Screw-on vehicle antenna

Abstract

Screw-on vehicle antenna (1), comprising - a threaded part (20) and a head part (21) adjoining an end region thereof, both of which are made of electrically non-conductive material, as well as - at least one antenna radiator (10) arranged at least within a part of the head section (21), and - a metallic disc (11) made of electrically conductive material, arranged on the head section (21) and serving as a reflector or ground plane - an RF connector (30) arranged on and attached to a region of the head part (21) opposite the threaded part (20), wherein - the antenna radiator (10) can be electrically connected to a plug (32) of the RF connector (30).

Description

[0001] The invention relates to a screw-on vehicle antenna.

[0002] 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 a communication link for wireless (near-field) communication inside the vehicle, e.g., to connect vehicle occupants to the entertainment system.

[0003] 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.

[0004] Mobile phone antennas are typically mounted outside the vehicle, often on the roof, as so-called shark fin antennas. For V2X communication in particular, the antenna system must meet stringent performance criteria, especially omnidirectional radiation patterns, to ensure reliable data transmission to other communication partners. Such antennas are generally implemented as separate enclosures or other antenna structures, such as foil antennas, which require additional integration volume and / or support structures.

[0005] Vehicle antennas are known, for example, from DE102012108786A1, EP1241731 A2, and EP3395617A1. Antennas usable in automotive engineering are also known from US 2011 / 0 199 173 A1, CN 105 206 929 A, and DE 100 56 473 C1.

[0006] The integration of antenna structures into or onto the vehicle body is usually limited due to aesthetic or design criteria, but also because of performance requirements. Furthermore, space is needed for integration, which is a limited resource.

[0007] The radiation characteristics of a vehicle antenna are primarily determined by the integration volume inside or on the exterior of the vehicle. Especially for high frequencies, such as in V2X communication, where communication currently takes place at 5.9 GHz, electromagnetic wave propagation can be considered quasi-optical, meaning that any metallic object in the vicinity of the antenna blocks or reflects the electromagnetic waves, resulting in shadowing effects.

[0008] Additionally, attaching the antenna element to the vehicle body presents a challenge, as requirements regarding safety, stability, durability, and vibration resistance must be met in addition to the specifications mentioned above. Furthermore, additional assembly steps are necessary to attach the antenna element to the vehicle body.

[0009] Due to the many disadvantages of known vehicle antennas described above, it is an object of this invention to provide a novel vehicle antenna that overcomes these disadvantages. This object is achieved according to the invention by the features of the independent claim. Advantageous embodiments are the subject of the dependent claims.

[0010] A screw-on vehicle antenna is proposed, comprising a threaded section and a head section adjoining one end of the threaded section, both made of electrically non-conductive material, as well as at least one antenna radiator arranged at least within a portion of the head section, and a metallic disc made of electrically conductive material arranged on the head section and serving as a reflector or ground plane. Furthermore, an RF connector is provided on and attached to a region of the head section opposite the threaded section, wherein the antenna radiator can be electrically connected to a plug of the RF connector.

[0011] By integrating an antenna, i.e., radiator and reflector or ground plane, into a screw, i.e., a mounting element that is needed anyway, both assembly steps and installation space are saved, without affecting the antenna's radiation characteristics.

[0012] Depending on the application, and especially the available space, a suitable RF connector is used, either waterproof or with a specified IP rating, or non-waterproof. Many applications utilize an RF connector specifically designed for the required application. In the automotive sector, these are often FAKRA connectors. A FAKRA connector is a familiar connector interface defined by the renowned Automotive Technical Working Group (FAKRA), used for vehicle communication both within the vehicle and with external devices. It is defined according to DIN 72594-1 and ISO 20860-1 and can be individually coded for different signals.

[0013] Furthermore, the metallic disc is designed to rest on the end of the head where the threaded part is located. This allows it to simultaneously serve as a washer and makes it easy to install by simply sliding it onto the threaded part.

[0014] Furthermore, the metallic disc is designed to be at least partially located within the head. This allows the length of the threaded section to be shortened. Depending on the design, it can be completely enclosed within the head, meaning it is not visible from the outside, for example, overmolded with plastic. Alternatively, it can be visible from the outside, thus dividing the head into two parts.

[0015] Furthermore, a mounting sleeve is provided around the head, or the head is formed in a predefined shape. This allows a standard mounting tool to be used for fastening the screw.

[0016] Furthermore, the thread can be either self-tapping or non-self-tapping. This allows for the fastening of components that have been pre-threaded or have a cavity, as well as components into which the screw cuts its own thread as it is screwed in.

[0017] Furthermore, the antenna is designed to provide V2X or near-field communication, including at least Bluetooth and WLAN. This allows the vehicle antenna to be used both inside the vehicle, e.g., to control functionalities such as the entertainment system via a mobile phone, and outside, e.g., for communication with a mobile phone or key.

[0018] Furthermore, the screw-on vehicle antenna is intended to be installed inside or on the exterior of a vehicle. The component should therefore meet water resistance requirements (IPx).

[0019] Furthermore, it is intended that the screw-on vehicle antenna will be used to connect two electrically non-conductive components.

[0020] Furthermore, the screw-on vehicle antenna is designed to include a PCB (Printed Circuit Board) positioned between the antenna element and the RF connector. This PCB is equipped with components to provide an amplifier circuit or matching network. One embodiment features an amplifier component powered by phantom power via a coaxial cable attached to the connector, further enhancing its functionality. By adding further electrical components, such as capacitors, an adaptive matching circuit can be implemented. This circuit, integrated into a new, previously unplanned installation space, allows for automatic retuning of the antenna based on its detuning. This increases flexibility in component placement.

[0021] 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.

[0022] 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 a screw-on vehicle antenna according to an embodiment of the present invention. Fig. Figure 2 shows a 3D cross-sectional view of the in Fig. 1 screwable vehicle antenna shown according to an embodiment of the present invention. Fig. Figure 3 shows a 3D sectional view of a screwable vehicle antenna according to an alternative embodiment of the present invention. Fig. Figure 4 shows a 3D cross-sectional view of the in Fig. 1 screwable vehicle antenna shown with an additional circuit board according to an embodiment of the present invention.

[0023] In the following figure descriptions, identical elements or functions are marked with the same reference symbols.

[0024] The basic concept of the invention is that by using an existing mounting element, the complexity of the assembly and the number of components required are reduced. The mounting element is a screw made of electrically non-conductive material.

[0025] Fig. Figure 1 shows a view of an embodiment of a screwable vehicle antenna 1 according to an exemplary embodiment. Fig. Figure 2 showed a 3D sectional view of this design. Fig. 3 and Fig. Figure 4 shows alternative designs of the screw-on vehicle antenna 1 in 3D sectional views.

[0026] As shown in the 3D cross-sectional views of the Fig. 2 (section through Fig. As shown in Figures 1 and 3, the antenna radiator 10 is designed as a rod antenna or monopole antenna and, for example, has a quarter-wave monopole, meaning that the conductor or rod length corresponds to one-quarter of the wavelength to be covered by the antenna radiator 10. In principle, other suitable antenna designs can also be used, provided they are appropriate for the application. The antenna radiator 10 is inserted into a plastic screw 1 designed as a screw-in antenna or vehicle antenna. Advantageously, the plastic screw 1 is used to attach one plastic component of the vehicle to another plastic component, e.g., a spoiler cover to a spoiler base. Alternatively, it is possible to screw the plastic screw 1 into a plastic component without attaching another plastic component to it, e.g., as a decorative element or in a concealed position.

[0027] The plastic screw 1 is made of an electrically non-conductive material, advantageously of plastic or glass fiber reinforced plastic, depending on the mechanical properties required for the application, i.e. the screw connection.

[0028] The plastic screw 1 further comprises a threaded section 20 and a head section 21, which is arranged at one end of the threaded section 20. An electrical connection in the form of an RF connector, advantageously a so-called FAKRA connector 30, as shown in the figures, is attached to the head section 21. The invention is described in more detail below with reference to the FAKRA connector 30 shown in the figures, whereby any RF connector suitable for the intended application can be used. The FAKRA connector 30 is attached to the head section 21. For electrical connection, a plug 32 is provided inside the FAKRA connector 30 for connection to a coaxial cable from inside the vehicle. The antenna radiator 10 is connected to the plug 32 directly or via a microstrip cable.

[0029] The thread of the threaded part 20 can be designed as a self-tapping or non-self-tapping thread, depending on the use of the screw.

[0030] In a Fig. In the embodiment shown in Figure 2, a metallic, electrically conductive disc 11 is mounted over the threaded part 20 and rests on the head part 21. This metallic disc 11 serves both as a washer and as a reflector or ground plane in monopole antennas. Its diameter is advantageously larger than the diameter of the head part 21 and is selected to achieve the desired electrical properties of the antenna. Furthermore, a ground connection can be established between the ground plane, which is realized by the metallic disc 11 and either rests on the head part 21 or—as described below—is embedded in it, and the outer conductor of the coaxial cable by suitable means.

[0031] In an alternative, in Fig. In the embodiment shown in Figure 3, the metallic disc 11 is formed as part of the head section 21 or divides the head section 21 into two parts. Thus, the threaded part 20 can be shorter than in the embodiment shown in Figure 3. Fig. In the embodiment shown in Figure 2, the rod of the antenna radiator 10 can also be partially arranged in the head section 21. Depending on the position of the metallic disc 11 in the head section 21, the length of the threaded part 20 can thus be shortened or lengthened.

[0032] Advantageously, either a mounting sleeve is formed around the head part 21 or the head part 21 is formed in the appropriate shape, e.g. as an external hexagon or external hexagon, in order to fasten the plastic screw 1 with a standard mounting tool.

[0033] In Fig.Figure 4 shows a further embodiment in which a PCB 4 (printed circuit board) is provided, which is arranged between the antenna radiator 10 or rod and the FAKRA connector 30. This PCB 4 can be equipped with components to function as an amplifier circuit or as a matching network. Furthermore, an amplifier component can be provided, and the amplifier component is powered by phantom power via the coaxial cable attached to the connector 32. It can include components that serve for compensation, i.e., to compensate for the line losses present due to high frequencies.

[0034] The screw-on vehicle antenna 1 can be used both for antennas intended to provide V2X communication (currently operating at 5.9 GHz) and for antennas that support other services, such as near-field communication like Bluetooth or WLAN. The services described represent only a subset of the supported services. Multiple services can also be covered by the same vehicle antenna.

[0035] The screw-on vehicle antenna can be used both externally as an external antenna and internally as an internal antenna. When installed inside the vehicle, it can also serve as an antenna for V2X communication if properly positioned. However, it must be ensured that there is no interference with the antenna signal, for example, due to coated glass panes or shadowing metal parts in the immediate vicinity of the antenna.

[0036] The screw-in vehicle antenna, designed as a plastic screw 1, advantageously replaces a plastic screw used to fasten attachments such as spoilers, fenders, front aprons, cover caps, fuel filler flaps, door handles, headlight housings, exterior trim elements, and interior trim elements, decorative elements, and other attachments. It is only necessary to ensure that the propagation of electromagnetic waves is not obstructed, for example, by metallic objects. Furthermore, different thread diameters and lengths can be implemented, depending on the application.

[0037] Combining the antenna element and mounting element into a single component simplifies assembly, saves installation space, and facilitates the integration of components into the vehicle. Furthermore, it may allow for the functionalization of currently unused installation spaces within the vehicle. Reference sign 100 screw-on antennas, vehicle antennas 1 plastic screw 10 antenna radiators 11 Reflector / Ground plane / Washer 20 threaded part 21 screw head 30 RF connectors, here FAKRA connectors 32 plugs 4 PCB / circuit board

Claims

[1] Screw-on vehicle antenna (1), comprising - a threaded part (20) and a head part (21) adjoining an end region thereof, both of which are made of electrically non-conductive material, as well as - at least one antenna radiator (10) arranged at least within a part of the head section (21), and - a metallic disc (11) made of electrically conductive material, arranged on the head section (21) and serving as a reflector or ground plane - an RF connector (30) arranged on and attached to a region of the head part (21) opposite the threaded part (20), wherein - the antenna radiator (10) can be electrically connected to a plug (32) of the RF connector (30). [2] Screwable vehicle antenna (1) according to claim 1, wherein the metallic disc (11) rests on the end region of the head part (21) on which the threaded part (20) is arranged. [3] Screw-on vehicle antenna (1) according to claim 1, wherein the metallic disc (11) is arranged at least partially within the head part (21). [4] Screw-on vehicle antenna (1) according to one of the preceding claims, wherein a mounting shell is formed around the head part (21), or the head part (21) is formed in a predetermined shape. [5] Screwable vehicle antenna (1) according to any of the preceding claims, wherein the thread is a self-tapping thread or a non-self-tapping thread. [6] Screw-on vehicle antenna (1) according to one of the preceding claims, wherein the antenna radiator (10) provides V2X communication or near field communication, comprising at least Bluetooth and WLAN. [7] Screw-on vehicle antenna (1) according to one of the preceding claims, which is arranged in the interior of a vehicle or an exterior area of ​​the vehicle. [8] Screw-on vehicle antenna (1) according to one of the preceding claims, which is used to connect two electrically non-conductive components. [9] Screwable vehicle antenna (1) according to one of the preceding claims, further comprising a PCB arranged between antenna radiator (10) and RF connector (30) and provided with components such that an amplifier circuit or matching network is provided. [10] Screwable vehicle antenna (1) according to claim 9, wherein an amplifier component is provided, the electrical supply of which is provided by means of a phantom power supply via a coaxial cable attached to the connector (32).

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