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

Abstract

The invention relates to an antenna arrangement (30) for a radar system, in particular for a vehicle, to a radar system, to a driver assistance system, to a vehicle, and to a method for operating a radar system. The antenna device (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 is a transmitting antenna element (Tx) and the other of the antenna element types is a receiving antenna element type (Rx). The Type 1 antenna elements (Tx) are arranged in a plane at the corners of an imaginary horizontal rectangle (46) and form a Type 1 antenna element field (42), in which the two sides of the rectangle (46) extend along a Type 1 antenna element main axis (50) parallel to an imaginary first arrangement axis (48), and in which the Type 1 antenna elements (Tx) are arranged in a plane at the corners of the imaginary horizontal rectangle (46) and form a Type 1 antenna element field (42). The other two sides of the rectangle (46) extend along a Type 1 antenna element transverse axis (54) parallel to an imaginary second arrangement axis (52) extending perpendicular to the first arrangement axis (48). At least two Type 2 antenna elements (Rx) are arranged on different imaginary Type 2 antenna element main axes (60) and form a Type 2 antenna element field (44), the Type 2 antenna element main axes (60) extending parallel to one another at a distance from one another and parallel to one of the arrangement axes (48). At least one antenna element field (42; 44) in the direction of the first arrangement axis (48) and in the direction of the second arrangement axis (52). 86, 72) have equal dimensions.

Description

Technical Field

[0001] The invention relates to an antenna arrangement for a radar system, in particular a radar system for a vehicle, 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 antenna element type is a transmitting antenna element and the other antenna element type is a receiving antenna element.

[0002] The present invention also relates to a radar system, in particular a radar system for a vehicle, having at least one antenna arrangement, which 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 antenna element type being a transmitting antenna element and the other antenna element type being a receiving antenna element.

[0003] The present invention further 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, 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 antenna element type being a transmitting antenna element and the other antenna element type being a receiving antenna element.

[0004] Furthermore, the invention relates to a vehicle having 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 antenna element type being a transmitting antenna element and the other antenna element type being a receiving antenna element.

[0005] Finally, the present invention relates to a method for operating a radar system, in particular a radar system for a vehicle, which radar system has 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 in the method, radar signals are transmitted with antenna elements of one antenna element type and echo signals originating from the transmitted radar signals are received with antenna elements of another antenna element type. Background Art

[0006] A radar device with a transmitting and receiving antenna arrangement is known from US 2021 / 0184367 A1. The number of transmitting antennas is 4 and the number of receiving antennas is 4. Transmitting antennas Tx #1 and Tx #2 form a first antenna group of transmitting antennas, which are in the same vertical position but different horizontal positions. Transmitting antennas Tx #3 and Tx #4 form a second antenna group, which is arranged at a position different from both the horizontal and vertical positions of the first antenna group. Receiving antennas Rx #1 to Rx #3 form a third antenna group of receiving antennas, which are in the same vertical position but different horizontal positions. Receiving antenna Rx #4 is a fourth antenna, which is arranged at a position different from both the horizontal and vertical positions of the third antenna group. In addition, the vertical position of the fourth antenna (Rx #4) is a position at a certain distance from the vertical position of the third antenna group (Rx #1 to Rx #3).

[0007] The object of the present invention is to design an antenna arrangement, a radar system, a driver assistance system, a vehicle and a method of the type mentioned at the outset in which measurements of the radar system can be used to improve, in particular to reduce, the sidelobe levels. Summary of the Invention

[0008] According to the present invention, this object is achieved by providing the following antenna arrangement:

[0009] The type 1 antenna element is arranged in a plane at the corners of an imaginary planar rectangle, two sides of the rectangle extending along a main axis of the type 1 antenna element parallel to an imaginary first arrangement axis, and the other two sides of the rectangle extending along a transverse axis of the type 1 antenna element parallel to an imaginary second arrangement axis, the second arrangement axis being perpendicular to the first arrangement axis,

[0010] At least two type 2 antenna elements are arranged on different imaginary type 2 antenna element main axes and form a type 2 antenna element field, the type 2 antenna element main axes extending parallel to and at a distance from each other and parallel to one of the arrangement axes, and

[0011] The maximum extent of the at least one antenna element field in the direction of the first arrangement axis and in the direction of the second arrangement axis has equal amplitude.

[0012] The antenna arrangement is intended for use in a radar system. The antenna arrangement allows for the transmission and reception of radar signals. Received radar signals can be converted into corresponding received signals, in particular electrical received signals, which can be further processed using suitable devices, in particular a control and evaluation device.

[0013] 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 the rectangle extend parallel to two mutually perpendicular arrangement axes. The four Type 1 antenna elements form a Type 1 antenna element field. At least two Type 2 antenna elements are arranged along a Type 2 antenna element main axis, which extends parallel to one of the arrangement axes. The Type 2 antenna elements form a Type 2 antenna element field.

[0014] The maximum extent of the at least one antenna element field in the direction of the first arrangement axis and in the direction of the second arrangement axis has equal amplitude. 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 can have equal amplitude. In this case, the rectangle at the corners of which the type 1 antenna elements are arranged will be a square. Alternatively or in addition, 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 can advantageously have equal amplitude. In this way, the type 2 antenna element field can have an imaginary square shape overall. In this case, not all type 2 antenna elements must be located at a corner of the square. It is also possible that no type 2 antenna element is located at a corner of the square. The antenna device according to the present invention thus has at least one square antenna element field.

[0015] Due to the square shape of the at least one antenna element field, the resolution in the direction of the first and second arrangement axes, in particular the angular resolution in azimuth and elevation, can become closer or even identical. This allows lower sidelobe levels to be achieved.

[0016] Due to the rectangular, and particularly square, arrangement of Type 1 antenna elements, when operating the radar system using the MIMO method, a virtual antenna array with an expanded aperture in two dimensions, particularly in azimuth and elevation, can be realized compared to an antenna arrangement. This allows for higher resolution in direction measurement in both dimensions, resulting in an overall improvement in accuracy when determining the direction of detected objects.

[0017] "Parallel" in the sense of the present invention means that the corresponding axes may also coincide, that is to say that the axes may be parallel or truly parallel.

[0018] The directional resolution, in particular the angular resolution, of a radar system depends directly on the aperture size of the virtual antenna array. Thanks to the present invention, a larger aperture can be achieved in two dimensions, in particular in azimuth and elevation, with a relatively small number of antenna elements.

[0019] In the sense of the present invention, a rectangle can have equal or different side lengths. Thus, a rectangle can also be a square.

[0020] “Parallel” in the sense of the present invention means that corresponding axes and / or planes may also coincide, that is, these axes and / or planes may be parallel or truly parallel.

[0021] The designations "first" and "second" for antenna element types are used only to make them easier to distinguish and do not imply preference over one type over the other. Similarly, the prefixes "Type 1" and "Type 2" are used only to make it easier to distinguish between the two types of antenna elements. A Type 1 antenna element can be a transmitting antenna element, and a Type 2 antenna element can be a receiving antenna element, and vice versa.

[0022] The designations "main axis" and "transverse axis" are also used only to make it easier to distinguish them and do not imply that one axis, in particular the main axis, takes precedence over the other, in particular the transverse axis. Accordingly, here again, the prefixes "Type 1" and "Type 2" are used only to make it easier to assign the axes to the corresponding antenna element types.

[0023] Radar systems can be used in vehicles, in particular motor vehicles. Radar systems can advantageously be used in land vehicles, in particular cars, trucks, buses, motorcycles, etc., aircraft, in particular drones, and / or watercraft. Radar systems can also be used in vehicles that can operate autonomously or at least partially autonomously.

[0024] The radar system can advantageously be connected to at least one electronic control device of a vehicle or machine, in particular a driver assistance system, or be part of such a control device. In this way, at least some functions of the vehicle can be performed autonomously or partially autonomously.

[0025] Radar systems can be used to detect stationary or moving objects, in particular vehicles, persons, animals, plants, obstacles, uneven driving surfaces, in particular potholes or stones, road edges, road signs, free spaces, in particular parking spaces, precipitation, etc., and / or movements and / or gestures.

[0026] In an advantageous embodiment, at least two Type-2 antenna elements can be arranged on different imaginary Type-2 antenna element transverse axes, which are parallel to each other and spaced apart, and extend perpendicular to the Type-2 antenna element main axis. In this way, the Type-2 antenna elements can be spaced apart in two dimensions, specifically, in the direction of the Type-2 antenna element main axis and in the direction of the Type-2 antenna element transverse axis. This allows for a so-called sparse array in the virtual antenna array. Consequently, gaps exist in the virtual antenna array. This allows for a larger virtual antenna array with a larger aperture in two dimensions, particularly in azimuth and elevation.

[0027] In another advantageous embodiment,

[0028] The antenna arrangement comprises at least three type 2 antenna element transverse axes at a distance from one another and at least three type 2 antenna elements, the at least three type 2 antenna elements being arranged on different type 2 antenna element transverse axes, and at least two distances between respective adjacent type 2 antenna element transverse axes being the same and / or at least two distances between respective adjacent type 2 antenna element transverse axes being different,

[0029] and / or

[0030] The antenna device may have at least four type-2 antenna elements, wherein one type-2 antenna element is arranged on one of the type-2 antenna element main axes, at least one type-2 antenna element is arranged on another type-2 antenna element main axis, and all other type-2 antenna elements are arranged on yet another type-2 antenna element main axis; in particular, it is possible that the transverse axis of a type-2 antenna element having a type-2 antenna element that is respectively independently arranged on one of the type-2 antenna element main axes is not located between the transverse axes of the other two type-2 antenna elements,

[0031] and / or

[0032] the antenna arrangement having at least four type-2 antenna elements, wherein one type-2 antenna element is arranged on one of the type-2 antenna element main axes, one type-2 antenna element is arranged on another type-2 antenna element main axis, and all other type-2 antenna elements are arranged on a further type-2 antenna element main axis, and the distance of the type-2 antenna element transverse axis on which one of the type-2 antenna elements is independently arranged on the corresponding type-2 antenna element main axis from the transverse axis of at least one adjacent type-2 antenna element is at most the same as the other distances between the transverse axes of the corresponding adjacent type-2 antenna elements,

[0033] and / or

[0034] the antenna arrangement having three type-2 antenna element main axes and at least three type-2 antenna element transverse axes, wherein one type-2 antenna element is respectively arranged on 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 are respectively located on one of the two outer type-2 antenna element main axes of the type-2 antenna element field,

[0035] and / or

[0036] The antenna arrangement may have exactly four type 2 antenna elements,

[0037] and / or

[0038] The antenna arrangement may have exactly three Type 2 antenna element main axes,

[0039] and / or

[0040] The distances between the main axes of respective adjacent type 2 antenna elements may be different.

[0041] In this way, overall a better distribution of the virtual antenna elements among the virtual antenna elements can be achieved.

[0042] Advantageously, at least two distances between the transverse axes of corresponding adjacent Type-2 antenna elements can be identical. This allows for a more uniform distribution of the virtual antenna elements in the virtual antenna array. Alternatively or additionally, at least two distances between the transverse axes of corresponding adjacent Type-2 antenna elements can be different. This allows for a more uniform distribution of the virtual antenna elements in the virtual antenna array.

[0043] Advantageously, as an alternative or in addition, one Type 2 antenna element can be arranged on one of the Type 2 antenna element main axes, another Type 2 antenna element can be arranged on another Type 2 antenna element main axis, and all other Type 2 antenna elements can be arranged on yet another Type 2 antenna element main axis. In this way, combined with the rectangular arrangement of Type 1 antenna elements, a uniform range of the virtual antenna array can be achieved.

[0044] Advantageously, as an alternative or in addition, it is possible for two Type 2 antenna element transverse axes, each with a Type 2 antenna element independently arranged on a corresponding Type 2 antenna element main axis, not to lie 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 consisting of Type 2 antenna elements.

[0045] Advantageously, alternatively or additionally, the transverse axis of at least one Type-2 antenna element, on which one of the Type-2 antenna elements is independently arranged on the main axis of the corresponding Type-2 antenna element, can be at most the same distance from the transverse axis of at least one adjacent Type-2 antenna element as other distances between the transverse axes of the corresponding adjacent Type-2 antenna elements. This allows gaps resulting from the offset of individual Type-2 antenna elements relative to other Type-2 antenna elements to be kept small. Consequently, a more uniform distribution of virtual antenna elements in the virtual antenna array can be achieved overall.

[0046] Advantageously, as an alternative or in addition, the antenna arrangement may have three Type-2 antenna element main axes and at least three Type-2 antenna element transverse axes, one of the Type-2 antenna elements being arranged on each of 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 main axes of the Type-2 antenna element field. In this way, the two outer Type-2 antenna elements may be arranged on diagonally opposite sides of the Type-2 antenna element field.

[0047] Advantageously, as an alternative or in addition, the antenna arrangement can have exactly four type 2 antenna elements. In this way, exactly four antenna elements can be implemented from each of the two antenna element types. Consequently, a correspondingly large number of virtual antenna elements can be implemented in the virtual antenna array.

[0048] Advantageously, as an alternative or in addition, the antenna arrangement may have exactly three Type 2 antenna element main axes. In this way, the extent of the Type 2 antenna element field perpendicular to the Type 2 antenna element main axes may be limited.

[0049] Advantageously, as an alternative or in addition, the antenna arrangement can include exactly four Type 2 antenna elements, which are arranged in a distributed manner along three Type 2 antenna element main axes and four Type 2 antenna element transverse axes. This increases the range of uniqueness in the virtual antenna array that can be implemented using the antenna arrangement. In particular, ambiguity regarding the direction of the arrangement axes, particularly in elevation or azimuth, can be avoided.

[0050] Advantageously, as an alternative or in addition, the distance between two of the main axes of three adjacent type 2 antenna elements can be different in each case. In this way, a better distribution of the virtual antenna elements in the virtual antenna array can be achieved.

[0051] In another advantageous embodiment,

[0052] the type 2 antenna element axes, in particular the type 2 antenna element main axis and the type 2 antenna element lateral axis, extend in a common imaginary plane,

[0053] and / or

[0054] The type 2 antenna element axes, in particular the type 2 antenna element main axis and the type 2 antenna element transverse axis, extend parallel to the plane in which the type 1 antenna element main axis and the type 1 antenna element transverse axis lie,

[0055] and / or

[0056] The type 1 antenna element and the type 2 antenna element are arranged on a common carrier, in particular a common carrier board. In this way, the antenna device can be produced, mounted and aligned more easily.

[0057] Advantageously, all Type 2 antenna element axes may extend in one imaginary plane. This way, the antenna arrangement may be easier to implement and align.

[0058] Advantageously, as an alternative or in addition, the type 2 antenna element axis can extend parallel to the type 1 antenna element axis, in particular the plane in which the main axis of the type 1 antenna element and the main axis of the type 2 antenna element lie. This simplifies the alignment of the type 1 antenna element and the arrangement of the type 2 antenna element.

[0059] Advantageously, as an alternative or in addition, the type 1 antenna element and the type 2 antenna element may be arranged on a common carrier. In this way, the antenna arrangement may be produced even more easily.

[0060] Advantageously, the Type 1 and Type 2 antenna elements can be implemented on a common carrier board, in particular a printed circuit board. This allows all antenna elements to be easily implemented in a single plane. Using a printed circuit board makes it particularly easy to make electrical connections to the antenna elements.

[0061] In another advantageous embodiment, the phase centers of at least some antenna elements, in particular the phase centers of all antenna elements, can be arranged on corresponding antenna element axes, in particular the main antenna element axis and / or the transverse antenna element axis. This allows the positions of the antenna elements to be more clearly defined.

[0062] Advantageously, the phase centers of at least some of the antenna elements may be located at the intersection of the main axis of the antenna element and the transverse axis of the antenna element.Thus, the positions of the antenna elements may be clearly defined.

[0063] In another advantageous embodiment, the respective distances between the axes of adjacent antenna elements of the same antenna element type, in particular the respective distances between the main axes and / or the respective distances between the transverse axes of adjacent antenna elements of the same antenna element type, can be integer multiples of a predetermined base distance, which is half the wavelength of the radar signal transmitted by the radar system. This allows for a particularly compact antenna arrangement. By specifying the base distance as half the wavelength of the radar signal, ambiguities and sidelobes can be reduced. Furthermore, a clearly directional radar signal can be achieved on the transmitter side. Furthermore, various angular measurements can be performed.

[0064] In another advantageous embodiment,

[0065] The range of the transmitting antenna element field composed of antenna elements of the transmitting antenna element type in the first arrangement axis direction may be greater than the range of the receiving antenna element field composed of antenna elements of the receiving antenna element type in the first arrangement axis direction, and the range of the transmitting antenna element field in the second arrangement axis direction may be greater than the range of the receiving antenna element field in the second arrangement axis direction.

[0066] and / or

[0067] The maximum range of the type 1 antenna element field in the direction of the first arrangement axis and in the direction of the second arrangement axis can have equal amplitude, and the maximum range of the type 2 antenna element field in the direction of the first arrangement axis and in the direction of the second arrangement axis can have equal amplitude.

[0068] Advantageously, the extent of the transmitting antenna element field in the direction of the two arrangement axes can be greater than the corresponding extent of the receiving antenna element field, so that the receiving antenna element field is adapted to a certain extent to the transmitting antenna element field.

[0069] The fact that the receive antenna element fields are smaller than the transmit antenna element fields allows ambiguities and sidelobes to be minimized.

[0070] Advantageously, the maximum extent of the field of a Type 1 antenna element in the direction of the first arrangement axis and in the direction of the second arrangement axis can have equal magnitude. Furthermore, the maximum extent of the field of a Type 2 antenna element in the direction of the first arrangement axis and in the direction of the second arrangement axis can have equal magnitude. In this way, the resolution in the direction of the first arrangement axis and in the direction of the second arrangement axis, particularly the angular resolution in azimuth and elevation, can be the same.

[0071] When the positions of the antenna elements of both antenna element types, in particular the transmitting antenna elements and the receiving antenna elements, are geometrically folded, the arrangement of type 1 antenna elements at the corners of an imaginary square results in a square virtual antenna array.

[0072] In another advantageous embodiment,

[0073] The antenna arrangement can be designed for use in radar systems according to the MIMO method,

[0074] and / or

[0075] Type 1 antenna elements may be individually activated and / or individually selected, and type 2 antenna elements may be individually activated and / or individually selected,

[0076] and / or

[0077] The antenna arrangement may be designed for use in a bistatic radar installation.

[0078] Advantageously, the antenna arrangement can be designed to operate the radar system according to the MIMO method. The radar system can be implemented as a so-called MIMO radar system. In the MIMO method (Multiple-Input Multiple-Output method), all antenna elements of the transmitting antenna element type can transmit differently coded radar signals. In this way, the radar signal at the receiver can be distributed according to the echo signals received by the antenna elements of the receiving antenna element type. Using a pure MIMO method, the aperture of the virtual antenna array implemented by the antenna arrangement can be correspondingly expanded.

[0079] Advantageously, antenna elements can be activated and / or selected individually. This allows for efficient use of multiple antenna elements, particularly with MIMO methods. Transmitting antenna elements can be activated individually. Receiving antenna elements can be selected individually. 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 implemented.

[0080] Advantageously, the antenna arrangement can be designed for a bistatic radar system. Advantageously, a bistatic radar system can have two radar systems. Each radar system can receive its own radar signal as well as the radar signal of the other radar system. This allows for more information about the monitored area, particularly the vehicle's surroundings.

[0081] Furthermore, the object of the radar system is achieved by providing a radar system having at least one antenna arrangement according to the invention.

[0082] 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, wherein one antenna element type is a transmitting antenna element and the other antenna element type is a receiving antenna element.

[0083] According to the present invention, type 1 antenna elements are arranged in a plane at the corners of an imaginary flat rectangle. Four type 1 antenna elements form a type 1 antenna element field. Two sides of the rectangle extend along a type 1 antenna element main axis, which is parallel to an imaginary first arrangement axis. The other two sides of the rectangle extend along a type 1 antenna element transverse axis, which is parallel to an imaginary second arrangement axis, which extends perpendicular to the first arrangement axis. At least two type 2 antenna elements are arranged on different imaginary type 2 antenna element main axes, which extend parallel to each other and at a certain distance from each other and are parallel to one of the arrangement axes. The type 2 antenna elements form a type 2 antenna element field. The maximum extent of at least one antenna element field in the direction of the first arrangement axis and in the direction of the second arrangement axis has equal amplitude.

[0084] Advantageously, the radar system can have means for operating the radar system according to the MIMO method. In this way, the resolution, in particular the angular resolution, can be increased when determining the direction of a detected object.

[0085] Advantageously, the radar system can be designed for use with a bistatic radar device. In this way, more information about the monitored area can be determined using the radar device.

[0086] According to the invention, the object for a driver assistance system can also be achieved by providing the driver assistance system with at least one antenna device according to the invention.

[0087] 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 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 is a transmitting antenna element, and the other antenna element type is a receiving antenna element.

[0088] According to the present invention, type 1 antenna elements are arranged in a plane at the corners of an imaginary planar rectangle in the antenna arrangement. Four type 1 antenna elements form a type 1 antenna element field. Two sides of the rectangle extend along a type 1 antenna element main axis that is parallel to an imaginary first arrangement axis. The other two sides of the rectangle extend along a type 1 antenna element transverse axis that is parallel to an imaginary second arrangement axis, the second arrangement axis being perpendicular to the first arrangement axis. At least three type 2 antenna elements are arranged on different imaginary type 2 antenna element main axes, the type 2 antenna element main axes extending parallel to each other and at a distance from each other and parallel to one of the arrangement axes. The type 2 antenna elements form a type 2 antenna element field. The maximum extent of at least one antenna element field in the direction of the first arrangement axis and in the direction of the second arrangement axis has equal amplitude.

[0089] With the radar system, objects in at least one monitoring area around the vehicle can be monitored.

[0090] With the driver assistance system, the vehicle can be operated autonomously or partially autonomously, in particular based on information obtained with the at least one radar system, in particular based on information about objects detected with the at least one radar system.

[0091] According to the present invention, a driver assistance system includes at least one antenna device according to the present invention. Advantageously, at least one radar system of the driver assistance system can include at least one antenna device according to the present invention. Since the at least one radar system is part of the driver assistance system, the antenna device according to the present invention of the at least one radar system is also part of the driver assistance system, that is, also the antenna device according to the present invention of the driver assistance system. This applies similarly to the antenna device according to the present invention of a vehicle having at least one driver assistance system and / or at least one radar system.

[0092] Furthermore, according to the invention, the object for a vehicle is achieved by providing the vehicle with at least one antenna arrangement according to the invention.

[0093] The vehicle includes at least one radar system and at least one antenna arrangement for the at least one radar system, the antenna arrangement including 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 antenna element type is a transmitting antenna element and the other antenna element type is a receiving antenna element.

[0094] With the radar system, objects in at least one monitoring area around the vehicle can be monitored.

[0095] The vehicle can advantageously have at least one driver assistance system, in particular at least one driver assistance system according to the present invention. By means of the driver assistance system, the vehicle can be operated autonomously or partially autonomously.

[0096] Advantageously, at least one radar system, in particular at least one radar system according to the present invention, can be connected to a driver assistance system, in particular at least one driver assistance system according to the present invention, or be part of such an assistance system. In this way, information obtained by the at least one radar system, in particular information about detected objects, can be used by the driver assistance system to operate the vehicle autonomously or partially autonomously.

[0097] Finally, according to the invention, the object for the method is achieved by providing a method for transmitting radar signals using an antenna arrangement according to the invention and for receiving echo signals using an antenna arrangement according to the invention.

[0098] According to the present invention, using four antenna elements of one antenna element type, radar signals can be transmitted from a plane, from the corners of an imaginary rectangular plane, or echo signals can be received from a plane, from the corners of an imaginary rectangular plane. The four antenna elements accordingly form a transmitting antenna element field or a receiving antenna element field. Two sides of the rectangle extend parallel to an imaginary first arrangement axis, and the other two sides of the rectangle extend parallel to an imaginary second arrangement axis, which extends perpendicular to the first arrangement axis. Using at least two antenna elements of another antenna element type, echo signals are received or radar signals are transmitted along different imaginary antenna element main axes. The antenna element main axes extend parallel to one of the arrangement axes and are spaced apart from each other. The two antenna elements of the other antenna element type accordingly form a receiving antenna element field or a transmitting antenna element field. The maximum extent of at least one antenna element field in the direction of the first arrangement axis and in the direction of the second arrangement axis has equal amplitude.

[0099] Advantageously, the radar system can operate according to a MIMO method. In this way, the direction of an object detected by the radar system can be determined more accurately.

[0100] Advantageously, two radar systems, in particular radar systems operating according to the present invention, can operate according to a bistatic method. Each radar system can detect and process radar signals transmitted by the other radar system, respectively.

[0101] In other respects, the features and advantages mentioned in conjunction with the antenna device 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, as well as their respective advantageous embodiments, apply accordingly to one another, and vice versa. The individual features and advantages can of course be combined with one another, in which case further advantageous effects can be achieved that exceed the sum of the individual effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] Other advantages, features and details of the present invention will become apparent from the following description, in which exemplary embodiments of the present invention are explained in more detail with reference to the accompanying drawings. A person skilled in the art will also readily consider the features disclosed in the drawings, the description and the claims in combination individually and combine them to form further useful combinations. Schematically, in the accompanying drawings:

[0103] Figure 1 A vehicle with a driver assistance system having a radar system is shown in plan view;

[0104] Figure 2 Shown in side view Figure 1 Vehicles in

[0105] Figure 3Shown Figure 1 and Figure 2 A front view of an antenna device of a vehicle radar system;

[0106] Figure 4 Shown Figure 1 and Figure 2 Front view of an alternative antenna arrangement for a vehicle radar system in FIG, and the resulting virtual antenna array.

[0107] In the drawings, the same components have the same reference numerals. DETAILED DESCRIPTION

[0108] exist Figure 1 In FIG. 1 , a vehicle 10 in the form of a passenger car is shown in plan view in a driving situation. Figure 2 A side view of vehicle 10 is shown.

[0109] The vehicle 10 comprises a driver assistance system 12. The driver assistance system 12 comprises a radar device, which comprises, for example, two radar systems 14 and a control device 16. Figure 1 and 2 , for greater clarity, only one radar system 14 is shown. The radar systems 14 are identical in function and structure.

[0110] For example, the radar systems 14 are arranged adjacent to each other on the front side of the vehicle 10. With the radar systems 14, objects 20 in a monitoring area 18 in front of the vehicle 10 can be monitored. Figure 1 and 2 In the embodiment, object 20 detectable by radar system 14 is arranged, for example, in front of vehicle 10. Radar system 14 can also be arranged at different locations of vehicle 10 and can also be aligned differently. Other radar systems 14 can also be arranged at different locations and have different alignments.

[0111] In the following, based on Figure 1 One radar system 14 is shown, and the radar system 14 is described by way of example.

[0112] Using the radar system 14 , 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 may be determined.

[0113] The radar system 14 is functionally connected to a control device 16 of the driver assistance system 14. Object information determined by means of the radar system 14 can thus be transmitted to the control device 16. With the driver assistance system 12, the vehicle 10 can be operated autonomously or partially autonomously.

[0114] For ease of orientation, the corresponding coordinates of the Cartesian xyz coordinate system are as follows Figures 1 to 4As shown. For 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 upward in space perpendicular to the xy plane. In the normal operating orientation 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.

[0115] Radar system 14 can transmit a radar signal 26 into surveillance area 18. Radar signal 26 reflected by object 20 in the direction of radar system 14 can be received by radar system 14 as echo signal 28. Corresponding object information can be determined from echo signal 28.

[0116] Radar system 14 includes an antenna device 30 and a control and evaluation device 32 .

[0117] From the monitoring area 18, the antenna device 30 is Figure 3 3. The antenna array 30 is shown in a front view. The antenna array 30 includes two types of antenna elements, specifically a transmitting antenna element Tx and a receiving antenna element Rx. The transmitting antenna element Tx can be used to transmit a radar signal 26. The receiving antenna element Rx can be used to receive an echo signal 28.

[0118] The antenna arrangement 30 has four transmitting antenna elements Tx and four receiving antenna elements Rx. The transmitting antenna elements Tx and the receiving antenna elements Rx are arranged on a common carrier in the form of a carrier board 34. The carrier board 34 can be designed as a printed circuit board, for example.

[0119] The control and evaluation device 32 can be used to activate the transmitting antenna element Tx to transmit the radar signal 26. Furthermore, the control and evaluation device 32 can detect and evaluate the echo signal 28 received by the receiving antenna element Rx and converted into an electrical receive signal. The control and evaluation device 32 can be used to determine the corresponding object information from the electrical receive signal and transmit it to the control device 16.

[0120] The radar system 14 operates according to the MIMO (Multiple Input Multiple Output) method. In the MIMO method, the transmitting antenna elements Tx are individually activated by the control and evaluation device 32 using transmit control signals. With the help of the corresponding transmit control signals, the radar signals 26 sent with the individual transmitting antenna elements Tx are made distinguishable, for example by encoding. Thus, on the receiver side, the signal paths of the radar signals 26 and the corresponding echo signals 28 can be assigned to the corresponding transmitting antenna elements Tx. Accordingly, the receiving antenna elements Rx are selected individually. The electrical receive signals converted from the echo signals 28 by the antenna elements Rx are assigned accordingly. Due to the individual 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. Figure 4In FIG. 3 , a virtual antenna array 36 is shown by way of example, which may be implemented with an alternative antenna arrangement 30, which is also shown in FIG. Figure 4 Shown in. Figure 4 The virtual antenna array 36 shown can also be used Figure 3 This is achieved by the antenna device 30.

[0121] Furthermore, a radar system having two radar systems 14 can operate as a bistatic radar system. Each radar system 14 can receive and process an echo signal 28 from a radar signal 26 transmitted by another radar system 14. Thus, the amount of information from the monitored area 18 can be increased.

[0122] exist Figure 3 and 4 In FIG. 3 , the phase center 38 of the transmit antenna element Tx is represented by a black filled circle. The phase center 40 of the receive antenna element Rx is represented by a black filled square.

[0123] exist Figure 3 In FIG, a transmitting antenna element field 42 consisting of four transmitting antenna elements Tx on the left and a receiving antenna element field 44 consisting of four receiving antenna elements Rx on the right are shown separately. The transmitting antenna element field 42 and the receiving antenna element field 44 can also be arranged relative to each other in some other way. Figure 4 As shown at the bottom, the transmit antenna element fields 42 and receive antenna element fields 44 may also overlap.

[0124] The transmitting antenna element Tx is arranged in a transmitting plane at the corners of an imaginary planar rectangle 46. The rectangle 46 has equal side lengths. The rectangle 46 is therefore square. Two sides of the rectangle 46 extend along an imaginary transmitting antenna element main axis 50, parallel to the imaginary first arrangement axis 48, at Figure 3 The other two sides of the rectangle 46 extend along the imaginary lateral axis 54 of the transmitting antenna element, parallel to the imaginary second arrangement axis 52, at Figure 3 The second arrangement axis 52 extends perpendicularly to the first arrangement axis 48 . The transmitting antenna elements Tx thus form a rectangular transmitting antenna element field 42 .

[0125] The phase center 38 of the transmitting antenna element Tx is arranged at the intersection of the transmitting antenna element main axis 50 and the corresponding transmitting antenna element transverse axis 54 .

[0126] The respective distances between the main axes 50 of adjacent transmitting antenna elements or between the transverse axes 54 of adjacent transmitting antenna elements, that is, the distances between the axes of respective adjacent antenna elements of the same antenna element type, are integer multiples 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 by the radar system 14.

[0127] exist Figure 3 In the exemplary embodiment shown, the distance 56 between the main axes 50 of the radiating antenna elements corresponds to five times the basic distance λ / 2, namely 2.5λ. The distance 58 between the transverse axes 54 of the radiating antenna elements also corresponds to five times the basic distance λ / 2, namely 2.5λ.

[0128] The phase centers 40 of the four receive antenna elements Rx are arranged in a distributed manner on three imaginary receive antenna element main axes 60 and four imaginary receive antenna element transverse axes 62. In this case, the phase centers 40 are respectively arranged at the intersection of the receive antenna element main axes 60 and the receive antenna element transverse axes 62.

[0129] The receiving antenna element main axes 60 extend parallel to and at a distance from each other and parallel to the first arrangement axis 48. The four receiving antenna element transverse axes 62 extend parallel to and at a distance from each other, perpendicular to the receiving antenna element main axes 60 and parallel to the second arrangement axis 52.

[0130] The receive antenna element main axis 60 and the receive antenna element transverse axis 62 extend in an imaginary receive plane. The receive antenna element main 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 main axis 50 and the transmit antenna element transverse axis 54 lie. The receive plane, which includes the receive antenna element main axis 60 and the receive antenna element transverse axis 62, extends parallel to the transmit plane, which includes the transmit antenna element main axis 50 and the transmit antenna element transverse axis 54. In the exemplary embodiment shown, the transmit and receive planes coincide.

[0131] The phase center 40 of one of the receiving antenna elements Rx is arranged on one of the receiving antenna element main axes 60. Figure 3 The phase center 40 of the other receiving antenna element Rx is arranged on the main axis 60 of the other receiving antenna element. Figure 3 The center is to the right of the lower receive antenna element main axis 60. The phase centers 40 of the two further receive antenna elements Rx are arranged on the third middle receive antenna element main axis 60. The phase centers 40 of the four receive antenna elements Rx are arranged on different receive antenna element transverse axes 62.

[0132] The receive antenna element transverse axis 62 is located at the left edge of the receive antenna element field 44, that is, not between the other two receive antenna element transverse axes 62. The phase center 40 of the receive antenna element Rx is located on the receive antenna element transverse axis 62. The receive antenna element Rx is independently arranged on the upper receive antenna element main axis 60. The receive antenna element transverse axis 62 is located at the right edge of the receive antenna element field 44, that is, not between the other two receive antenna element transverse axes 62. The phase center 40 of the receive antenna element Rx is located on the receive antenna element transverse axis 62. The receive antenna element Rx is independently arranged on the lower receive antenna element main axis 60.

[0133] A receiving antenna element Rx is arranged on each of the two outer antenna element transverse axes 62 of the receiving antenna element field 44. The receiving antenna elements Rx located on the two outer antenna element transverse axes 62 are each located on one of the two outer antenna element main axes 60. Figure 3 In the exemplary embodiment of FIG. 4 , the individual receive antenna element Rx is located at the upper left in receive antenna field 44 at the intersection of upper receive antenna element main axis 60 and left receive antenna element transverse axis 62. The individual receive antenna element Rx at the lower right in receive antenna field 44 is located at the intersection of lower receive antenna element main axis 60 and right receive antenna element transverse axis 62. Two outer receive antenna elements Rx are arranged on diagonally opposite sides of receive antenna field 44.

[0134] The respective distances between respective adjacent antenna element axes of the same antenna element type, in particular the respective distances between adjacent receiving antenna element main axes 60 or between adjacent receiving antenna element transverse axes 62 , are integer multiples of the basic distance λ / 2.

[0135] Figure 3 The distance 70 between the upper and middle receive antenna element main axes 60 and 60 is different from the distance 84 between the middle and lower receive antenna element main axes 60 and 60 .

[0136] exist Figure 3 In the exemplary embodiment shown, 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 corresponds to three times the basic distance λ / 2, i.e., 1.5λ. 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 corresponds to one times the basic distance λ / 2.

[0137] Figure 3Distance 64 between first and second receive antenna element transverse axes 62, from center left, corresponds to distance 66 between second and third receive antenna element transverse axes 62, 62. Distance 68 between third and fourth receive antenna element transverse axes 62, 62, and distances 64 and 66 between other corresponding adjacent receive antenna element transverse axes 62 are different.

[0138] The distance 64 between the transverse axis 62 of the receiving antenna element on which the phase center 40 of the individual receiving antenna element Rx lies and the adjacent transverse axis 62 of the receiving antenna element is smaller than the distance 68 between the transverse axes 62 of the second and third receiving antenna elements from the left. Figure 3 On the upper receive antenna element main axis 60 to the left of the middle receive antenna element field 44 .

[0139] The distance 64 between the transverse axis 62 of the receiving antenna element Rx on the left and the adjacent transverse axis 62 of the second receiving antenna element in the receiving antenna field 44 corresponds to one times the basic distance λ / 2. The distance 66 between the transverse axis 62 of the second receiving antenna element and the transverse axis 62 of the third receiving antenna element from the left also corresponds to one times the basic distance λ / 2. The transverse axis 62 of the third receiving antenna element from the left and the transverse axis 62 of the fourth receiving antenna element from the left (i.e. Figure 3 The distance 68 between the transverse axes 62 of the right-hand receive antenna elements in the middle receive antenna element field 44 corresponds to twice the basic distance λ / 2, ie λ.

[0140] The extent of the transmitting antenna element field 42 in the direction of the first arrangement axis 48 is greater than the extent 72 of the receiving antenna element field 44 in the direction of the first arrangement axis 48. Figure 3 In the exemplary embodiment shown, the extent of transmit antenna element field 42 in the direction of first arrangement axis 48 corresponds to distance 58 between transmit antenna element transverse axes 54, that is, five times the basic distance λ / 2, or 2 / 5λ. The extent 72 of receive antenna element field 44 in the direction of first arrangement axis 48 corresponds to the sum of distances 64, 66, and 68 between receive antenna element transverse axes 62, that is, four times the basic distance λ / 2, or 4λ.

[0141] The extent of transmit antenna element field 42 in the direction of second arrangement axis 52 is greater than the extent 86 of receive antenna element field 44 in the direction of second arrangement axis 52. In the exemplary embodiment shown, the extent of transmit antenna element field 42 in the direction of second arrangement axis 52 corresponds to the distance 56 between the main axes 50 of the transmit antenna elements, that is, five times the basic distance λ / 2, or 2.5λ. The extent 86 of receive antenna field 44 in the direction of second arrangement axis 52 corresponds to the sum of the distances 70 and 84 between the main axes 60 of the receive antenna elements, that is, four times the basic distance λ / 2, or 2λ.

[0142] exist Figure 4 In the Figure 3 An alternative to the antenna arrangement 30 and a virtual antenna array 36 that can be implemented therewith. Figure 3 Similar elements of the first exemplary embodiment bear the same reference numerals. For ease of orientation, coordinate axes with y and z coordinates are also shown. The y and z coordinates are each expressed in wavelength λ. For easier orientation, the origin (0.0) of the coordinate system is placed at the phase center 38 of the lower left transmitting antenna element Tx.

[0143] Figure 4 The alternative antenna arrangement 30 shown in FIG. 1 comprises Figure 3 The transmitting antenna element field 42 and the receiving antenna element field 44 in the Figure 3 Compared to the antenna arrangement 30 of FIG. 3 , in the alternative antenna arrangement 30, the receive antenna element field 44 is largely positioned within the transmit antenna element field 42. In this case, the lower transmit antenna element main axis 50 and the middle receive antenna element main axis 60 coincide. In addition, the left transmit antenna element transverse axis 54 and the left receive antenna element transverse axis 62 coincide.

[0144] exist Figure 4 In the diagram, for greater clarity, by way of example, only two transmit antenna elements Tx with phase center 38 and one receive antenna element Rx with phase center 40 are provided with reference numerals.

[0145] The receive antenna element field 44 is arranged so that the phase center 38 of the lower left transmit antenna element Tx is located at the intersection of the lower receive antenna element main axis 60 and the left receive antenna element transverse axis 62. The lower left transmit antenna element Tx is located in the gap in the receive antenna element field 44, which gap is caused by the offset of the left receive antenna element Rx upward toward the upper receive antenna element main axis 60. In general, Figure 4 The alternative antenna device is 30 times Figure 3 The antenna device 30 has a more space-saving structure.

[0146] use Figure 3 The antenna device 30 and Figure 4 The antenna device 30 can achieve Figure 4 A virtual antenna array 36 is shown.

[0147] Using Figure 4 The alternative antenna arrangement 30 and correspondingly utilizes the Figure 3 Antenna arrangement 30 of the embodiment of the present invention generates an antenna array 36 having a total of 16 virtual antenna elements Vx during operation of radar system 14. Virtual antenna array 36 is realized by geometric folding of the geometric positions of phase centers 38 of transmit antenna elements Tx and phase centers 40 of receive antenna elements Rx of antenna arrangement 30 or an alternative to antenna arrangement 30. Virtual antenna elements Vx serve as virtual receive antenna elements for echo signals 28.

[0148] exist Figure 4 , a virtual antenna element Vx of the virtual antenna array 36 is shown. A virtual phase center 73 of the virtual antenna element Vx of the virtual antenna array 70 is represented as a white filled triangle. Figure 4 In FIG. 1 , for example, only some of the virtual antenna elements Vx have reference numerals.

[0149] Virtual antenna array 36 includes four virtual antenna element fields 74. Virtual antenna element fields 74 are identically configured, having the same size and orientation. Each virtual antenna element field 74 includes 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 antenna arrangement 30.

[0150] The virtual antenna element fields 74 are each arranged at the corners of a virtual square. Two sides of the square extend along respective virtual main axes 76 parallel to the first arrangement axis 48. The other two sides of the square extend along respective virtual transverse axes 78 parallel to the second arrangement axis 52.

[0151] exist Figure 4 In the exemplary embodiment shown, left imaginary lateral axis 78 coincides with left transmit antenna element lateral axis 54 and left receive antenna element lateral axis 62. Upper imaginary principal axis 76 coincides with lower transmit antenna element principal axis 50 and middle receive antenna element principal axis 60. Lower imaginary principal axis 76 extends below lower transmit antenna element principal axis 50. Right imaginary lateral axis 78 extends to the right of right transmit antenna element lateral axis 54.

[0152] The virtual phase center 73 of the left virtual antenna element Vx of the upper left virtual antenna element field 74 is located at the intersection of an upper virtual main axis 76, which coincides with the lower transmit antenna element main axis 50, and a left virtual transverse axis 78, which coincides with the left transmit antenna element transverse axis 54. This virtual antenna element Vx thus coincides with the lower left transmit antenna element Tx of the transmit antenna element field 42.

[0153] The free space below the left virtual antenna element Vx of the lower left virtual antenna element field 74 is located at the intersection of the lower virtual main axis 76 and the left virtual lateral axis 78 .

[0154] The left virtual antenna element Vx of the upper right virtual antenna element field 74 is located at the intersection of the upper virtual main axis 76, which coincides with the lower transmit antenna element main axis 50, and the right transmit antenna element transverse axis 54. This virtual antenna element Vx therefore coincides with the lower right transmit antenna element Tx of the transmit antenna element field 42.

[0155] The virtual phase center 73 of the right virtual antenna element Vx of the lower right virtual antenna element field 74 is located at the intersection of the lower virtual main axis 76 and the right virtual lateral axis 78 .

[0156] The distance 88 between the right virtual antenna element transverse axis 90 of the two left virtual antenna element fields 74 and the left virtual antenna element transverse axis 90 of the two right virtual antenna elements 74 corresponds to one basic distance λ / 2.

[0157] The distance 92 between the lower virtual antenna element main axis 94 of the two upper virtual antenna element fields 74 and the upper virtual antenna element transverse axis 94 of the two lower virtual antenna element fields 74 likewise corresponds to the basic distance λ / 2.

[0158] The lower right virtual antenna element Vx of the upper left antenna element field 74 and the upper left virtual antenna element Vx of the lower right antenna element field 74 are arranged diagonally at a distance of one-fold λ / 2 in the horizontal direction (y direction) and the vertical direction (z direction), respectively. In summary, a greater density of virtual antenna elements Vx can be achieved across the entire virtual antenna array 36. This improves the sidelobe levels in the horizontal direction (x direction) and the vertical direction (z direction).

[0159] The virtual phase center 73 of the upper virtual antenna element Vx of the virtual antenna array 36 lies on an upper virtual principal axis 76. The phase center 73 of the lower virtual antenna element Vx lies on a lower virtual principal axis 76. The distance 80 between the upper and lower virtual principal axes 76 represents the aperture of the virtual antenna array 36 in that direction, for example, in the vertical direction. Distance 80, and therefore, for example, the vertical aperture, corresponds to nine times the base distance λ / 2, or 4.5λ. Distance 80 corresponds to the sum of the vertical extent of the transmit antenna field 42 (specifically, distance 56) and the vertical extent 86 of the receive antenna element field 44.

[0160] The virtual phase center 73 of the left virtual antenna element Vx of the virtual antenna array 36 lies on a left virtual transverse axis 78. The phase center 73 of the right virtual antenna element Vx lies on a right virtual transverse axis 78. The distance 82 between the left and right virtual transverse axes 78 represents the aperture of the virtual antenna array 36 in that direction, for example, in the horizontal direction. Distance 82, and therefore, for example, the horizontal aperture, corresponds to nine times the base distance, or 4.5λ. 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).

[0161] In general, the ratio of the vertical aperture to the horizontal aperture of the virtual antenna array 36 is one to one, thereby achieving a balance between the 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 a radar system (14) for a vehicle (10), comprising 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 antenna element type is a transmitting antenna element (Tx) and the other antenna element type is a receiving antenna element (Rx), It is characterized by: The type 1 antenna element (Tx) is arranged in a plane at the corners of an imaginary planar rectangle (46) and forms a type 1 antenna element field (42), two sides of the rectangle (46) extending along a type 1 antenna element main axis (50) parallel to an imaginary first arrangement axis (48), and the other two sides of the rectangle (46) extending along a type 1 antenna element transverse axis (54) parallel to an imaginary second arrangement axis (52), the second arrangement axis (52) being perpendicular to the first arrangement axis (48), At least two type 2 antenna elements (Rx) are arranged on different imaginary type 2 antenna element main axes (60) and form a type 2 antenna element field (44), the type 2 antenna element main axes (60) extending parallel to each other and at a distance therefrom and parallel to one of the arrangement axes (48), and A maximum extent (56, 58; 59) of at least one antenna element field (42; 44) in the direction of the first arrangement axis (48) and in the direction of the second arrangement axis (52) 86, 72) have equal amplitudes.

2. The antenna device according to claim 1, wherein At least three type 2 antenna elements (Rx) are arranged on different imaginary type 2 antenna element transverse axes (62), which extend parallel to each other and at a distance and perpendicular to the type 2 antenna element main axis (60).

3. The antenna device according to claim 2, wherein The antenna device (30) has at least three type 2 antenna element transverse axes (62) at a distance from each other, at least three type 2 antenna elements (Rx) are arranged on different type 2 antenna element transverse axes (62), and at least two distances (66, 68) between respective adjacent type 2 antenna element transverse axes (62) are the same and / or at least two distances (64, 66, 68) between respective adjacent type 2 antenna element transverse axes (62) are different, and / or The antenna device (30) has at least four type-2 antenna elements (Rx), wherein one type-2 antenna element (Rx) is arranged on one type-2 antenna element main axis (60), at least one type-2 antenna element (Rx) is arranged on another type-2 antenna element main axis (60), and all other type-2 antenna elements (Rx) are arranged on yet another type-2 antenna element main axis (60); in particular, the type-2 antenna element transverse axis (62) of each type-2 antenna element (Rx) independently arranged on one type-2 antenna element main axis (60) is not located between two other type-2 antenna element transverse axes (62). and / or The antenna device (30) has at least four type 2 antenna elements (Rx), one of the type 2 antenna elements (Rx) being arranged on one of the type 2 antenna element main axes (60), one of the type 2 antenna elements (Rx) being arranged on another type 2 antenna element main axis (60), and all other type 2 antenna elements (Rx) being arranged on yet another type 2 antenna element main axis (60), and the type 2 antenna element transverse axis (62) on which one of the type 2 antenna elements (Rx) being independently arranged on the corresponding type 2 antenna element main axis (60) being at most the same distance (64) from at least one adjacent type 2 antenna element transverse axis (62) as the other distances (66, 68) between the corresponding adjacent type 2 antenna element transverse axes (62), and / or The antenna arrangement (30) has three type 2 antenna element main axes (60) and at least three type 2 antenna element transverse axes (62), wherein one type 2 antenna element (Rx) is respectively arranged on 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 respectively located on one of the two outer type 2 antenna element main axes (60) of the type 2 antenna element field (44), and / or The antenna device (30) has exactly four type 2 antenna elements (Rx), and / or The antenna device (30) has exactly three Type 2 antenna element main axes (60), and / or The distances (70, 84) between the major axes (60) of respective adjacent type 2 antenna elements are different.

4. Antenna device according to any one of the preceding claims, characterized in that The type 2 antenna element axes, in particular the type 2 antenna element main 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 main axis (60) and the type 2 antenna element transverse axis (62), extend parallel to the plane in which the type 1 antenna element main axis (50) and the type 1 antenna element transverse 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 board.

5. Antenna device according to any one of the preceding claims, characterized in that The phase centers (38, 40) of at least some antenna elements (Rx, Tx), in particular the phase centers (38, 40) of all antenna elements (Rx, Tx), are arranged on 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. Antenna device according to any one of the preceding claims, characterized in that The respective distances between the axes of adjacent antenna elements of the same antenna element type, in particular the respective distances (56; 70, 84) between the main axes (50; 60) of adjacent antenna elements of the same antenna element type and / or the respective distances (58; 64, 66, 68) of the lateral axes (54; 62) of adjacent antenna elements, are integer multiples of a predetermined basic distance, which corresponds to half the wavelength of a radar signal (26) transmitted by the radar system (14).

7. Antenna device according to any one of the preceding claims, characterized in that the extent (58) of a transmitting antenna element field (42) consisting of antenna elements of a transmitting antenna element type (Tx) in the direction of a first arrangement axis (48) is greater than the extent (72) of a receiving antenna element field (44) consisting of antenna elements of a receiving antenna element type (Rx) in the direction of the first arrangement axis (48), and the extent (54) of the transmitting antenna element field (42) in the direction of a second arrangement axis (52) is greater than the extent (86) of the receiving 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 arrangement axis (48) and in the direction of the second arrangement axis (52) have equal magnitudes, and the maximum extents (72, 86) of the type 2 antenna element field (44) in the direction of the first arrangement axis (48) and in the direction of the second arrangement axis (52) have equal magnitudes.

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

9. A radar system (14) having at least one antenna arrangement (30), in particular a radar system (14) for a vehicle (10), the antenna arrangement (30) 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 antenna element type is a transmitting antenna element (Tx) and the other antenna element type is a receiving antenna element (Rx), characterized in that The radar system (14) comprises at least one antenna arrangement (30) according to any one of claims 1 to 8.

10. A driver assistance system (12) having at least one radar system (14) and at least one antenna device (30) for the at least one radar system (14), the at least one antenna device (30) 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, one antenna element type being a transmitting antenna element (Tx) and the other antenna element type being a receiving antenna element (Rx), characterized in that The driver assistance system (12) comprises at least one antenna device (30) according to any one of claims 1 to 8.

11. 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), the at least one antenna arrangement (30) 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, one antenna element type being a transmitting antenna element (Tx) and the other antenna element type being a receiving antenna element (Rx), characterized in that The vehicle (10) has at least one antenna arrangement (30) according to any one of claims 1 to 8.

12. A method for operating a radar system (14), in particular a radar system (14) for a vehicle (10), the radar system (14) having at least one antenna arrangement (30), the antenna arrangement (30) 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: In the method, a radar signal (26) is transmitted using an antenna element (Tx) of one antenna element type, and an echo signal (28) originating from the transmitted radar signal (26) is received using an antenna element (Rx) of another antenna element type, wherein the radar signal (26) is transmitted using an antenna device (30) according to any one of claims 1 to 8, and the echo signal (28) is received using an antenna device (30) according to any one of claims 1 to 8.

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