Antenna device for a radar system, radar system, driver assistance system, vehicle, and method for operating a radar system

Abstract

The invention relates to an antenna assembly (30) for a radar system, in particular for a vehicle, a radar system, a driver assistance system, a vehicle and a method for operating a radar system. The antenna assembly (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 (Rx). The Type 1 antenna elements (Tx) are arranged on a plane at corners of an imaginary flat rectangle (46), two sides of the rectangle (46) extending parallel to an imaginary first mounting axis (48) and forming a Type 1 antenna element main axis (50), and the other two sides of the rectangle (46) extending parallel to an imaginary second mounting axis (52) and forming a Type 1 antenna element transverse axis (54), the second fitting axis (52) extends perpendicular to the first fitting axis (48). At least two type 2 antenna elements (Rx) are arranged on different imaginary type 2 antenna element main axes (60), which extend parallel to one another in a mutually spaced manner and parallel to one of the mounting axes (48).

Description

Technical Field

[0001] The invention relates to an antenna arrangement for a radar system, in particular a radar system for a vehicle, 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.

[0002] The present invention further relates to a radar system 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, wherein one antenna element type is a transmitting antenna element and the other antenna element type is 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, 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, 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, when performing direction measurement with the radar system, it is possible to increase the resolution of the direction in two dimensions, in particular in azimuth and elevation. Summary of the Invention

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

[0009] The type 1 antenna element is arranged in a plane at the corner of an imaginary planar rectangle, wherein two sides of the rectangle extend parallel to an imaginary first arrangement axis and form a main axis of the type 1 antenna element, and the other two sides of the rectangle extend parallel to an imaginary second arrangement axis and form a lateral axis of the type 1 antenna element, the second arrangement axis extending 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, which extend parallel to and at a distance from each other and parallel to one of the arrangement axes.

[0011] 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.

[0012] 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. 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.

[0013] Due to the rectangular 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 achieved compared to an antenna system. This allows for higher resolution in direction measurement in both dimensions, resulting in improved accuracy when determining the direction of detected objects.

[0014] The directional resolution, and especially the angular resolution, of a radar system is directly dependent on the aperture size of the virtual antenna array. Therefore, in general, a larger aperture can be achieved in two dimensions, especially in azimuth and elevation, with a relatively small number of antenna elements.

[0015] In the sense of the present invention, a rectangle can have equal or different side lengths. Thus, a rectangle can also be a square.

[0016] "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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] In an advantageous embodiment, at least two Type-2 antenna elements can be arranged on different imaginary Type-2 antenna element transverse axes, with the Type-2 antenna element transverse axes being parallel to each other and spaced apart, and extending perpendicular to the Type-2 antenna element main axis. In this manner, 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. Thus, a known sparse array can be implemented 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.

[0023] In another advantageous embodiment,

[0024] The antenna arrangement may have at least three type-2 antenna element transverse axes at a distance from one another and at least three type-2 antenna elements, wherein all distances between respective adjacent type-2 antenna element transverse axes are different and the at least three type-2 antenna elements are arranged on different type-2 antenna element transverse axes,

[0025] and / or

[0026] The antenna arrangement may have at least three type-2 antenna elements, wherein one type-2 antenna element is arranged on one of the main axes of the type-2 antenna element and all other type-2 antenna elements are arranged on another main axis of the type-2 antenna element; in particular, it is possible that the transverse axis of a type-2 antenna element comprising a type-2 antenna element independently arranged on a main axis of a type-2 antenna element is not located between the transverse axes of two other type-2 antenna elements,

[0027] and / or

[0028] 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 and all other type-2 antenna elements are arranged on another type-2 antenna element main axis, and a type-2 antenna element transverse axis on which a type-2 antenna element is independently arranged on the corresponding type-2 antenna element main axis is at a distance from a transverse axis of at least one adjacent type-2 antenna element that is smaller than other distances between the transverse axes of the corresponding adjacent type-2 antenna elements,

[0029] and / or

[0030] The antenna arrangement may have exactly four type 2 antenna elements. In this way, the overall aperture of the virtual antenna array may be increased in the direction of the main axis of the type 2 antenna elements.

[0031] The distances between the transverse axes of respective adjacent type 2 antenna elements may advantageously be different. In this way, a better distribution of the virtual antenna elements in the virtual antenna array may be achieved.

[0032] Advantageously, as an alternative or in addition, one of the Type 2 antenna elements can be arranged on one of the Type 2 antenna element main axes, and all other Type 2 antenna elements can be arranged on another Type 2 antenna element main axis. In this way, combined with the rectangular arrangement of Type 1 antenna elements, a greater range of the virtual antenna array can be achieved.

[0033] Advantageously, as an alternative or in addition, a type 2 antenna element transverse axis comprising a type 2 antenna element independently arranged on a type 2 antenna element main axis may not be located between two other type 2 antenna element transverse axes. This allows for an overall L-shaped arrangement of type 2 antenna elements.

[0034] Advantageously, as an alternative or in addition, the distance between the transverse axis of a Type 2 antenna element, on which a Type 2 antenna element is independently arranged on the main axis of the Type 2 antenna element, and the transverse axis of at least one adjacent Type 2 antenna element can be smaller than other distances between the transverse axes of corresponding adjacent Type 2 antenna elements. Thus, gaps resulting from the offset of individual antenna elements relative to other antenna elements can be kept small. Consequently, a more uniform distribution of virtual antenna elements can be achieved overall.

[0035] 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.

[0036] In another advantageous embodiment,

[0037] The type 2 antenna element axes, in particular the type 2 antenna element main axis and the type 2 antenna element lateral axis, may extend in a common imaginary plane,

[0038] and / or

[0039] The type 2 antenna element axes, in particular the type 2 antenna element main axis and the type 2 antenna element lateral axis, may extend parallel to a plane spanned by the type 1 antenna element main axis and the type 1 antenna element lateral axis,

[0040] and / or

[0041] The type 1 antenna element and the type 2 antenna element can be arranged on a common carrier, in particular a common carrier board. In this way, the antenna arrangement can be produced, mounted and aligned more easily.

[0042] 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.

[0043] Advantageously, as an alternative or in addition, the Type 2 antenna element axis can extend parallel to a plane spanned by the Type 1 antenna element axes, in particular the Type 1 antenna element main axis and the Type 2 antenna element main axis. This simplifies the alignment of the Type 1 antenna element and the arrangement of the Type 2 antenna element.

[0044] 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.

[0045] 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 easier to make electrical connections to the antenna elements.

[0046] 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 position of the antenna elements to be defined more precisely.

[0047] Advantageously, the phase centre 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.

[0048] 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.

[0049] In another advantageous embodiment,

[0050] 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.

[0051] and / or

[0052] The rectangle of the type 1 antenna element can have different side lengths, with the longer side extending parallel to the arrangement axis, and the type 2 antenna element axis, in particular the type 2 antenna element main axis or the type 2 antenna element transverse axis, in which direction the type 2 antenna element field composed of the type 2 antenna element has the largest range, also extends relative to the arrangement axis.

[0053] 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.

[0054] When the positions of the antenna elements of the two antenna element types (specifically 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 rectangle with different side lengths results in a larger virtual antenna array in the direction of the longer side of the rectangle.

[0055] The fact that the receive antenna element fields are smaller than the transmit antenna element fields allows ambiguities and sidelobes to be minimized.

[0056] Advantageously, the antenna element fields of type 1 antenna elements and the antenna element fields of type 2 antenna elements can each be aligned so that they extend to a greater extent in the direction of the same arrangement axis. In this way, the resulting virtual array can also have a greater extent in the direction of one arrangement axis than in the direction of another arrangement axis.

[0057] In another advantageous embodiment,

[0058] The antenna arrangement can be designed for use in radar systems according to the MIMO method,

[0059] and / or

[0060] 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.

[0061] 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 correspond to the echo signal 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 enlarged.

[0062] Advantageously, antenna elements can be activated and / or selected individually. This allows for efficient utilization of multiple antenna elements. 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.

[0063] Furthermore, the object of the radar system is achieved by providing that the radar system has at least one antenna arrangement according to the invention.

[0064] The radar system comprises 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 antenna element type is a transmitting antenna element and the other antenna element type is a receiving antenna element.

[0065] According to the present invention, a Type 1 antenna element is arranged in a plane at the corners of an imaginary planar rectangle. Two sides of the rectangle extend parallel to an imaginary first arrangement axis and form the Type 1 antenna element's main axis. The other two sides of the rectangle extend parallel to an imaginary second arrangement axis and form the Type 1 antenna element's transverse axis, with the second arrangement axis extending perpendicular to the first arrangement axis. At least two Type 2 antenna elements are arranged on different imaginary Type 2 antenna element main axes, with the Type 2 antenna element main axes extending parallel to each other and at a distance therefrom, and parallel to one of the arrangement axes.

[0066] 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.

[0067] According to the invention, the object for a driver assistance system can also be achieved by providing that the driver assistance system has at least one antenna arrangement according to the invention.

[0068] The driver assistance system includes at least one radar system and at least one antenna arrangement for the at least one radar system, the 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 antenna element type is a transmitting antenna element and the other antenna element type is a receiving antenna element.

[0069] According to the present invention, a Type 1 antenna element is arranged in a plane at the corners of an imaginary planar rectangle. Two sides of the rectangle extend parallel to an imaginary first arrangement axis and form the Type 1 antenna element's main axis. The other two sides of the rectangle extend parallel to an imaginary second arrangement axis and form the Type 1 antenna element's transverse axis, with the second arrangement axis extending perpendicular to the first arrangement axis. At least two Type 2 antenna elements are arranged on different imaginary Type 2 antenna element main axes, with the Type 2 antenna element main axes extending parallel to each other and at a distance therefrom, and parallel to one of the arrangement axes.

[0070] With the radar system, objects in at least one monitoring area around the vehicle can be monitored.

[0071] 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.

[0072] 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.

[0073] Furthermore, according to the invention, the object for a vehicle is achieved by providing that the vehicle has at least one antenna arrangement according to the invention.

[0074] 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.

[0075] With the radar system, objects in at least one monitoring area around the vehicle can be monitored.

[0076] According to the present invention, a Type 1 antenna element is arranged in a plane at the corner of an imaginary planar rectangle. Two sides of the rectangle extend parallel to an imaginary first arrangement axis and form a Type 1 antenna element main axis. The other two sides of the rectangle extend parallel to an imaginary second arrangement axis and form a Type 1 antenna element transverse axis, the second arrangement axis extending perpendicular to the first arrangement axis. At least two Type 2 antenna elements are arranged on different imaginary Type 2 antenna element main axes, with the Type 2 antenna element main axes extending parallel to each other at a distance and parallel to one of the arrangement axes.

[0077] 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.

[0078] 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.

[0079] Finally, according to the invention, the object of 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.

[0080] According to the present invention, radar signals are transmitted from a plane at the corners of an imaginary planar rectangle using antenna elements of one antenna element type, in particular transmitting antenna elements. 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. Echo signals are received using at least two antenna elements of another antenna element type, in particular receiving antenna elements, on different imaginary antenna element main axes, which extend parallel to one of the arrangement axes and at a distance from each other.

[0081] 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.

[0082] 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

[0083] 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:

[0084] Figure 1 shows a plan view of a vehicle having a driver assistance system with a radar system;

[0085] Figure 2 Shown in side view Figure 1 Vehicles in

[0086] Figure 3 Shown Figure 1 and Figure 2 A front view of an antenna device of a vehicle radar system;

[0087] 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.

[0088] In the drawings, the same components have the same reference numerals. DETAILED DESCRIPTION

[0089] 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.

[0090] The vehicle 10 comprises a driver assistance system 12 . The driver assistance system 12 has, for example, a radar system 14 and a control device 16 .

[0091] The radar system 14 is arranged, for example, at the front side of the vehicle 10. The radar system 14 can be used to monitor objects 20 in a monitoring area 18 in front of the vehicle 10. 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. Multiple radar systems 14 can also be provided at different locations and with different alignments.

[0092] 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.

[0093] 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.

[0094] For ease of orientation, the corresponding coordinates of the Cartesian xyz coordinate system are as follows Figures 1 to 4 As 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.

[0095] 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.

[0096] Radar system 14 includes an antenna device 30 and a control and evaluation device 32 .

[0097] From the monitoring area 18, the antenna device 30 is Figure 3 . The antenna arrangement 30 comprises 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.

[0098] 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 plate 34.

[0099] 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.

[0100] 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 4 In 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.

[0101] 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.

[0102] 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.

[0103] The transmitting antenna elements Tx are arranged in a transmitting plane at the corners of an imaginary planar rectangle 46. The rectangle 46 has different side lengths. The two longer sides of the rectangle 46 are parallel to Figure 3 The imaginary first arrangement axis 48 extending horizontally in the middle extends and forms an imaginary main axis 50 of the transmitting antenna element. The other two shorter sides of the rectangle 46 are parallel to Figure 3 An imaginary second arrangement axis 52 extending vertically in the middle extends and forms an imaginary transmit antenna element transverse axis 54. The second arrangement axis 52 extends perpendicularly to the first arrangement axis 48. The transmit antenna elements Tx thus form a rectangular transmit antenna element field 42.

[0104] 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 .

[0105] 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.

[0106] exist Figure 3 In the exemplary embodiment shown, the distance 56 between the main axes 50 of the radiating antenna elements corresponds to ten times the basic distance λ / 2, ie 5λ. The distance between the transverse axes 54 of the radiating antenna elements corresponds to 18 times the basic distance λ / 2, ie 9λ.

[0107] The phase centers 40 of the four receive antenna elements Rx are arranged so as to be distributed on two imaginary receive antenna element main axes 60 and four imaginary receive antenna element transverse axes 62. In this case, the phase centers 40 are each arranged at the intersection of the receive antenna element main axes 60 and the receive antenna element transverse axes 62.

[0108] 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.

[0109] 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 plane spanned by the transmit antenna element main axis 50 and the transmit antenna element transverse axis 54. The receive plane, having the receive antenna element main axis 60 and the receive antenna element transverse axis 62, extends parallel to the transmit plane, having the transmit antenna element main axis 50 and the transmit antenna element transverse axis 54.

[0110] 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 center is the upper receiving antenna element main axis 60. The phase centers 40 of the other three receiving antenna elements Rx are each arranged on another lower receiving antenna element axis 60. The phase centers 40 of the four receiving antenna elements Rx are arranged on different receiving antenna element transverse axes 62.

[0111] The receiving antenna element transverse axis 62 is located at the left edge of the receiving antenna element field 44, that is, not between the other two receiving antenna element transverse axes 62, and the phase center 40 of the receiving antenna element Rx is located on the receiving antenna element transverse axis 62. The receiving antenna element Rx is independently arranged on the upper receiving antenna element main axis 60.

[0112] The respective distances between the main axes 60 of adjacent receiving antenna elements or between the transverse axes 62 of adjacent receiving antenna elements, i.e., the distances between the axes of corresponding adjacent antenna elements of the same antenna element type, are integer multiples of the basic distance λ / 2. All distances between the transverse axes 62 of corresponding adjacent receiving antenna elements are different.

[0113] The distance 64 between the transverse axis 62 of the receiving antenna element and the transverse axis 62 of the adjacent second receiving antenna element from the left is smaller than the other distances 66 and 68 between the corresponding adjacent transverse axes 62 of the other receiving antenna elements. The phase center 40 of the individual receiving antenna element Rx is located on the transverse axis 62 of the receiving antenna element. The receiving antenna elements Rx are independently arranged on the corresponding main axes 60 of the receiving antenna elements. Figure 3 The left edge of the receiving antenna element field 44.

[0114] exist Figure 3 In the exemplary embodiment shown, the distance 70 between the main axes 60 of the receiving antenna elements corresponds to twice the basic distance λ / 2, i.e. λ. The distance 64 between the transverse axis 62 of a receiving antenna element of a single receiving antenna element Rx at the left edge of the receiving antenna field and the transverse axis 62 of the adjacent second receiving antenna element corresponds to one basic distance λ / 2, i.e. 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 corresponds to twice the basic distance λ / 2, i.e. λ. 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 receiving antenna elements at the right edge of the receiving antenna field 44 in φ corresponds to three times the basic distance λ / 2, ie 1.5λ.

[0115] The long sides of rectangle 46 of transmit antenna element Tx, that is, the long sides of transmit antenna element field 42, extend parallel to the arrangement axis, and the receive antenna element axis, in the direction of which receive antenna element field 40 has its greatest extent, also extends relative to this arrangement axis. In the illustrated embodiment, transmit antenna element main axis 50 and receive antenna element main axis 60 are parallel to one another and to first arrangement axis 48.

[0116] 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 the transmit antenna element field 42 in the direction of the first arrangement axis 48 corresponds to the distance 58 between the transverse axes of the transmit antenna elements, that is, 18 times the basic distance λ / 2, or 9λ. The extent 72 of the receive antenna element field 44 in the direction of the first arrangement axis 48 corresponds to the sum of the distances 64, 66, and 68 between the transverse axes 62 of the receive antenna elements, that is, six times the basic distance λ / 2, or 3λ.

[0117] The extent of the transmit antenna element field 42 in the direction of the second arrangement axis 52 is greater than the extent of the receive antenna element field 44 in the direction of the second arrangement axis 52. In the exemplary embodiment shown, 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 main axes 50 of the transmit antenna elements, that is, 10 times the basic distance λ / 2, or 5λ. The extent of the receive antenna field 44 in the direction of the second arrangement axis 52 corresponds to the distance 70 between the main axes 60 of the receive antenna elements, that is, twice the basic distance λ / 2, or λ.

[0118] exist Figure 4 In the Figure 3 30 and a virtual antenna array 36 that can be implemented therewith. 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.

[0119] 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 Figure 3 and Figure 4 Not drawn to scale. Figure 3 Compared to the antenna arrangement 30 of FIG. 3 , in the alternative antenna arrangement 30, the receiving antenna element field 44 is placed within the transmitting antenna element field 42. In this case, the lower transmitting antenna element main axis 50 and the lower receiving antenna element main axis 60 coincide. In addition, the left transmitting antenna element transverse axis 54 and the left receiving antenna element transverse axis 62 coincide. Figure 4 In the figures, for greater clarity, by way of example only one transmitting antenna element Tx with phase center 38 and one receiving antenna element Rx with phase center 40 are each provided with a reference numeral.

[0120] The receive antenna element field 44 is arranged such that 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. It can be said that the lower left transmit antenna element Tx is located in a gap in the receive antenna element field 44, which gap is caused by the upward offset of the left receive antenna element Rx relative to 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.

[0121] 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.

[0122] For those from 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.

[0123] 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, for example, only four virtual antenna elements Vx are marked.

[0124] 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.

[0125] The virtual antenna element fields 74 are each arranged at the corners of a virtual rectangle. The long sides of the rectangle extend parallel to the first arrangement axis 48 and form corresponding virtual main axes 76. The short sides of the rectangle extend parallel to the second arrangement axis 52 and form corresponding virtual transverse axes 78.

[0126] exist Figure 4In 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. Lower imaginary major axis 76 extends between upper transmit antenna element major axis 50 and lower transmit antenna element major axis 50 and above upper receive antenna element major axis 60. Upper imaginary major axis 76 extends above upper transmit antenna element major axis 50. Right imaginary lateral axis 78 extends to the right of right transmit antenna element lateral axis 54.

[0127] 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 the upper virtual main axis 76 and the left virtual lateral axis 78 .

[0128] 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 .

[0129] The free space above the right 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 and the right virtual lateral axis 78 .

[0130] 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 .

[0131] Overall, the virtual phase center 73 of the uppermost virtual antenna element Vx of the virtual antenna array 36 thus lies on an upper virtual principal axis 76. The phase center 73 of the lowermost virtual antenna element Vx lies on a lower virtual principal axis 76. Therefore, 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 12 times the base distance λ / 2, or 6λ. Distance 80 corresponds to the sum of the vertical extent of the transmit antenna field 42 (specifically, distance 56) and the vertical extent 70 of the receive antenna element field 44.

[0132] The virtual phase center 73 of the leftmost virtual antenna element Vx of virtual antenna array 36 lies on a left virtual transverse axis 78. The phase center 73 of the rightmost 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 virtual antenna array 36 in that direction, for example, horizontally. Distance 82, and therefore, for example, the horizontal aperture, corresponds to 24 times the base distance, or 12λ. Distance 82 corresponds to the sum of the horizontal extent of transmit antenna field 42 (specifically, distance 58) and the horizontal extent of receive antenna element field 44 (specifically, distance 72).

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 in that The type 1 antenna element (Tx) is arranged in a plane at the corners of an imaginary planar rectangle (46), wherein two sides of the rectangle (46) extend parallel to an imaginary first arrangement axis (48) and form a type 1 antenna element main axis (50), and the other two sides of the rectangle (46) extend parallel to an imaginary second arrangement axis (52) and form a type 1 antenna element transverse axis (54), the second arrangement axis (52) extending perpendicularly to the first arrangement axis (48), At least two of the type 2 antenna elements (Rx) are arranged on different imaginary type 2 antenna element main axes (60), which extend parallel to each other and at a distance and parallel to one of the arrangement axes (48).

2. The antenna device according to claim 1, wherein At least two 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 from each other and are perpendicular to the type 2 antenna element main axis (60).

3. The antenna device according to claim 2, wherein The antenna arrangement (30) comprises at least three type 2 antenna element transverse axes (62) at a distance from one another and at least three type 2 antenna elements (Rx), wherein all distances (64, 66, 68) between respective adjacent type 2 antenna element transverse axes (62) are different and the at least three type 2 antenna elements (Rx) are arranged on different type 2 antenna element transverse axes (62), and / or The antenna device (30) has at least three type-2 antenna elements (Rx), wherein one type-2 antenna element (Rx) is arranged on one of the type-2 antenna element main axes (60), and all other type-2 antenna elements (Rx) are arranged on another type-2 antenna element main axis (60); in particular, a type-2 antenna element transverse axis (62) including a type-2 antenna element (Rx) independently arranged on a 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 type 2 antenna element (Rx) being arranged on one of the type 2 antenna element main axes (60), and all other type 2 antenna elements (Rx) being arranged on another type 2 antenna element main axis (60), and a type 2 antenna element transverse axis (62) on which a type 2 antenna element (Rx) is independently arranged on a corresponding type 2 antenna element main axis (60) being at a distance (64) from at least one adjacent type 2 antenna element transverse axis (62) being smaller than other distances (66, 68) between corresponding adjacent type 2 antenna element transverse axes (62), and / or The antenna arrangement (30) has exactly four type 2 antenna elements (Rx).

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 a plane spanned by the type 1 antenna element main axis (50) and the type 1 antenna element transverse axis (54), and / or The type 1 antenna element (Tx) and the type 2 antenna element (Rx) are arranged on a common carrier (34), in particular 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) 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 the 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 the second arrangement axis (52) is greater than the extent (70) of the receiving antenna element field (44) in the direction of the second arrangement axis (52), and / or The rectangle (46) for the type 1 antenna element (Tx) has different side lengths, the longer side extending parallel to the arrangement axis (48), and the type 2 antenna element (Rx) axis, in particular the type 2 antenna element main axis (60) or the type 2 antenna element transverse axis (62) in the direction of which the type 2 antenna element field (44) composed of the type 2 antenna element (Rx) has the maximum extent (72), also extending relative to the arrangement axis (48).

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) may be individually activated and / or individually selected, and the type 2 antenna elements (Rx) may be individually activated and / or individually selected.

9. A 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, 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 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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