Antenna module for vehicle

Abstract

Antenna module (100) for a vehicle, comprising the following: - a first printed circuit board (201) housed horizontally in a casing, - at least one second printed circuit board (205a) with a high-frequency antenna mounted vertically on the first printed circuit board (201) and protruding from an upper surface of the housing, - a hood (101) mounted on the housing, configured to cover at least the second printed circuit board (205a), wherein the antenna module (100) is characterized in that the hood (101) comprises a shell (206) and an elastic element (207), wherein the elastic element (207) is configured to exert pressure on the upper section of the second circuit board (205a) when the hood is on the housing at the location to ensure an electrical contact between the lower section of the second circuit board (205a) and at least one flexible contact element (300) on the surface of the first circuit board (201).

Description

Technical field

[0001] The present invention relates to the field of antennas for road vehicles and in particular aims at a vertical antenna module that is integrated into a roof spoiler of a vehicle. State of the art

[0002] Nowadays, road vehicles are increasingly equipped with compact roof-mounted antennas configured to enable data exchange between the vehicle and Wi-Fi or cellular communication networks, reception of radio programs, or reception of signals transmitted by GNSS positioning satellites (positioning satellites of a global navigation satellite system). These antennas are generally referred to as smart antennas because they include signal processing circuitry in addition to the antennas themselves.

[0003] The antennas for vehicles of this type are conventionally housed in an antenna enclosure located on the vehicle's roof and protected by a cover, for example, a spoiler-shaped cover mounted on a base (see, for example, EP3761446A1, US2021 / 050655A1, WO2017 / 178384A1, FR3092440A3). The antenna module comprises a first horizontal printed circuit board on which at least one second printed circuit board is arranged vertically, comprising one or more specific antenna patterns. The second printed circuit board forms the actual antenna, which may be electrically connected to a surface of the first circuit board by means of a connecting element attached to the first board, forming a terminal into which the second board is inserted. However, such a connection mode between the first and second circuit boards is bulky and expensive.

[0004] Alternatively, the second circuit can be connected to the first circuit by soldering. However, this is a difficult operation that complicates the assembly process and raises reliability issues over time, particularly due to vibration and / or deformation caused by temperature changes, which can weaken the solder joints.

[0005] Consequently, there is a need for an antenna module that does not have the aforementioned disadvantages. Summary of the invention

[0006] An antenna module for a vehicle is proposed, comprising the following: - a first printed circuit board (PCB) housed horizontally in a casing, - at least one second printed circuit board with a high-frequency antenna, mounted vertically on the first printed circuit board and protruding from an upper surface of the housing, - a hood mounted on the housing, configured to cover at least the second printed circuit board.

[0007] An embodiment of the antenna module according to the invention is that the hood comprises a shell and an elastic element, wherein the elastic element is configured to exert pressure on the upper section of the second circuit board when the hood is located on the housing in order to ensure electrical contact between the lower section of the second circuit board and at least one compliant contact element on the surface of the first circuit board.

[0008] This results in a mounting of the first circuit board onto the second circuit board that is robust, easy to implement and provides a secure electrical contact between the two vertical circuit boards, which withstands vibrations, temperature changes and loosening of the plastic parts due to aging.

[0009] The flexible contact element, with which the lower section of the second circuit board comes into contact, makes it possible to absorb the play and the relative displacements of one circuit board in relation to the other, thus ensuring a permanent contact.

[0010] The elastic element, which is located between the hood and the upper section of the second circuit board, exerts a vertical pressure on the second circuit board, which makes it possible to ensure plating of the lower section of the second circuit board to the compliant contact elements located on the surface of the first circuit board.

[0011] This simplifies the assembly of the antenna module and eliminates a soldering step, while ensuring good electrical continuity between the first and second circuit boards. The result is a robust, reliable, and easy-to-assemble antenna module.

[0012] According to a special embodiment, the elastic element is configured to exert pressure on the upper section of the second circuit board by means of at least one push button.

[0013] In this way, the element applies and exerts a localized force on one or more points of the upper section of the antenna. The applied force is thus controlled along the length of the upper section of the antenna, unlike with continuous contact, where irregularities in the antenna's cross-section and / or the shape of the elastic element would make the exerted pressure force and its distribution along the antenna uncertain.

[0014] According to a special embodiment, this is at least one flexible contact element of the spring finger type.

[0015] The use of spring fingers makes it possible to ensure contact between the first and second circuit boards at a lower cost.

[0016] According to a specific embodiment, at least one flexible contact element is made of a conductive elastomer material.

[0017] Such an arrangement improves contact reliability by preventing oxidation and allows for better absorption of mechanical tolerances. Furthermore, a compliant contact made of conductive elastomer offers greater resistance to the risk of pull-out and / or deformation during handling compared to metallic Z- or clamping spring-type contacts.

[0018] In a particular embodiment, the second circuit board comprises at least one shoulder forming a stop that rests against the housing to limit the crushing of the at least one compliant contact element by the lower section of the second circuit board.

[0019] The shoulder on the housing limits the vertical travel of the antenna. This prevents crushing of the flexible contact points. As a result, excessive crushing of the flexible contacts avoids deformation of the contact points and a disruption of electrical continuity. This design improves the reliability of the antenna module.

[0020] According to a specific design, the elastic element is produced by overmolding an internal part of the shell with a thermoplastic elastomer.

[0021] Overmolding allows for more precise positioning of the flexible element. Furthermore, unlike an attached component, it can be manufactured automatically; in particular, given the required flexibility, it can be processed by a robot. This improves both the quality and cost of manufacturing the antenna module.

[0022] In a special embodiment, the elastic element comprises at least one pair of lateral ribs configured to receive the upper section of the second plate and to limit its lateral displacements.

[0023] The upper section of the antenna is thus held laterally. This prevents the occurrence of vibration phenomena that can cause noise and alter the contact between the vertical circuit board and the main board. Unlike other techniques where the upper part of the board is held by structures provided for this purpose inside the housing, such as a slot, the insertion of the printed circuit board with the antenna between manufactured compliant ribs can be performed with controlled mechanical force, which simplifies assembly and does not place any stress on the printed circuit.

[0024] In a special embodiment, the elastic element has a hardness between 45 and 55 Shore A, preferably 50 Shore A.

[0025] Such a hardness value makes it possible to limit the mounting force required when attaching the hood, while still allowing for satisfactory vibration absorption. The elastomer is also designed to offer a low dielectric loss factor so as not to interfere with the function of the vertical antennas protected by the hood.

[0026] According to another aspect, the invention relates to a vehicle with an antenna module as described above.

[0027] Such a vehicle offers at least advantages analogous to those conferred upon the antenna module described above. Brief description of the characters

[0028] Other aspects, objectives, and advantages of the invention will become apparent upon reading the following description of embodiments, which are given as a non-limiting example. The invention will also be better understood with reference to the accompanying drawings, which show: [ Fig. 1] Fig. 1 a perspective view of an antenna module according to a specific embodiment; [ Fig. 2] Fig. 2. An expanded view of an antenna module according to a specific design; [ Fig. 3] Fig. 3 a sectional view of an antenna module according to a special embodiment according to section line AA, which is shown in Fig. 1 is shown; and [ Fig. 4] Fig. 4 A view of the inside of the hood from below with an elastic element and a PCB antenna according to a special design. Detailed description

[0029] The following description presents numerous specific details to enable a person skilled in the art to better understand the present invention. However, it is obvious that the embodiment of the present invention need not include certain of these specific details.

[0030] Furthermore, it must be understood that the present invention is not limited to the specific embodiments described. On the contrary, it is conceivable to implement the present invention with any combination of the following features and elements, whether they imply different embodiments or not. Consequently, the aspects, features, embodiments, and advantages described are for illustrative purposes only and should not be considered as elements or limitations of the claims unless explicitly stated in the claims.

[0031] Fig. Figure 1 shows a perspective view of an antenna module 100 according to a specific embodiment. The antenna module 100 is intended to be integrated into the roof of a vehicle and comprises a housing 102 to which a cover 101 is attached. The housing 102 includes at least one connecting element 103, which is intended to connect an electronic circuit board contained in the housing 102 to at least one device of the vehicle into which the antenna module is integrated.

[0032] Fig. Figure 2 is an exploded view of the antenna module 100 according to a particular embodiment. The housing 102 consists of a lower part 200 and an upper part 202, between which a printed circuit board 201, also called a mainboard, is arranged horizontally. The lower part 200 and the upper part 202 of the housing are joined together, for example, by screws. In a particular embodiment, the upper part 202 is made of metal to ground the module to the vehicle and to shield the connection between the antennas and the mainboard.

[0033] The circuit board or motherboard 201 can consist of a single board containing, for example, electrical power supply circuits, baseband signal processing circuits, and a high-frequency processing circuit. However, without modifying the invention, the motherboard can consist of different boards carrying different circuits.

[0034] The upper part 202 of the housing includes a recess 203 through which one or more vertical PCB antennas 205a, 205b protrude. A PCB antenna is defined as a printed circuit board on which one or more conductive traces forming an antenna pattern are laid, and / or printed circuit boards with one or more three-dimensional antennas, such as a wire extending on the board, a metallic element, or a chip antenna.

[0035] Although the figures, which depict a specific embodiment of the antenna module, show two PCB antennas 205a and 205b, the number and position of these antennas can vary without modifying the invention. For example, the antenna module can comprise a single antenna 205a.

[0036] For the sake of clarity and brevity, the present description deals with describing the properties of the invention with regard to the antenna 205a, wherein the same invention concepts apply analogously to the antenna 205b and / or other vertical PCB antennas that may be included in the antenna module.

[0037] Antenna 205a, for example, is configured to enable the transmission and / or reception of high-frequency signals. It can be an antenna for receiving an analog or digital radio signal, a Wi-Fi signal, or an antenna for establishing connections with a cellular access network, such as a 2G, 3G, 4G, or 5G network.

[0038] The PCB antenna 205a is arranged perpendicular to the motherboard 201. According to a particular embodiment, the antenna module includes a guide element 204 to hold the PCB antenna 205a in the vertical position, perpendicular to the motherboard. In a particular embodiment, the guide element is formed by a special feature of the upper part 202 of the housing.

[0039] Fig. Figure 2 also shows a hood 101 in the shape of a "shark fin" intended to cover the antenna 205a. The hood 101 comprises a shell 206, made of a non-metallic material and attached to the upper part 202 of the housing, for example by screws or clamps, as well as an elastic element 207.

[0040] The elastic element 207 is inserted between the upper internal part of the shell 206 and the upper part of the antenna 205a, such that at least a portion of the elastic element 207 is in contact with the upper internal part of the shell 206 and the upper section of the PCB antenna 205a. The elastic element is preferably a thermoplastic elastomer (TPE) with low hardness, for example 50 Shore A, which has a low dielectric loss factor, preferably less than 0.07 to 6 GHz. In a particular embodiment, the elastic element 207 is injection-molded into the shell 206.

[0041] It is noted that the upper part of the shell 206 and the upper edge of the antenna 205a have an essentially identical profile. Since the shell 206 is intended to project from the roof of a vehicle, its shark-fin shape helps to limit aerodynamic disturbances. Thus, the shape of the antenna 205a is designed to optimally fill the interior of the shell 206 and to allow the elastic element 207 to fit between the shell 206 and the antenna 205a, using a minimum of material.

[0042] Fig. Figure 3 is a longitudinal section of the assembled antenna module along a section line AA, which is shown in Fig. 1 is shown. Fig. Figure 3 shows compliant contacts 300 that electrically connect the antenna 205a to the motherboard 201. The compliant contacts 300 are in contact with a conductive part of the lower section of the antenna 205a and are connected to a circuit on the motherboard. They thus enable electrical continuity between the antenna 205a and the motherboard, while allowing relative displacement of the antenna 205a with respect to the motherboard 201. Such a mounting therefore provides tolerance for deformations, expansions, or vibrations without loss of electrical continuity. According to a particular embodiment, the compliant contact points 300 are spring-type contact fingers. In another particular embodiment, the compliant contact points 300 are made of a conductive elastomer material, for example, a resilient silicone elastomer filled with copper particles.

[0043] The number of compliant contacts naturally depends on the number and / or type of antenna 205a with which the antenna module is equipped. The motherboard 201, for example, may include a single compliant contact point 300.

[0044] The antenna 205a includes at least one paragraph 301 configured to support itself against a section of the upper part 202 of the housing to guarantee a minimum distance between the lower section of the antenna 205a and the motherboard and to limit the crushing of the contact points 300.

[0045] Fig. Figure 3 shows two push buttons 302 formed by the elastic element 207, configured to exert pressure on the upper section of the antenna 302 when the shell 206 is in position, thus ensuring plating of the shoulders 301 on the housing and minimal compression of the compliant contact points 300. The width of a push button is, for example, between 1.5 and 3 millimeters.

[0046] A push button is understood to be a part of the elastic element 207 whose height is greater than the space available between the top of the internal part of the shell 206 and the upper section of the antenna 205a, so that when the hood is in place, the elastic element 207 between the shell 206 and the antenna 205a is compressed and exerts a vertical downward pressure on the upper section of the antenna 205a.

[0047] According to a special embodiment, the upper section of the antenna 205a comprises at least one horizontal part 303, on which a push button 302 applies pressure, so that the pressure is exerted vertically on the circuit board.

[0048] Fig. Figure 4 is an internal view of the hood 101 according to a special design, in which the elastic element 207 and the antenna 205a are distinguished. Fig. Figure 4 shows lateral retaining elements, such as a pair of ribs 400, arranged opposite each other and configured to receive the PCB antenna 205a and limit its lateral movement. These ribs have a width of, for example, 2 to 5 millimeters. This arrangement allows the upper part of the antenna 205a to be held in place when the cover 101 is attached, and dampens any vibration phenomena that may occur in the upper part of the antenna 205a. Furthermore, the insertion of the upper part of the antenna 205a between the ribs when attaching the cover 101 can be performed with a controlled mechanical force, thus limiting the stress exerted on the circuit boards.

[0049] Finally, it shows Fig. 4 a conductive part 501 of the lower section of the antenna 205a, which is intended to establish electrical contact with the compliant contacts 300 of the motherboard described above.

[0050] As previously stated, a specific version of the antenna module can include multiple PCB antennas. Fig. 2, Fig. 3 and Fig. Figure 4 shows, for example, a second vertical PCB antenna 205b, which is arranged perpendicular to the motherboard, wherein the plane of antenna 205b is perpendicular to the plane of antenna 205a. Fig. Figure 4 shows a push button 401 formed in the elastic element 207 and configured to exert pressure on the upper section of the antenna 205b to press it against a compliant contact element on the surface of the motherboard. Analogous to what was previously described with reference to the antenna 205a, the antenna 205b comprises at least one step connected to 206 in Fig. 2 is designated, which is configured to rest on the upper part 202 of the housing and to crush a compliant contact that is 300 in Fig. 3 is to limit, which allows electrical continuity between the antenna 205b and the mainboard 201. The lateral movements of the antenna 205b are limited by retaining elements, which are labelled 402 in Fig. 4 are designated as ribs or tongues formed by the compliant element 207.

[0051] The properties described above make it possible to obtain a particularly reliable antenna module, the cost and assembly effort of which are reduced in relation to the state of the art. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 3761446A1

[0003] US 2021 / 050655A1

[0003] WO 2017 / 178384A1

[0003] FR 3092440A3

[0003]

Claims

[1] Antenna module (100) for a vehicle, comprising: - a first printed circuit board (201) housed horizontally in a housing, - at least one second printed circuit board (205a) having a radio frequency antenna mounted vertically on the first printed circuit board (201) and projecting from an upper surface of the housing, - a hood (101) mounted on the housing, which is configured to cover at least the second printed circuit board (205a), wherein the antenna module (100) characterized by is that the hood (101) comprises a shell (206) and an elastic element (207), wherein the elastic element (207) is configured to exert pressure on the upper portion of the second circuit board (205a) when the hood is in place on the housing to ensure electrical contact between the lower portion of the second circuit board (205a) and at least one resilient contact element (300) on the surface of the first circuit board (201). [2] The antenna module according to claim 1, wherein the elastic member is configured to apply pressure to the upper portion of the second board by means of at least one push button. [3] Antenna module according to one of the preceding claims, wherein the at least one resilient contact element is of the spring finger type. [4] Antenna module according to one of claims 1 and 2, wherein the at least one compliant contact element is made of a conductive elastomer material. [5] Antenna module according to one of the preceding claims, wherein the second board comprises at least one shoulder forming a stop which bears against the housing in order to limit the crushing of the at least one resilient contact by the lower portion of the second board. [6] Antenna module according to one of the preceding claims, wherein the elastic element is made by overmolding an internal part of the shell with a thermoplastic elastomer. [7] An antenna module according to any one of the preceding claims, wherein the elastic member comprises at least one pair of lateral ribs configured to receive the upper portion of the second board and to limit the lateral displacements thereof. [8] Antenna module according to one of the preceding claims, wherein the elastic element has a hardness between 45 and 55 Shore A. [9] Vehicle with an antenna module according to one of the preceding claims.

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