attachment 10, but is still readily accessible for assembly.

[0038] The vehicle or body 1 serves as a base plate or counter pole for the vehicle antenna 20, which couples to the respective vehicle antenna 20 via the screw 30.

[0039] According to the invention, the holder 23 has an anti-rotation device 25 in an area beyond the recess 24, i.e., on the other side of the recess 24 where the antenna structure 22 is provided. This anti-rotation device is formed at an outer end and has the shape of a bracket to prevent rotation when mounting the vehicle antenna 20 on a projection of the bodywork 1 or an attachment 10, as shown in Fig. 1 shown, to rest on and hold the vehicle antenna 20 in position during screwing, thus preventing the vehicle antenna 20 from twisting.

[0040] The shape of the holder 23 is advantageously adapted to the area of ​​the body 1 or the attachment 10, i.e. the area with the recess 24 and the anti-rotation device 25 can be, as in Fig. 1 and Fig. 2 shown, at an angle to the area with the antenna structure 22.

[0041] The vehicle antenna 20 is designed as a monopole antenna, and its mechanical dimensions are adapted to the available installation space or cavity, thereby maximizing electrical performance. Several vehicle antennas 20 can be integrated into a single cavity. These are advantageously arranged at a distance from one another. For example, one vehicle antenna 20 is positioned on the left side and one on the right side of a rear spoiler. The cables for the electrical connection to the telematics unit are then bundled in a wiring harness and routed to the telematics unit. If the vehicle antennas 20 are located in a wet area of ​​the vehicle, it is advantageous to provide a waterproof cable outlet 50 through which the cables are routed until they reach the transition to the dry area containing the telematics unit. A grommet is advantageously provided at the transition point to seal it.In dry areas, waterproof cable routing is no longer necessary.

[0042] The proposed mounting device allows for the improved integration of high-performance, multi-band vehicle antennas 20 into existing free installation spaces in the vehicle body 1 or an add-on part 10. These antennas are suitable for use in mobile communications and V2X applications, as well as near-field communication such as Bluetooth, UWB, and WLAN. Pre-assembly of the vehicle antennas 20 reduces installation effort. By mounting the vehicle antennas 20 within a free installation space in the vehicle body 1 or an add-on part 10, the vehicle antenna 20 is not visible from the outside.

[0043] By placing the vehicle antenna 20 in an exposed position on the vehicle, i.e. as high up on the vehicle as possible, even better performance, transmission and reception performance and omnidirectional radiation characteristics are achieved compared to vehicle antennas that are attached inside the vehicle or at lower positions on the vehicle such as on the exterior mirror or bumpers. Reference sign 1 Bodywork 2 screw holes or press-fit nuts 10 Add-on part, here spoiler lower shell 20 vehicle antennas 21 Support element for antenna structure 22 Antenna structure 23 holders 231 Fastening element holder / carrier 24 Recess for receiving the screw 30 25 Anti-rotation device 30 screw 40 spring washer 50 cable outlet

Claims

[1] Vehicle antenna (20), comprising - a support element (21) made of dielectric material with an antenna structure (22) arranged on it, as well as - a holder (23) made of electrically conductive material, which is attached to the support element (21) by means of fastening elements (231), wherein the holder (23) has a recess (24) and a screw connection with an electrically conductive screw (30) at one end region facing away from the antenna structure (22), which is guided through the recess to a rear side of the holder (23) in such a way that the vehicle antenna (20) can be connected to an electrically conductive area of ​​a vehicle body (1), wherein the holder (23) has an anti-rotation device (25) at one end region facing away from the antenna structure and beyond the recess (24), characterized by , that the anti-rotation device (25) is designed as a bracket. [2] Vehicle antenna (20) according to claim 1, wherein the screw connection further comprises a spring washer (40) arranged on the back of the holder (23), through which the screw (30) is guided and secured in a loss-proof manner. [3] Vehicle antenna (20) according to claim 1 or 2, wherein the screw (30) - a self-tapping screw (30) is, or - a thread-cutting screw (30) is, or - has a thread corresponding to a press-fit nut (2) present in the vehicle body (1). [4] Vehicle antenna (20) according to one of the preceding claims, wherein the area of ​​the holder (23) having the recess (24) is arranged at an angle to the area of ​​the holder (23) which is connected to the support element (21). [5] Vehicle antenna (20) according to one of the preceding claims, wherein a direct contact plug or a cable tail with a plug (50) is provided on the vehicle antenna (20) for electrical connection with a predetermined control unit. [6] Vehicle comprising a body (1) and a vehicle antenna (20) attached to the body according to one of the preceding claims, wherein the body (1) has an electrically conductive area for fastening the screw (30) of the vehicle antenna (20), in which - a screw hole (2) is provided for receiving the screw (30), or - a screw hole (2) with a press-fit nut (2) pressed into it for receiving the screw (30) of the vehicle antenna (20) is provided. [7] Vehicle according to claim 6, wherein the electrically conductive area is a free installation space of the body (1) in which at least one vehicle antenna (20) is attached in a manner not visible from the outside. [8] Vehicle according to claim 6, further comprising an attachment part (10) for attachment to the body of the vehicle, wherein the attachment part (10) has a cavity and through holes corresponding to screw holes (2) of the body (1), wherein at least one vehicle antenna (20) is attached in the cavity in a manner invisibly to the outside by means of the screw connection such that the screw connection attaches the attachment part (10) to the body (1) via an associated through hole. [9] Attachment part (10) of a vehicle, comprising a bracket and a vehicle antenna (20) according to one of claims 1 to 5, which is attached to the bracket by means of the electrically conductive screw (30). [10] Attachment part (10) according to claim 9, which is formed as a rear spoiler of a vehicle, wherein the holder with the vehicle antenna (20) is arranged on a spoiler lower shell.

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