Antenna arrangement for a radar system having at least one square antenna element field, radar system, driver assistance system, vehicle, and method for operating a radar system

Abstract

The present invention relates to an antenna arrangement (30) for a radar system, in particular for a radar system for a vehicle, a radar system, a driver assistance system, a vehicle, and a method for operating a radar system. The antenna arrangement (30) has four Type 1 antenna elements (Tx) of a first antenna element type and at least two Type 2 antenna elements (Rx) of a second antenna element type, one of the antenna element types being a transmit antenna element (Tx) and the other of the antenna element types being a receive antenna element type (Rx). The Type 1 antenna elements (Tx) are arranged in a plane at the corners of a notional level rectangle (46) to form a Type 1 antenna element field (42), two sides of which extend along Type 1 antenna element major axes (50) parallel to a notional first arrangement axis (48), and the other two sides of the rectangle (46) extend along Type 1 antenna element transverse axes (54) parallel to a notional second arrangement axis (52) and perpendicular to the first arrangement axis (48). At least two of the Type 2 antenna elements (Rx) are arranged on different notional Type 2 antenna element major axes (60) to form a Type 2 antenna element field (44), the Type 2 antenna element major axes (60) being spaced apart and parallel to one of the arrangement axes (48). The magnitude of the maximum extension (56, 58, 86, 72) of at least one of the antenna element fields (42, 44) in the direction of the first alignment axis (48) and in the direction of the second alignment axis (52) is equal.

Description

[Technical Field]

[0001] The present invention relates to an antenna arrangement for a radar system, in particular for a vehicle radar system, having four Type 1 antenna elements of a first antenna element type and at least two Type 2 antenna elements 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 invention further relates to a radar system, in particular a radar system for a vehicle, having at least one antenna arrangement having four Type 1 antenna elements of a first antenna element type and at least two Type 2 antenna elements 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 also relates to a driver assistance system having at least one radar system and at least one antenna arrangement for the at least one radar system, wherein the at least one antenna arrangement has four Type 1 antenna elements of a first antenna element type and at least two Type 2 antenna elements of a second antenna element type, one of the antenna element types being transmitting antenna elements and the other of the antenna element types being receiving antenna elements.

[0004] The present invention further relates to a vehicle having at least one radar system and at least one antenna arrangement for the at least one radar system, wherein the at least one antenna arrangement has four Type 1 antenna elements of a first antenna element type and at least two Type 2 antenna elements of a second antenna element type, one of the antenna element types being transmitting antenna elements and the other of the antenna element types being receiving antenna elements.

[0005] Finally, the invention relates to a method for operating a radar system, in particular for a vehicle, having at least one antenna arrangement with four Type 1 antenna elements of a first antenna element type and at least two Type 2 antenna elements of a second antenna element type, in which radar signals are transmitted using antenna elements of one of the antenna element types and echo signals resulting from the transmitted radar signals are received using antenna elements of the other antenna element type. [Background technology]

[0006] A radar device with an arrangement of transmitting and receiving antennas is known from US Patent Application Publication No. 2021 / 0184367. 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 identical 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 in both horizontal and vertical positions from the first antenna group. The receiving antennas Rx#1 to Rx#3 form a third group of receiving antennas that are identical in vertical position but different in horizontal position. The receiving antenna Rx#4 is a fourth antenna that is arranged at a position different in both horizontal and vertical positions from the third antenna group. Furthermore, the vertical position of the fourth antenna (Rx#4) is away from the vertical positions of the third antenna group (Rx#1 to Rx#3).

[0007] The invention is based on the object of designing an antenna arrangement, a radar system, a driver assistance system, a vehicle and a method of the type mentioned at the beginning, which allows an improvement in measurements with radar systems, in particular a reduction in the side lobe level. [Prior art documents] [Patent documents]

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

[0009] The purpose of this is to the type 1 antenna elements are arranged in one plane at the corners of an imaginary planar rectangle to form a type 1 antenna element field, two of the sides of the rectangle extending along the type 1 antenna element major axis and parallel to an imaginary first arrangement axis, and two other sides of the rectangle extending along the type 1 antenna element transverse axis and parallel to an imaginary second arrangement axis extending perpendicular to the first arrangement axis; At least two of the type 2 antenna elements are arranged on different assumed type 2 antenna element major axes to form a type 2 antenna element field, the type 2 antenna element major axes extending parallel to and spaced apart from one another and parallel to one of the arrangement axes; At least one maximum extent of the antenna element field in the direction of the first alignment axis and in the direction of the second alignment axis is equal in magnitude; This is achieved by the present invention with respect to antenna arrangement.

[0010] The antenna arrangement is intended for a radar system and allows for the transmission and reception of radar signals, which can be converted into corresponding received signals, in particular electrical received signals, which can be further processed by suitable means, in particular a control and evaluation device.

[0011] 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, the sides of which extend parallel to two mutually orthogonal arrangement axes. The four Type 1 antenna elements form a Type 1 antenna element field. At least two Type 2 antenna elements are arranged on a Type 2 antenna element major axis which extends parallel to one of the arrangement axes. The Type 2 antenna elements form a Type 2 antenna element field.

[0012] The maximum extent of at least one of the antenna element fields in the direction of the first arrangement axis and the direction of the second arrangement axis may be equal in size. Advantageously, the maximum extent of the type 1 antenna element field in the direction of the first arrangement axis and the maximum extent of the type 1 antenna element field in the direction of the second arrangement axis may be equal in size. In this case, the rectangle at the corners of which the type 1 antenna elements are arranged is a square. Alternatively or additionally, the maximum extent of the type 2 antenna element field in the direction of the first arrangement axis and the maximum extent of the type 2 antenna element field in the direction of the second arrangement axis may advantageously be equal in size. In this way, the type 2 antenna element field may have an assumed square shape as a whole. In this case, it is not necessary for all type 2 antenna elements to be located at one corner of the square. It is also possible for none of the type 2 antenna elements to be located at a corner of the square. Thus, the antenna arrangement according to the present invention has at least one square antenna element field.

[0013] Due to the square shape of at least one of the antenna element fields, the resolution in the direction of the first and second alignment axes, in particular the angular resolution in azimuth and elevation, may be close or even identical, which allows low sidelobe levels to be achieved.

[0014] The rectangular, particularly square, arrangement of Type 1 antenna elements allows a virtual antenna array with an expanded aperture in two dimensions, particularly in azimuth and elevation, compared to the antenna arrangement when operating a radar system according to the MIMO method. Therefore, a high resolution can be achieved for direction measurements in both dimensions. Overall, this allows for improved accuracy when determining the direction in which a detected object is located.

[0015] The directional resolution, and especially the angular resolution, of a radar system depends directly on the size of the aperture of the virtual antenna array. The present invention allows for a large aperture to be achieved in both dimensions, especially in azimuth and elevation, using a relatively small number of antenna elements.

[0016] A rectangle in the sense of the present invention may have both equal and unequal side lengths. A rectangle may therefore also be a square.

[0017] "Parallel" in the sense of the present invention means that corresponding axes and / or planes may also coincide, ie the axes and / or planes may be parallel or truly parallel.

[0018] It should be noted that the designations "first" and "second" for antenna element types are used merely for ease of distinction and do not imply that one of the antenna element types is preferred. Correspondingly, the prefixes "Type 1" and "Type 2" are used merely to facilitate distinction between two types of antenna elements. 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.

[0019] The notations "major axis" and "horizontal axis" are also used only to facilitate distinction between them and do not imply that one of the axes, in particular the major axis, has priority over the other axis, in particular the horizontal axis. Correspondingly, the prefixes "Type 1" and "Type 2" are also used here only to facilitate assignment of the axes to the corresponding antenna element types.

[0020] The radar system may be used in vehicles, in particular automobiles. The radar system 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 system may also be used in vehicles that can be operated autonomously or at least partially autonomously.

[0021] The radar system may be advantageously connected to at least one electronic control device of the vehicle or machine, in particular a driver assistance system, or may be part of such a control device, so that at least some of the functions of the vehicle can be performed autonomously or partly autonomously.

[0022] Radar systems may be used to detect stationary or moving objects, in particular vehicles, people, animals, plants, obstacles, uneven driving surfaces, in particular potholes or stones, road boundaries, road signs, open spaces, in particular parking spaces, precipitation, etc., and / or movements and / or gestures.

[0023] In an advantageous embodiment, at least two of the type 2 antenna elements may be arranged on different assumed type 2 antenna element transverse axes that are parallel to and spaced apart from each other and perpendicular to the type 2 antenna element major axis. In this way, the type 2 antenna elements may be spaced apart in two dimensions, specifically in the direction of the type 2 antenna element major axis and in the direction of the type 2 antenna element transverse axis. In this way, a so-called sparse array can be realized in the virtual antenna array. Therefore, the virtual antenna array is spaced apart. This allows for the realization of very large virtual antenna arrays with very large apertures in two dimensions, specifically in azimuth and elevation.

[0024] In a further advantageous embodiment, the antenna arrangement has at least three type 2 antenna element horizontal axes spaced apart from one another and at least three type 2 antenna elements, at least three of the type 2 antenna elements being arranged on different type 2 antenna element horizontal axes, and at least two distances between each adjacent type 2 antenna element horizontal axes being the same and / or at least two distances between each adjacent type 2 antenna element horizontal axes being different; and / or The antenna arrangement may have at least four type 2 antenna elements, one of the type 2 antenna elements being arranged on one of the type 2 antenna element major axes, at least one of the type 2 antenna elements being arranged on another type 2 antenna element major axis, and all others of the type 2 antenna elements being arranged on yet another type 2 antenna element major axis, and in particular, the type 2 antenna element transverse axis having a type 2 antenna element each arranged singly on one of the type 2 antenna element major axes may not be located between two other type 2 antenna element transverse axes; and / or the antenna arrangement has at least four type 2 antenna elements, one of the type 2 antenna elements disposed on one of the type 2 antenna element major axes, one of the type 2 antenna elements disposed on another one of the type 2 antenna element major axes, and all other type 2 antenna elements disposed on still other ones of the type 2 antenna element major axes, wherein the distance between a type 2 antenna element horizontal axis on which one of the type 2 antenna elements disposed singly on a corresponding type 2 antenna element major axis resides and at least one adjacent type 2 antenna element horizontal axis is at most the same as the other distance between each adjacent type 2 antenna element horizontal axis; and / or the antenna arrangement has three type 2 antenna element major axes and at least three type 2 antenna element transverse axes, one of the type 2 antenna elements being located on each of the two outer type 2 antenna element transverse axes of the type 2 antenna element field, and the type 2 antenna elements located on the two outer type 2 antenna element transverse axes being located on each of the two outer type 2 antenna element major axes of the type 2 antenna element field; and / or The antenna arrangement may have exactly four Type 2 antenna elements; and / or The antenna arrangement may have exactly three Type 2 antenna element principal axes; and / or The distance between the major axes of each adjacent type 2 antenna element may be different.

[0025] In this way, a good distribution of the virtual antenna elements in the virtual antenna element as a whole can be achieved.

[0026] Advantageously, at least two distances between the horizontal axes of each adjacent type 2 antenna element may be the same. In this way, the virtual antenna elements in the virtual antenna array can be evenly spaced. Alternatively, or in addition, at least two distances between the horizontal axes of each adjacent type 2 antenna element may be different. In this way, a good distribution of the virtual antenna elements in the virtual antenna array can be achieved.

[0027] Advantageously, alternatively or additionally, one of the Type 2 antenna elements may be arranged on one of the Type 2 antenna element major axes, another of the Type 2 antenna elements may be arranged on another Type 2 antenna element major axis, and all further Type 2 antenna elements may be arranged on yet another Type 2 antenna element major axis, etc. In this way, in combination with a rectangular arrangement of the Type 1 antenna elements, uniform coverage of the virtual antenna array can be achieved.

[0028] Advantageously, alternatively or additionally, two type 2 antenna element transverse axes, each having a type 2 antenna element arranged singly on a corresponding type 2 antenna element major axis, may not be located between two other type 2 antenna element transverse axes, in this way individual type 2 antenna elements can be arranged at the edge of a type 2 antenna element field of type 2 antenna elements.

[0029] Advantageously, alternatively or additionally, the distance between the transverse axis of at least one type 2 antenna element, on which one of the type 2 antenna elements is located singly on the corresponding type 2 antenna element main axis, 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. In this way, gaps created by the offset of individual type 2 antenna elements relative to other type 2 antenna elements can be kept smaller. Thus, an overall uniform distribution of the virtual antenna elements in the virtual antenna array can be achieved.

[0030] Advantageously, alternatively or additionally, the antenna arrangement may have three Type 2 antenna element major axes and at least three Type 2 antenna element transverse axes, one of the Type 2 antenna elements being located on each of the two outer Type 2 antenna element transverse axes of the Type 2 antenna element field formed by the Type 2 antenna elements, and the Type 2 antenna elements located on the two outer Type 2 antenna element transverse axes being located on each of the two outer Type 2 antenna element major axes of the Type 2 antenna element field. In this way, the two outer Type 2 antenna elements can be located on diagonals of the Type 2 antenna element field.

[0031] Advantageously, alternatively or additionally, the antenna arrangement may have exactly four type 2 antenna elements. In this way, exactly four antenna elements each can be realized from both antenna element types. A correspondingly large number of virtual antenna elements can therefore be realized in the virtual antenna array.

[0032] Advantageously, alternatively or additionally, the antenna arrangement may have exactly three Type 2 antenna element major axes, in this way limiting the extent of the Type 2 antenna element fields perpendicular to the Type 2 antenna element major axes.

[0033] Advantageously, alternatively or additionally, the antenna arrangement may have exactly four type 2 antenna elements distributed over three type 2 antenna element major axes and four type 2 antenna element lateral axes. In this way, the uniqueness range of the virtual antenna array that can be realized from the antenna arrangement can be increased. In particular, ambiguity in the direction of the arrangement axes, in particular in elevation or azimuth, can be avoided.

[0034] Advantageously, alternatively or additionally, the distance between two of the main axes of three adjacent Type 2 antenna elements in each case may be different, thus achieving a good distribution of the virtual antenna elements within the virtual antenna array.

[0035] In a further advantageous embodiment, the type 2 antenna element axes, in particular the type 2 antenna element major axis and the type 2 antenna element transverse axis, extend in a common imaginary plane; and / or the type 2 antenna element axes, in particular the type 2 antenna element major axis and the type 2 antenna element lateral axis, extend parallel to a plane in which the type 1 antenna element major axis and the type 1 antenna element lateral axis lie; and / or The type 1 and type 2 antenna elements are arranged on a common carrier, in particular a common carrier plate, in this way the antenna arrangement can be easily manufactured, mounted and aligned.

[0036] Advantageously, all Type 2 antenna element axes may extend in one imaginary plane, in this way the antenna arrangement can be easily realized and aligned.

[0037] Advantageously, alternatively or additionally, the type 2 antenna element axis may extend parallel to the type 1 antenna element axis, in particular the plane in which the type 1 antenna element main axis and the type 2 antenna element main axis lie, in this way the alignment of the type 1 antenna element and the placement of the type 2 antenna element can be simplified.

[0038] Advantageously, alternatively or additionally, the type 1 antenna elements and the type 2 antenna elements may be arranged on a common carrier, in this way making the antenna arrangement easier to manufacture.

[0039] Advantageously, the type 1 and type 2 antenna elements may be realized on a common carrier plate, in particular a printed circuit board. In this way, all antenna elements can be easily realized in one plane. When using a printed circuit board, in particular, the electrical connections to the antenna elements can be easily realized.

[0040] In a further advantageous embodiment, 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 corresponding antenna element axes, in particular on the antenna element main axes and / or transverse antenna element axes, in this way the positions of the antenna elements can be clearly defined.

[0041] Advantageously, the phase centres of at least some of the antenna elements may be located at the intersection of the antenna element major axis and the antenna element transverse axis, thus allowing the position of the antenna elements to be clearly defined.

[0042] In a further advantageous embodiment, the respective distances between adjacent antenna element axes for the same antenna element type, in particular the respective distances between adjacent antenna element major axes and / or adjacent antenna element transverse axes for the same antenna element type, may be an integer multiple of a predetermined base distance, the base distance being half the wavelength of the radar signal transmitted by the radar system. In this way, a particularly compact antenna arrangement can be realized. By specifying the base distance as half the wavelength of the radar signal, ambiguities and side lobes can be reduced. Furthermore, clearly directed radar signals can be realized at the transmitter side. Furthermore, separate angle measurements can be performed.

[0043] In a further advantageous embodiment, The range of a transmitting antenna element field consisting of antenna elements of a transmitting antenna element type in the direction of the first arrangement axis may be greater than the range of a receiving antenna element field consisting of antenna elements of a receiving antenna element type in the direction of the first arrangement axis, and the range of a transmitting antenna element field in the direction of the second arrangement axis may be greater than the range of a receiving antenna element field in the direction of the second arrangement axis; and / or The maximum extent of the type 1 antenna element field in the direction of the first arrangement axis and the direction of the second arrangement axis may be equal in magnitude, and the maximum extent of the type 2 antenna element field in the direction of the first arrangement axis in the direction of the second arrangement axis may be equal in magnitude.

[0044] Advantageously, the extent of the transmitting antenna element fields in the direction of both alignment axes may be greater than the corresponding extent of the receiving antenna element fields, in this way the receiving antenna element fields are adapted to a certain extent to the transmitting antenna element fields.

[0045] The fact that the receive antenna element field is smaller than the transmit antenna element field makes it possible to minimize ambiguities and side lobes.

[0046] Advantageously, the maximum extent of the type 1 antenna element field in the direction of the first arrangement axis and in the direction of the second arrangement axis may be equal in magnitude, and the maximum extent of the type 2 antenna element field in the direction of the first arrangement axis may be equal in magnitude, so that the resolution in the direction of the first arrangement axis and in the direction of the second arrangement axis, in particular the angular resolution in azimuth and elevation, may be identical.

[0047] The placement of Type 1 antenna elements at the corners of an imaginary square results in a square virtual antenna array when the positions of the antenna elements of the two antenna element types, specifically the transmitting and receiving antenna elements, are geometrically folded.

[0048] In a further advantageous embodiment, The antenna arrangement may be designed for use in a radar system according to a MIMO method; and / or Type 1 antenna elements are respectively activated and / or and the Type 2 antenna elements can each be activated and / or selected separately; and / or The antenna arrangement may be designed for a bistatic radar device.

[0049] Advantageously, the antenna arrangement may be designed for operating the radar system according to the MIMO method. The radar system may be realized as a so-called MIMO radar system. In the MIMO method (multiple-input / multiple-output method), all antenna elements of a transmitting antenna element type can transmit differently coded radar signals. In this way, the radar signals at the receiver side can be assigned to the antenna elements of a receiving antenna element type corresponding to the received echo signals. Using the pure MIMO method, the aperture of the virtual antenna array realized in the antenna arrangement can be correspondingly enlarged.

[0050] Advantageously, the antenna elements can each be activated and / or selected separately. In this way, the number of antenna elements can be used efficiently, in particular using MIMO methods. The transmit antenna elements can be activated separately. The receive antenna elements can be selected separately. Thus, even with a relatively small number of antenna elements, a virtual antenna array with a correspondingly large number of virtual antenna elements can be realized.

[0051] Advantageously, the antenna arrangement may be designed for a bistatic radar device. Advantageously, the bistatic radar device may have two radar systems, each capable of receiving its own radar signal and the radar signal of the other radar system. In this way, more information about the surveillance area, particularly the surroundings of the vehicle, can be obtained.

[0052] Furthermore, this object is realized for a radar system by providing that the radar system comprises at least one antenna arrangement according to the invention.

[0053] The radar system comprises at least one antenna arrangement comprising four Type 1 antenna elements of a first antenna element type and at least two Type 2 antenna elements of a second antenna element type, one of the antenna element types being transmit antenna elements and the other of the antenna element types being receive antenna elements.

[0054] According to the present invention, type 1 antenna elements are arranged in one plane at the corners of an imaginary planar rectangle. Four type 1 antenna elements form a type 1 antenna element field. Two of the rectangle's sides extend along a type 1 antenna element major axis parallel to an imaginary first arrangement axis. Two other sides of the rectangle extend along a type 1 antenna element transverse axis parallel to an imaginary second arrangement axis extending perpendicular to the first arrangement axis. At least two type 2 antenna elements extend parallel to and spaced apart from each other and are arranged on different imaginary type 2 antenna element major axes parallel to one of the arrangement axes. The type 2 antenna elements form a type 2 antenna element field. At least one maximum extent of the antenna element field in the direction of the first arrangement axis and in the direction of the second arrangement axis is equal in size.

[0055] Advantageously, the radar system may comprise means enabling it to operate according to the MIMO method, in this way improving the resolution, in particular the angular resolution, when determining the direction of detected objects.

[0056] Advantageously, the radar system may be designed for use in the case of a bistatic radar device, in which case a lot of information about the monitored area can be determined using the radar device.

[0057] This object is also achieved by the invention for a driver assistance system by providing that the driver assistance system comprises at least one antenna arrangement according to the invention.

[0058] The driver assistance system includes at least one radar system and at least one antenna arrangement for the at least one radar system, the at least one antenna arrangement having four Type 1 antenna elements of a first antenna element type and at least two Type 2 antenna elements 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.

[0059] According to the present invention, Type 1 antenna elements are arranged in one plane at the corners of an imaginary planar rectangle within the antenna arrangement. Four Type 1 antenna elements form a Type 1 antenna element field. Two of the rectangle's sides extend along a Type 1 antenna element major axis parallel to an imaginary first arrangement axis. Two other sides of the rectangle extend along a Type 1 antenna element transverse axis parallel to an imaginary second arrangement axis extending perpendicular to the first arrangement axis. At least two of the Type 2 antenna elements extend parallel to and spaced apart from each other and are arranged on different imaginary Type 2 antenna element major axes parallel to one of the arrangement axes. The Type 2 antenna elements form a Type 2 antenna element field. At least one maximum extent of the antenna element field in the direction of the first arrangement axis and in the direction of the second arrangement axis is equal in magnitude.

[0060] The radar system may be used to monitor objects in at least one monitoring region around the vehicle.

[0061] The driver assistance system can be used to operate the vehicle autonomously or semi-autonomously, in particular based on information obtained using at least one radar system, in particular based on information about objects detected using at least one radar system.

[0062] According to the present invention, a driver assistance system comprises at least one antenna arrangement according to the present invention. Advantageously, at least one radar system of a driver assistance system may comprise at least one antenna arrangement according to the present invention. Since at least one radar system is part of a driver assistance system, the antenna arrangement according to the present invention of the at least one radar system is consequently likewise part of the driver assistance system, i.e., also the antenna arrangement according to the present invention of the driver assistance system. This applies equally to the antenna arrangement according to the present invention of a vehicle having at least one driver assistance system and / or at least one radar system.

[0063] Additionally, this object is achieved by the invention for a vehicle by providing that the vehicle comprises at least one antenna arrangement according to the invention.

[0064] The vehicle comprises at least one radar system and at least one antenna arrangement for the at least one radar system comprising four Type 1 antenna elements of a first antenna element type and at least two Type 2 antenna elements of a second antenna element type, one of the antenna element types being transmit antenna elements and the other of the antenna element types being receive antenna elements.

[0065] The radar system may be used to monitor objects in at least one monitoring region around the vehicle.

[0066] The vehicle may advantageously comprise at least one driver assistance system, in particular at least one driver assistance system according to the invention, by means of which the vehicle can be driven autonomously or partly autonomously.

[0067] Advantageously, at least one radar system, in particular at least one radar system according to the invention, can be connected to or part of a driver assistance system, in particular at least one driver assistance system according to the invention, in this way information acquired by means of the at least one radar system, in particular information about detected objects, can be used by the driver assistance system for operating the vehicle autonomously or partially autonomously.

[0068] Finally, this object is achieved by the invention for the method by providing that radar signals are transmitted using an antenna arrangement according to the invention and that echo signals are received using an antenna arrangement according to the invention.

[0069] According to the present invention, four antenna elements of one antenna element type can be used to transmit radar signals from one plane at the corners of an imaginary planar rectangle, or to receive echo signals in one plane at the corners of an imaginary planar rectangle. The four antenna elements thus form a transmitting antenna element field or a receiving antenna element field. Two of the rectangle's sides extend parallel to an imaginary first arrangement axis, and two of the rectangle's other sides extend parallel to an imaginary second arrangement axis that extends perpendicular to the first arrangement axis. At least two of the antenna elements of the other antenna element type receive echo signals or transmit radar signals along different imaginary antenna element major axes. The antenna element major axes extend parallel to one of the arrangement axes and at a distance from each other. Thus, two antenna elements of the other antenna element type form a receiving antenna element field or a transmitting antenna element field. At least one maximum range of the antenna element fields in the direction of the first arrangement axis and in the direction of the second arrangement axis is equal in magnitude.

[0070] Advantageously, the radar system can operate according to the MIMO method, in this way the direction of an object detected by the radar system can be determined accurately.

[0071] Advantageously, two radar systems, particularly those operating in accordance with the present invention, can operate in a bistatic manner, each capable of detecting and processing radar signals transmitted by the other radar system.

[0072] Otherwise, the features and advantages indicated in connection with the antenna arrangement according to the invention, the radar system 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, and their respective advantageous designs, 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.

[0073] 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 the disclosed features individually in combination with the drawings, the specification and the claims, and combine them to form further suitable combinations. [Brief explanation of the drawings]

[0074] [Figure 1] 1 is a plan view of a vehicle having a driver assistance system with a radar system; [Figure 2] FIG. 2 is a side view of the vehicle of FIG. [Figure 3] FIG. 3 is a front view of the antenna arrangement of the radar system of the vehicle of FIGS. 1 and 2. [Figure 4] FIG. 3 is a front view of an alternative antenna arrangement for the radar system of the vehicle of FIGS. 1 and 2 and the virtual antenna array realized therefrom. DETAILED DESCRIPTION OF THE INVENTION

[0075] In the drawings, the same components are given the same reference numerals.

[0076] In Figure 1, a vehicle 10 in the form of a passenger car is shown in plan view in a driving situation, and in Figure 2, the vehicle 10 is shown in side view.

[0077] The vehicle 10 is equipped with a driver assistance system 12. The driver assistance system 12 includes, for example, a radar device having two radar systems 14, and a control device 16. For clarity, only one of the radar systems 14 is shown in Figures 1 and 2. The radar systems 14 are identical in function and structure.

[0078] The radar systems 14 are illustratively positioned adjacent to one another in front of the vehicle 10. The radar systems 14 can be used to monitor objects 20 in a surveillance area 18 in front of the vehicle 10. In Figures 1 and 2, the objects 20 that can be detected by the radar systems 14 are illustratively positioned in front of the vehicle 10. The radar systems 14 may also be positioned at different locations on the vehicle 10 and may be aligned differently. Yet another radar system 14 may also be provided at a different location and with a different alignment.

[0079] In the following, the radar system 14 will be described as an example based on one radar system 14 shown in FIG.

[0080] The radar system 14 may be used to determine 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 .

[0081] The radar system 14 is operatively connected to a control device 16 of the driver assistance system 12. Thus, object information determined by the radar system 14 can be transmitted to the control device 16. The driver assistance system 12 can be used to operate the vehicle 10 autonomously or semi-autonomously.

[0082] For simple directions, the corresponding coordinates in a Cartesian xyz coordinate system are shown in Figures 1-4. By way of example, the x-axis of the xyz coordinate system extends parallel to the vehicle longitudinal axis 22 of the vehicle 10. The y-axis extends parallel to the vehicle transverse axis 24 of the vehicle 10, and the z-axis extends spatially upward, perpendicular to the xy-plane. In the normal operating direction of the vehicle 10, the azimuth angle θ lies in a plane parallel to the xy-plane, and the elevation angle Φ lies in a plane perpendicular to the xy-plane.

[0083] The radar system 14 may be used to transmit a radar signal 26 into the monitored area 18. The radar signal 26 may be reflected by an object 20 in the direction of the radar system 14 and received by the radar system 14 as an echo signal 28. Corresponding object information may be determined from the echo signal 28.

[0084] The radar system 14 comprises an antenna arrangement 30 and a control and evaluation device 32 .

[0085] The antenna arrangement 30 is shown in Figure 3 in a front view as seen from the surveillance area 18. The antenna array 30 comprises two antenna element types, specifically transmit antenna elements Tx and receive antenna elements Rx. The transmit antenna elements Tx can be used to transmit radar signals 26. The receive antenna elements Rx can be used to receive echo signals 28.

[0086] The antenna arrangement 30 comprises four transmit antenna elements Tx and four receive antenna elements Rx, which are arranged on a common carrier in the form of a carrier plate 34. The carrier plate 34 can be designed, for example, as a printed circuit board.

[0087] Using the control and evaluation device 32, the transmitting antenna elements Tx can be activated to emit radar signals 26. Furthermore, using the control and evaluation device 32, echo signals 28 received by the receiving antenna elements Rx and converted into electrical receive signals can be detected and evaluated. Using the control and evaluation device 32, corresponding object information can be determined from the electrical receive signals and transmitted to the control device 16.

[0088] The radar system 14 is operated according to a MIMO (multiple-input, multiple-output) method. In the MIMO method, the transmitting antenna elements Tx are separately activated by the control and evaluation device 32 using transmit control signals. The corresponding transmit control signals make the radar signals 26 transmitted using the individual transmitting antenna elements Tx distinguishable, for example, by encoding. Therefore, at the receiver side, the signal paths of the radar signals 26 and the corresponding echo signals 28 can be assigned to the respective transmitting antenna elements Tx. Correspondingly, the receiving antenna elements Rx are separately selected. The electrical receive signals converted from the echo signals 28 by the antenna elements Rx are assigned accordingly. By separate activation or selection, all positions of the transmitting antenna elements Tx and all positions of the receiving antenna elements Rx can be used to realize a virtual antenna array 36. FIG. 4 shows a virtual antenna array 36 by way of example, which can be realized using an alternative antenna arrangement 30, also shown in FIG. 4. The virtual antenna array 36 shown in FIG. 4 may also be realized using the antenna arrangement 30 of FIG. 3.

[0089] A radar device having two radar systems 14 may also operate as a bistatic radar device, with each radar system 14 receiving and processing echo signals 28 from radar signals 26 transmitted using the other radar system 14, thereby increasing the amount of information from the monitored area 18.

[0090] 3 and 4, the phase centres 38 of the transmit antenna elements Tx are shown as filled circles, and the phase centres 40 of the receive antenna elements Rx are shown as filled squares.

[0091] In Figure 3, the transmit antenna element field 42 of four transmit antenna elements Tx on the left is shown separately from the receive antenna element field 44 of four receive antenna elements Rx on the right. The transmit antenna element field 42 and the receive antenna element field 44 may also be positioned relative to each other in some other way. As shown at the bottom of Figure 4, the transmit antenna element field 42 and the receive antenna element field 44 may also overlap.

[0092] The transmit antenna elements Tx are arranged in the transmit plane at the corners of an imaginary planar rectangle 46. The sides of the rectangle 46 are equal in length. Thus, the rectangle 46 is a square. Two of the sides of the rectangle 46 extend along an imaginary transmit antenna element major axis 50 that is parallel to an imaginary first arrangement axis 48 that extends horizontally in FIG. 3. Two other sides of the rectangle 46 extend along an imaginary transmit antenna element lateral axis 54 that is parallel to an imaginary second arrangement axis 52 that extends vertically in FIG. 3. 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.

[0093] 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 .

[0094] The distance between adjacent transmitting antenna element major axes 50 or adjacent transmitting antenna element transverse axes 54, i.e., between adjacent antenna element axes of the same antenna element type, is an integer multiple of a predetermined fundamental distance λ / 2, which corresponds to half the wavelength λ / 2 of the radar signal 26 transmitted by the radar system 14.

[0095] 3, 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.

[0096] The phase centers 40 of the four receive antenna elements Rx are arranged so as to be distributed across three 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.

[0097] The receive antenna element major axes 60 are parallel and spaced apart from one another and extend parallel to the first arrangement axis 48. The four receive antenna element transverse axes 62 are parallel and spaced apart from one another and extend perpendicular to the receive antenna element major axes 60 and parallel to the second arrangement axis 52.

[0098] 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 transmit plane in which the transmit antenna element major axis 50 and the transmit antenna element transverse axis 54 lie. The receive plane, which has the receive antenna element major axis 60 and the receive antenna element transverse axis 62, extends parallel to the transmit plane, which has the transmit antenna element major axis 50 and the transmit antenna element transverse axis 54. In the exemplary embodiment shown, the transmit and receive planes are coincident.

[0099] The phase center 40 of one of the receive antenna elements Rx is located on one of the receive antenna element major axes 60, on the left side of the upper receive antenna element major axis 60 in FIG. 3. The phase center 40 of another receive antenna element Rx is located on another of the receive antenna element major axes 60, on the right side of the lower receive antenna element major axis 60 in FIG. 3. The phase centers 40 of two further receive antenna elements Rx are located on a third, middle 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.

[0100] The receive antenna element horizontal axis 62 on which the phase center 40 of the receive antenna element Rx located solely on the upper receive antenna element major axis 60 exists is located on the left edge of the receive antenna element field 44, i.e., not between the other two 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 located solely on the lower receive antenna element major axis 60 exists is located on the right edge of the receive antenna element field 44, i.e., not between the other two receive antenna element horizontal axes 62.

[0101] One receive antenna element Rx is located on each of the two outer antenna element horizontal axes 62 of the receive antenna element field 44. Each receive antenna element Rx located on the two outer antenna element horizontal axes 62 is located on one of the two outer antenna element major axes 60. In the exemplary embodiment of FIG. 3 , at the upper left side of the receive antenna field 44, an individual receive antenna element Rx is located at the intersection of the upper receive antenna element major axis 60 and the left receive antenna element horizontal axis 62. At the lower right side of the receive antenna field 44, an individual receive antenna element Rx is located 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 diagonally across the receive antenna field 44.

[0102] The distance between adjacent antenna element axes of the same antenna element type, specifically, between adjacent receiving antenna element major axes 60 or adjacent receiving antenna element lateral axes 62, is an integer multiple of the basic distance λ / 2.

[0103] 3, the distance 70 between the main axis 60 of the upper receiving antenna element and the main axis 60 of the middle receiving antenna element is different from the distance 84 between the main axis 60 of the middle receiving antenna element and the main axis 60 of the lower receiving antenna element.

[0104] 3, the distance 70 between the upper and middle receive antenna element major axes 60 corresponds to three times the fundamental distance λ / 2, i.e., 1.5λ. The distance 84 between the middle and lower receive antenna element major axes 60 corresponds to one time the fundamental distance λ / 2.

[0105] 3, a distance 64 between a first receive antenna element horizontal axis 62 and a second receive antenna element horizontal axis 62 corresponds to a distance 66 between the second receive antenna element horizontal axis 62 and a third antenna element horizontal axis 62. A distance 68 between the third receive antenna element horizontal axis 62 and a fourth receive antenna element horizontal axis 62, as well as the distances 64 and 66 between each other adjacent receive antenna element horizontal axis 62, are different.

[0106] The distance 64 between the horizontal axis 62 of the receiving antenna element on which the phase center 40 of an individual receiving antenna element Rx located singly on the upper left-hand side of the receiving antenna element field 44 in Figure 3 is located, i.e., the horizontal axis of the second receiving antenna element from the left, is smaller than the distance 68 between the horizontal axes 62 of the second and third receiving antenna elements from the left.

[0107] A distance 64 between the horizontal axis 62 of the receive antenna element Rx on the left side of the receive antenna field 44 and the horizontal axis 62 of the adjacent second receive antenna element corresponds to 1 times the basic distance λ / 2. A 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 also corresponds to 1 times the basic distance λ / 2. A 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 element field 44 in FIG. 3, corresponds to 2 times the basic distance λ / 2, i.e., λ.

[0108] 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. 3 , 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., five times the fundamental distance λ / 2, i.e., 2 / 5λ. 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., four times the fundamental distance λ / 2, i.e., 4λ.

[0109] The extent of the transmit antenna element field 42 in the direction of the second arrangement axis 52 is greater than the extent 86 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., five times the fundamental distance λ / 2, i.e., 2.5λ. The extent 86 of the receive antenna field 44 in the direction of the second arrangement axis 52 corresponds to the sum of the distances 70 and 84 between the receive antenna element major axes 60, i.e., four times the fundamental distance λ / 2, i.e., 2λ.

[0110] Figure 4 shows an alternative to the antenna arrangement 30 of Figure 3, along with a virtual antenna array 36 that may be implemented. Elements similar to those of the first exemplary embodiment of Figure 3 are given the same reference numerals. For directional clarity, coordinate axes with y and z coordinates are also shown. The y and z coordinates are each expressed in wavelength λ. The origin of the coordinate system (0.0) is located at the phase center 38 of the lower left transmit antenna element Tx for directional clarity.

[0111] An alternative antenna arrangement 30 shown in Figure 4 comprises the transmit antenna element field 42 and receive antenna element field 44 of Figure 3. In contrast to the antenna arrangement 30 of Figure 3, in the alternative antenna arrangement 30, the receive antenna element field 44 is located mostly within the transmit antenna element field 42. In this case, the lower transmit antenna element major axis 50 and the middle 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.

[0112] In FIG. 4, only two of the transmit antenna elements Tx with phase centers 38 and one of the receive antenna elements Rx with phase center 40 are labeled by way of example for clarity.

[0113] The receive antenna element field 44 is positioned such that the phase center 38 of 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 transverse axis 62. The lower left transmit antenna element Tx is located directly in the gap in the receive antenna element field 44 created by offsetting the left receive antenna element Rx upward toward the upper receive antenna element major axis 60. Overall, the alternative antenna arrangement 30 of FIG. 4 is a more space-saving design than the antenna arrangement 30 of FIG. 3.

[0114] Both the antenna arrangement 30 of FIG. 3 and the antenna arrangement 30 of FIG. 4 can be used to realize the virtual antenna array 36 shown in FIG.

[0115] Using the alternative antenna arrangement 30 of Figure 4, an antenna array 36 having a total of 16 virtual antenna elements Vx corresponding to the antenna arrangement 30 of Figure 3 is generated during operation of the radar system 14. The virtual antenna array 36 is realized by geometric folding of the geometric locations of the phase centers 38 of the transmit antenna elements Tx and the phase centers 40 of the receive antenna elements Rx of the antenna arrangement 30 or the alternative antenna arrangement 30. The virtual antenna elements Vx act as virtual receive antenna elements for the echo signals 28.

[0116] 4 shows the virtual antenna elements Vx of the virtual antenna array 36. The virtual phase centers 73 of the virtual antenna elements Vx of the virtual antenna array 70 are shown as open triangles. For clarity, only some of the virtual antenna elements Vx are labeled in FIG. 4 by way of example.

[0117] The virtual antenna array 36 comprises four virtual antenna element fields 74. The virtual antenna element fields 74 are identically configured, have the same size, and have the same orientation. Each of the virtual antenna element fields 74 comprises four virtual antenna elements Vx. The four virtual antenna elements Vx of each virtual antenna element field 74 are arranged to correspond to the four receive antenna elements Rx of the antenna arrangement 30.

[0118] The virtual antenna element fields 74 are respectively positioned at the corners of an imaginary square. Two sides of the square extend along respective imaginary major axes 76 parallel to the first alignment axis 48. Two other sides of the square extend along respective imaginary transverse axes 78 parallel to the second alignment axis 52.

[0119] 4, the left imaginary transverse axis 78 coincides with the left transmit antenna element transverse axis 54 and the left receive antenna element transverse axis 62. The upper imaginary major axis 76 coincides with the lower transmit antenna element major axis 50 and the middle receive antenna element major axis 60. The lower imaginary major axis 76 extends below the lower transmit antenna element major axis 50. The right imaginary transverse axis 78 extends to the right of the right transmit antenna element transverse axis 54.

[0120] The virtual phase center 73 of the left virtual antenna element Vx in the upper-left virtual antenna element field 74 is located at the intersection of the upper imaginary major axis 76, which coincides with the lower transmit antenna element major axis 50, and the left imaginary horizontal axis 78, which coincides with the left transmit antenna element horizontal axis 54. Therefore, this virtual antenna element Vx coincides with the lower-left transmit antenna element Tx in the transmit antenna element field 42.

[0121] The free space below the left virtual antenna element Vx in the lower left virtual antenna element field 74 is located at the intersection of the lower imaginary major axis 76 and the left imaginary horizontal axis 78 .

[0122] The left virtual antenna element Vx in the upper right virtual antenna element field 74 is located at the intersection of the upper imaginary major axis 76, which coincides with the lower transmit antenna element major axis 50, and the right transmit antenna element horizontal axis 54. Therefore, this virtual antenna element Vx coincides with the lower right transmit antenna element Tx in the transmit antenna element field 42.

[0123] The virtual phase center 73 of the right virtual antenna element Vx in the lower right virtual antenna element field 74 is located at the intersection of the lower virtual major axis 76 and the right virtual horizontal axis 78 .

[0124] The distance 88 between the right virtual antenna element horizontal axes 90 of the two left virtual antenna element fields 74 and the left virtual antenna element horizontal axes 90 of the two right virtual antenna elements 74 corresponds to 1 times the basic distance λ / 2.

[0125] The distance 92 between the lower virtual antenna element major axis 94 of the two upper virtual antenna element fields 74 and the upper virtual antenna element horizontal axis 94 of the two lower virtual antenna element fields 74 similarly corresponds to the basic distance λ / 2.

[0126] The virtual antenna element Vx on the lower right side of the upper left antenna element field 74 and the virtual antenna element Vx on the upper left side of the lower right antenna element field 74 are arranged diagonally at a basic distance of λ / 2 in both the horizontal direction (y direction) and the vertical direction (z direction), respectively. Therefore, a high density of virtual antenna elements Vx can be realized across the entire virtual antenna array 36. This makes it possible to improve the sidelobe levels in the horizontal direction (x direction) and the vertical direction (z direction).

[0127] The virtual phase center 73 of the upper virtual antenna element Vx of the virtual antenna array 36 lies on the upper imaginary major axis 76. The phase center 73 of the lower virtual antenna element Vx lies on the lower imaginary major axis 76. A 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 this direction, for example, the vertical direction. Thus, the distance 80, for example, the vertical aperture, corresponds to 9 times the basic distance λ / 2, or 4.5λ. The distance 80 corresponds to the extent of the transmit antenna field 42 in the vertical direction, specifically, the sum of the distance 56 and the vertical extent 86 of the receive antenna element field 44.

[0128] The virtual phase center 73 of the left virtual antenna element Vx of the virtual antenna array 36 lies on the left virtual horizontal axis 78. The phase center 73 of the right virtual antenna element Vx lies on the right virtual horizontal axis 78. A 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 this direction, for example, the horizontal direction. Thus, for example, the distance 82, for example, the horizontal aperture, corresponds to 9 times the base distance, i.e., 4.5λ. The distance 82 corresponds to the sum of the horizontal extent of the transmit antenna field 42, specifically distance 58, and the horizontal extent of the receive antenna element field 44, specifically distance 72.

[0129] Overall, the ratio of vertical aperture to horizontal aperture of the virtual antenna array 36 is one to one, thus achieving a balance between resolution in the z-axis direction (vertical direction) and the x-axis direction (horizontal direction).

Claims

1. An antenna arrangement (30) for a radar system (14), in particular for a radar system (14) for a vehicle (10), having four Type 1 antenna elements (Tx) of a first antenna element type and at least two Type 2 antenna elements (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 type 1 antenna elements (Tx) are arranged in one plane at the corners of an imaginary planar rectangle (46) forming a type 1 antenna element field (42), two of the sides of the rectangle (46) extending parallel to an imaginary first arrangement axis (48) along 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) along a type 1 antenna element transverse axis (54); At least two of said type 2 antenna elements (Rx) are arranged on different assumed type 2 antenna element major axes (60) to form a type 2 antenna element field (44), said type 2 antenna element major axes (60) extending parallel to and spaced apart from one another and parallel to one of said arrangement axes (48); the maximum extents (56, 58, 86, 72) of at least one of the antenna element fields (42, 44) in the direction of the first alignment axis (48) and in the direction of the second alignment axis (52) are equal in magnitude; An antenna arrangement (30) characterized in that

2. 2. An antenna arrangement according to claim 1, characterized in that at least three of said type 2 antenna elements (Rx) are arranged on different assumed type 2 antenna element transverse axes (62) extending parallel to and at a distance from one another and perpendicular to said type 2 antenna element major axis (60).

3. the antenna arrangement (30) has at least three type 2 antenna element transverse axes (62) spaced apart from one another, at least three of the type 2 antenna elements (Rx) are arranged on different type 2 antenna element transverse axes (62), at least two distances (66, 68) between adjacent type 2 antenna element transverse axes (62) are the same, and / or at least two distances (64, 66, 68) between adjacent type 2 antenna element transverse axes (62) are different; and / or the antenna arrangement (30) has at least four type 2 antenna elements (Rx), one of the type 2 antenna elements (Rx) is arranged on one of the type 2 antenna element major axes (60), at least one of the type 2 antenna elements (Rx) is arranged on another type 2 antenna element major axis (60), and all of the remaining type 2 antenna elements (Rx) are arranged on yet another type 2 antenna element major axis (60), and in particular, the type 2 antenna element transverse axis (62) having the type 2 antenna element (Rx) arranged solely on one of the type 2 antenna element major axes (60) is not located between two other type 2 antenna element transverse axes (62); and / or the antenna arrangement (30) has at least four type 2 antenna elements (Rx), one of the type 2 antenna elements (Rx) is arranged on one of the type 2 antenna element major axes (60), one of the type 2 antenna elements (Rx) is arranged on another of the type 2 antenna element major axes (60), and all other type 2 antenna elements (Rx) are arranged on still other of the type 2 antenna element major axes (60), and a distance (64) between a type 2 antenna element horizontal axis (62) on which one of the type 2 antenna elements (Rx) arranged singly on the corresponding type 2 antenna element major axis (60) is present and at least one adjacent type 2 antenna element horizontal axis (62) is at most equal to the other distances (66, 68) between the respective adjacent type 2 antenna element horizontal axes (62); and / or the antenna arrangement (30) has three type 2 antenna element major axes (60) and at least three type 2 antenna element transverse axes (62), one of the type 2 antenna elements (Rx) is arranged on each of the two outer type 2 antenna element transverse axes (62) of the type 2 antenna element field (44), and the type 2 antenna elements (Rx) located on the two outer type 2 antenna element transverse axes (62) are each located on one of the two outer type 2 antenna element major axes (60) of the type 2 antenna element field (44); and / or said antenna arrangement (30) having exactly four type 2 antenna elements (Rx); and / or the antenna arrangement (30) has exactly three Type 2 antenna element major axes (60); and / or The distances (70, 84) between the respective adjacent Type 2 antenna element major axes (60) are different.

3. An antenna arrangement according to claim 2, characterized in that:

4. the type 2 antenna element axes, in particular the type 2 antenna element major axis (60) and the type 2 antenna element transverse axis (62), extend in a common imaginary plane; and / or 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 in which the type 1 antenna element major axis (50) and the type 1 antenna element lateral axis (54) lie; and / or the type 1 antenna element (Tx) and the type 2 antenna element (Rx) are arranged on a common carrier (34), in particular on a common carrier plate; Antenna arrangement according to any one of claims 1 to 3, characterized in that it comprises:

5. 5. An antenna arrangement according to claim 1, wherein the phase centers (38, 40) of at least some of the antenna elements (Rx, Tx), in particular the phase centers (38, 40) of all of the antenna elements (Rx, Tx), are arranged on the corresponding antenna element axes (50, 54, 60, 62), in particular the antenna element main axes (50, 60) and / or the antenna element transverse axes (54, 62).

6. 6. The antenna arrangement according to claim 1, wherein each distance between adjacent antenna element axes for the same antenna element type, in particular each distance between adjacent antenna element major axes (50, 60) and / or each distance 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 by the radar system (14).

7. a range (58) of a transmit antenna element field (42) consisting of the antenna elements of the transmit antenna element type (Tx) in the direction of the first arrangement axis (48) may be greater than a range (72) of a receive antenna element field (44) consisting of the antenna elements of the receive antenna element type (Rx) in the direction of the first arrangement axis (48), and a range (54) of the transmit antenna element field (42) in the direction of the second arrangement axis (52) may be greater than a range (86) of the receive antenna element field (44) in the direction of the second arrangement axis (52); and / or the maximum extents (56, 58) of the type 1 antenna element field (42) in the direction of the first placement axis (48) and the direction of the second placement axis (52) are equal in magnitude, and the maximum extents (72, 86) of the type 2 antenna element field (44) in the direction of the first placement axis (48) in the direction of the second placement axis (52) are equal in magnitude; Antenna arrangement according to any one of claims 1 to 6, characterized in that it comprises:

8. the antenna arrangement (30) is designed for use in the radar system (14) according to a MIMO method, and / or said type 1 antenna elements (Tx) are respectively activated and / or and the Type 2 antenna elements (Rx) can be individually activated and / or selected, and / or The antenna arrangement (30) is designed for a bistatic radar device. Antenna arrangement according to any one of claims 1 to 7, characterized in that it comprises:

9. A radar system (14), in particular a radar system (14) for a vehicle (10), having at least one antenna arrangement (30) with four Type 1 antenna elements (Tx) of a first antenna element type and at least two Type 2 antenna elements (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 system (14) has at least one antenna arrangement (30) according to any one of claims 1 to 8.

10. 10. A driver assistance system (12) comprising at least one radar system (14) and at least one antenna arrangement (30) for the at least one radar system (14), wherein the at least one antenna arrangement (30) comprises four type 1 antenna elements (Tx) of a first antenna element type and at least two type 2 antenna elements (Rx) of a second antenna element type, one of the antenna element types being transmitting antenna elements (Tx) and the other of the antenna element types being receiving antenna elements (Rx), characterized in that the driver assistance system (12) comprises at least one antenna arrangement (30) according to any one of claims 1 to 8.

11. 10. A vehicle (10) having at least one radar system (14) and at least one antenna arrangement (30) for the at least one radar system (14), wherein the at least one antenna arrangement (30) has four type 1 antenna elements (Tx) of a first antenna element type and at least two type 2 antenna elements (Rx) of a second antenna element type, one of the antenna element types being transmitting antenna elements (Tx) and the other of the antenna element types being receiving antenna elements (Rx), characterized in that the vehicle (10) has at least one antenna arrangement (30) according to any one of claims 1 to 8.

12. 1. A method for operating a radar system (14), in particular a radar system (14) for a vehicle (10), having at least one antenna arrangement (30) with four Type 1 antenna elements (Tx) of a first antenna element type and at least two Type 2 antenna elements (Rx) of a second antenna element type, wherein a radar signal (26) is transmitted using the antenna elements (Tx) of one of the antenna element types and an echo signal (28) resulting from the transmitted radar signal (26) is received using the antenna elements (Rx) of the other antenna element type, characterized in that the radar signal (26) is transmitted using the antenna arrangement (30) of any one of claims 1 to 8 and the echo signal (28) is received using the antenna arrangement (30) of any one of claims 1 to 8.

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