Radar sensor with absorber and a method for installing the absorber

Abstract

A radar sensor for emitting and/or receiving wave-shaped electromagnetic signals, having at least one housing and at least one absorber. The absorber is disposed inside the housing and a surface of the absorber has raised rib-like sections which are disposed adjacently to one another on the surface of the absorber. The absorber is an injection molded component.

Claims

1. A radar sensor for emitting and/or receiving wave-shaped electromagnetic signals comprising: at least one housing and at least one absorber, wherein the absorber is disposed inside the housing, wherein a surface of the absorber has raised, rib-like sections that are disposed adjacent to one another on the surface of the absorber to form a herringbone pattern, wherein the absorber is an injection molded component, and wherein the absorber is formed as a plate-shaped element and exhibits a variable thickness along the plate-shaped element.

2. The radar sensor according to claim 1, wherein the radar sensor has a receiving area, which is bordered by an at least partially encompassing border region, wherein the absorber can be placed in the receiving area such that it fits precisely therein.

3. The radar sensor according to claim 1 wherein the raised rib-like sections form a wave-shaped pattern on the surface of the absorber, wherein the wave height between wave peaks and wave troughs disposed adjacently to one another is variable along the course of the pattern.

4. The radar sensor according to claim 3 wherein the wave-shaped pattern has straight raised rib-like sections, which run parallel to one another.

5. The radar sensor according to claim 1 the raised rib-like sections rise from said plate-shaped element in a direction along a surface normal on the plate-shaped element.

6. The radar sensor according to claim 2 wherein the absorber and/or the receiving area exhibits a spacer, wherein the absorber can be positioned in relation to the receiving area by the spacer along an insertion direction and/or a direction transverse to the insertion direction.

7. The radar sensor according to claim 1 wherein the absorber is designed for the absorption of high-frequency waves, wherein high-frequency waves have a frequency of 10 GHz or more.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.

(2) FIG. 1 shows a view of a housing for a radar sensor, as known from the prior art, wherein a self-adhesive absorber is disposed in the housing, wherein the absorber is cut from a standard material in the form of a mat,

(3) FIG. 2 shows a view of three different absorbers, wherein the absorbers are designed as injection molded components, and have a rib-like structure on one surface, wherein an absorber with straight raised rib-like sections, which are disposed parallel to one another, is shown on the left, and an absorber with raised rib-like sections, which form a herringbone pattern, is shown in the middle, and an absorber having additional regions of different thicknesses is shown on the right,

(4) FIG. 3 shows a view of a housing for a radar sensor, wherein a receiving area is formed, which is bordered by an encompassing edge,

(5) FIG. 4 shows another view of the housing according to FIG. 3, wherein an absorber corresponding to that in FIG. 2 is inserted in the receiving area, and

(6) FIG. 5 shows a sectional view, cut through the housing, with an absorber according to FIG. 4 inserted therein, wherein the absorber is spaced apart from the housing by at least one spacer.

DETAILED DESCRIPTION OF THE DRAWINGS

(7) FIG. 1 shows a view of a radar sensor 1 as it is used in the prior art. The radar sensor 1 has, aside from a not shown sensor unit, in particular, a housing 2, which closes the radar sensor 1 to the exterior.

(8) The housing 2 has, furthermore, numerous receiving areas 5, in which an individual absorber 3, 4, respectively, is inserted. Absorbers 3, 4 are placed in each of the two left receiving areas 5, which are preferably formed by self-adhesive foam mats. The shown absorbers 3, 4 are normally cut manually thereby from mat elements, which are produced from standard materials. The absorbers 3, 4 are self-adhesive in the solutions in the prior art, and can be inserted in the respective receiving areas thereby.

(9) The receiving areas 5 are each bordered by edges 6 in the directions transverse to the direction of insertion. The absorbers 3, 4 are normally cut to fit precisely to the contours of the receiving areas 5. The radar sensor 1 shown in FIG. 1 corresponds to the typical construction for radar sensors in the prior art. The absorbers 3, 4 are disposed on an exterior surface of the radar sensor 1 thereby.

(10) In alternative known embodiments, instead of using the absorbers made of foam, absorber films can also be used, which are self-adhesive, and bonded to the housing for the radar sensors.

(11) FIG. 2 shows, in each case, three views disposed next to one another, of an absorber 10. The absorber 10 is designed as an injection molded component thereby, and already adapted to its final shape, accordingly, in the production thereof. This means that both the outer contours of the absorber 10 as well as the surface structure, as well as the thickness of the absorber 10, including the possible height profiles 10, are already defined in the production process.

(12) The three absorbers 10, disposed adjacent to one another, are each formed by a plate-like element, the two main directions of extension thereof being in one plane. The third direction of extension for the absorber 10 forms the thickness thereof, which is smaller in comparison with the two other main directions of extension. The absorbers 10 have numerous straight exterior edges, and numerous curved cut-outs. The outer contour of the absorber 10 is adapted thereby, in particular, to the geometry of the respective receiving area on the radar sensor in which the absorber 10 is inserted.

(13) The left absorber 10 has numerous raised rib-like sections 11, which form straight structures disposed parallel to one another. In this manner, a rib structure is formed on the surface of the absorber 10, in which, in particular in its spacing of the individual raised sections 11 to one another, the height of the raised sections 11 as well as the width of the raised sections 11 are adapted specifically to the respective interference signals that are to be absorbed, which are present in a wave-shaped form.

(14) By means of a simple adjustment of the production process, the absorber can thus be adapted to different interference signals with little effort, and furthermore, can be adapted to different receiving areas inside the radar sensors. The absorbers 10 shown in FIG. 2 are provided, in particular, for use inside the housing of a radar sensor, in order to absorb the interference signals, in particular in the region of the sensor unit.

(15) The middle absorber 10 has, in differing from the absorber 10 depicted on the left, raised rib-like sections 12, which form a rib-like herringbone pattern along the surface of the absorber 10. The individual raised rib-like sections 12 are likewise disposed adjacent to one another such that they are parallel, by means of which a wave structure is generated on the surface of the absorber 10. As with the left embodiment example of the absorber 10, the height, thickness, and spacing of the raised rib-like sections 12 can be varied in relation to one another, in order to absorb specific frequencies of the interference signals in a targeted manner.

(16) Another depiction of an absorber 10 is shown in the right portion of FIG. 2. This likewise has raised rib-like sections 12 on its surface, which, like the absorber 10 in the central region, form a herringbone pattern. Furthermore, the absorber 10 has a region having a smaller thickness 13 at the upper right end region.

(17) The right portion of FIG. 2 shows an embodiment example having a specifically adapted geometry of the absorber 10. The region having a smaller thickness 13 is separated thereby, by a sharp-edged stepped course, from the remaining region of the absorber 10. In alternative embodiments, continuous thickness increases and thickness decreases can also be provided. Likewise, a change in the uniform rib structure can be provided along the surface of the absorber. In this manner, by way of example, differently shaped rib-like structures can also be provided, for example, in circular configurations, or in wave-shaped configurations.

(18) The absorbers in FIG. 2 form, in particular with regard to the outer contour of the respective absorber 10, an exemplary design, and furthermore, do not limit the shape of the absorber 10.

(19) FIG. 3 shows a view of a radar sensor 20 with a housing 21. The housing 21 has numerous receiving areas 22, in each of which absorbers can be inserted, as described in reference to the preceding figures. The lower right receiving area 22 has, by way of example, a spacer 23, which serves to space the absorber apart from the flat floor region of the receiving area 22. The spacer 23 ensures thereby, in particular, that a defined spacing between the housing 21 and the absorber is maintained in the final installation state, by means of which, in particular, the adhesive layer, which is applied to the back surface of the absorber for installation purposes, is of a defined thickness.

(20) The receiving area 22 is bordered in the directions transverse to the insertion direction by an encompassing edge 24. Preferably, the absorber is precisely adapted to the shape of the receiving area 22, with only very small tolerances. This should prevent, in particular, the formation of appreciable gaps between the absorber and the edge 23, which would reduce the absorption properties on the whole.

(21) As can be seen in FIG. 3, the receiving area 22 has a specific outer contour, which has, by way of example, sections for threads provided in the housing 21, by means of which, in particular, the absorber must likewise have an outer contour adapted thereto, in order to be able to be precisely inserted into the receiving area.

(22) FIG. 4 shows a view of the housing 21 for the radar sensor 20, wherein an absorber 25 is inserted in the receiving area 22 thereof. The absorber corresponds thereby, substantially, to the absorbers 10 already shown in FIG. 2. Because of the precise shape of the absorber 25, it can be inserted in the receiving area 21 such that it is flush with the edge 24.

(23) FIG. 5 shows a view of a housing 21 having an absorber 25 inserted therein, in the right region of the figure. In the left region, a sectional view is shown, cut through the absorber 25 and the housing 21. In the lower left region, in which the floor region of the receiving area 22 transitions into the border region 24, a spacer 27 is provided in FIG. 5, which generates a spacing of the absorber 25 to the housing 21. The spacer 27 serves, like the spacer 23 shown in FIG. 3, to generate a defined spacing between the absorber 25 and the housing 21. This serves, in particular, to ensure that the adhesive layer, which is applied to the back surface of the absorber prior to its insertion, maintains a defined thickness, and thus, that a positive adhesion is obtained to the greatest possible extent.

(24) The gaps between the absorber 25 and the border region 24 are preferably as small as possible, in order to avoid interferences. For this, in particular, the production of the absorber 25 as an injection molded component is advantageous, because very precise designs and low tolerances can be obtained in injection molding processes. Furthermore, in injection molding processes, in particular, numerous different materials can be used. This allows for an adaptation, in particular, of the absorber 25 to the respective specific required absorption properties.

(25) The embodiment examples shown in FIGS. 2 to 5 are only exemplary, in particular with regard to the material selection, the geometric design, as well as the configuration of the individual elements in relation to one another. Thus, they have no limiting characteristic in this regard.

LIST OF REFERENCE SYMBOLS

(26) 01 radar sensor 02 housing 03 absorber made of foam 04 absorber made of foam 05 receiving area 06 border 10 absorber as an injection molded component 11 raised section/rib-like section 12 raised section/rib-like section 13 region having smaller thickness 20 radar sensor 21 housing 22 receiving area 23 spacer 24 border region 25 absorber as an injection molded component 26 raised section/rib-like section 27 spacer