Radar sensor

Abstract

A radar sensor includes a layer including at least one active region and at least one passive region. The active region includes a plurality of antenna elements configured to transmit and receive radar waves, and the passive region is free of antenna elements. The passive region is provided with a diffraction grating surface.

Description

Technical Field

[0001] The present disclosure relates to a radar sensor, which may be an automotive radar sensor mounted on a vehicle. Background Art

[0002] The internal components of an automotive radar sensor are typically housed in a sensor housing, topped by a fairing. The housing and fairing enclose and protect the internal sensor components from environmental factors such as dust, moisture, corrosion, rust, and mechanical damage. For aerodynamic and aesthetic reasons, automotive radar sensors are often integrated into or hidden behind other vehicle components, i.e., behind the vehicle's exterior. Such components can include bumpers, facias, and vehicle logos.

[0003] For example, if another vehicle component is placed in front of the antenna of an automotive radar sensor, the performance of the radar sensor will be degraded relative to its ideal performance. This can be due to the fact that placing the radar sensor behind the vehicle component will cause interference and undesirable effects, including fairing insertion and transmission loss, boresight error, antenna mainlobe ripple, radar sensor beamwidth and field of view reduction, increased sidelobe levels, depolarization effects, etc. Therefore, the design and integration of the fairing is a critical and challenging task in automotive radar technology.

[0004] Even if the fairing of the radar sensor is well designed and integrated into the vehicle, most of the aforementioned interference effects may still remain, for example due to destructive interference caused by specular multiple reflections between the radar sensor's flat metallic surfaces and vehicle components. These metallic surfaces may have a high reflectivity for radar waves and may be present within the radar sensor, at the antenna plate and / or the top surface of the fairing, and additionally at other vehicle components, such as the vehicle's bumper or front fascia.

[0005] If the radar sensor uses metal waveguide antenna technology, such as air waveguide (AWG), ridge gap waveguide (RGW), or slotted waveguide (GGW), then reflections between the radar sensor's metal surfaces must also be considered. Metal waveguide antenna technology often suffers from a significant structural radar cross section (RCS) due to the presence of highly reflective flat metal surfaces in such radar sensors.

[0006] To overcome these interference effects, known radar sensors can be equipped with highly dissipative dielectric materials as an absorbing layer, for example, on top of the antenna plate. This material provides good isolation between antenna elements and effectively absorbs surface waves and multiple reflections. However, the use of such absorbing materials leads to high radar sensor costs.

[0007] Therefore, there is a need for a radar sensor that can mitigate interference effects when the radar sensor is mounted behind or adjacent to another component of a vehicle. Summary of the Invention

[0008] The present disclosure provides a radar sensor and a vehicle according to the independent claims. Embodiments are given in the dependent claims, the description and the drawings.

[0009] In one aspect, the present disclosure relates to a radar sensor comprising a layer including at least one active region and at least one passive region. The active region includes a plurality of antenna elements configured to transmit and receive radar waves, and the passive region is devoid of antenna elements. The passive region is provided with a diffraction grating surface.

[0010] The radar sensor may include various layers, including, for example, a layer or board for electronic components such as an MMIC (monolithic microwave integrated circuit), a layer forming a bottom cover for the antenna, a layer forming a top cover for the antenna, and a layer forming a fairing. A passive region may be located within the layer forming the top cover for the antenna, the passive region including a diffraction grating surface.

[0011] The active region may contain only the antenna element without any other items, such as a structure containing corrugations as described below. In other words, the layer of the radar sensor may contain only the antenna element and a surface configured as a diffraction grating.

[0012] Thanks to the diffraction grating surface, the contribution of specular multiple reflections can be scattered away from the radar cone corresponding to the radar sensor's field of view. In addition, such a diffraction grating surface can have the ability to adjust and optimize the diffraction pattern of the radar waves with respect to its heat dissipation pattern.

[0013] Due to the diffraction of reflected radar waves in the passive zone, specular reflections are reduced, and the concentration of reflected energy at the boresight is reduced. As a result, the radar cross section of the structure in the boresight direction is reduced due to the higher diffraction modes being deviated from the radar sensor's field of view. In addition, the radar sensor does not need to use different expensive materials (for example, for absorbers), resulting in an extremely cost-effective design.

[0014] In summary, the diffraction grating surface in the passive region reduces interference effects on the radar sensor's performance. Consequently, the radar sensor's angular measurement performance is improved, and coverage can be improved in both azimuth and elevation. This also applies if the radar sensor operates at different frequencies, such as within the entire bandwidth of 76 to 81 GHz currently used in automotive radar sensors, as well as at frequencies exceeding 100 GHz, such as in the frequency band around 120 GHz associated with advanced automotive radar sensors.

[0015] According to one embodiment, a diffraction grating surface may include a surface profile in which the maxima and minima of the surface profile are periodically arranged. For example, the periodic structure may extend in two directions perpendicular to each other. This surface profile with periodically arranged maxima and minima can function as a diffraction grating, scattering radar wave reflections generated by multiple effects outside the area corresponding to the radar sensor's instrument field of view. A surface structure including periodic maxima and minima can be manufactured at low cost. Alternatively, the passive region may include a flat surface, which may be provided with an internal structure functioning as a diffraction grating.

[0016] The periodicity of the highest and lowest points of the surface profile may be adapted to at least two diffraction modes of radar waves, such that radar waves associated with the at least two diffraction modes may be scattered outside a predetermined field of view of the radar sensor. The predetermined field of view of the radar sensor may be related to an instrumented field of view or instrumented field of view, which may be defined by a specific range of azimuth and elevation angles relative to a boresight direction of the radar sensor.

[0017] The periodicity of the highest and lowest points can be related to one or both dimensions or directions of the surface profile. If the surface profile is sinusoidal for both directions, the periodicity can be expressed in terms of the sine or cosine frequencies that define the surface profile in the corresponding perpendicular directions.

[0018] For example, if the surface profile is formed as a one-dimensional grating, that is, having a periodic structure along only one axis, then in addition to zero-order specular reflection, there are first-order positive and negative diffraction modes. Therefore, the periodicity of the one-dimensional grating can be configured so that radar waves from the two first-order diffraction modes are scattered outside the radar sensor's field of view. As a second example, if the surface profile is formed as a two-dimensional grating with a periodic structure along two perpendicular axes, there are four first-order diffraction modes. In this case, the periodicity of the two-dimensional grating can be configured in two directions so that radar waves from the four first-order diffraction modes are scattered outside the radar sensor's field of view.

[0019] Therefore, by appropriately adjusting the periodicity of the highest and lowest points within the surface profile, a desired number of diffraction patterns of radar waves can be scattered outside the radar sensor's field of view. Specifically, the diffraction angle of a corresponding diffraction pattern can be directly influenced by the corresponding periodicity along at least one of the directions. Thus, the effect of the cross-grating profile on the energy of the incident wave and on mitigating the effects of specular multiple reflections can be controlled and optimized. Furthermore, the distance between the highest and lowest points, i.e., the height of the surface profile, can determine or define the power or energy distribution in different diffraction patterns.

[0020] The highest and lowest points of the surface profile can have the same periodicity in two perpendicular directions. In other words, the surface profile can be symmetrical about the two perpendicular directions. For such a surface profile, the scattering behavior of the passive region can be independent of the polarization of the radar wave. Therefore, a passive region with the same periodicity for the highest and lowest points in two perpendicular directions is suitable for dual-polarization radar sensors that use two different polarization modes.

[0021] Alternatively, the highest and lowest points of the surface profile can have different periodicities for two perpendicular directions. This configuration of the passive region surface profile may be relevant for automotive radars that have a wider field of view in azimuth than in elevation. For this configuration, the periodicity along one axis can be increased, while the periodicity along the perpendicular axis can be decreased, compared to the symmetrical surface profile described above.

[0022] Because the periodicity of the maxima and nadirs along two perpendicular directions or axes differs, more diffraction modes can be excited, for example, in azimuth, for which the automotive radar can have a wider field of view. This results in a better distribution of scattered energy outside the radar cone or field of view, which can enhance the suppression of specular reflections. This concept is applicable to applications using a single polarization.

[0023] Furthermore, the surface profile may be sinusoidal for two directions perpendicular to each other. This is true for symmetrical surface profiles as well as for asymmetrical surface profiles, ie for surface profiles with the same periodicity of highest and lowest points in two perpendicular directions as well as for surface profiles with different periodicities.

[0024] According to another embodiment, a corresponding dual-purpose structure may be associated with each antenna element of the active region, wherein each dual-purpose structure may be configured to isolate the associated antenna element from the other radar elements with respect to transmitted and received radar waves. Simultaneously, each dual-purpose structure may be configured to suppress and deflect reflections of incident radar waves (i.e., reflections that reach the dual-purpose structure).

[0025] Within the layer forming the antenna roof, a corresponding dual-purpose structure associated with one of the antenna elements can be arranged, for example, on either side of the corresponding antenna element. The dual-purpose structure can include elements capable of preventing surface waves from propagating across the corresponding structure. By appropriately arranging the structure between the antenna elements, the dual-purpose structure can isolate the associated antenna element from the other antenna elements with respect to radar wave propagation between the antenna elements. Consequently, interference effects between the antenna elements can be reduced or avoided.

[0026] At the same time, the elements of the dual-purpose structure can suppress and deflect reflections of incoming radar waves, which can be caused, for example, by multiple effects. Incoming radar waves can be suppressed by deflecting them and / or by canceling back-reflected radar waves caused by destructive interference (also known as "180° phase cancellation"). For example, radar waves reaching the dual-purpose structure can be deflected out of the spatial region corresponding to the radar sensor's field of view, and these waves can also be suppressed by destructive interference. This measure allows the dual-purpose structure to reduce its radar cross section in the boresight direction.

[0027] Each dual-purpose structure may include a corresponding set of corrugations, and each corrugation may include protrusions and depressions. Each set of corrugations may include at least one angled corrugation, and the angled corrugation may include at least one portion extending in a direction different from the predetermined arrangement direction of the associated antenna elements.

[0028] Because each set of corrugations can include at least one angled corrugation, specular reflections can be reduced, further lowering the concentration of reflected energy at the boresight axis. Furthermore, a corresponding set of corrugations associated with one antenna element can be arranged on either side of the corresponding antenna element within the layer forming the antenna cap. This creates an air waveguide that isolates the corresponding antenna element from other antenna elements within the active area.

[0029] According to a further embodiment, a corresponding set of corrugations can be at least partially covered by a dielectric layer. For example, a material with a dielectric constant greater than that of air can be placed on top of the corrugations. As a result, the operating wavelength of radar waves within the dielectric layer can be smaller than the "free space" wavelength in air. Consequently, the depth between protrusions and depressions, as well as the distance between adjacent protrusions and depressions, can be reduced. This can lead to a more compact design for the entire radar sensor. Furthermore, some of the energy of the incident radar wave can be dissipated within the dielectric layer, further reducing the radar cross section of the structure.

[0030] A pair of protrusions on the corrugated portion adjacent to a corresponding antenna element can extend parallel to the predetermined alignment direction of the corresponding antenna element. In other words, the first two corrugated portions around each antenna element can have protrusions extending parallel to or straight along the corresponding antenna element. This allows for achieving and maintaining isolation between the antenna elements in the active area while simultaneously reducing the overall layer's structural radar cross section.

[0031] At least one angled corrugated portion may include two side portions that are arranged at opposing angles greater than zero relative to the predetermined alignment direction of the associated antenna elements. One of the opposing angles may be positive, while the other may be negative, relative to the predetermined alignment direction of the associated antenna elements. In other words, the side portions may be inclined toward the same side relative to the alignment direction. The opposing angles may have the same magnitude or absolute value.

[0032] The two side portions are angled or tilted relative to the arrangement direction of the antenna elements, which can reduce the contribution of specular multiple reflections to the detected radar signal of the radar sensor because the specular multiple reflections are deflected out of the boresight direction by the angled or tilted side portions of the angled corrugation portion.

[0033] At least one of the angled corrugated portions may further include a central portion extending parallel to the predetermined alignment direction of the associated antenna element, such that the side portions may extend from respective ends of the central portion. Because the central portion extends along the associated antenna element, the corresponding antenna element may be properly isolated from one or more adjacent antenna elements. However, the side portions may alternatively be directly connected to one another without a central portion therebetween.

[0034] Within each side of at least one angled corrugation, corresponding protrusions and corresponding depressions may extend parallel to one another. More than one angled corrugation with such parallel protrusions and depressions may be arranged adjacent to one another, and all groups of corrugations may include such angled corrugations with parallel protrusions and depressions. The protrusions and depressions within the sides of the angled corrugations may be provided with consistent inclination angles. Due to the consistent inclination, reflections from the outer edges of the corrugations can be directly deflected. Furthermore, the structural radar cross section of the radar sensor can be reduced by destructive interference of radar waves between such angled corrugations.

[0035] Alternatively, within each side of at least one angled corrugation, corresponding protrusions and corresponding recesses may be arranged at opposite angles. Again, one or more angled corrugations having such protrusions and recesses arranged at opposite angles may be adjacent to each other, and within each set of corrugations associated with a corresponding antenna element, there may be angled corrugations having protrusions and recesses at opposite angles on its sides. The opposing angles of inclination of the corresponding protrusions and recesses may have the same magnitude or absolute value. Furthermore, due to the opposing angles of inclination, the ends of the protrusions and recesses on the corresponding sides may be connected. Due to the opposing angles of the protrusions and recesses within the side, backreflections of radar waves may be destructively canceled.

[0036] Furthermore, the height of a protrusion relative to an adjacent depression (i.e., its maximum height when tilted at opposite angles) can be equal to one-quarter the wavelength of the radar wave transmitted by the corresponding antenna element (i.e., the operating wavelength), with a height tolerance of one-sixteenth the wavelength. This allows for phase cancellation of radar waves reaching the dual-use structure, reducing the structure's radar cross-section. Furthermore, isolation requirements can be fully met or maintained along each antenna element.

[0037] The corresponding set of corrugations can further comprise a metallic antenna waveguide structure for the associated antenna element. Due to the metallic structure, expensive dielectric materials, such as absorber layers, are not required. Consequently, the layers of the radar sensor are compatible with cost-effective die-casting production techniques. However, as mentioned above, a dielectric layer can also be positioned on top of the corrugations to enhance the dissipation of incident radar waves. The set of corrugations can be considered an air waveguide (AWG). However, the concept of angled corrugations is also applicable to radar sensors using ridge gap waveguide (RGW) and / or slot gap waveguide (GGW) technology.

[0038] According to a further embodiment, a corresponding set of corrugations may be associated with each antenna element in the active area, and at least one set of corrugations may include at least one angled corrugation, for which the protrusions and recesses of the corresponding side portions of the angled corrugation may be arranged at opposite angles, and at the same time, the passive area may be provided with a surface profile, in which the highest points and the lowest points of the surface profile may have the same periodicity with respect to two directions perpendicular to each other.

[0039] As an alternative, a corresponding set of corrugations may be associated with each antenna element in the active area, and at least one set of corrugations may include at least one angled corrugation, for which the protrusions and recesses of the corresponding sides of the angled corrugations may extend parallel to each other, and at the same time, the passive area may be provided with a surface profile in which the highest points and the lowest points of the surface profile may have different periodicities with respect to two directions perpendicular to each other.

[0040] With this configuration, the active and passive regions can synergistically contribute to mitigating specular multi-reflection effects (e.g., between the antenna plate or antenna layer and the fairing of the radar sensor, and, if the radar sensor is installed in a vehicle, between the radar sensor itself and other vehicle components, such as the front fascia or bumper). Due to this synergistic effect in mitigating interference effects, the structural radar cross section can be significantly reduced in the direction of the radar sensor's boresight.

[0041] In another aspect, the present disclosure relates to a vehicle comprising a vehicle component and a radar sensor as described above, wherein the radar sensor is arranged near the vehicle component. The vehicle component may be, for example, a front face, a bumper, or a vehicle logo. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Exemplary embodiments and functionality of the present disclosure are described herein in conjunction with the following drawings, which schematically illustrate:

[0043] Figure 1A and Figure 1B shows a radar sensor installed in a vehicle;

[0044] Figure 2 for Figure 1A and Figure 1B An exploded view of the radar sensor is shown;

[0045] Figures 3A to 3C Show Figure 1A 、 Figure 1B and Figure 2 Details of the radar sensor shown;

[0046] Figures 4A to 4D An embodiment of a radar sensor is shown, which includes a corrugation in an active region of an antenna layer;

[0047] 5A to 5D Another embodiment of a radar sensor is shown, which includes a corrugation in the active region of the antenna layer;

[0048] Figure 6 The corrugated portion is shown covered by a dielectric layer;

[0049] Figure 7 Another embodiment of a radar sensor is shown, comprising a sinusoidal surface profile in a passive region of an antenna layer;

[0050] Figure 8 shows the configuration of a sinusoidal surface profile and its diffraction characteristics for radar waves; and

[0051] Figure 9 Another configuration of a sinusoidal surface profile and its diffraction characteristics for radar waves is shown. DETAILED DESCRIPTION

[0052] Figure 1A Radar sensor 100 is schematically depicted as being mounted in vehicle 110 behind a vehicle component 120, such as a bumper or fascia of vehicle 110. Automotive radar sensors, such as radar sensor 100, are typically located behind the exterior of vehicle 110 for aesthetic and aerodynamic reasons.

[0053] exist Figure 1Bshows an enlarged perspective view of radar sensor 100. Radar sensor 100 includes a housing 140, in which the various boards or layers of the radar sensor are mounted as internal components. These internal components include a board 150 for electronic components such as a monolithic microwave integrated circuit (MMIC) and a board or layer 160 for an air waveguide (AWG) antenna. Furthermore, radar sensor 100 includes a fairing 170. Housing 140 and fairing 170 enclose and protect internal components of radar sensor 100, such as boards 150 and 160, from environmental factors such as dust, moisture, corrosion, rust, and mechanical damage.

[0054] The surface of the vehicle component 120 and the surfaces of some plates or layers of the radar sensor 100 are formed as metallic flat surfaces. Therefore, these surfaces have high reflectivity for the radar waves transmitted by the sensor 100. For this reason, specular multiple reflection occurs. Figure 1A and Figure 1B Specular multiple reflections are depicted in FIG by arrows designated 130. Specular multiple reflections 130 may occur between radar sensor 100 and vehicle component 120. Furthermore, specular multiple reflections 130 may also occur between the flat metal surface of fairing 170 and the layer or plate 160 containing the AWG antenna. Reflections 130 can be accompanied by undesirable interfering effects on the performance of radar sensor 100, such as fairing insertion loss and transmission loss, pointing errors, antenna mainlobe ripple, reduced beamwidth and field of view of radar sensor 100, increased sidelobe levels, and depolarization effects.

[0055] Even if the fairing 170 is properly designed and installed to minimize such unwanted interference effects, a significant portion of these interference effects may remain due to specular reflections. Therefore, the radar sensor 100 according to the present disclosure is configured to minimize such interference effects.

[0056] Figure 2 An exploded view of radar sensor 100 is depicted, which includes housing 140, electronics board 150, two antenna boards 160, and fairing 170. Antenna boards 160 include an AWG antenna bottom or base layer 162 and an AWG antenna top or top layer 164, which contains antenna element 312 and corrugations 314, described in detail below.

[0057] Figure 3A Depicted is an enlarged view of an AWG antenna top cover or layer 164. This layer 164 includes an active region 310, where antenna or radiator elements 312 of all transmit and receive (Tx and Rx) antennas of the radar sensor 100 are located, and a passive region 320, where no antenna or radiator elements 312 are located.

[0058] On either side of each antenna element 312, several corrugations 314 are located within the active region 310. Thus, a corresponding set of corrugations 314 is associated with each antenna element 312 within the active region 310. The corresponding set of corrugations 314 is also denoted as a dual-purpose structure 313, and the two purposes of this structure 313 will be explained in detail below.

[0059] exist Figure 3B , another embodiment of layer 164 is depicted. This embodiment includes Figure 3A The same elements as in the embodiment make Figure 3A The description also applies to Figure 3B The only difference relates to the arrangement of active area 310, which includes two portions that are spatially separated from one another. Thus, active area 310 is not necessarily a continuous region within layer 164, but may include different regions separated by a portion of inactive area 320, which may be located between the different regions of active area 310.

[0060] like Figure 3C As shown, each corrugated portion 314 of the structure 313 includes a protrusion 315 and a recess 316 , which extend along the arrangement direction of the corresponding antenna element 312 .

[0061] The corrugations 314 prevent surface waves from propagating across the corresponding isolation structures 313 formed by the corrugations 314 disposed between a pair of antenna elements 312 (see also FIG. Figure 3C ) and provide cross isolation between adjacent antenna elements 312. Figure 3C As shown by arrow 317 in the figure, corrugated portion 314 prevents radar waves from propagating in a direction perpendicular to the direction in which protrusions 315 and recesses 316 of corrugated portion 314 extend. In contrast, radar waves are not blocked from propagating in a direction parallel to the direction in which protrusions 315 and recesses 316 extend, that is, in a direction parallel to the arrangement direction of antenna elements 312. Figure 3C This is indicated by arrow 318 in FIG.

[0062] In other words, if Figure 3C The structure 313 shown, including the corrugated portion 314, can be considered an electromagnetically soft surface in the direction indicated by arrow 317 extending perpendicularly to the protrusions 315 and recesses 316, and can be considered an electromagnetically hard surface in the direction indicated by arrow 318 extending along the protrusions 315 and recesses 316. In other words, the protrusions 314 function as an air waveguide (AWG) for radar waves transmitted by the antenna element 312.

[0063] To provide adequate isolation between antenna elements 312 by blocking the propagation of surface waves, isolation structure 313 requires at least three corrugations 314 per operating wavelength. Furthermore, the height H of protrusions 315, or correspondingly, the depth of recesses 316, is equal to one-quarter the radar wavelength, with a tolerance for height H of approximately one-sixteenth the wavelength. Furthermore, the distance, or pitch P, between adjacent protrusions 315 is selected to be less than or equal to one-third the wavelength.

[0064] In order to alleviate the above Figure 1A and Figure 1B In order to prevent the interference effect of the mirror multiple reflections 130 described above, an embodiment of the radar sensor 100 is provided as follows. Figures 4A to 4D and 5A to 5D The modified corrugated portion 400 is shown. That is, relative to Figures 3A to 3C While straight corrugations 314 are shown, at least some of the corrugations 400 are modified.

[0065] Figure 4A A perspective view of a portion of layer 164 is depicted, including an active region 310 and a portion of an inactive region 320. Within active region 310, isolation structures 313 are positioned in association with respective antenna elements 312. That is, a respective isolation structure 313 is disposed on both sides of each antenna element 312. In addition to a straight corrugated portion 314 having straight protrusions extending parallel to respective antenna elements 312, the isolation structure also includes a corrugated portion 400 having, in addition to a middle portion 410, two angled side portions 412, 414.

[0066] Due to the angled sides 412, 414 of the corrugated portion 400, the isolation structure 313 is able to deflect the incident radar waves and cancel the incident radar waves by destructive interference, e.g. Figure 4D The context explains this in detail. In addition to isolating the corresponding associated antenna element 312 from other antenna elements 312 of radar sensor 312, structure 313 is also configured to suppress and redirect incident radar waves reflected by corrugations 314, 400. Therefore, structure 313 including corrugations 314, 400 is denoted as a dual-purpose structure 313. Furthermore, corrugations 400 are denoted as angled corrugations 400 due to their angled sides 412, 414.

[0067] Figure 4B A side view of one of the angled corrugations 400 is depicted, the angled corrugations 400 comprising a middle portion 410 extending parallel to an alignment direction 420 of the corresponding antenna element 312 (see also FIG. Figure 4C), and angled or inclined side portions 412, 414 extending from respective ends of the middle portion 410. The extending direction of the angled side portions 412, 414 of the corrugated portion 400 is indicated by 422, and the inclination angle between the extending direction 422 of the side portion 412 and the arrangement direction 420 of the antenna elements 312 is indicated by a double arrow 424.

[0068] Figure 4C Also depicted is a perspective view of another portion of layer 164 including an active region 310 and a portion of an inactive region 320, i.e., Figure 4A In a similar way. However, Figure 4C In the portion shown, antenna elements 312 are arranged side by side. Figure 4C Also shown are an arrangement direction 420 of the corresponding antenna elements 312 , an extension direction 422 of the side portion 412 , and an inclination angle 424 .

[0069] The two side portions 412, 414 are arranged at opposite angles 424 relative to the predetermined arrangement direction 420 of the corresponding antenna elements 312 associated with the corresponding set of corrugated portions 314, 400, which surround the antenna elements 312 in a direction perpendicular to the arrangement direction 420 of the antenna elements 312. For this embodiment, the tilt angle 424 is approximately 7 degrees. However, this value is an arbitrary choice related to the design of the active area 310. A larger or smaller tilt angle 424 can also be used to provide similar technical effects. Accordingly, Figure 4B and Figure 4C A tilt angle 424 greater than 7 degrees is depicted.

[0070] Figures 4A to 4D The angled corrugations 400 of the illustrated embodiment have a consistent inclination angle 424 for all sides 412, 414. That is, the protrusions 315 and recesses 316 of the angled corrugations 400 extend parallel to each other over the entire length of the corresponding angled corrugations 400, as shown in FIG. Figure 4B The most clearly shown.

[0071] The distance H between the top of the protrusion 315 and the bottom of the recess 316 is consistently equal to one-quarter of the operating wavelength of the radar wave transmitted by the antenna element 312 in order to maintain the cross isolation function between the antenna elements 312, wherein the tolerance of the height H is approximately one-sixteenth of the operating wavelength. Figure 4D The isolation function of the structure 313 is also indicated by arrow 317. In the direction of arrow 317, the structure 313 is an electromagnetically soft surface, that is, the entire length of the corrugated portion 400 in the middle portion 410 and the side portions 412, 414 is an electromagnetically soft surface.

[0072] In order to Figures 3A to 3CThe illustrated embodiment of the active region 310 comprising only straight ripples 314 maintains this isolation function, with the active region 310 being provided on both sides (see FIG. Figure 4A and Figure 4C ) The projection 315 of the corrugation portion 314 adjacent to the corresponding antenna element 312 remains unchanged, i.e., is not provided with the angled side portions 412, 414. In other words, the straight corrugation portion 314 is directly adjacent to the corresponding antenna element 312, so that the projection 315 of the adjacent corrugation portion 314 of the corresponding antenna element 312 extends parallel to the antenna element 312 over its entire length.

[0073] exist Figure 4D The lower part of the dual-purpose structure 313 is depicted in perspective (see Figure 4A ). For the sake of clarity, the straight corrugations 314 are omitted so that only three angled corrugations 400 are shown. In the upper part, the same structure is shown in a more schematic and simplified manner.

[0074] Due to the angled sides 412, 414 of the corrugation 314, specular multiple reflections are directly deflected, thereby reducing the structural radar cross section of the layer 164. This is illustrated by the waves 440 reflected at the respective angled sides 412, 414 of the angled corrugation 400. Furthermore, due to destructive interference, out-of-phase cancellation occurs for the waves 440 reflected at the protrusions 315 and recesses 316 of each angled corrugation 400. This destructive interference also occurs for the waves 450 reflected at the central portion 410. In summary, due to the deflection at the sides 412, 412 and the destructive interference at all portions 410, 412, 414, the incident radar wave is suppressed by the angled corrugations 400 of the structure 313.

[0075] A further reduction in the radar cross section of the structure is achieved by the addition of a central region 430 (see Figure 4C ) is caused by the destructive interference of radar waves in the central region, where the oppositely inclined sides 412, 414 of different groups of corrugations 400 face each other. For this embodiment, the passive region 320 of the layer 164 is relative to Figures 3A to 3C The reference model of radar sensor 100 shown remains unchanged. That is, passive region 320 comprises a flat and uniform surface.

[0076] exist 5A to 5D Another embodiment of layer 164 of radar sensor 100 is depicted in FIG. Figures 4A to 4D The description of the illustrated embodiment also applies to 5A to 5D The embodiments shown are described in detail so that the description of the corresponding features will not be repeated. Figure 5A and Figure 5C A corresponding perspective view of a portion of layer 164 is depicted, and Figure 5B depicts a side view of the angled corrugation 400 according to this embodiment, and Figure 5D A perspective view of structure 313 is depicted.

[0077] 5A to 5D The embodiment shown is Figures 4A to 4D The embodiment shown differs in that within the structure 313, i.e. within each set of corrugations 314, 400 associated with some of the antenna elements 312, the angled corrugations 400 have sides 412, 414 in which the protrusions 315 and recesses 316 are arranged at opposite inclination angles 424. Figure 5B As shown in the side view, the protrusions 315 and recesses 316 of the angled corrugation 400 have corresponding inclined portions 512 , 513 that are arranged at opposite inclination angles relative to the arrangement direction 420 of the antenna elements 312 .

[0078] Because the protrusions 315 and recesses 316 have opposite inclination angles 424, the protrusions 315 and recesses 316 of the angled corrugations 400 are connected to each other at respective ends of the corrugations 400 along respective antenna elements 312. In the middle region 410 of the corrugations 400 (which have such oppositely inclination angles of protrusions 315 and recesses 316 within their sides 412, 414), the height H of the protrusions relative to the recesses 316 remains equal to one-quarter of the operating wavelength of the radar waves transmitted by the antenna elements 312. This distance, equal to one-quarter of the wavelength, maintains the isolation function of the corrugations 314 in the middle region 410. The tolerance for height H is approximately one-sixteenth of the operating wavelength. Figure 5D Arrow 317 in the illustrated middle section 410 again illustrates the isolating function.

[0079] Due to these opposite inclination angles 424 of the inclined portions 512, 513, back reflections of the incident radar waves are deflected into different directions, e.g. Figure 5D As shown by waves 520 and 530. Figure 5D Waves reflected at the same deflection angle as shown in pairs of waves 520, 530, and 540 are canceled out by destructive interference of radar waves. This applies to both the middle portion 410 and the side portions 412 and 414. For the side portions 412 and 414, the corresponding distance 515 between the inclined portion 512 of the protrusion 315 of one side portion 412 and 414 and the inclined portion 513 of the recess 316 of the opposite side portion 412 and 414 is also approximately equal to one-quarter of the operating wavelength, with a tolerance of one-sixteenth of the wavelength. This facilitates destructive interference between the paired waves 520 and 530. In summary, through deflection and destructive interference, the structural radar cross-section of layer 164 is further reduced.

[0080] Furthermore, for this embodiment, the inclination angle 424 of the oppositely inclined protrusions 315 and recesses 316 is also approximately 7 degrees relative to the arrangement direction 420 of the antenna elements 312. As mentioned above, this value is again an arbitrary choice related to the design of the active area 310, and larger or smaller inclination angles 424 can also be used to provide similar technical effects. Accordingly, for illustrative purposes, 5A to 5D A tilt angle 424 greater than 7 degrees is shown.

[0081] according to Figure 6 In another embodiment shown, the dual-purpose structure 313 and the corresponding set of corrugations 314, 400 are at least partially covered by a dielectric layer 600. Figure 6 On the left side, three angled corrugations 400 are depicted, which have uniformly inclined protrusions 315 and depressions 316, i.e., according to Figures 4A to 4D In contrast, in the embodiment shown Figure 6 On the right side, three angled corrugations 400 are depicted, which have oppositely inclined protrusions 315 and recesses 316, i.e., relative to the 5A to 5D The arrangement directions 420 of the antenna elements 312 of the illustrated embodiment are arranged at opposite angles.

[0082] Therefore, a material with a dielectric constant greater than that of air is positioned on top of the corrugations. For this reason, the operating wavelength of radar waves within the dielectric layer is smaller than the "free space" wavelength in air. Therefore, the depth H of the recesses 316 between the protrusions 315 is smaller than that of the embodiment in which the corrugations 314, 400 are not covered by the dielectric layer 600. Figures 3A to 3C ) and the corresponding distance P between adjacent protrusions 315 and recesses 316 can be reduced. This results in a more compact design of the entire radar sensor 100. In addition, part of the energy of the incident radar wave is dissipated within the dielectric layer 600, which leads to a further reduction in the structural radar cross section.

[0083] Figure 7 、 Figure 8 and Figure 9 Other embodiments of radar sensor 100 are depicted for which inactive region 320 of layer 164 (see also Figures 3A to 3C ) has a diffraction grating surface 700, 800, 900, so that the scattering pattern of the radar waves in the passive area is optimized in a special way. Figure 7 、 Figure 8 and Figure 9 In the embodiment shown, the surfaces 700, 800, 900 of the passive region 320 are perpendicular to each other in two directions (i.e., Figure 7 Represented along the length I x and I y) is a sinusoidal curve. The sinusoidal surface profile 700 of the passive region 320 can be analytically described by the following formula:

[0084]

[0085] Where z represents the local height of the surface profile 700 relative to the planar surface (xy plane), h is the amplitude or height factor of the profile, and P x is the period length along the x-axis, and P y is the period length along the y-axis. Therefore, P x and P y Determines the periodicity or frequency along the sinusoidal profile in two directions perpendicular to each other.

[0086] Such a sinusoidal surface profile 700 acts as a cross-diffraction grating, deflecting reflected radar waves (e.g., from the fairing, fascia, or bumper) outside the radar sensor's field of view over a wide angular range. Generally speaking, a surface profile with a periodic structure in two perpendicular directions is suitable for achieving this technical effect of deflecting radar waves through diffraction. Therefore, surface profile 700 does not necessarily need to be a sinusoidal curve. Instead, surface profile 700 only needs to have a regular or periodic structure with maxima 702 and nadirs 704.

[0087] exist Figure 7 , radar cone 710 corresponds to the field of view of radar sensor 100. An incident wave 720, which may be caused by reflections at the fairing, fascia, or bumper, results in specular reflections 730, i.e., the (0,0) order diffraction mode 730, within the field of view or radar cone 710, while higher order diffraction modes 732 are deflected out of the radar cone or field of view 710 of the radar sensor due to diffraction of the radar wave at the surface profile 700. Therefore, the energy or intensity of the specular reflections 730 is significantly reduced due to the higher order diffraction modes 732 being scattered or deflected out of the radar cone 710. Therefore, the surface profile 700 of the passive region 320 also significantly reduces specular multiple reflections 130 (see Figure 1A and Figure 1B ).

[0088] The sinusoidal surface profile 700 described by equation (1) above provides the ability to adjust and optimize the diffraction pattern relative to its scattering pattern outside the radar cone or field of view of the radar sensor 100. Generally speaking, this scattering pattern of a structured metal surface can be described by the periodic reflectarray theorem, or by the generalized Snell's law in the reflection mechanism to describe the anomalous reflection of a diffraction grating structure.

[0089] When considering the analytical formula (1) provided above, there are three parameters by which the scattering pattern of the surface profile 700 can be optimized. The amplitude or height factor h directly affects the power distribution of the different diffraction modes. The period length P along the x-axis and y-axis x and P y Defines the number of possible diffraction modes and the diffraction angles along the x-axis and y-axis, respectively.

[0090] for Figure 8 For the embodiment of the radar sensor 100 shown, the surface profile 800 of the passive region 320 has the same periodicity or period length along the x-axis and the y-axis, ie, P x =P y Therefore, the surface profile 800 can also be called a symmetrical sinusoidal profile. Figure 8 and Figure 9 In , the angle θ represents the azimuth angle, and the angle ψ represents the elevation angle relative to the boresight direction along the z-axis.

[0091] Figure 8 The respective intensities of the different diffraction modes are depicted by the respective polar representations, where the intensity of the specular reflection is represented by 820 and the respective intensity of the higher diffraction modes is represented by 830. Figure 8 As can be seen in FIG. 8 , most of the incident wave intensity is transferred to higher diffraction modes. Accordingly, the intensity 820 of the specular reflection is significantly reduced compared to the incident intensity.

[0092] Since the surface profile 800 has the same periodicity P along the x-axis and the y-axis x 、P y The scattering behavior of the surface profile 800 of the passive region 320 is independent of the polarization of the transmitted radar wave. Therefore, the surface profile 800 that is a symmetrical sinusoidal curve with respect to spatial periodicity is suitable for a dual-polarity radar sensor using two different polarization modes.

[0093] Since many automotive radar sensors have a wider field of view in azimuth angle θ than in elevation angle ψ, Figure 9 Another embodiment of the radar sensor 100 shown includes a surface profile 900 of the passive region 320 having different periodicities along the x-axis and the y-axis. Figure 8 For equal periodicity on both axes, the periodicity or period length P is shown y increases along the y-axis, while the periodicity or period length P x Decreases along the x-axis.

[0094] Sinusoidal surface profile 900 therefore has an asymmetric design with respect to the periodicity of the highest and lowest points in the x- and y-directions. As a result, more diffraction modes can be excited in azimuth, resulting in an increase in the intensity of the higher diffraction modes scattered out of the radar cone or field of view of radar sensor 100. This can be seen by the polarity of the intensity of the higher diffraction modes, respectively denoted by 930. Thus, with Figure 8 Compared to the intensity 820 shown, the specular reflection intensity represented by 920 is even more suppressed. Figure 9 The illustrated asymmetric surface profile 900 is suitable for a radar sensor 100 that uses a single polarization mode.

[0095] To investigate the feasibility of the above concept, the antenna cover or layer 164 (see Figure 2 and Figures 3A to 3C The corresponding bistable radar cross section (RCF) is simulated for different models over the entire relevant frequency band from 76 GHz to 81 GHz. For this simulation, the assumptions are that the incident wave is incident on the boresight and has a purely horizontal polarization.

[0096] Model 1 (M1) used as a reference model is, for example, Figure 3A or Figure 3B and has only straight corrugations 314 in the active region 310 and a flat profile in the inactive region 320. Model 2 (M2) Figure 8 and has a symmetrical sinusoidal surface profile 800 only in the inactive region 320, but only straight corrugations 314 and no angled corrugations 400 in the active region. Model 3 (M3) 5A to 5D Model 4 (M4) is a model having a corrugated portion 400 with protrusions 315 and depressions 316 at opposite tilt angles 424 only in the active region 310, but a flat passive region 320 without a diffraction grating surface. 5A to 5D and Figure 8 Thus, M4 has a symmetrical sinusoidal surface profile 800 in the passive region 320 (see Figure 8 ), and a corrugated portion 400 having protrusions 315 and recesses 316 with opposite inclination angles 424 in the active region 310 (see 5A to 5D ).

[0097] Model 5 (M5) has an asymmetric sinusoidal surface profile 900 only in the passive region 320 (see Figure 9 ), but only straight corrugations 314 are provided in the active region 310 without angled corrugations 400. In contrast, model 6 (M6) only provides corrugations 400 with a uniform tilt angle 424 in the active region 310 (see FIG. Figures 4A to 4D), but a flat surface profile is set in the passive region 320 without a diffraction grating surface. Finally, Model 7 (M7) is Figure 9 and Figures 4A to 4D Thus, M7 has an asymmetric sinusoidal surface profile 900 in the passive region 320 (see Figure 9 ), and having an angled corrugation 400 with a uniform tilt angle 424 in the active region 310 (see Figures 4A to 4D ).

[0098] The following table summarizes the simulation results for different models M1 to M7. From the results of models M2, M3, M5, and M6, it can be seen that the embodiments with inclined corrugations 400 in the active region 310 or with sinusoidal surface profiles 800 or 900 in the passive region 320 have already resulted in a significant reduction in RCS values. However, models M4 and M7, which have sinusoidal surface profiles in the passive region and inclined corrugations in the active region 310, have significantly reduced structural radar cross-section ratios (RCSR ratios), namely, RCSR ratios of approximately 10 dB across the entire frequency band from 76 to 81 GHz. Notably, model M4, which has a symmetrical sinusoidal surface profile 800 and oppositely inclined corrugations 400, and model M7, which has an asymmetrical sinusoidal surface profile 900 and uniformly inclined corrugations 400, show the best results.

[0099]

[0100]

[0101] Furthermore, the influence of the front face on the azimuth and elevation coverage was simulated for the above-mentioned models M1 to M7. For the simulation, the radar sensor 100 comprising the models M1 to M7, respectively, was combined with a front face having a reflectivity of -14 dB and an elevation angle of -4°. The results show that the model M2 (see FIG. 1 ) having a symmetrical sinusoidal surface profile 800 in the passive region 320 has a Figure 8 ) has improved azimuth and elevation coverage, that is, even without Figures 4A to 4D and 5A to 5D The same is true for the angled corrugations 400 shown. Furthermore, compared to the related art provided by model M1, model M4 (see FIG. 1 ) having a symmetrical sinusoidal surface profile 800 in the passive region 320 and corrugations 400 with protrusions 315 and recesses 316 at opposite angles is shown. 5A to 5D ) further improves the radar integration results.

[0102] Consequently, the angular measurement capability of radar sensor 100 having angled corrugations 400 in active region 310 and / or having one of sinusoidal surface profiles 800 , 900 in passive region 320 is improved.

[0103] According to the present disclosure, a radar sensor may include a layer including at least one active region and at least one passive region, wherein the active region includes a plurality of antenna elements configured to transmit and receive radar waves, and the passive region is free of antenna elements. The passive region may be provided with a diffraction grating surface.

[0104] According to various embodiments, the diffraction grating surface may include a surface profile in which highest points and lowest points of the surface profile are periodically arranged.

[0105] According to various embodiments, the surface profile may be sinusoidal for two directions perpendicular to each other.

[0106] According to various embodiments, the periodicity of the highest and lowest points of the surface profile may be adapted to at least two diffraction modes of radar waves such that radar waves associated with the at least two diffraction modes are scattered outside a predetermined field of view of the radar sensor.

[0107] According to various embodiments, the highest points and the lowest points of the surface profile may have the same periodicity for two directions perpendicular to each other.

[0108] According to various embodiments, the highest points and the lowest points of the surface profile may have different periodicities for two directions perpendicular to each other.

[0109] According to various embodiments, a respective dual-purpose structure may be associated with each antenna element in the active region, wherein each dual-purpose structure may be configured to isolate the associated antenna element from the other antenna elements with respect to transmitted and received radar waves, and to suppress and redirect reflections of incident radar waves.

[0110] According to various embodiments, each dual-purpose structure may include a corresponding set of corrugations, each corrugation including a protrusion and a recess. Each set of corrugations may include at least one angled corrugation, wherein the angled corrugation may include at least one portion extending in a direction different from the predetermined arrangement direction of the associated antenna elements.

[0111] According to various embodiments, a respective set of corrugations may be at least partially covered by a dielectric layer.

[0112] According to various embodiments, a pair of protrusions of the corrugated portion adjacent to the corresponding antenna element may extend parallel to a predetermined arrangement direction of the corresponding antenna element.

[0113] According to various embodiments, at least one angled corrugation may include two side portions, which may be arranged at opposite angles greater than zero with respect to a predetermined arrangement direction of the associated antenna element.

[0114] According to various embodiments, the respective protrusions and the respective recesses within each side of the at least one angled corrugation may extend parallel to each other.

[0115] According to various embodiments, the respective protrusions and respective recesses within each side of the at least one angled corrugation may be arranged at opposite angles.

[0116] According to various embodiments, a respective set of corrugations may be a metallic antenna waveguide structure for an associated antenna element.

[0117] According to various embodiments, a corresponding set of corrugations may be associated with each antenna element in the active area, and at least one set of corrugations may include at least one angled corrugation, for which the protrusions and recesses of the corresponding sides of the angled corrugations are arranged at opposite angles, and the passive area may be provided with a surface profile, in which the highest points and the lowest points of the surface profile may have the same periodicity with respect to two directions perpendicular to each other.

[0118] According to various embodiments, a corresponding set of corrugations may be associated with each antenna element in the active area, and at least one set of corrugations may include at least one angled corrugation, for which the protrusions and recesses of the corresponding sides of the angled corrugations may extend parallel to each other, and the passive area may be provided with a surface profile, in which the highest points and the lowest points of the surface profile may have different periodicities with respect to two directions perpendicular to each other.

[0119] Furthermore, a vehicle may include a vehicle component and a radar sensor as described above, which may be arranged in the vicinity of the vehicle component.

[0120] Reference Signs List

[0121] 100 radar sensors

[0122] 110 vehicles

[0123] 120 Vehicle parts, such as front fascia or bumpers

[0124] 130 Specular Multiple Reflections

[0125] 140 housing

[0126] 150 electronic boards

[0127] 160 Antenna Layer

[0128] 162 Antenna bottom cover

[0129] 164 Antenna cover

[0130] 170 fairing

[0131] 310 active area

[0132] 312 antenna elements

[0133] 313 dual-purpose structure

[0134] 314 straight corrugated part

[0135] 315 protrusion

[0136] 316 Depression

[0137] 317 Electromagnetic Soft Surface

[0138] 318 Electromagnetic Hard Surface

[0139] 400 Angled corrugated section

[0140] 410 middle part

[0141] 412 Side

[0142] 414 Side

[0143] 420 Arrangement direction of antenna elements

[0144] 422 extension direction of the angled corrugated portion

[0145] 424 Tilt Angle

[0146] 430 Area with oppositely inclined sides

[0147] 440 Waves deflected at the sides

[0148] 450 Waves deflected at the middle

[0149] 512, 513 oppositely inclined parts

[0150] 520 Waves deflected at the sides

[0151] 530 Waves deflected at the sides

[0152] 540 Waves deflected at the middle

[0153] 600 dielectric layer

[0154] 700 Sinusoidal surface profile of the passive area

[0155] 710 Radar cone or field of view

[0156] 720 Incident Wave

[0157] 730 Specular reflection or zero-order diffraction pattern

[0158] 732 Higher Diffraction Mode

[0159] 800 Symmetrical sinusoidal profile

[0160] 820 Specular reflection intensity

[0161] 830 Higher diffraction pattern intensity

[0162] 900 Asymmetric sinusoidal profile

[0163] 920 Specular reflection intensity

[0164] 930 Higher diffraction pattern intensity

Claims

1. A radar sensor (100), comprising: A layer (164) comprising at least one active region (310) and at least one passive region (320), wherein the active region (310) comprises a plurality of antenna elements (312) configured to transmit and receive radar waves, and the passive region (320) is free of antenna elements (312), The passive region (320) is provided with a diffraction grating surface (700, 800, 900).

2. The radar sensor (100) according to claim 1, wherein The diffraction grating surface (700, 800, 900) includes a surface profile (700, 800, 900) in which the highest points (702) and the lowest points (704) of the surface profile (700, 800, 900) are periodically arranged.

3. The radar sensor (100) according to claim 1 or 2, wherein The periodicity of the highest points (602) and the lowest points (604) of the surface profile (600, 700, 800) is adapted to at least two diffraction patterns (632) of radar waves, so that radar waves associated with the at least two diffraction patterns (632) are scattered outside a predetermined field of view of the radar sensor (100).

4. The radar sensor (100) according to any one of claims 1 to 3, wherein The highest points (702) and the lowest points (704) of the surface profile (800) have the same periodicity with respect to two directions perpendicular to each other.

5. The radar sensor (100) according to any one of claims 1 to 3, wherein The highest point (702) and the lowest point (704) of the surface profile (900) have different periodicities with respect to two directions perpendicular to each other.

6. The radar sensor (100) according to any one of claims 1 to 5, wherein In the active region (310), a respective dual-purpose structure (313) is associated with each antenna element (312), each dual-purpose structure (313) being configured to isolate the associated antenna element (312) from the other antenna elements (312) with respect to transmitted and received radar waves, and to suppress and redirect reflections of incident radar waves.

7. The radar sensor (100) according to claim 6, wherein Each dual-purpose structure (313) includes a corresponding set of corrugated portions (314, 400), each corrugated portion (314, 400) includes a protrusion (315) and a recess (316), and Each set of corrugations (314, 400) includes at least one angled corrugation (400) including at least one portion (412, 414, 512, 513) extending in a direction different from a predetermined arrangement direction (420) of an associated antenna element (312).

8. The radar sensor (100) according to claim 7, wherein The respective set of corrugations (314, 400) is at least partially covered by a dielectric layer (600).

9. The radar sensor (100) according to claim 7 or 8, wherein A pair of protrusions (315) of the corrugated portion (314) adjacent to the corresponding antenna element (312) extends parallel to a predetermined arrangement direction (420) of the corresponding antenna element (312).

10. The radar sensor (100) according to any one of claims 7 to 9, wherein The at least one angled corrugation (400) includes two side portions (412, 414) arranged at opposite angles (424) greater than zero relative to a predetermined alignment direction (420) of an associated antenna element (312).

11. The radar sensor (100) according to claim 10, wherein In each side portion (412, 414) of the at least one angled corrugated portion (400), a corresponding protrusion (315) and a corresponding recess (316) extend parallel to each other.

12. The radar sensor (100) according to claim 10, wherein Within each side (412, 414) of the at least one angled corrugated portion (400), a respective protrusion (315) and a respective recess (316) are arranged at opposite angles (424).

13. The radar sensor (100) according to any one of claims 1 to 4, wherein In the active region (310), a respective set of corrugations (314, 400) is associated with each antenna element (312), and at least one set of corrugations (314, 400) includes at least one angled corrugation (400) for which protrusions (315) and recesses (316) of respective sides (412, 414) of the angled corrugation (400) are arranged at opposite angles (424), and The passive region (320) is provided with a surface profile (800), wherein the highest points (702) and the lowest points (704) of the surface profile (800) have the same periodicity with respect to two directions perpendicular to each other.

14. The radar sensor (100) according to any one of claims 1 to 3 or 5, wherein In the active region (310), a respective set of corrugations (314, 400) is associated with each antenna element (312), and at least one set of corrugations (314, 400) includes at least one angled corrugation (400) for which the protrusions (315) and recesses (316) of respective sides (412, 414) of the angled corrugations (400) extend parallel to each other, and The passive region (320) is provided with a surface profile (900), wherein the highest point (702) and the lowest point (704) of the surface profile (900) have different periodicities with respect to two directions perpendicular to each other.

15. A vehicle (100), comprising: Vehicle component (120) and The radar sensor (100) according to any one of claims 1 to 14, wherein the radar sensor is arranged in the vicinity of the vehicle component (120).

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