Radarsensor

Abstract

A radar sensor (10), particularly for use in a vehicle, is proposed, comprising at least one printed circuit board (6) and at least one antenna (7), which is particularly designed as a waveguide antenna, wherein the antenna (7) is connected to the printed circuit board (6), and the connection between the printed circuit board (6) and the antenna (7) is made by means of a frame (1) which is attached to the printed circuit board (6) and which presses the antenna (7) flat against the printed circuit board (6).

Description

[0001] The present invention relates to a radar sensor, particularly for use in a vehicle, comprising at least one printed circuit board and at least one antenna, which is preferably designed as a waveguide antenna. The antenna is connected to the printed circuit board, and the connection between the printed circuit board and the antenna is made by means of a frame that is attached to the printed circuit board and that presses the antenna onto the printed circuit board. State of the art

[0002] Radar sensors available on the market have for many years consisted of printed circuit boards with planar antennas, whereby the planar antennas were structured on the top copper layer and thus automatically firmly connected to the printed circuit board.

[0003] Currently, radar sensors are being developed where the circuit board is not connected to a separate antenna, particularly a waveguide antenna. This connection must be permanent, conductive, and robust to ensure the radar sensor's operation throughout its product lifespan. Core and advantages of the invention

[0004] The core of the present invention is to specify a radar sensor consisting of at least one circuit board and at least one antenna, and to specify particularly advantageous connection options or mounting options for the at least one circuit board and the at least one antenna.

[0005] According to the invention, this is solved by the features of the independent claim. Advantageous further developments and embodiments result from the dependent claims.

[0006] Furthermore, it is advantageous that the radar sensor, which may be intended for use in a vehicle, comprises at least one circuit board and at least one antenna. The antenna can be particularly advantageously designed as a waveguide antenna. The antenna is connected to the circuit board, and the connection between the circuit board and the antenna is made by means of a frame. The frame is advantageously attached to the at least one circuit board and presses the antenna onto the circuit board.

[0007] Advantageously, the antenna rests on the circuit board. It can be particularly advantageous if the antenna lies flat on the circuit board and / or is pressed flat against it by applying force to the antenna and the circuit board.

[0008] Furthermore, it is advantageous if the frame rests on the antenna at its outer edges. This ensures that the holding force is applied evenly to the antenna at the outer edge, resulting in a very uniform distribution of the holding force and a secure, long-lasting position with minimal mechanical stress.

[0009] Advantageously, the antenna is permanently fixed to the circuit board solely by the force-fit of the frame. This eliminates the need for additional fastening using soldering, gluing, screws, rivets, or similar joining techniques, thus preventing mechanical stress and consequently dimensional deviations.

[0010] The frame is particularly advantageous when made of sheet metal. Sheet metal is inexpensive and possesses elasticity without permanently deforming. This allows for a clamping force that can be maintained over time. Furthermore, it is beneficial that the sheet metal frame is manufactured as a stamped and / or bent metal part. This is simple and inexpensive to produce.

[0011] Advantageously, the frame has several press-fit pins (3) on the side facing the printed circuit board. These press-fit pins can be manufactured integrally during the frame's production or attached after the frame is completed using a joining process, such as welding or soldering. Press-fit pins are well-known in the manufacture of electronic products and are frequently used to contact electrical conductors. A hole is provided in the printed circuit board in the area of ​​the conductor, into which the needle-shaped press-fit pin is pressed and which anchors itself in the hole due to its spring elasticity.

[0012] It is advantageous if the frame has mechanical stops on the side facing the circuit board (PCB) to prevent the press-fit pins from being pressed too deeply into the PCB. These mechanical stops ensure that the distance between the frame and the PCB, and thus the pressing force with which the antenna is pressed onto the PCB, is neither too high nor too low. Another function of the mechanical stops is to ensure that the press-fit pins are only pressed into the PCB to the point where their clamping area reaches the ideal depth. These mechanical stops can be provided all around the edge of the frame or only at specific points on the frame. It is advantageous to have at least three mechanical stops to prevent the frame from tilting after reaching a mechanical stop.Due to the rectangular shape of the frame, it is particularly advantageous to provide four mechanical stops on the frame, especially at the corners. According to another embodiment, the mechanical stops can be located in the area of ​​the press-fit pins.

[0013] Furthermore, it is advantageous that the frame, on the side facing away from the circuit board (i.e., the transmitting and receiving side of the sensor), has cutouts at the locations where the antenna has transmitting and receiving apertures. For this purpose, the frame has at least one or more openings, cutouts, or windows in its interior, so that the antenna apertures are not obscured by the frame.

[0014] Advantageously, the frame can further be provided with spring tongues on the side facing away from the circuit board. These tongues rest against the side of the antenna facing away from the circuit board and press the antenna onto the circuit board. The spring tongues can be formed as grooves or curved grooves, so that the frame presses the antenna onto the circuit board with a predetermined force. The spring tongues can be formed from the sheet metal of the frame. It is advantageous if the spring tongues are aligned parallel to the surface of the antenna on the side facing away from the circuit board.

[0015] Furthermore, it is advantageous that the antenna has contact surfaces at its edges on which the spring tongues of the frame rest and through which the contact force is exerted on the antenna.

[0016] The contact surfaces can have an edge profile, for example in the form of a recess in the antenna, so that the spring tongues rest in this edge profile or in these recesses on the antenna and cannot slip against each other due to the profile or the edges of the recess.

[0017] Advantageously, the holding force of all press-fit pins is designed to be significantly greater than the pressing force of all spring tongues. This ensures that the spring force, which would otherwise attempt to pull the press-fit pins out of the circuit board, does not become so great as to cause them to be pulled out.

[0018] It is particularly advantageous if the holding force of all the press-in pins is approximately 2 to 10 times, and especially 3 to 5 times, greater than the opposing spring force of the spring tongues.

[0019] Advantageously, the antenna is provided with centering elements on the side facing the printed circuit board (PCB). These centering elements are formed on the contact surface with the PCB, so that they engage in holes in the PCB and ensure the antenna's relative positioning to the PCB. The centering elements can be advantageously designed as centering pins, particularly round ones, and the holes in the PCB can be round with approximately the same diameter as the centering pins. The pins and holes advantageously form a precise fit with their respective diameters, preferably with sufficient tolerance.

[0020] Furthermore, it is advantageous that the antenna is coated on its outside with an electrically conductive metallization and that the metallization of the antenna is connected to the electrical ground of the circuit board via the conductive frame.

[0021] This design ensures that the circuit board and the antenna are at the same ground potential and therefore do not require any further connections, soldering or other connection techniques.

[0022] Advantageously, at least one electronic component is mounted on the circuit board. This allows for a single circuit board to be used, as it houses both the electronic components for the transmitting and receiving circuits and simultaneously provides the antenna connection. This enables a cost-effective and space-saving design.

[0023] Further features, applications, and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, which are illustrated in the figures of the drawing. All described or illustrated features, individually or in any combination, constitute the subject matter of the invention, irrespective of their inclusion in the claims or their cross-references, and irrespective of their formulation or representation in the description or in the drawings. Drawings

[0024] Exemplary embodiments of the invention are explained below with reference to the drawings. The drawings show... Fig. 1 a perspective view of an exemplary embodiment of the frame, Fig. 2 a further, perspective view of an embodiment of a device according to the invention, comprising a circuit board, antenna and frame, Fig. 3 an exemplary embodiment of a detailed view of the spring tongues of the frame and the antenna, Fig. 4 a top view of an exemplary embodiment of the mounted frame on the circuit board with antenna and Fig. 5 A schematic side view of an exemplary embodiment in the assembled state. Description of exemplary implementations

[0025] In Fig. Figure 1 shows a frame 1 as it is installed as part of the radar sensor according to the invention. The frame 1 serves to permanently and over a flat area connect a waveguide antenna 7 to a circuit board 6. For this purpose, the illustrated frame 1, which is made, for example, from a sheet metal part, is used to mount the sensor. For this purpose, the frame 1 is, for example, punched out of sheet metal and then as shown in Figure 1. Fig. 1 is shown, bent so that a rectangular frame 1 with one or more recesses in the "lid area" and frame edges 2, advantageously four frame edges 2, is formed. The bent frame edges 2 give the frame 1 very high stability against bending of the entire frame 1.

[0026] Press-fit pins 3 are provided on several sides, advantageously three or four locations, of the frame. These press-fit pins 3 can, for example, be stamped out during the manufacturing process so that they are produced integrally with the frame 1. Alternatively, the press-fit pins 3 can be manufactured separately and welded or soldered to the frame 1 during a manufacturing step. The press-fit pins 3 are positioned such that they align the frame 1 with its central surface parallel to a printed circuit board 6 (in Fig. (1 not shown) can be fixed.

[0027] In one embodiment, in addition to the press-fit pins 3, press-fit stops 4 are provided. These press-fit stops 4 have a closing edge in the press-fit direction, which rests on the circuit board 6 when the desired press-fit depth of the press-fit pins 3 is reached, thus preventing further or deeper press-fit of the press-fit pins 3. This fixes the press-fit pins 3 at their optimally effective press-fit depth. The press-fit stops 4 do not necessarily have to be arranged near the press-fit pins 3; they can also be arranged at a distance from them.

[0028] According to another embodiment, spring tongues 5 can be provided on the frame 1. These spring tongues 5, depending on the chosen outer shape of the antenna 7 (waveguide antenna), can press the waveguide antenna 7 against the circuit board 6. The spring tongues 5 are then bent laterally within the elastic material limits by the counterforce of the waveguide antenna 6, so that the spring tongues 5 of the frame 1 generate a predetermined pressing force. These spring tongues 5 can, for example, be integrally formed on the upper surface of the frame 1 in the area of ​​the opening through which the waveguide antenna 7 radiates and receives.

[0029] In Fig. 2 is the frame made of Fig. Figure 1 shows a side view, depicting both the circuit board 6 and the waveguide antenna 7 with the frame 1 in their assembled state. The circuit board 6 is shown at the bottom, without any traces or soldered components. In reality, the circuit board 6 typically has traces, vias, and soldered components.

[0030] The antenna 7, which is designed here as a waveguide antenna, is mounted on the circuit board 6. A waveguide antenna consists of a material containing channels, which guide electromagnetic waves within the antenna. The dimensions of the channels must be manufactured with high precision, otherwise the frequency of the guided electromagnetic waves will be altered. Metal is most commonly chosen as the material for the waveguide antenna 7. However, it is also possible to use a different conductive material or to manufacture the antenna from a non-conductive material such as plastic coated with a metallization layer, ensuring that at least the surfaces of the waveguide channels are metallized.

[0031] The waveguide antenna 7 and the circuit board 6 are placed on top of each other so that they touch, in particular over their entire surface. However, these two parts are not soldered or glued together, but are held permanently connected by the frame 1.

[0032] For this purpose, frame 1 is placed onto the waveguide antenna 7, and the press-fit pins 3 of frame 1 are pressed into the corresponding holes in the circuit board 6. Pressing in the press-fit pins 3 presses the waveguide antenna 7 onto the circuit board 6 and holds it there permanently. The press-fit stops 4 ensure that the press-fit pins 3 of frame 1 are not pressed too deeply or not deeply enough into the holes of the circuit board 6. The press-fit stops 4 on frame 1 allow the press-fit pins 3 to be pressed in with excess force, and when the press-fit stops 4 are placed on the circuit board 6, it is ensured that the correct press-fit depth has been achieved.

[0033] Furthermore, spring tongues 5 can be provided in the upper area of ​​the frame 1, which rest on suitable edges of the waveguide antenna 7. Pressing the frame into place and the waveguide antenna 7 resting on the circuit board 6 elastically deforms the spring tongues 5 resting on the waveguide antenna 7, resulting in a spring force. This deformation of the spring tongues 5 occurs as follows: Fig. As can be seen in Figure 2, the spring tongues 5 are bent upwards, thereby exerting a permanent and predefined force on the waveguide antenna 7, which presses the waveguide antenna 7 onto the circuit board 6. This causes the spring tongues 5 to bend beyond the plane defined by the edges 2 of the frame 1. Lateral slippage of the waveguide antennas 7 on the circuit board 6 is not possible in the claimed design, since the frame is positively locked against slippage parallel to the circuit board 6 by the press-fit pins 3 pressed into the circuit board 6 and cannot be moved without damage.

[0034] The waveguide antenna 7 may have recesses into which the ends of the spring tongues 5 fit exactly, thus preventing any displacement of the waveguide antenna 7 relative to the frame 1.

[0035] The frame 1 is open at least at one point in its center, allowing electromagnetic radiation emitted or received by the waveguide antenna 7 to pass through unimpeded. Depending on the embodiment of the waveguide antenna 7, a portion of the antenna block may protrude through this opening. The antenna openings 8 of the waveguide antenna 7, often also called antenna apertures 8, are shown on the top surface of the waveguide antenna 7, and the frame 1 is designed such that it does not impair the transmitting or receiving performance.

[0036] In Fig. Figure 3 shows a further embodiment of the arrangement according to the invention. Again, the printed circuit board 6 is shown, which may have conductor tracks and components (not shown). A waveguide antenna 7 rests on the printed circuit board 6. The contact area of ​​the waveguide antenna 7 can be the entire underside, or alternatively, only a small part or several small parts of the underside of the waveguide antenna 7 can be configured as contact areas 16. For example, it is advantageous to configure only those parts of the underside of the waveguide antenna 7 as contact areas 16 in which the transitions are located, through which the electromagnetic signals are coupled from the printed circuit board 6 into the waveguide antenna 7 or vice versa.This variant, in which only parts of the underside of the waveguide antenna 7 are provided as contact surfaces 16, has the advantage that the contact area 16, which is only present around the areas of the coupling structures, experiences even greater pressing forces and thus a possible air gap between circuit board 6 and waveguide antenna 7 (as may result from thermal stress, for example) can be avoided even more effectively.

[0037] In the left part of the Fig. Figure 3 shows the frame 1, which, with its molded-on press-fit pins 3, was pressed into holes in the circuit board 6. At the upper left edge of the frame 1, the bending edge 2 of the frame can be seen, where the vertical part with the press-fit pins 3 transitions into the flat, upper area of ​​the frame 1 ("cover area"). This upper cover area of ​​the frame 1 has at least one opening through which the top of the waveguide antenna 7 protrudes, allowing the electromagnetic signals of the waveguide antenna 7 to be radiated and received. In this area of ​​the Fig. Figure 3 shows the side area of ​​frame 1 that lies outside the depicted section plane with a dashed line.

[0038] Furthermore, the waveguide antenna 7 is shown, which often consists of two partial shells that have been assembled. A contact surface 12 is shown on the upper half of the waveguide antenna 7, on which the spring tongue 5 of the frame 1 rests. This contact surface 12 of the waveguide antenna 7 can be described as a raised form, as in Fig. 2 shown, be formed, or alternatively, be designed as a recess or trough formed in the outer contour of the waveguide antenna 7 in the area of ​​the upper edge of the waveguide antenna 7. In the illustrated variation, the spring tongue 5 rests on this contact surface 12 of the molding and bends in the area of ​​elastic deformation of the spring tongue 5, as shown. Through this elastic deformation, the spring tongues 5 exert a pressing force that acts on the waveguide antenna 7 and presses the waveguide antenna 7 perpendicularly and permanently onto the circuit board 6.

[0039] Another embodiment is shown in the center of the image. Fig. Figure 3 shows a centering element 9. This can be formed in one piece on the underside of the waveguide antenna 7 and, for example, have a diameter that fits precisely into a hole 11 in the circuit board 6, which serves as a centering hole. The hole 11 in the circuit board 6 can be designed to fit the centering element 9, so that even with only a slight pressing force of the waveguide antenna 7 onto the circuit board 6, these two parts cannot slip relative to each other.

[0040] In Fig. Figure 4 shows a further embodiment variant in which the frame has not just one recess on its upper side (cover side) but several, for example, two recesses. The circuit board 6 is again shown, which may have conductor tracks and components not shown. The frame 1, which is shown in the drawing of the Fig. The frame 1 is diagonally hatched. The frame 1 secures the waveguide antenna 7 by means of the four spring tongues 5 shown and presses it onto the circuit board 6. The antenna apertures 8, arranged, for example, in antenna groups, are shown on the top side of the waveguide antenna 7. If the arrangement of the antenna apertures 8 allows, it is possible to modify the frame 1 so that it has a spring bar 13 that divides the opening of the frame 1 on the "cover side" into two partial openings. Due to the spring bar 13 dividing the opening in the frame 1, the frame 1 has greater rigidity and twists less under load. A further advantage is that the center of the spring bar 13 can exert an elastic pressure on the center of the waveguide antenna 7, thereby supporting the spring tongues 5 and distributing the pressing forces 15 more evenly over the waveguide antenna 7.For example, in this design the spring tongues 5 at the edge of the frame 1 can even be completely omitted.

[0041] To increase the effect of this central pressing force 15 by the spring beam 13 of the frame 1, a further variation is provided in Fig. 5 shown. Fig. Figure 5 shows the circuit board 6 and the waveguide antenna 7. The waveguide antenna 7 rests on the circuit board 6 with one or more contact areas 16. It is also possible for the waveguide antenna 7 to rest flat on the circuit board 6. The waveguide antenna 7 is fixed by the frame 1, which is pressed into holes in the circuit board 6 using the press-fit pins 3 at its edge. The frame 1 has one or more openings on its upper side through which the antenna apertures 8 can emit and receive electromagnetic radiation.

[0042] To apply the clamping force 15 to the waveguide antenna 7 at specific points, or to increase the clamping force through the frame 1, lens-shaped protrusions 14 or pressure pads 14 can be attached to the upper side of the waveguide antenna 7, i.e., in the area of ​​the spring bar(s) 13. This pressure pad 14 lies beneath the spring bar 13, so that the elastically yielding spring bar 13 of the frame 1 exerts a clamping force on the lens-shaped pressure pad 14, and the clamping force 15 of the waveguide antenna 7 can be applied with high precision.

[0043] In Fig.In Figure 5, the individual parts – circuit board 6, waveguide antenna 7, frame 1 – were shown in such a way that they do not touch each other, as they are depicted in an exploded view. In the assembled state, the waveguide antenna 7 rests on the circuit board 6, and the frame 1 presses down on the pressure ball 14 with its spring bar 13, causing the spring bar 13 to deform and exert a pressing force 15 on the pressure ball 14.

Claims

[1] radar sensor (10), in particular for use in a vehicle, comprising - at least one printed circuit board (6), - at least one antenna (7), which is in particular designed as a waveguide antenna, wherein the antenna (7) is connected to the circuit board (6), characterized by , that the connection between the circuit board (6) and the antenna (7) is made by means of a frame (1), which is attached to the circuit board (6) and which presses the antenna (7) onto the circuit board (6). [2] Radar sensor (10) according to claim 1, characterized by that the antenna (7) rests on the circuit board (6). [3] Radar sensor (10) according to claim 1 or 2, characterized by that the antenna (7) lies flat on the circuit board (6) or is pressed flat onto it. [4] Radar sensor (10) according to any one of the preceding claims, characterized by, that the frame (1) rests on the antenna (7) mainly at the outer edges (12) of the antenna (7). [5] Radar sensor (10) according to any one of the preceding claims, characterized by , that the antenna (7) is permanently fixed to the circuit board (6) only by the force-fit of the frame (1). [6] Radar sensor (10) according to any one of the preceding claims, characterized by , that the frame (1) was made of sheet metal, in particular as a metallic stamped part and / or bent part. [7] Radar sensor (10) according to any of the preceding claims, characterized by , that the frame (1) has several press-fit pins (3) on the side facing the circuit board (6) which are pressed into holes in the circuit board (6), in particular that the press-fit pins (3) are integrally formed with the frame (1). [8] Radar sensor (10) according to any one of the preceding claims, characterized by, that the frame (1) has mechanical stops (4) on the side facing the circuit board (6) which prevent the press-in pins (3) from being pressed too deeply into the circuit board (6). [9] Radar sensor (10) according to any of the preceding claims, characterized by , that the frame (1) on the side facing away from the circuit board (6) (transmitting and receiving side of the sensor (10)) has recesses at the locations where the antenna has transmitting and receiving openings (8). [10] Radar sensor (10) according to any of the preceding claims, characterized by , that the frame (1) has spring tongues (5) on the side facing away from the circuit board (6) which rest on the side of the antenna (7) facing away from the circuit board (6) and press the antenna (7) onto the circuit board. [11] Radar sensor (10) according to any of the preceding claims, characterized by, that the antenna (7) has contact surfaces (12) at its edges on which the spring tongues (12) of the frame (1) rest and via which the contact force is exerted on the antenna (7). [12] Radar sensor (10) according to any of the preceding claims, characterized by , that the holding force of all press-in pins (3) is significantly greater than the pressing force of all spring tongues (5), in particular that the holding force of the press-in pins (3) is 2 times to 10 times, in particular 3 times to 5 times greater than the spring force of the spring tongues (5). [13] Radar sensor (10) according to any of the preceding claims, characterized by , that the antenna (7) has centering bodies (9) on the side facing the circuit board (6) which are formed on the contact surface to the circuit board (6) so that these centering bodies (9) engage in holes (11) of the circuit board (6) and ensure the relative positioning of the antenna (7) to the circuit board (6). [14] Radar sensor (10) according to any of the preceding claims, characterized by , that the antenna (7) is coated on its outside with an electrically conductive metallization and the metallization of the antenna (7) is connected to the electrical ground of the circuit board (6) via the conductive frame 1. [15] Radar sensor (10) according to any of the preceding claims, characterized by , that at least one electronic component (17) is mounted on the circuit board (6).

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