Antenna device for a radar device having at least two antenna arrangements, radar device, driver assistance system, vehicle, and method for operating a radar device

Abstract

The present invention describes an antenna device (33) for a radar device, particularly for a bistatic radar device, particularly for a vehicular radar device, a radar device, a driver assistance system, a vehicle, and a method for operating the radar device. The antenna device (33) has at least one type 1 antenna element (Tx) of a first antenna element type and at least one type 2 antenna element (Rx) of a second antenna element type. One of the antenna element types is a transmit antenna element (Tx), and the other antenna element type is a receive antenna element (Rx). The antenna device (33) has at least two antenna arrangements (30) of identical design. The position of at least one antenna element (Rx, Tx) of the antenna arrangement (30) within the antenna device (33) results from a geometric transformation of the position of at least one other corresponding antenna element (Rx, Tx) of the antenna arrangement (30). The geometric transformation comprises at least one rotation (88) of the positions of the antenna elements (Rx, Tx) of at least one second-mentioned antenna arrangement (30) around an assumed direction axis (86) by a predetermined rotation angle, the assumed direction axis (86) indicating the direction in which the antenna arrangement (30) is pointed.

Description

[Technical Field]

[0001] The present invention relates to an antenna device for a radar device, in particular for a bistatic radar device, in particular for a vehicle radar device, having at least one antenna arrangement with at least one Type 1 antenna element of a first antenna element type and at least one Type 2 antenna element of a second antenna element type, wherein one of the antenna element types is a transmitting antenna element and the other of the antenna element types is a receiving antenna element.

[0002] The present invention further relates to a radar device, in particular a radar device for a vehicle, having at least one antenna device with at least one antenna arrangement having at least one Type 1 antenna element of a first antenna element type and at least one Type 2 antenna element of a second antenna element type, wherein one of the antenna element types is a transmitting antenna element and the other of the antenna element types is a receiving antenna element.

[0003] The present invention further relates to a driver assistance system with at least one radar device, in particular a bistatic radar device, comprising at least one antenna device with at least one antenna arrangement for the at least one radar device, wherein the at least one antenna arrangement comprises at least one Type 1 antenna element of a first antenna element type and at least one Type 2 antenna element of a second antenna element type, one of the antenna element types being a transmitting antenna element and the other of the antenna element types being a receiving antenna element.

[0004] The present invention also relates to a vehicle having at least one radar device, in particular a bistatic radar device, equipped with at least one antenna device having at least one antenna arrangement for the at least one radar device, wherein the at least one antenna arrangement comprises at least one Type 1 antenna element of a first antenna element type and at least one Type 2 antenna element of a second antenna element type, one of the antenna element types being a transmitting antenna element and the other of the antenna element types being a receiving antenna element.

[0005] Finally, the invention relates to a method for operating a radar device, in particular a radar device for a vehicle, in particular a bistatic radar device, having at least one antenna device with at least one antenna arrangement having at least one type 1 antenna element of a first antenna element type and at least one type 2 antenna element of a second antenna element type, in which one antenna element of the antenna element type is used to transmit radar signals and another antenna element of the antenna element type is used to receive echo signals resulting from the transmitted radar signals. [Background technology]

[0006] U.S. Patent Application Publication No. 2021 / 0184367 discloses a radar unit having an arrangement of transmitting antennas and receiving antennas. The number of transmitting antennas is four, and the number of receiving antennas is four. The transmitting antennas Tx#1 and Tx#2 form a first antenna group of transmitting antennas that are the same in vertical position but different in horizontal position. The transmitting antennas Tx#3 and Tx#4 form a second antenna group that is arranged at a position different from both the horizontal and vertical positions of the first antenna group. The receiving antennas Rx#1 to Rx#3 form a third group of receiving antennas that are the same in vertical position but different in horizontal position. The receiving antenna Rx#4 is a fourth antenna that is arranged at a position different from both the horizontal and vertical positions of the third antenna group. The vertical position of the fourth antenna (Rx#4) is located away from the vertical positions of the third antenna group (Rx#1 to Rx#3).

[0007] The present invention is based on the object of designing an antenna device, a radar device, a driver assistance system, a vehicle and a method of the type mentioned in the introduction, which allows improving the directional resolution when performing directional measurements using a radar system. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] US Patent Application Publication No. 2021 / 0184367 Summary of the Invention

[0009] This object is achieved by the present invention in the case of antenna arrangements in that an antenna device has at least two antenna arrangements of identical design, wherein the position of at least one antenna element of the antenna arrangements in the antenna device results from a geometric transformation of the position of at least one other corresponding antenna element of the antenna arrangements, the geometric transformation comprising at least one rotation of the positions of the antenna elements of at least one second mentioned antenna arrangement around an assumed direction axis by a predetermined rotation angle, the assumed direction axis indicating the direction in which the antenna arrangements are pointed.

[0010] According to the present invention, an antenna device has at least two identically designed antenna arrangements. The position of at least one antenna element of the antenna arrangements in the antenna device results from a geometric transformation of the positions of at least one other corresponding antenna element of the antenna arrangements. The geometric transformation includes at least one rotation of the positions of the antenna elements of the second mentioned antenna arrangement around an assumed direction axis by a predetermined rotation angle. The rotation of the positions of the antenna elements is realized by a rotation of the entire antenna arrangement. Thus, at least one second mentioned antenna arrangement is rotated around its assumed direction axis with respect to at least one first mentioned antenna arrangement.

[0011] In addition to the rotation, the geometric transformation may also include at least one tilt and / or at least one displacement of the positions of the antenna elements of the second-mentioned antenna arrangement. The tilt and / or displacement of the positions of the antenna elements may be realized by tilting and / or displacing the entire antenna arrangement, thereby allowing the at least two antenna arrangements to be oriented in different directions and / or spaced apart from each other.

[0012] The positions of the antenna elements of at least one antenna arrangement may be effected from the positions of the corresponding antenna elements of the other antenna arrangements by rotation about a direction axis and by further translation of at least one second-mentioned antenna arrangement, in particular by displacement and / or tilt of the direction axis.

[0013] The directional axis of the antenna arrangement defines the direction in which the antenna elements of the antenna arrangement are pointed, i.e., the direction in which the transmitting antenna elements can transmit radar signals and the receiving antenna elements can receive radar signals and echo signals.

[0014] The "first" and "second" antenna element types are merely for ease of distinction and do not imply a preference for one of the antenna element types. Thus, the designations "Type 1" and "Type 2" simply serve to distinguish between two antenna element types. A Type 1 antenna element may be a transmitting antenna element, and a Type 2 antenna element may be a receiving antenna element, or vice versa.

[0015] The antenna device is intended for a radar device. The antenna arrangement of the antenna device may be used to transmit radar signals and receive radar signals or echo signals. The received radar signals, in particular echo signals resulting from the radar signals, may be converted into corresponding receive signals, in particular electrical receive signals. The receive signals may be processed using suitable means, in particular a control and evaluation device.

[0016] Advantageously, the antenna device may be designed for use in a bistatic radar device. Advantageously, the antenna device for a bistatic radar device may have two antenna arrangements. In this case, each antenna arrangement may receive its own radar signal, each of the echo signals resulting from its own radar signal, and the radar signal or echo signals of the other antenna arrangement. This makes it possible to obtain a lot of information about the surveillance area captured by the radar device, in particular the surroundings of the vehicle.

[0017] The radar device may be used in vehicles, in particular automobiles. Radar systems may also be advantageously used in land vehicles, in particular cars, trucks, buses, motorcycles, etc., in aircraft, in particular drones, and / or watercraft. The radar device may also be used in vehicles that can be operated autonomously or at least semi-autonomously.

[0018] The radar device may advantageously be connected to or be part of at least one electronic control device of the vehicle or of the machine, in particular a driver assistance system, so that at least some of the functions of the vehicle may be performed autonomously or semi-autonomously.

[0019] The radar device may be used to detect stationary or moving objects, in particular vehicles, people, animals, plants, obstacles, uneven road surfaces, in particular potholes or rocks, road boundaries, traffic signs, open spaces, in particular parking spaces, precipitation, etc., and / or movements and / or gestures.

[0020] In one advantageous embodiment, The directional axes of each of the at least two antenna arrangements may extend parallel; and / or The respective directional axes may extend perpendicular to a plane in which the antenna elements of the antenna arrangements are arranged, whereby the at least two antenna arrangements, in particular the antenna elements of the at least two antenna arrangements, may be aligned in the same direction.

[0021] In another advantageous embodiment, The predetermined rotation angle may be 180°; and / or The geometric transformation may include at least one displacement of a directional axis of the at least one antenna arrangement by a predetermined distance; and / or The at least two antenna arrangements may be located a predetermined distance from each other.

[0022] Advantageously, the predetermined rotation angle may be 180°, thereby making it possible to realize an additional virtual antenna element in the middle of the virtual array generated through the geometric convolution of the positions of the phase centers of the type 1 and type 2 antenna elements of the at least two antenna arrangements.

[0023] Advantageously, alternatively or additionally, the geometric transformation may comprise displacing the directional axis of at least one antenna arrangement by a predetermined distance. Advantageously, alternatively or additionally, at least one rotation arrangement may be positioned at a predetermined distance from at least one other antenna arrangement, thereby enabling a correspondingly large virtual array to be realized through a geometric convolution of the positions of the phase centers of the type 1 and type 2 antenna elements. The larger the distance, the larger the virtual array. The size of the virtual array defines the aperture. The aperture may therefore be enlarged by increasing the distance.

[0024] In a further advantageous embodiment, the at least two antenna arrangements may each have four Type 1 antenna elements arranged in a plane at the corners of an imaginary planar rectangle, two of the sides of the rectangle extending parallel to an imaginary first arrangement axis and forming Type 1 antenna element major axes, and the other two sides of the rectangle extending parallel to an imaginary second arrangement axis extending perpendicular to the first arrangement axis and forming Type 1 antenna element transverse axes, and the at least two antenna arrangements each have at least two Type 2 antenna elements extending parallel to and at a distance from each other and arranged on different imaginary Type 2 antenna element major axes parallel to one of the arrangement axes.

[0025] According to the present invention, four Type 1 antenna elements of a first antenna element type are arranged at the four corners of a rectangle whose sides extend parallel to two mutually perpendicular arrangement axes, and at least two Type 2 antenna elements are arranged on a Type 2 antenna element major axis that extends parallel to one of the arrangement axes.

[0026] As a result of the rectangular arrangement of Type 1 antenna elements, when operating a radar system in a MIMO manner, it is possible to realize a virtual antenna array with an enlarged two-dimensional aperture, in particular in azimuth and elevation, compared to an antenna arrangement. Therefore, in the case of direction measurement, it is possible to achieve a high resolution in both dimensions, thus improving the overall accuracy of determining the direction in which a detected object is located.

[0027] The directional resolution, and especially the angular resolution, of a radar device depends directly on the size of the aperture of the virtual antenna array, making it possible to achieve a large overall aperture in both dimensions, especially in azimuth and elevation, with a relatively small number of antenna elements.

[0028] A rectangle within the meaning of the present invention may have both the same side length and different side lengths. A rectangle may therefore also be a square.

[0029] Within the meaning of the present invention, "parallel" means that the corresponding axes may also coincide, i.e. the axes may be parallel or truly parallel.

[0030] The terms "major axis" and "lateral axis" are merely for the sake of simplicity and do not imply a preference for one axis, in particular the major axis, over the other, in particular the transverse axis. Therefore, the additions "Type 1" and "Type 2" serve only in this specification for the easy assignment of axes to corresponding antenna element types.

[0031] In a further advantageous embodiment, at least two of the type 2 antenna elements may be arranged on different assumed type 2 antenna element transverse axes extending parallel to each other and perpendicular to the type 2 antenna element major axis at a distance from each other. This allows the type 2 antenna elements to be spaced apart in two dimensions, i.e., in the direction of the type 2 antenna element major axis and in the direction of the type 2 antenna element transverse axis. This allows for the realization of a known sparse array in the virtual antenna array. Thus, gaps are created in the virtual antenna array. This allows for the realization of a significantly larger virtual antenna array with a significantly larger aperture in two dimensions, particularly in azimuth and elevation.

[0032] In another advantageous embodiment, Each of the at least two antenna arrangements may have at least three Type 2 antenna element transverse axes spaced apart from one another and at least three Type 2 antenna elements, with at least three of the Type 2 antenna elements positioned on different Type 2 antenna element transverse axes; and / or Each of the at least two antenna arrangements may have at least three type 2 antenna elements, and only one of the type 2 antenna elements is arranged on at least one of the type 2 antenna element major axes, and / or at least two of the type 2 antenna elements are arranged on at least one of the type 2 antenna element major axes, and in particular, at least one of the type 2 antenna element transverse axes, including one of the type 2 antenna elements arranged solely on the type 2 antenna element major axis, may not be located between two other type 2 antenna element transverse axes; and / or Each of the at least two antenna arrangements may have at least four type 2 antenna elements, where only one of the type 2 antenna elements is arranged on at least one of the type 2 antenna element major axes, and / or at least two of the type 2 antenna elements are arranged on at least one of the type 2 antenna element major axes, and the distance between at least one type 2 antenna element horizontal axis on which the type 2 antenna element arranged solely on the corresponding type 2 antenna element major axis is located and at least one adjacent type 2 antenna element horizontal axis may be at most the same as other distances between the respective adjacent type 2 antenna element horizontal axes; and / or Each of the at least two antenna arrangements may have exactly four Type 2 antenna elements, whereby the aperture of the virtual antenna array may be generally enlarged in the direction of the Type 2 antenna element major axes.

[0033] Advantageously, only one of the type 2 antenna elements may be arranged on at least one of the type 2 antenna element main axes and / or at least two of the type 2 antenna elements may be arranged on at least one of the type 2 antenna element main axes, which in combination with a rectangular arrangement of the type 1 antenna elements makes it possible to achieve a large range of the virtual antenna array.

[0034] Advantageously, alternatively or additionally, at least one of the type 2 antenna element transverse axes, including one of the type 2 antenna elements arranged singly on the type 2 antenna element main axis, may not be located between two other type 2 antenna element transverse axes, thereby making it possible to achieve an overall L-, U- or S-shaped arrangement of the type 2 antenna elements.

[0035] Advantageously, as an alternative or in addition, the distance between the transverse axis of at least one type 2 antenna element, on which a type 2 antenna element arranged singly on the type 2 antenna element main axis is located, and the transverse axis of at least one adjacent type 2 antenna element may be at most the same as other distances between the transverse axes of the respective adjacent type 2 antenna elements, thereby making it possible to keep small gaps resulting from the offset of individual antenna elements relative to other antenna elements, thereby making it possible to achieve an overall uniform distribution of virtual antenna elements.

[0036] Advantageously, alternatively or additionally, each of the at least two antenna arrangements may have exactly four type 2 antenna elements, so that exactly four antenna elements may be realized in total for both antenna element types, which allows a correspondingly large number of virtual antenna elements to be realized in the virtual antenna array.

[0037] In another advantageous embodiment, In each of the at least two antenna arrangements, the type 2 antenna element axes, in particular the type 2 antenna element major axis and the type 2 antenna element lateral axis, may extend in a common imaginary plane; and / or In each of the at least two antenna arrangements, the type 2 antenna element axes, in particular the type 2 antenna element major axis and the type 2 antenna element lateral axis, may extend parallel to a plane spanned by the type 1 antenna element major axis and the type 1 antenna element lateral axis; and / or In each of the at least two antenna arrangements, the type 1 antenna element and the type 2 antenna element may be arranged on a common carrier, in particular a common carrier plate; and / or All type 1 and type 2 antenna element axes of the antenna arrangement of the antenna device may extend in a common imaginary plane, so that the antenna arrangement can be easily manufactured, assembled, and aligned.

[0038] Advantageously, in each of the at least two antenna arrangements, all type 2 antenna element axes may extend in an imaginary plane, so that the antenna arrangements can be easily realized and aligned.

[0039] Advantageously, alternatively or additionally, in each of the at least two antenna arrangements, the type 2 antenna element axis may extend parallel to the type 1 antenna element axis, in particular to a plane spanned by the type 1 antenna element main axis and the type 2 antenna element main axis, which may simplify the alignment of the type 1 antenna elements and the placement of the type 2 antenna elements.

[0040] Advantageously, alternatively or additionally, in each of the at least two antenna arrangements, the Type 1 antenna elements and the Type 2 antenna elements may be arranged on a common carrier, which may make the antenna arrangements easier to manufacture.

[0041] Advantageously, in each of the at least two antenna arrangements, the type 1 and type 2 antenna elements may be realized on a common carrier plate, in particular a printed circuit board, so that all antenna elements can be easily realized in one plane. When using a printed circuit board, electrical connections to the antenna elements can be particularly easily realized.

[0042] Advantageously, alternatively or additionally, all type 1 and type 2 antenna element axes of the antenna arrangement of the antenna device may extend in a common imaginary plane, thereby allowing the antenna device to be realized in a space-saving manner in the dimension perpendicular to the common plane.

[0043] In a further advantageous embodiment, in each of the at least two antenna arrangements, the phase centers of at least some of the antenna elements, in particular the phase centers of all of the antenna elements, may be arranged on a corresponding antenna element axis, in particular the antenna element main axis and / or the antenna element transverse axis, so that the position of the antenna elements within the antenna arrangement can be precisely defined.

[0044] Advantageously, the phase centres of at least some of the antenna elements of the antenna arrangement may be located at the intersection of the antenna element major axis and the antenna element transverse axis.

[0045] In a further advantageous embodiment, in each of the at least two antenna arrangements, the respective distances between adjacent antenna element axes of the same antenna element type, in particular the respective distances between adjacent antenna element main axes and / or adjacent antenna element transverse axes of the same antenna element type, may be an integer multiple of a predetermined base distance, the base distance corresponding to half the wavelength of a radar signal transmitted using the radar system. This allows for a particularly compact arrangement to be realized. The base distance being half the wavelength of the radar signal allows for reduced ambiguities and side lobes. Furthermore, separate angle measurements may be performed, which may allow for clearly directed radar signals to be realized at the transmitter side.

[0046] In another advantageous embodiment, In each of the at least two antenna arrangements, the extent of a transmit antenna element field consisting of antenna elements of a transmit antenna element type in the direction of a first arrangement axis may be greater than the extent of a receive antenna element field consisting of antenna elements of a receive antenna element type in the direction of the first arrangement axis, and the extent of a transmit antenna element field in the direction of a second arrangement axis may be greater than the extent of a receive antenna element field in the direction of the second arrangement axis.

[0047] Advantageously, in each of the at least two antenna arrangements, the extent of the transmitting antenna element fields in the direction of both arrangement axes may be greater than the corresponding extent of the receiving antenna element fields, so that the receiving antenna element fields are, as it were, contained within the transmitting antenna element fields. The fact that the receiving antenna element fields are smaller than the transmitting antenna element fields makes it possible to minimize ambiguities and side lobes.

[0048] In another advantageous embodiment, The at least two antenna arrangements may be designed for use in a radar system according to a MIMO method; and / or The type 1 antenna elements of the at least two antenna arrangements are each separately activatable and / or readable, and the type 2 antenna elements of the at least two antenna arrangements are each separately activatable and / or readable.

[0049] Advantageously, at least two antenna arrangements may be designed for the operation of the radar device according to the MIMO method. The radar device may be realized as a so-called MIMO radar device. In the MIMO (multiple-input / multiple-output) method, all antenna elements of a transmitting antenna element type may be used to emit different coded radar signals. Thereby, the radar signals on the receiver side may be assigned correspondingly to the echo signals received using the antenna elements of the receiving antenna element type. Therefore, in the pure MIMO method, the aperture of the virtual antenna array realized in the antenna device may be correspondingly enlarged.

[0050] Advantageously, each antenna element may be driven and / or read separately, thereby making efficient use of the number of antenna elements. In this case, the transmit antenna elements may be driven separately, and the receive antenna elements may be read separately. Thus, even with a relatively small number of antenna elements, it is possible to realize a virtual antenna array with a correspondingly large number of virtual antenna elements.

[0051] In the case of a radar device, this object is further realized in that the radar device comprises at least one antenna device according to the invention.

[0052] The radar device has at least one antenna device with at least two antenna arrangements each having at least one Type 1 antenna element of a first antenna element type and at least one Type 2 antenna element of a second antenna element type, one of the antenna element types being a transmit antenna element and the other of the antenna element types being a receive antenna element.

[0053] According to the invention, at least one antenna device has at least two antenna arrangements of identical design, where the position of at least one antenna element of an antenna arrangement in the antenna device results from a geometric transformation of the position of at least one other corresponding antenna element of the antenna arrangement, where the geometric transformation comprises at least one rotation of the position of the antenna element of at least one second mentioned antenna arrangement around an assumed direction axis by a predetermined rotation angle, where the assumed direction axis indicates the direction in which the antenna arrangement is pointed.

[0054] In the at least two antenna arrangements, the Type 1 antenna elements may each be advantageously arranged in a plane at a corner of an imaginary planar rectangle. Two of the rectangle's sides may extend parallel to an imaginary first arrangement axis and form Type 1 antenna element major axes. Two other sides of the rectangle may extend parallel to an imaginary second arrangement axis that extends perpendicular to the first arrangement axis and form Type 1 antenna element transverse axes. At least two of the Type 2 antenna elements may be arranged on different imaginary Type 2 antenna element major axes that extend parallel to and at a distance from each other and are parallel to one of the arrangement axes.

[0055] Advantageously, the radar device may comprise means enabling it to operate according to the MIMO method, which makes it possible to improve the resolution, in particular the angular resolution, when determining the direction of detected objects.

[0056] Advantageously, the radar device may be a bistatic radar device, whereby the radar device may be used to ascertain a great deal of information about the monitored area.

[0057] This object is further achieved by the invention in that in the case of a driver assistance system, at least one radar device comprises at least one antenna device according to the invention.

[0058] The at least one radar device includes at least one antenna device having at least one antenna arrangement, the at least one antenna arrangement having at least one Type 1 antenna element of a first antenna element type and at least one Type 2 antenna element of a second antenna element type, one of the antenna element types being a transmit antenna element and the other of the antenna element types being a receive antenna element.

[0059] The radar device may be used to monitor at least one surveillance area around the vehicle for objects.

[0060] The driver assistance system may be used to operate the vehicle autonomously or semi-autonomously, in particular based on information obtained using at least one radar device, in particular based on information about objects detected using at least one radar device.

[0061] This object is also achieved by the invention in that, in the case of a vehicle, at least one radar device comprises at least one antenna device according to the invention.

[0062] The vehicle includes at least one radar device having at least one antenna device having at least one Type 1 antenna element of a first antenna element type and at least one Type 2 antenna element of a second antenna element type, one of the antenna element types being a transmitting antenna element and the other of the antenna element types being a receiving antenna element.

[0063] The at least one radar device may be used to monitor at least one surveillance area around the vehicle for objects.

[0064] Advantageously, the vehicle may have at least one bistatic radar device with two radar systems. One of the antenna arrangements of the antenna device may be assigned to each radar system. Each radar system may then be used to receive its own radar signal and the radar signals or corresponding echo signals transmitted by each of the other antenna arrangements. This allows more information to be ascertained about the surveillance area captured by the radar device.

[0065] The vehicle may advantageously comprise at least one driver assistance system, in particular at least one driver assistance system according to the invention, which may be used to operate the vehicle autonomously or semi-autonomously.

[0066] At least one radar device, in particular at least one radar device according to the invention, may be advantageously connected to or part of a driver assistance system, in particular at least one driver assistance system according to the invention, so that information obtained using the at least one radar device, in particular information about detected objects, may be used by the driver assistance system for autonomous or semi-autonomous operation of the vehicle.

[0067] Finally, this object is achieved by the invention in that, in the method, radar signals are transmitted using an antenna device according to the invention and echo signals are received using an antenna device according to the invention.

[0068] Advantageously, the radar device may be operated according to a bistatic method, which makes it possible to obtain a lot of information about the surroundings, in which each antenna arrangement may receive its own radar signal, each of the echo signals resulting from its own radar signal, and the radar signals or echo signals of the other antenna arrangements.

[0069] Advantageously, the radar device may be operated according to the MIMO method, so that the direction of an object detected using the radar device can be ascertained with precision.

[0070] Otherwise, the features and advantages given in relation to the antenna device according to the invention, the radar device according to the invention, the driver assistance system according to the invention, the vehicle according to the invention and the method according to the invention, as well as their respective advantageous configurations, apply correspondingly to one another and vice versa. Of course, individual features and advantages may also be combined with one another, in which case further advantageous effects may be obtained that exceed the sum of the individual effects.

[0071] Further advantages, features and details of the present invention will become apparent from the following description in which exemplary embodiments of the present invention are described in more detail with reference to the drawings. Those skilled in the art will also be able to consider individually the features disclosed in the drawings, the description and the claims in combination and combine them to form further useful combinations. [Brief explanation of the drawings]

[0072] [Figure 1] FIG. 1 is a plan view of a vehicle having a driver assistance system with a radar device. [Figure 2] FIG. 2 is a side view of the vehicle of FIG. [Figure 3] 2 is a functional diagram of the driver assistance system of FIG. 1, in which the radar device comprises two radar systems with an antenna device having two antenna arrangements for the radar systems. [Figure 4] 4 is a front view of an antenna device for the radar device of FIGS. 1 to 3 having two antenna arrangements according to a first exemplary embodiment; FIG. [Figure 5] 4 is a front view of an antenna arrangement according to a second exemplary embodiment of an antenna device for the radar device of FIGS. 1 to 3. FIG. [Figure 6] 6 is a front view of an antenna device for the radar device of FIGS. 1 to 3 with two antenna arrangements according to the second exemplary embodiment of FIG. 5 and a virtual antenna array realized with the antenna device. [Figure 7] 4 is a front view of an antenna arrangement according to a third exemplary embodiment of an antenna device for the radar device of FIGS. 1 to 3. FIG. [Figure 8] 4 is a front view of an antenna arrangement according to a fourth exemplary embodiment of an antenna device for the radar device of FIGS. 1 to 3. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0073] In the drawings, identical components are designated by the same reference numerals.

[0074] Figure 1 shows a plan view of a vehicle 10 in the form of an automobile. Figure 2 shows a side view of the vehicle 10.

[0075] The vehicle 10 is equipped with a driver assistance system 12. By way of example, the driver assistance system 12 includes a radar device 13 and a control unit 16. Figure 3 shows the driver assistance system 12 including the radar device 13 as a functional diagram.

[0076] The radar device 13 is positioned, for example, in front of the vehicle 10. The radar device 13 may be used to monitor a surveillance area 18 in front of the vehicle 10 for objects 20. In Figures 1 and 2, by way of example, the objects 20 are positioned in front of the vehicle 10 and can be detected using the radar device 13. The radar device 13 may also be positioned elsewhere within the vehicle 10 and in various alignments. It is also possible to provide multiple radar devices 13 in various locations and with various alignments.

[0077] The radar device 13 may be used to ascertain object information, such as distance D, direction, eg, azimuth angle Θ and elevation angle Φ, and velocity of the detected object 20 relative to the vehicle 10 .

[0078] The radar device 13 is operatively connected to a controller 16 of the driver assistance system 12. Accordingly, object information identified using the radar device 13 may be transmitted to the controller 16. The driver assistance system 12 may be used to operate the vehicle 10 autonomously or semi-autonomously.

[0079] For simple directions, the corresponding coordinates in a Cartesian xyz coordinate system are shown in Figures 1-8. By way of example, the x-axis of the xyz coordinate system extends parallel to the longitudinal vehicle axis 22 of the vehicle 10. The y-axis extends parallel to the transverse vehicle axis 24 of the vehicle 10, and the z-axis extends upward in space, perpendicular to the xy plane.

[0080] Radar device 13 may be used to transmit radar signals 26 into surveillance area 18. Radar signals 26 reflected from objects 20 in the direction of radar device 13 may be received by radar device 13 as echo signals 28. Corresponding object information may be ascertained from echo signals 28.

[0081] The radar device 13 comprises two radar systems 14. Each of the radar systems 14 comprises an antenna arrangement 30 and a control and evaluation unit 32. The two antenna arrangements 30 are combined to form a common antenna device 33. By way of example, the two antenna arrangements 30 are fixed on a common carrier.

[0082] An antenna device 33 comprising two antenna arrangements 30 according to a first exemplary embodiment is shown in FIG. 4 in a front view seen from the surveillance area 18 .

[0083] The antenna device 33 comprises two antenna element types, namely, a transmitting antenna element Tx and a receiving antenna element Rx. The transmitting antenna element Tx may be used to transmit the radar signal 26. The receiving antenna element Rx may be used to receive the echo signal 28.

[0084] The two antenna arrangements 30 of the antenna device 33 are of identical design. Within the antenna device 33, the two antenna arrangements 30 are rotated by 180° relative to each other and displaced relative to each other in the direction of the y-axis, as will be explained in more detail below.

[0085] Each of the antenna arrangements 30 has four transmit antenna elements Tx and four receive antenna elements Rx. The transmit antenna elements Tx and receive antenna elements Rx of each antenna arrangement 30 are arranged on a common carrier in the form of a carrier plate 34. The antenna device 33 therefore has two carrier plates 34. The two carrier plates 34 may be fixed to a common carrier, as will not be further noted here.

[0086] The control and evaluation unit 32 may be used to drive the transmitting antenna elements Tx of each antenna arrangement 30 to emit radar signals 26. Furthermore, the control and evaluation unit 32 may be used to acquire and evaluate echo signals 28 that are received using the receiving antenna elements Rx of each antenna arrangement 30 and converted into electrical receive signals. The control and evaluation unit 32 may be used to ascertain corresponding object information from the electrical receive signals and transmit the information to the control unit 16.

[0087] Furthermore, the control and evaluation units 32 of the two antenna arrangements 30 are signal-connected to each other. Thus, the radar system 14 may be synchronized. The radar device 13 is operated according to a bistatic method. In the bistatic method, each of the antenna arrangements 30 may receive its own radar signal 26 or a corresponding echo signal 28, as well as echo signals 28 resulting from the radar signal 26 of each of the other antenna arrangements 30.

[0088] The radar system 14 is operated according to the MIMO (multiple-input, multiple-output) method. In the MIMO method, the transmit antenna elements Tx are separately driven by transmit control signals from the control and evaluation unit 32. The corresponding transmit control signals are used to differentiate the radar signals 26 transmitted using the individual transmit antenna elements Tx, for example by coding. At the receiver side, it is therefore possible to assign the signal paths of the radar signals 26 and the corresponding echo signals 28 to the respective transmit antenna elements Tx. The receive antenna elements Rx are read separately accordingly. In this case, the electrical receive signals converted from the echo signals 28 by the antenna elements Rx are assigned accordingly. The separate driving or reading allows a virtual antenna array 36 to be realized using all positions of the transmit antenna elements Tx and all positions of the receive antenna elements Rx.

[0089] Figure 6 shows, by way of example, a virtual antenna array 36 that can be realized by an antenna device 33 having an antenna arrangement 30 according to the second exemplary embodiment shown in Figure 5. The virtual antenna array 36 shown in Figure 6 may also be realized using an antenna device 33 having an antenna arrangement 30 according to the first exemplary embodiment of Figure 4.

[0090] 4 to 8, the transmit antenna elements Tx with their phase centers 38 are shown as filled circles. The receive antenna elements Rx with their phase centers 40 are shown as filled squares. For clarity, only the transmit antenna elements Tx and some of their phase centers 38, and only the receive antenna elements Rx and some of their phase centers 40, are labeled with reference numerals.

[0091] Figure 4 shows two antenna arrangements 30 of an antenna device 33. As already mentioned, the antenna arrangements 30 are of identical design.

[0092] The antenna arrangements 30, as viewed in the direction of the y-axis, are spaced apart at a distance 84 at the same height as viewed in the direction of the z-axis. The distance 84 is, for example, the distance between the centers of the antenna arrangements 30. The distance 84 is an integer multiple of a predetermined basic distance λ / 2. The basic distance λ / 2 corresponds to half the wavelength λ / 2 of the radar signal 26 transmitted using the radar system 14. For example, the distance 84 is 400 times the basic distance, i.e., 200λ. In FIG. 4, the distance 84 is not drawn to scale.

[0093] Both antenna arrangements 30 are pointed in the same direction, i.e., toward the monitoring area 18. The directional axes 86 of the respective antenna arrangements 30 extend parallel to one another, as shown in Figure 3. The directional axes 86 indicate the direction relative to the antenna device 33 toward which the respective antenna arrangements 30 are pointed. In Figure 4, the directional axes 86 extend perpendicular to the plane of the drawing. The antenna arrangement 30 on the right side of Figure 4 is rotated by a rotation 88 around its directional axis 86 by a rotation angle of 180° compared to the antenna arrangement 30 on the left side.

[0094] The positions of the transmit antenna elements Tx and receive antenna elements Rx of the right antenna arrangement 30 result from a geometric transformation of the positions of the corresponding transmit antenna elements Tx and receive antenna elements Rx of the left antenna arrangement 30. The geometric transformation includes a rotation 88 about the direction axis 86, which is a rotation angle of 180°, and a displacement 94 in the direction of the y-axis by the distance 84. The rotation 88 of the positions of the transmit antenna elements Tx and receive antenna elements Rx is achieved by rotating the antenna arrangement 30.

[0095] The two antenna arrangements 30 are described below using the example of the antenna arrangement 30 on the left side of FIG.

[0096] The antenna arrangement 30 has a transmit antenna element field 42 consisting of four transmit antenna elements Tx and a receive antenna element field 44 consisting of four receive antenna elements Rx. In the antenna arrangement 30 shown in Figure 4, the receive antenna elements 44 are positioned to the right and outside of the transmit antenna elements 42. The transmit antenna element field 42 and the receive antenna element field 44 may also be positioned differently relative to each other. As shown in a second exemplary embodiment in Figure 5, the transmit antenna element field 42 and the receive antenna element field 44 may overlap.

[0097] The transmit antenna elements Tx are arranged in the transmit plane at the corners of an imaginary planar rectangle 46. The rectangle 46 has sides of different lengths. The two long sides of the rectangle 46 extend parallel to an imaginary first arrangement axis 48 that extends horizontally and is parallel to the y-axis of FIG. 4, forming an imaginary transmit antenna element major axis 50. The other two short sides of the rectangle 46 extend parallel to an imaginary second arrangement axis 52 that extends perpendicular to and parallel to the z-axis of FIG. 4, forming an imaginary transmit antenna element horizontal axis 54. The second arrangement axis 52 extends perpendicular to the first arrangement axis 48. Thus, the transmit antenna elements Tx form a rectangular transmit antenna element field 42.

[0098] The directional axis 86 extends perpendicular to the plane spanned by the first alignment axis 48 below the second alignment axis 52 .

[0099] The phase center 38 of a transmit antenna element Tx is located at the intersection of the transmit antenna element major axis 50 and the corresponding transmit antenna element transverse axis 54 .

[0100] The respective distances between adjacent transmitting antenna element major axes 50 or adjacent transmitting antenna element transverse axes 54, i.e., between respective adjacent antenna element axes of the same antenna element type, are integer multiples of a predetermined basic distance λ / 2.

[0101] 4, the distance 56 between the transmitting antenna element major axes 50 corresponds to 10 times the fundamental distance λ / 2, or 5λ. The distance 58 between the transmitting antenna element transverse axes 54 corresponds to 18 times the fundamental distance λ / 2, or 9λ.

[0102] The phase centers 40 of the four receive antenna elements Rx are arranged so as to be distributed across two assumed receive antenna element major axes 60 and four assumed receive antenna element transverse axes 62. In this case, each phase center 40 is arranged at the intersection of the receive antenna element major axis 60 and the receive antenna element transverse axis 62.

[0103] The receive antenna element major axes 60 extend parallel to and spaced apart from one another and parallel to the first alignment axis 48. The four receive antenna element transverse axes 62 extend parallel to and spaced apart from one another and perpendicular to the receive antenna element major axes 60 and parallel to the second alignment axis 52.

[0104] The receive antenna element major axis 60 and the receive antenna element transverse axis 62 extend in an assumed receive plane. The receive antenna element major axis 60 and the receive antenna element transverse axis 62, i.e., the receive plane, also extend parallel to the plane spanned by the transmit antenna element major axis 50 and the transmit antenna element transverse axis 54. The receive plane, which includes the receive antenna element major axis 60 and the receive antenna element transverse axis 62, extends parallel to the transmit plane, which includes the transmit antenna element major axis 50 and the transmit antenna element transverse axis 54.

[0105] 4, the receive antenna element major axis 60, the receive antenna element lateral axis 62, the transmit antenna element major axis 50, and the transmit antenna element lateral axis 50 are positioned in a common plane. Thus, all of the transmit antenna elements Tx and all of the receive antenna elements Rx are positioned in a common plane.

[0106] The phase center 40 of one of the receive antenna elements Rx is located on one of the receive antenna element major axes 60, i.e., the upper receive antenna element major axis 60 in Figure 4. The phase centers 40 of the other three receive antenna elements Rx are each located on another lower receive antenna element major axis 60. The phase centers 40 of the four receive antenna elements Rx are located on different receive antenna element horizontal axes 62.

[0107] The receive antenna element horizontal axis 62 on which the phase center 40 of the receive antenna element Rx, which is placed alone on the upper receive antenna element major axis 60, is located is located to the left of the receive antenna element field 44, i.e., not between two other receive antenna element horizontal axes 62.

[0108] The distance between adjacent receiving antenna element major axes 60 or adjacent receiving antenna element transverse axes 62, i.e., between adjacent antenna element axes of the same antenna element type, is an integer multiple of the basic distance λ / 2. The distances between adjacent receiving antenna element transverse axes 62 are all different.

[0109] On the left side of the receiving antenna element field 44 in Figure 4, the distance 64 between the receiving antenna element horizontal axis 62 on which the phase center 40 of a single receiving antenna element Rx arranged alone on the corresponding receiving antenna element main axis 60 is located and the adjacent second receiving antenna element horizontal axis 62 from the left is smaller than the other distances 66 and 68 between the other adjacent receiving antenna element horizontal axes 62, respectively.

[0110] In the exemplary embodiment shown in FIG. 4 , the distance 70 between the receive antenna element major axes 60 corresponds to twice the fundamental distance λ / 2, i.e., λ. The distance 64 between the receive antenna element horizontal axis 62 including a single receive antenna element Rx on the left side of the receive antenna element field 44 and the adjacent second receive antenna element horizontal axis 62 corresponds to one fundamental distance λ / 2. The distance 66 between the second receive antenna element horizontal axis 62 and the third receive antenna element horizontal axis 62 from the left corresponds to twice the fundamental distance λ / 2, i.e., λ. The distance 68 between the third receive antenna element horizontal axis 62 from the left and the fourth receive antenna element horizontal axis 62 from the left, i.e., the receive antenna element horizontal axis 62 on the right side of the receive antenna field 44 in FIG. 4 , corresponds to three fundamental distances λ / 2, i.e., 1.5λ.

[0111] The long side of the rectangle 46 of the transmit antenna element Tx, i.e., the long side of the transmit antenna element field 42, extends parallel to the alignment axis along which the receive antenna element axis extends, in the direction of maximum extent of the receive antenna element field 40. In the illustrated exemplary embodiment, the transmit antenna element major axis 50 and the receive antenna element major axis 60 extend parallel to each other and parallel to the first alignment axis 48.

[0112] The extent of the transmit antenna element field 42 in the direction of the first placement axis 48 is greater than the extent 72 of the receive antenna element field 44 in the direction of the first placement axis 48. In the exemplary embodiment shown in FIG. 4 , the extent of the transmit antenna element field 42 in the direction of the first placement axis 48 corresponds to the distance 58 between the transmit antenna element horizontal axes 54, i.e., 18 times the fundamental distance λ / 2, or 9λ. The extent 72 of the receive antenna element field 44 in the direction of the first placement axis 48 corresponds to the sum of the distances 64, 66, and 68 between the receive antenna element horizontal axes 62, i.e., 6 times the fundamental distance λ / 2, or 3λ.

[0113] The extent of the transmit antenna element field 42 in the direction of the second arrangement axis 52 is greater than the extent of the receive antenna element field 44 in the direction of the second arrangement axis 52. In the illustrated exemplary embodiment, the extent of the transmit antenna element field 42 in the direction of the second arrangement axis 52 corresponds to the distance 56 between the transmit antenna element major axes 50, i.e., 10 times the fundamental distance λ / 2, i.e., 5λ. The extent of the receive antenna field 44 in the direction of the second arrangement axis 52 corresponds to the distance 70 between the receive antenna element major axes 60, i.e., 2 times the fundamental distance λ / 2, i.e., λ.

[0114] 5 illustrates an antenna arrangement 30 according to a second exemplary embodiment. The second exemplary embodiment of the antenna arrangement 30 includes the transmit antenna element field 42 and the receive antenna element field 44 of the first exemplary embodiment of the antenna arrangement 30 in FIG. 4. In contrast to the antenna arrangement 30 according to the first exemplary embodiment of FIG. 4, in the second exemplary embodiment, the receive antenna element field 44 is disposed within the transmit antenna element field 42. In this case, the lower transmit antenna element major axis 50 and the lower receive antenna element major axis 60 coincide. Furthermore, the left transmit antenna element horizontal axis 54 and the left receive antenna element horizontal axis 62 coincide.

[0115] The receive antenna element field 44 is positioned such that the lower left transmit antenna element Tx is located at the intersection of the lower receive antenna element major axis 60 and the left receive antenna element horizontal axis 62. The lower left transmit antenna element Tx is located, so to speak, in a gap in the receive antenna element field 44 resulting from the upward offset of the left receive antenna element Rx relative to the upper receive antenna element major axis 60. Overall, the alternative antenna arrangement 30 of FIG. 5 is a more space-saving design than the antenna arrangement 30 of FIG. 4.

[0116] The virtual antenna array 36 shown in FIG. 6 can be realized both with an antenna device 33 having two antenna arrangements 30 according to the first exemplary embodiment of FIG. 4 and with an antenna device 33 having two antenna arrangements 30 according to the second exemplary embodiment of FIG. 5.

[0117] Figure 6 shows an antenna device 33 having two of the antenna arrangements 30 according to the second exemplary embodiment of Figure 5 and a virtual antenna array 36 that can be realized thereby. In this case, similar to the antenna device 33 of Figure 4, the right-hand antenna arrangement 30 is rotated 180° about its orientation axis 86. Furthermore, the right-hand antenna arrangement 30 is displaced to the right by a distance 84 of 200λ in the direction of the y-axis and upward in the direction of the z-axis. The illustration of Figure 6 is not to scale in the direction of the y-axis.

[0118] Corresponding to the antenna arrangement 30 according to the second exemplary embodiment of Fig. 5 and the antenna arrangement 30 according to the first exemplary embodiment of Fig. 4, an antenna array 36 having a total of 64 virtual antenna elements Vx is generated during operation of the radar system 14. The virtual antenna array 36 is realized through a geometric convolution of the geometric positions of the phase centers 38 of the transmitting antenna elements Tx and the phase centers 40 of the receiving antenna elements Rx of the two antenna arrangements 30 of the antenna device 33. The virtual antenna elements Vx act as virtual receiving antenna elements for the echo signals 28.

[0119] 6 shows the virtual antenna elements Vx of the virtual antenna array 36 as open triangles, with their respective virtual phase centers 73. For clarity, only some of the virtual antenna elements Vx and of the corresponding phase centers 73 are labeled with reference numerals as an example in FIG.

[0120] The virtual antenna array 36 comprises 16 virtual antenna element fields 74, each having four virtual antenna elements Vx. The virtual antenna element fields 74 are identical in design, size, and alignment. Eight of the antenna element fields 74 are oriented in the same direction as the receive antenna element fields 44 of the left antenna arrangement 30. The other eight antenna element fields 74 are rotated 180° and oriented in the same direction as the receive antenna element fields 44 of the right antenna arrangement 30, which are also rotated 180°.

[0121] The four virtual antenna elements Vx of each virtual antenna element field 74 are arranged according to the four receive antenna elements Rx of the antenna arrangement 30 or of the antenna arrangement 30 rotated by 180°.

[0122] The virtual antenna element fields 74 are arranged in two rows, each containing eight antenna element fields 74. Each of the rows extends parallel to the first arrangement axis 48, i.e., parallel to the y-axis, such that in each case, two of the virtual antenna element fields 74 are arranged below the other in the respective row.

[0123] In both rows, in each case, as viewed in the direction of the arrangement axis 48, from the left, the first, second, third and fifth virtual antenna element fields 74 are oriented according to the receive antenna element fields 44 of the left antenna arrangement 30. As viewed in the direction of the arrangement axis 48, the fourth, sixth, seventh and eighth virtual antenna element fields 74 are oriented according to the receive antenna element fields 44 of the right antenna arrangement 30, i.e., rotated by 180° compared to the antenna element fields 74 on the left.

[0124] In both columns, the third and fourth virtual antenna element fields 74 from the left overlap each other. The virtual antenna element field Vx on the right side of each of the third virtual antenna element fields 74 matches the virtual antenna element Vx on the left side of each of the fourth virtual antenna element fields 74. Also, the fifth and sixth virtual antenna element fields 74 from the left overlap each other. The virtual antenna element field Vx on the right side of each of the fifth virtual antenna element fields 74 matches the virtual antenna element Vx on the left side of each of the sixth virtual antenna element fields 74.

[0125] The matching virtual antenna elements Vx may additionally be used to synchronize the phase between the radar signals 26 of the two radar systems 14. The echo signal 28 arriving from the object 20 generates the same phase at both matching virtual antenna elements Vx.

[0126] 6 , the virtual phase center 73 of the topmost virtual antenna element Vx of the virtual antenna array 36 is located on the upper imaginary major axis 76. The phase center 73 of the bottommost virtual antenna element Vx is located on the lower imaginary major axis 76. The distance 80 between the upper imaginary major axis 76 and the lower imaginary major axis 76 indicates the aperture of the virtual antenna array 36 in the vertical direction, e.g., in the z-axis direction. The distance 80, and therefore the vertical aperture, corresponds to 14 times the fundamental distance λ / 2, i.e., 7λ.

[0127] The virtual phase center 73 of the leftmost virtual antenna element Vx of the virtual antenna array 36 in FIG. 6 is located on the left virtual horizontal axis 78. In this example, the left virtual horizontal axis 78 coincides with the left transmit antenna element horizontal axis 54 and the left receive antenna element horizontal axis 62 of the left antenna arrangement 30. The phase center 73 of the rightmost virtual antenna element Vx is located on the right virtual horizontal axis 78. The distance 82 between the left virtual horizontal axis 78 and the right virtual horizontal axis 78 indicates the aperture of the virtual antenna array 36 in the horizontal direction, e.g., in the direction of the y-axis. The distance 82, and therefore the horizontal aperture, is greater than 800 times the base distance, i.e., >400λ. The distance 82 is greater than twice the distance 84 between the antenna arrangements 30.

[0128] 7 shows an antenna arrangement 30 according to a third exemplary embodiment for an antenna device 33. Elements similar to those of the first exemplary embodiment of FIG. 4 are designated by the same reference numerals. The third exemplary embodiment differs from the first exemplary embodiment in that the phase centers 40 of the four receive antenna elements Rx are distributed among three potential receive antenna element major axes 60 and four potential receive antenna element transverse axes 62. In this case, each phase center 40 is located at the intersection of the receive antenna element major axis 60 and the receive antenna element transverse axis 62.

[0129] The phase center 40 of one of the receive antenna elements Rx is located on one of the receive antenna element major axes 60, i.e., the upper receive antenna element major axis 60 in Figure 7. The phase center 40 of another receive antenna element Rx is located on another of the receive antenna element major axes 60, i.e., the lower receive antenna element major axis 60 in Figure 7. The phase centers 40 of two further receive antenna elements Rx are located on a third, central receive antenna element major axis 60. The phase centers 40 of four receive antenna elements Rx are located on different receive antenna element horizontal axes 62.

[0130] The receive antenna element horizontal axis 62 on which the phase center 40 of the receive antenna element Rx arranged alone on the upper receive antenna element major axis 60 is located is located on the left side of the receive antenna element field 44, i.e., not between two other receive antenna element horizontal axes 62. The receive antenna element horizontal axis 62 on which the phase center 40 of the receive antenna element Rx arranged alone on the lower receive antenna element major axis 60 is located is located on the right side of the receive antenna element field 44, i.e., not between two other receive antenna element horizontal axes 62.

[0131] In each case, one of the receive antenna elements Rx is located on one of the two outer antenna element horizontal axes 62 of the receive antenna element field 44. The receive antenna elements Rx located on the two outer antenna element horizontal axes 62 are each located on one of the two outer antenna element major axes 60. In the exemplary embodiment of FIG. 7 , the single receive antenna element Rx at the upper left of the receive antenna field 44 is located at the intersection of the upper receive antenna element major axis 60 and the left receive antenna element horizontal axis 62. The single receive antenna element Rx at the lower right of the receive antenna field 44 is positioned at the intersection of the lower receive antenna element major axis 60 and the right receive antenna element horizontal axis 62. The two outer receive antenna elements Rx are located on diagonals of the receive antenna field 44.

[0132] On the other hand, in FIG. 7, the distance 70 between the main axis 60 of the upper receiving antenna element and the main axis 60 of the central receiving antenna element is different from the distance 90 between the main axis 60 of the central receiving antenna element and the main axis 60 of the lower receiving antenna element.

[0133] 7 , the distance 70 between the upper and central receive antenna element major axes 60 corresponds to three times the fundamental distance λ / 2, i.e., 1.5λ. The distance 90 between the central and lower receive antenna element major axes 60 corresponds to the fundamental distance λ / 2. The extent 92 of the receive antenna element field 44 in the direction of the second arrangement axis 52, i.e., the vertical direction (z-axis), corresponds to the sum of the distances 70 and 90 between the receive antenna element major axes 60. In the illustrated exemplary embodiment, the extent 92 corresponds to four times the fundamental distance λ / 2, i.e., 2λ.

[0134] 7, the distance 66 between the second and third receive antenna element horizontal axes 62 corresponds to the distance 68 between the third and fourth receive antenna element horizontal axes 62. The distance 64 between the first and second receive antenna element horizontal axes 62, as well as the distances 66 and 68 between each of the other adjacent receive antenna element horizontal axes 62, are different.

[0135] On the left side of the receiving antenna element field 44 in Figure 7, the distance 64 between the receiving antenna element horizontal axis 62 on which the phase center 40 of a single receiving antenna element Rx arranged alone on the upper receiving antenna element main axis 60 is located and the adjacent second receiving antenna element horizontal axis 62 from the left is smaller than the other distances 66 and 68 between the other adjacent receiving antenna element horizontal axes 62, respectively.

[0136] The distance 64 between the horizontal axis 62 of the receive antenna element including the single receive antenna element Rx on the left side of the receive antenna element field 44 and the horizontal axis 62 of the adjacent second receive antenna element corresponds to 1 times the basic distance λ / 2. The distance 66 between the horizontal axis 62 of the second receive antenna element and the horizontal axis 62 of the third receive antenna element from the left corresponds to 2 times the basic distance λ / 2, i.e., λ. The distance 68 between the horizontal axis 62 of the third receive antenna element from the left and the horizontal axis 62 of the fourth receive antenna element from the left, i.e., the horizontal axis 62 of the receive antenna element on the right side of the receive antenna field 44 in FIG. 7, corresponds to 2 times the basic distance λ / 2, i.e., λ.

[0137] The extent 72 of the receive antenna element field 44 in the direction of the first alignment axis 48 corresponds to the sum of the distances 64, 66 and 68 between the receive antenna element transverse axes 62, ie, 5 times the basic distance λ / 2, or 2.5λ.

[0138] 8 shows an antenna arrangement 30 according to a fourth exemplary embodiment for an antenna device 33. Elements similar to those of the third exemplary embodiment of FIG. 7 are given the same reference numerals. The fourth exemplary embodiment differs from the third exemplary embodiment in that the transmitting antenna elements Tx are arranged at the corners of an imaginary planar rectangle 46 of equal side lengths. The rectangle 46 is therefore square. The transmitting antenna elements Tx therefore form a square transmitting antenna element field 42.

[0139] 8, the distance 56 between the transmitting antenna element major axes 50 corresponds to five times the fundamental distance λ / 2, or 2.5λ. The distance 58 between the transmitting antenna element transverse axes 54 also corresponds to five times the fundamental distance λ / 2, or 2.5λ.

[0140] The distance 70 between the upper and central receiving antenna element major axes 60 corresponds to three times the basic distance λ / 2, i.e., 1.5λ. The distance 90 between the central and lower receiving antenna element major axes 60 corresponds to one time the basic distance λ / 2.

[0141] The distance 64 between the horizontal axis 62 of the receiving antenna element on the left side of the receiving antenna element field 44 and the horizontal axis 62 of the adjacent second receiving antenna element corresponds to 1 times the basic distance λ / 2. The distance 66 between the horizontal axis 62 of the second receiving antenna element and the horizontal axis 62 of the third receiving antenna element from the left also corresponds to 1 times the basic distance λ / 2. The distance 68 between the horizontal axis 62 of the third receiving antenna element from the left and the horizontal axis 62 of the fourth receiving antenna element from the left, i.e., the horizontal axis 62 of the receiving antenna element on the right side of the receiving antenna element field 44 in FIG. 8, corresponds to 2 times the basic distance λ / 2, i.e., λ.

[0142] The extent 72 of the receive antenna element field 44 in the direction of the first alignment axis 48, i.e., the horizontal direction, corresponds to the sum of the distances 64, 66, and 68 between the receive antenna element horizontal axes 62, i.e., four times the fundamental distance λ / 2, or 2λ. The extent 92 of the receive antenna element field 44 in the direction of the second alignment axis 52, i.e., the vertical direction, corresponds to the sum of the distances 70 and 90 between the receive antenna element major axes 60, i.e., four times the fundamental distance λ / 2, or 2λ. Thus, the extent 72 of the receive antenna element field 44 in the horizontal direction corresponds to the extent 92 in the vertical direction.

[0143] In the antenna arrangements 30 according to the third exemplary embodiment of Figure 7 and the fourth exemplary embodiment of Figure 8, the respective receive antenna element fields 44 and transmit antenna element fields 42 may overlap, similar to the first exemplary embodiment of Figure 4. Furthermore, the antenna device 33 may be implemented similarly to the first exemplary embodiment of Figure 4, in each case having two corresponding antenna arrangements 30.

Claims

1. An antenna device (33) for a radar device (13), in particular for a bistatic radar device (13), in particular for a radar device (13) on a vehicle (10), having at least one antenna arrangement (30) with at least one type 1 antenna element (Tx) of a first antenna element type and at least one type 2 antenna element (Rx) of a second antenna element type, wherein one of the antenna element types is a transmitting antenna element (Tx) and the other of the antenna element types is a receiving antenna element (Rx), the antenna device (33) has at least two antenna arrangements (30) of identical design, the position of at least one of the antenna elements (Rx, Tx) of the antenna arrangement (30) in the antenna device (33) resulting from a geometric transformation of the position of the corresponding antenna element (Rx, Tx) of at least one other of the antenna arrangements (30), the geometric transformation comprising at least one rotation (88) of the position of the antenna element (Rx, Tx) of the at least one second-mentioned antenna arrangement (30) around the assumed direction axis (86) by a predetermined rotation angle, the assumed direction axis (86) indicating the direction in which the antenna arrangement (30) is pointed, An antenna device (33) characterized in that:

2. the respective directional axes (86) of the at least two antenna arrangements (30) extend parallel; and / or the respective directional axes (86) extend perpendicular to a plane in which the antenna elements (Rx, Tx) of the antenna arrangement (30) are arranged; 2. An antenna device according to claim 1, characterized in that it comprises:

3. The predetermined rotation angle is 180°. and / or the geometric transformation includes at least one displacement (94) of the directional axis (86) of the at least one antenna arrangement (30) over a predetermined distance (84); and / or the at least two antenna arrangements (30) are arranged at a predetermined distance (84) from each other; 3. An antenna device according to claim 1 or 2, characterized in that it comprises:

4. each of the at least two antenna arrangements (30) has four Type 1 antenna elements (Tx) arranged in a plane at the corners of an imaginary planar rectangle (46), two sides of the rectangle (46) extending parallel to an imaginary first arrangement axis (48) and forming a Type 1 antenna element major axis (50), and two other sides of the rectangle (46) extending parallel to an imaginary second arrangement axis (52) extending perpendicular to the first arrangement axis (48) and forming a Type 1 antenna element transverse axis (54); each of said at least two antenna arrangements (30) having at least two Type 2 antenna elements (Rx) extending parallel to and at a distance from each other and arranged on different assumed Type 2 antenna element main axes (60) parallel to one of said arrangement axes (48); Antenna device according to any one of claims 1 to 3, characterized in that it comprises:

5. 5. The antenna device according to claim 4, characterized in that at least two of said type 2 antenna elements (Rx) are arranged on different assumed type 2 antenna element transverse axes (62) extending parallel to each other, spaced apart and perpendicular to said type 2 antenna element major axis (60).

6. Each of the at least two antenna arrangements (30) has at least three type 2 antenna element horizontal axes (62) spaced apart from one another and at least three type 2 antenna elements (Rx), at least three of the type 2 antenna elements (Rx) being arranged on different type 2 antenna element horizontal axes (62); and / or each of the at least two antenna arrangements (30) has at least three type 2 antenna elements (Rx), and only one of the type 2 antenna elements (Tx) is arranged on at least one of the type 2 antenna element main axes (60), and / or at least two of the type 2 antenna elements (Tx) are arranged on at least one of the type 2 antenna element main axes (60), and in particular, at least one of the type 2 antenna element transverse axes (62) including one of the type 2 antenna elements (Rx) arranged solely on a type 2 antenna element main axis (60) may not be located between two other type 2 antenna element transverse axes (62); and / or each of the at least two antenna arrangements (30) has at least four type 2 antenna elements (Rx), only one of the type 2 antenna elements (Rx) is arranged on at least one of the type 2 antenna element major axes (60), and / or at least two of the type 2 antenna elements (Rx) are arranged on at least one of the type 2 antenna element major axes (60), and a distance (64) between at least one type 2 antenna element horizontal axis (62) on which a type 2 antenna element (Rx) arranged solely on the corresponding type 2 antenna element major axis (60) is located and at least one adjacent type 2 antenna element horizontal axis (62) is at most comparable to other distances (66, 68) between the respective adjacent type 2 antenna element horizontal axes (62); and / or each of said at least two antenna arrangements (30) having exactly four type 2 antenna elements (Rx); 6. An antenna device according to claim 4 or 5, characterized in that it comprises:

7. In each of the at least two antenna arrangements (30), the type 2 antenna element axes, in particular the type 2 antenna element major axis (60) and the type 2 antenna element lateral axis (62), extend in a common imaginary plane; and / or In each of the at least two antenna arrangements (30), the type 2 antenna element axes, in particular the type 2 antenna element major axis (60) and the type 2 antenna element lateral axis (62), extend parallel to a plane spanned by the type 1 antenna element major axis (50) and the type 1 antenna element lateral axis (54); and / or In each of said at least two antenna arrangements (30), said type 1 antenna element (Tx) and said type 2 antenna element (Rx) are arranged on a common carrier (34), in particular on a common carrier plate; and / or all type 1 antenna element axes (50, 54) and type 2 antenna element axes (60, 62) of the antenna arrangement (30) of the antenna device (33) extend in a common imaginary plane; Antenna device according to any one of claims 4 to 6, characterized in that it comprises:

8. 8. The antenna device according to claim 4, wherein in each of the at least two antenna arrangements (30), the phase centers (38, 40) of at least some of the antenna elements (Rx, Tx), in particular the phase centers (38, 40) of all the antenna elements (Rx, Tx), are arranged on the corresponding antenna element axis (50, 54, 60, 62), in particular the antenna element main axis (50, 60) and / or the antenna element transverse axis (54, 62).

9. 9. The antenna device according to claim 4, wherein in each of the at least two antenna arrangements (30), a respective distance between adjacent antenna element axes for the same antenna element type, in particular a respective distance (56, 70) between adjacent antenna element major axes (50, 60) and / or a respective distance (58, 64, 66, 68) between adjacent antenna element lateral axes (54, 62) for the same antenna element type, is an integer multiple of a predetermined basic distance, the basic distance corresponding to half the wavelength of a radar signal (26) transmitted using the radar system (14).

10. In each of the at least two antenna arrangements (30), a range (58) of a transmitting antenna element field (42) consisting of the antenna elements of the transmitting antenna element (Tx) type in the direction of the first arrangement axis (48) is greater than a range (72) of a receiving antenna element field (44) consisting of the antenna elements of the receiving antenna element (Rx) type in the direction of the first arrangement axis (48), and a range (54) of the transmitting antenna element field (42) in the direction of the second arrangement axis (52) is greater than a range (70) of the receiving antenna element field (44) in the direction of the second arrangement axis (52). Antenna device according to any one of claims 4 to 9, characterized in that it is

11. the at least two antenna arrangements (30) are designed for use in the radar system (14) according to a MIMO method; and / or The type 1 antenna elements (Tx) of the at least two antenna arrangements (30) are each separately activatable and / or readable, and the type 2 antenna elements (Rx) of the at least two antenna arrangements (30) are each separately activatable and / or readable. Antenna device according to any one of claims 1 to 10, characterized in that it comprises:

12. 12. A radar device (13), in particular a radar device (13) for a vehicle (10), having at least one antenna device (33) with at least one antenna arrangement (30) having at least one type 1 antenna element (Tx) of a first antenna element type and at least one type 2 antenna element (Rx) of a second antenna element type, wherein one of the antenna element types is a transmitting antenna element (Tx) and the other of the antenna element types is a receiving antenna element (Rx), characterized in that the radar device (13) has at least one antenna device (33) according to any one of claims 1 to 11.

13. 12. A driver assistance system (12) having at least one radar device (13), in particular a bistatic radar device (13), comprising at least one antenna device (33) having at least one antenna arrangement (30) for the at least one radar device (13), wherein the at least one antenna arrangement (30) comprises at least one type 1 antenna element (Tx) of a first antenna element type and at least one type 2 antenna element (Rx) of a second antenna element type, one of the antenna element types being a transmitting antenna element (Tx) and the other of the antenna element types being a receiving antenna element (Rx), characterized in that the at least one radar device (13) comprises at least one antenna device (33) according to any one of claims 1 to 11.

14. 12. A vehicle (10) having at least one radar device (13), in particular a bistatic radar device (13), comprising at least one antenna device (33) having at least one antenna arrangement (30) for the at least one radar device (13), wherein the at least one antenna arrangement (30) has at least one type 1 antenna element (Tx) of a first antenna element type and at least one type 2 antenna element (Rx) of a second antenna element type, one of the antenna element types being a transmitting antenna element (Tx) and the other of the antenna element types being a receiving antenna element (Rx), characterized in that the at least one radar device (13) has at least one antenna device (33) according to any one of claims 1 to 11.

15. 12. A method for operating a radar device (13), in particular a radar device (13) for a vehicle (10), in particular a bistatic radar device (13), having at least one antenna device (33) with at least one antenna arrangement (30) having at least one type 1 antenna element (Tx) of a first antenna element type and at least one type 2 antenna element (Rx) of a second antenna element type, wherein the antenna elements (Tx) of one of the antenna element types are used to transmit a radar signal (26) and the antenna elements (Rx) of the other of the antenna element types are used to receive an echo signal (28) resulting from the transmitted radar signal (26), characterized in that the radar signal (26) is transmitted using the antenna device (33) of any one of claims 1 to 11 and the echo signal (28) is received using the antenna device (33) of any one of claims 1 to 11.

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