Radar sensor system having a waveguide antenna that is fastened to a circuit board by means of a snap-in connection

Abstract

The invention relates to a radar sensor system (1) comprising a waveguide antenna (2), a radome (3), a housing (4) and a circuit board, wherein the radome (3) is attached to the housing (4) and the housing (4) and the radome (3) together surround the circuit board (5) and the waveguide antenna (2) and radar signals generated by the circuit board (5) can be emitted by means of the waveguide antenna (2), wherein the waveguide antenna (2) is attached to the circuit board (5) by means of a snap-fit ​​connection.

Description

Technical field

[0001] The invention relates to a radar sensor system, particularly for use in a vehicle, comprising a circuit board, a radome, a housing, and a waveguide antenna. The invention further relates to a method for manufacturing a radar sensor system. State of the art

[0002] Radar sensor systems typically use waveguide antennas to transmit radar waves generated by a microchip on a printed circuit board. These radar waves are coupled into the inputs of the waveguide antenna channels via so-called "ports" on the circuit board. It is known to attach the waveguide antenna to the circuit board with screws to establish contact between the inputs and the ports.

[0003] The invention is based on the objective of designing a radar sensor system and a method for manufacturing the radar sensor system in which the manufacturing of the radar sensor system can be simplified. Disclosure of the invention

[0004] A radar sensor system comprising a waveguide antenna, a radome, a housing, and a printed circuit board is proposed. The radome is attached to the housing, with the housing and the radome together enclosing the printed circuit board and the waveguide antenna. Radar signals generated by the printed circuit board can be transmitted via the waveguide antenna. The waveguide antenna is attached to the printed circuit board by means of a snap-fit ​​connection.

[0005] By attaching the waveguide antenna to the circuit board using a snap-fit ​​connection, the assembly of the radar sensor system could be simplified. Instead of screwing the waveguide antenna to the circuit board, it could be positioned against the board and secured by closing the snap-fit ​​connection. To close the connection, the waveguide antenna could simply be pressed against the circuit board until the snap-fit ​​connection clicks into place. This method of attaching the waveguide antenna to the circuit board using the snap-fit ​​connection would be faster than screwing it in place. Furthermore, no additional tools, such as a screwdriver, or materials, such as screws, are required to close the connection.

[0006] According to one variant, the snap-fit ​​connection has a first joining element and a second joining element. The first joining element extends perpendicularly from the waveguide antenna towards the circuit board. Furthermore, the first joining element has an enlarged cross-section at its end piece, which is spaced away from the waveguide antenna, for snapping into the second joining element. The second joining element is arranged on the circuit board and has at least one edge for snapping into the first joining element.

[0007] In most cases, the connecting element of a snap-fit ​​connection that has an enlarged cross-section at its end—in this case, the first connecting element—is more complex to manufacture than the one that has the edge—in this case, the second connecting element. In a simple embodiment, the second connecting element can simply have the edge, i.e., be shaped like the edge. Because the first connecting element extends from the waveguide antenna, it is located on the waveguide antenna and not on the circuit board. Furthermore, since the first connecting element has the end piece with the enlarged cross-section, it is the more complex of the two connecting elements located on the waveguide antenna. This could allow the more complex connecting element—i.e., the first connecting element—to be manufactured together with the waveguide antenna using a 3D printing process.However, the printed circuit board cannot usually be manufactured solely using a 3D printing process.

[0008] Manufacturing the waveguide antenna together with the first joining element using 3D printing makes it possible, in particular, to produce the more complex of the two joining elements relatively easily. Specifically, the first joining element does not need to be screwed onto the waveguide antenna, which could simplify the assembly of the radar sensor system. Therefore, in a specific embodiment of the radar sensor system, the waveguide antenna, and especially the waveguide antenna and the first joining element, are manufactured using a 3D printing process.

[0009] When manufacturing a waveguide antenna and its first connecting element using 3D printing, the antenna and the first connecting element are built up layer by layer from a liquid or solid material. During this process, physical and / or chemical hardening and / or melting processes are carried out. Materials used include, for example, plastic, synthetic resin, or a metal in powder form. The waveguide antenna and the first connecting element are, for example, made of plastic. In a special variant, the waveguide antenna is metallized.

[0010] The first joining element extends, in particular, from a rear side of the waveguide antenna facing the circuit board, towards the circuit board. The first joining element has a principal axis that runs, in particular, perpendicular to the rear side. The first joining element is designed such that its length, measurable along the principal axis, is greater than its width, measurable perpendicular to the principal axis. For example, the length is more than twice the width. The enlarged cross-section of the end piece means that the width of the first joining element at the end piece is greater than the width of the first joining element at a first part of the first joining element, which is located between the rear side and the end piece. The enlarged cross-section of the end piece could allow for the formation of a locking element for the snap-fit ​​connection at the end piece.

[0011] If the waveguide antenna is attached to the circuit board using the locking mechanism, the locking mechanism is closed. During the assembly of the radar sensor system, the waveguide antenna and the circuit board are initially not connected, i.e., the locking mechanism is open.

[0012] To close the snap-fit ​​connection, the first joining element is brought close to the second joining element so that the first joining element touches the second joining element. For this purpose, the first joining element is moved relative to the second joining element, specifically in a joining direction. In most cases, the joining direction runs parallel to the main axis of the first joining element. Once the two joining elements are in contact, the first joining element can be moved relative to the second joining element in the joining direction to close the snap-fit ​​connection.

[0013] The first joining element, particularly in combination with the second joining element, is designed such that, when the first joining element moves relative to the second joining element in the joining direction, it can interact with the second joining element in such a way that at least an elastic part of the first joining element deforms in a deformation direction perpendicular to the joining direction. Such deformation of the elastic part could, in particular, overcome a blockage of relative movement between the first and second joining elements in the joining direction. To effect deformation of the elastic part of the first joining element in the deformation direction, the end piece of the first joining element can have a butt edge or butt surface arranged at an acute angle to the principal axis.The acute angle can, for example, be in a range of about 5 to 30 degrees, especially in a range of about 10 to 20 degrees.

[0014] The deformation of the elastic component could, in particular, allow the first joining element to be shifted further in the joining direction relative to the second joining element such that the first joining element passes the second joining element. Furthermore, the first joining element, especially in combination with the second joining element, is designed such that the elastic component can deform in the opposite direction to the deformation direction once it has passed the second joining element and is located behind it in the joining direction. A deformation of the elastic component in the opposite direction to the deformation direction represents, in particular, a variant of the aforementioned snap-in engagement of the first joining element.

[0015] In a further embodiment, the waveguide antenna has at least one support element. This support element extends towards the circuit board to provide a defined distance between the waveguide antenna and the circuit board. The support element is specifically located on the rear side of the waveguide antenna. When the locking connection is closed, the support element contacts a side of the circuit board facing the waveguide antenna. The defined distance that the waveguide antenna maintains from the circuit board due to the support element could enable the inputs of the waveguide antenna, into which radar waves generated by components on the circuit board can be coupled via ports on the circuit board, to be correctly positioned in a direction perpendicular to the circuit board relative to the ports.This could increase the reliability of the transmission of radar waves from the ports to the waveguide antenna.

[0016] In a further development, the first joining element is adapted to the support element in such a way that, in the engaged state of the snap-fit ​​connection, the first joining element is under tensile stress. In this further development, the first joining element is placed under tensile stress, particularly in the engaged state, by blocking movement of the end piece against the joining direction through a mechanical interaction between the edge of the second joining element and the end piece. In this process, a compressive force can act from the edge of the second joining element in the joining direction onto the end piece, especially onto its back side. This could generate a frictional force between the edge and the back side of the end piece, which could prevent the snap-fit ​​connection from opening spontaneously. The tensile stress of the first joining element could therefore reduce the risk of the snap-fit ​​connection opening spontaneously.

[0017] To adapt the first joining element to the support element in such a way that the first joining element is under tensile stress when the snap-fit ​​connection is engaged, the distance between the back of the end piece, against which the edge rests in the engaged state, and the back of the waveguide antenna can be slightly smaller, for example, in the range of 0.1 to 1 millimeter, than the sum of the extension of the support element in a direction perpendicular to the back of the waveguide antenna and the thickness of the circuit board. This would allow the support element to press the circuit board, and thus the edge, in the joining direction, while simultaneously the edge is pulled in the opposite direction by the end piece of the first joining element. This could, in particular, enable the frictional force described above and thus ensure that the snap-fit ​​connection remains securely engaged.

[0018] In particular, the waveguide antenna features multiple support elements. This allows for more precise positioning of the waveguide antenna relative to the circuit board before snapping it into place. This ensures, in particular, that the waveguide antenna inputs are correctly positioned relative to the ports before the snap connection is closed. Specifically, at least three support elements reduce the risk of the waveguide antenna being tilted relative to the circuit board before the snap connection is closed. While four support elements would further prevent tilting, this number places higher demands on the tolerances of the support elements than three.

[0019] In a further embodiment, the first joining element comprises the first part described above, which extends away from the waveguide antenna and to which the end piece is attached. In this embodiment, the end piece has a recess that divides it into at least two parts that move relative to each other when snapped into place. The edge is specifically designed as a circumferential edge surrounding the first part, completely enclosing it when the snap-fit ​​connection is engaged.

[0020] The circumferential edge could have the advantage of providing centering for the end piece even when the snap-fit ​​connection is still open. Centering is particularly effective when the end piece contacts the circumferential edge before being pushed further into the insertion direction to engage. The end piece has, in particular, a conical section, which is referred to below as the cone. An outer surface of the cone can, in particular, rest against the circumferential edge before engagement, thereby centering the waveguide antenna relative to the circuit board. The two parts of the end piece that move relative to each other during engagement, referred to below as the locking elements, could allow the width of the end piece to be reduced by moving these two locking elements relative to each other. This would allow the end piece to be pushed past the circumferential edge into the insertion direction.After the locking elements have passed the surrounding edge, they could move away from each other. The circuit board has a free space behind the surrounding edge, in the assembly direction, to allow this.

[0021] Furthermore, combining the circumferential edge with the locking elements of the end piece could offer the advantage that the locking connection can be positioned at any point on the printed circuit board (PCB) located between the PCB's outer edges. In particular, this combination allows the locking connection to be implemented in a central area encompassing at least one inner half of the PCB. This would enable a tensile force acting on the circumferential edge, and especially one caused by the tensile stress within the first joining element, to be distributed more evenly across the PCB than would be the case if the tensile force acted on an edge of the PCB.

[0022] It goes without saying that the end piece can also have two or more recesses, dividing it into more than two, for example three or four, locking sections that can move towards each other when snapping into place. This could reduce stress on the circuit board during snapping.

[0023] According to another possible variant, the first joining element has a locking arm to which the end piece is attached. In this variant, the end piece has a locking lug that engages with the edge of the second joining element. This variant could have the advantage that the locking lug can be manufactured more easily than two or more of the aforementioned locking parts. In particular, the stiffness of the first joining element could be increased, thereby ensuring more accurate maintenance of the defined distance between the waveguide antenna and the circuit board over the radar sensor's lifetime.

[0024] The locking arm can, in principle, deform from a section adjacent to the rear of the waveguide antenna in a deformation direction perpendicular to the joining direction, thus enabling movement of the locking lug in the deformation direction and subsequent engagement. Even with relatively high stiffness, deformation of the locking arm in its deformation direction, and thus movement of the locking lug perpendicular to the joining direction, can be achieved over a certain length of the locking arm, allowing the locking lug to pass the edge of the second joining element. The aforementioned locking components can typically only deform in a region of the end piece and would therefore, in most applications, exhibit lower stiffness than the locking arm. The deformation of the locking arm in the deformation direction integrates over its length, resulting in a deflection of the end piece in the deformation direction.The length of the locking arm is, in particular, at least three times the length of the end piece measured in a direction parallel to the main axis of the first joining element.

[0025] Furthermore, the locking arm could allow the locking connection to be located on an outer area of ​​the circuit board. This could save space in an inner area of ​​the circuit board, where electronic components and wires are typically located. Accordingly, in another possible embodiment, the edge is designed as an outer edge of the circuit board.

[0026] In principle, if the first joining element has the locking arm, the edge of the second joining element can, in a further embodiment, be designed as an additional circumferential edge, defining a further opening in the printed circuit board. In this embodiment, the end piece could be slid through the additional opening without deforming it. The locking lug can then be pushed past the additional circumferential edge through the additional opening to cause the locking lug to deflect in the direction of deformation. This additional opening can be located in the central area of ​​the printed circuit board. This would allow the tensile force to be distributed more evenly across the circuit board. At the same time, this embodiment would allow the advantage of the higher stiffness of the locking arm to be utilized.

[0027] In general, the first joining element is elastic, i.e., the first joining element exhibits elastic behavior which allows the first joining element to snap into the second joining element.

[0028] According to one variant, the elastic behavior could allow the end piece to move in the direction of deformation perpendicular to the joining direction as it is slid past the second joining element. Furthermore, the elastic behavior could allow the end piece to move in the opposite direction to the deformation direction towards the main axis and spring back after the first joining element has passed the second joining element.

[0029] In another variant, the elastic behavior could allow the two locking elements to move towards each other when the buttress edge or surface is pushed past the edge. The end piece is designed to be elastic, particularly in a transition zone located between the two locking elements and adjacent to the recess. Furthermore, the elastic behavior could allow the two locking elements to move away from each other after the buttress edge or surface has passed the edge. In principle, the material of the transition zone can be more elastic than another material in a different area of ​​the first joining element.

[0030] Furthermore, a method for manufacturing a radar sensor system comprising a waveguide antenna, a radome, a housing, and a printed circuit board is proposed. The method includes assembling the radar sensor system in the following steps. In a first step, the waveguide antenna is brought close to the printed circuit board. This can be done by a person or, alternatively, using robotic arms. In a second step, the waveguide antenna is pressed against the printed circuit board to close a snap-fit ​​connection between the waveguide antenna and the printed circuit board. In particular, the waveguide antenna is pressed in the aforementioned joining direction relative to the printed circuit board. In a third step, the waveguide antenna and the printed circuit board, which is attached to the waveguide antenna by means of the snap-fit ​​connection, are inserted into the housing. In a fourth step, the housing is closed by attaching the radome to the housing.The radome can, for example, be welded to the housing.

[0031] In one possible embodiment of the process, the method comprises the fabrication of the waveguide antenna and a first joining element of the snap-fit ​​connection using a 3D printing process. The 3D printing process is carried out in such a way that at least part of the first joining element is manufactured as an integral component of the waveguide antenna. In this 3D printing process, a material is applied layer by layer and / or hardened layer by layer. As an integral component of the waveguide antenna, the first joining element shares a common layer of the same material with the waveguide antenna or at least has a first boundary layer that adjoins a second boundary layer of the waveguide antenna. In particular, the first boundary layer is fused with the second boundary layer. Specifically, the first boundary layer and the second boundary layer are manufactured sequentially in a single 3D printing process.The 3D printing process involves the layer-by-layer application of material, in particular the first and second boundary layers or the common layer, wherein during the application a position of the waveguide antenna, in particular a first layer of the waveguide antenna, relative to a stationary support of a robot arm from which the material for layer-by-layer application emerges remains unchanged. Brief description of the drawings

[0032] Further advantages, features, and details of the invention will become apparent from the following description, in which exemplary embodiments of the invention are explained in more detail with reference to the drawings. The drawings schematically depict... Figure 1: A vehicle with a radar sensor; Figure 2: A sectional view of a variant of the [in Figure 2] Figure 1The radar sensor shown comprises a circuit board, a radome, and a waveguide antenna, and a variant of a snap-fit ​​connection between the waveguide antenna and the circuit board in a closed state; Figure 3 in Figure 2 The variant of the locking connection shown in an open state; Figure 4 shows an upper edge of the in Figure 3 shown snap-fit ​​connection on a front side of the circuit board; Figure 5 a lower edge of the in Figure 3 shown snap-fit ​​connection on the back side of the circuit board; Figure 6 a sectional view of another variant of a snap-fit ​​connection between the waveguide antenna and the circuit board in a closed state; Figure 7 a top view of the in Figure 6 waveguide antenna shown; Figure 8 another sectional view of the in Figure 1 radar sensor shown with circuit board, radome and waveguide antenna; Figure 9 in Figure 6Figure 10 shows another variant of the locking connection in an open state; Figure 10 shows a perspective view of the circuit board and the waveguide antenna with a locking arm engaged at an edge of the circuit board; Figure 11 shows another perspective view of the Figure 10 shown circuit board and waveguide antenna with the in Fig. 2 shown variant of the rest connection and the one in Figure 6 shown variant of the rest connection.

[0033] In the figures, identical components are labelled with the same reference symbols. embodiment(s) of the invention

[0034] Fig. 1Figure 1 shows a vehicle 10 equipped with a radar sensor system 1 for detecting an object 8 in the vicinity of the vehicle 10. The object 8 may be another vehicle. The radar sensor system 1 is specifically configured to emit and / or receive radar waves. Conveniently, the radar sensor system 1 is controlled by a control unit 9. The control unit 9 may be configured to process received signals from the radar sensor system 1 based on the received radar waves, which were, for example, reflected by the object 8.

[0035] Fig. 2Figure 1 shows a possible variant of the radar sensor system 1 in a sectional view. The radar sensor system 1 comprises a waveguide antenna 2, a radome 3, a housing 4, and a circuit board 5. The radome 3 is attached to the housing 4. The housing 4 and the radome 3 together surround the circuit board 5 and the waveguide antenna 2. In principle, the radome 3 can also be considered part of the housing 4. The waveguide antenna 2 is attached to the circuit board 5 using a snap-fit ​​connection. For assembly of the radar sensor system 1, the circuit board 5 and the waveguide antenna 2 can be inserted together as a unit into a space enclosed by the housing 4. Subsequently, the radome 3 can be attached to a top surface of the housing 4, for example, by welding.

[0036] The radar waves can be generated, in particular, with the aid of the circuit board 5, and especially with the aid of a radar wave generator 6. The radar waves generated with the aid of the radar wave generator 6 can be transmitted with the aid of the waveguide antenna 2.

[0037] For this purpose, radar waves can be used in Fig. 2 For clarity, the channels of the waveguide antenna 2, not shown, are coupled in. The inputs of the channels can be connected to... Fig. 2 The radar wave generator 6 can be configured, in particular, as a high-frequency microchip. Furthermore, the radar wave generator 6 can be equipped with additional components located in the circuit board 5. Fig. 2 The components of the circuit board 5, which are not shown, can be controlled.

[0038] Fig. 2 This shows one variant of how the waveguide antenna 2 can be attached to the circuit board 5 using a first snap-fit ​​connection. Here, it shows Fig. 2The first snap-fit ​​connection is in a locked, i.e., closed, state. The first snap-fit ​​connection has a first joining element 11 and a second joining element 12, which is in Fig. 3 The first joining element 11 of the first snap-fit ​​connection, hereinafter referred to as the first joining element 11, extends in particular perpendicularly from the waveguide antenna 2 in the direction of the circuit board 5.

[0039] Furthermore, the first joining element 11 can have an enlarged cross-section at its end piece 11.2, which is spaced apart from the waveguide antenna 2, for snapping into the second joining element 12 of the first snap-fit ​​connection, hereinafter referred to as the second joining element 12. The second joining element 12 can be arranged on the printed circuit board 5 and has at least one edge, such as a second edge 12.2, for snapping the first joining element 11 into it.

[0040] The second joining element 12 is located in the Fig. 2, 3, 4, 5The illustrated embodiment of the radar sensor system 1 is designed in the form of a bore. The bore is enclosed by a Fig. 4 The first circumferential edge 12.1, shown, is located on a side of the circuit board 5 facing the waveguide antenna 2, hereinafter referred to as the front of the circuit board 5, and defines a second circumferential edge 12.2. The second circumferential edge 12.2 is located on a side of the circuit board 5 facing away from the waveguide antenna 2, hereinafter referred to as the back of the circuit board 5, and is in Fig. 5 The first edge 12.1 therefore limits the hole on the front side of the circuit board 5 and the second circumferential edge 12.2 limits the hole on the back side of the circuit board 5.

[0041] Fig. 3Figure 1 shows an optional division of the first joining element 11 into a first part 11.1, which extends away from the waveguide antenna 2 along a principal axis 100 of the first joining element 11 and on which the end piece 11.2 is arranged, and the end piece 11.2, which forms a second part of the first joining element 11. The end piece 11.2 can, in particular, be conical. Furthermore, the end piece 11.2 can be divided into at least two parts that move towards each other when snapping into place, namely a first snapping part 14.1 and a second snapping part 14.2.

[0042] Out of Fig. 3It is evident that the width of the end piece 11.2 is greater than the width of the first part 11.1, at least in one region of the end piece 11.2. The width is measured in a direction 102 that runs perpendicular to the main axis 100. In particular, the greatest width of the end piece 11.2 is greater than the diameter of the bore 12. This causes the two locking parts 14.1 and 14.2 to be pressed together when the first joining element 11 is pushed through the bore 12 in a joining direction 101. To facilitate the movement of the two locking parts 14.1 and 14.2 towards each other, the end piece 11.2 can have at least one recess 13. As the two locking parts 14.1 and 14.2 move towards each other, the greatest width of the end piece 11.2 is reduced, allowing the end piece 11.2 to be pushed through the bore 12. After the end piece 11.Once the end piece 11.2 has passed through the bore 12, meaning that, viewed in the joining direction 101, it is located behind the bore 12, specifically behind the second circumferential edge 12.2, the two locking elements 14.1 and 14.2 can move apart again. The circuit board 5 has a free space on its back side for this purpose, located immediately behind the second circumferential edge 12.2 in the joining direction 101. The two locking elements 14.1, 14.2 can spring back into this free space, particularly due to their elastic properties, after the end piece 11.2 has passed the second circumferential edge 12.2. In principle, the two locking elements 14.1, 14.2 can also be pressed together without the recess 13 due to their elastic properties. In this case, the two locking elements 14.1, 14.2 are not separated from each other but form a dome-shaped end piece. However, recess 13 could allow for easier engagement and opening of the first locking connection.

[0043] According to one possible embodiment, the waveguide antenna 2 can have a support element 19 which extends from a surface 20 of the waveguide antenna 2 facing the circuit board 5 towards the circuit board 5. The support element 19 may be formed by the walls of the channels of the waveguide antenna 2. Alternatively, the support element 19 may be arranged separately from the walls of the channels.

[0044] The first joining element 11 is adapted to the support element 19 in such a way that, in a locked state of the first snap-fit ​​connection, the first joining element 11 is under tensile stress. This can be achieved, in particular, by making the length 18 of the first part 11.1 of the first joining element 11, which is measurable in the direction of the main axis 100, slightly smaller, i.e., for example, 0.1 to 1 mm smaller, than the sum of the thicknesses of the printed circuit board 5, in particular the distance between the first circumferential edge 12.1 and the second circumferential edge 12.2 in the direction of the main axis 100, and the extension of the support element 19 in a direction parallel to the main axis 100.

[0045] Fig. 6 shows another variant of the radar sensor system 1. In the Fig. 6 In the variant shown, the waveguide antenna 2 is attached to the circuit board 5 using a second snap connection. Fig. 6The second snap-fit ​​connection is shown in a locked, i.e., closed, state. The second snap-fit ​​connection has a first joining element 21 and a second joining element 22, which is in Fig. 9 The first joining element 21 of the second snap-fit ​​connection, hereinafter referred to as first joining element 21, can extend from the waveguide antenna 2 towards the circuit board 5 and have an enlarged cross-section at its end piece 21.3, which is spaced apart from the waveguide antenna 2, for snapping into the second joining element 22 of the second snap-fit ​​connection, hereinafter referred to as second joining element 22. The second joining element 22 is shown in the Fig. 6, 7 , 8 and 9The illustrated variant of the radar sensor system 1 is formed in the form of an edge of the printed circuit board 5. The edge is bounded by a first upper edge 22.1 of the printed circuit board 5, which is located on the front side of the printed circuit board 5, and a second lower edge 22.2, which is located on the back side of the printed circuit board 5. The end piece 21.3, in particular a locking lug 21.4 of the end piece 21.3, can engage with the second edge 22.2.

[0046] Fig. 7 The figure shows the waveguide antenna 2 in a top view and the radome 3 in a section view. Fig. 6 shows the housing 4 and the radome 3 in a cross-section in the Fig. 7 Section plane CC shown. To provide space for the first joining element 21, a recess 70 is provided in the housing 4, which is in Fig. 6 and Fig. 7 The recess 70 can extend particularly through the radome 3. Fig. 8 The radar sensor system 1 is shown in a cross-section along the in Fig. 7shown section plane DD.

[0047] In Fig. 9 It can be seen that the first joining element 21 has a locking arm 21.1 on which the end piece 21.3 is arranged. In the closed state of the second locking connection, the locking lug 21.4 is engaged on the second edge 22.2 of the second joining element 22. Fig. 9 shows the second locking connection in an open state.

[0048] To close the second locking connection, the first joining element 21 is moved in the joining direction 101, thereby approaching the second joining element 22. The first joining element 21 is moved in the joining direction 101 until a contact surface 90 of the end piece 21.3 touches the first edge 22.1 of the second joining element 22. If the first joining element 21 is moved further in the joining direction 101 after the contact surface 90 has touched the first edge 22.1, the end piece 21.3 moves in a displacement direction 201 perpendicular to the joining direction 101, bending the locking arm 21.1 in the direction 201.

[0049] A displacement of the end piece 21.3 in direction 201 allows the locking lug 21.4 to slide past the edge of the circuit board 5, i.e., the second joining element 22, in the direction of the second edge 22.2. After the locking lug 21.4 has passed the second edge 22.2, the end piece 21.3 can spring back in a direction opposite to the displacement direction 201. To allow the end piece 21.3 to spring back, a free space is provided behind the second edge 22.2 when viewed in the joining direction 101.

[0050] The butt surface 90 is oriented obliquely to a principal extension direction 200 of the first joining element 21. In particular, the butt surface 90 can have an angle to the principal extension direction 200 of approximately 5 to 20 degrees.

[0051] Out of Fig. 9It is further evident that the end piece 21.3 has a greater width than the locking arm 21.1, the width being measurable in a direction transverse to the main extension direction 200.

[0052] A second part 21.2 of the first joining element 21 can extend along the main direction 200 of the waveguide antenna 2. The second part 21.2 is, in particular, integrated into the waveguide antenna 2. Such integration of the second part 21.2 into the waveguide antenna 2 can, for example, be achieved by manufacturing the first joining element 21 together with the waveguide antenna 2 using a 3D printing process.

[0053] Fig. 10 shows a perspective view of the waveguide antenna 2, the first joining element 21, the circuit board 5 and the second joining element 22 with the upper first edge 22.1 and the lower second edge 22.2.

[0054] Fig. 11Figure 1 shows a variant of the radar sensor system 1 in which the waveguide antenna 2 is attached to the circuit board 5 using the first and second locking connections. In this variant, the second locking connection is located opposite the first locking connection. Accordingly, in the Fig. 11 The variant of radar sensor system 1 shown, the circuit board 5, both of which are in Figs. 2 and 3 The illustrated bore 12 is for snapping in the first joining element 11, and the second joining element 22 is for snapping in the first joining element 21. According to one possible embodiment, the waveguide antenna 2 can be attached to the circuit board 5 by means of further snap connections. The further snap connections can each be designed analogously to the first or the second snap connection.

Claims

1. Radar sensor system (1) comprising a waveguide antenna (2), a radome (3), a housing (4) and a printed circuit board, wherein the radome (3) is attached to the housing (4) and the housing (4) and the radome (3) together surround the printed circuit board (5) and the waveguide antenna (2) and radar signals generated by the printed circuit board (5) can be emitted by means of the waveguide antenna (2), wherein the waveguide antenna (2) is attached to the printed circuit board (5) by means of a snap-fit ​​connection.

2. Radar sensor system (1) according to claim 1, wherein the waveguide antenna (2) is manufactured using a 3D printing process.

3. Radar sensor system (1) according to claim 1 or 2, wherein the snap-fit ​​connection has a first joining element (11; 21) and a second joining element (12; 22) and the first joining element (11; 21) extends perpendicularly from the waveguide antenna (2) in the direction of the circuit board (5) and has an enlarged cross-section at its end piece (11.2; 21.3) spaced apart from the waveguide antenna (2) for snapping onto the second joining element (12; 22) and the second joining element (12; 22) is arranged on the circuit board (5) and has at least one edge (12.2; 22.2) for snapping the first joining element (11; 21).

4. Radar sensor system (1) according to one of the preceding claims, wherein the waveguide antenna (2) has at least one support element (19) which extends in the direction of the circuit board (5) to provide a defined distance between the waveguide antenna (2) and the circuit board (5).

5. Radar sensor system (1) according to claim 4, wherein the first joining element (11; 21) is adapted to the support element (19) such that in a locked state of the locking connection the first joining element (11; 21) is under tensile stress.

6. Radar sensor system (1) according to claim 3, wherein the first joining element (11) has a first part (11.1) extending away from the waveguide antenna (2) and on which the end piece (11.2) is arranged, and the end piece (11.2) has a recess (13) which divides the end piece (11.2) into at least two parts (14.1, 14.2) which move towards each other when snapping into place, and the edge (12.2) is designed as an edge circumferential to the first part (11.1) which completely surrounds the first part (11.1) in the snapped state of the snap connection.

7. Radar sensor system (1) according to claim 3, wherein the first joining element (21) has a locking arm (21.1) on which the end piece (21.3) is arranged, wherein the end piece (21.3) has a locking lug (21.4) which is engaged on the edge (22.2) of the second joining element (22).

8. Radar sensor system (1) according to claim 7, wherein the edge (22.2) is formed in the form of an outer edge of the circuit board (5).

9. Method for manufacturing a radar sensor system (1) comprising a waveguide antenna (2), a radome, a housing (4) and a printed circuit board (5), the method comprising assembling the radar sensor system (1) by the following steps: - bringing the waveguide antenna (2) close to the printed circuit board (5); - pressing the waveguide antenna (2) against the printed circuit board (5) to close a snap connection between the waveguide antenna (2) and the printed circuit board (5); - inserting the waveguide antenna (2) and the printed circuit board (5) attached to the waveguide antenna (2) by means of the snap connection into the housing (4); - closing the housing (4) by attaching the radome (3) to the housing (4).

10. Method according to claim 9, wherein the method comprises manufacturing the waveguide antenna (2) and a first joining element (11, 21) of the snap connection using a 3D printing method, wherein the 3D printing method is carried out in such a way that at least a part of the first joining element (11, 21) is manufactured as an integral part of the waveguide antenna (2).

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