Antenna assembly for vehicle

Abstract

The invention relates to an antenna assembly (303) for a vehicle (300), in which the antenna assembly (303) comprises a plurality of antennas comprising a plurality of transmitting antennas for emitting radiation and a plurality of receiving antennas for receiving radiation emitted by the respective transmitting antennas, the plurality of transmitting antennas comprise a first transmitting antenna (Tx0), a second transmitting antenna (Tx1) and a third transmitting antenna (Tx2), the antenna assembly (303) comprises a plurality of receiving antennas, and the plurality of receiving antennas comprise a first receiving antenna (Rx0), a second receiving antenna (Rx1), a third receiving antenna (Rx2) and a fourth receiving antenna (Rx3).

Description

Technical Field

[0001] The present invention relates to an antenna assembly, a radar sensor, and a vehicle. Background Art

[0002] An antenna assembly having multiple antennas can be used in a so-called "multiple-input multiple-output" (MIMO) configuration to emit radiation directionally by means of so-called "beamforming", in such a way that the transmission power of a single antenna is increased relative to the other antennas and / or offset in time.

[0003] Furthermore, MIMO radar applications are known in the field of vehicles, which are used to detect objects in the environment of a vehicle.

[0004] The radiation pattern of most antennas exhibits a "lobed" pattern at various angles and directions, in which the signal intensity radiated reaches a maximum, and these lobes are separated by "nulls", at which the radiated signal intensity drops to zero.

[0005] In a directional antenna (in which the aim is to emit a radiation wave in one direction), the lobe in that direction is set to have a greater field strength than the other lobes; this is the "main lobe". The other lobes are referred to as "side lobes" or "sidelobes", and generally represent unwanted radiation in unwanted directions.

[0006] The longer the antenna is relative to the radio wavelength, the more lobes its radiation pattern has. In a transmitting antenna, excessive sidelobe radiation wastes energy and may interfere with other devices. Another disadvantage is that confidential information may be intercepted by an unintended recipient. In a receiving antenna, sidelobes may receive interfering signals and increase the noise level in the receiver.

[0007] The power density in the sidelobes is generally much smaller than the power density in the main radiation. It is generally desirable to minimize the sidelobe level (SLL), which is measured in decibels relative to the peak of the main radiation. The main lobe and the sidelobes occur not only during transmission but also during reception.

[0008] Since the far-field radiation pattern of an antenna is the Fourier transform of its aperture distribution, most antennas generally have sidelobes. Summary of the Invention

[0009] In this context, the object of the present invention proposed is to provide an antenna assembly for a vehicle that generates as small sidelobes as possible.

[0010] Therefore, according to a first aspect of the present invention proposed, an antenna assembly for a vehicle is proposed.

[0011] The proposed antenna assembly includes a plurality of antennas, said plurality of antennas including a plurality of transmitting antennas for emitting radiation and a plurality of receiving antennas for receiving the radiation emitted by the respective transmitting antennas.

[0012] The plurality of transmitting antennas include a first transmitting antenna, a second transmitting antenna, and a third transmitting antenna.

[0013] The antenna assembly further includes a plurality of receiving antennas, wherein the plurality of receiving antennas include a first receiving antenna, a second receiving antenna, a third receiving antenna, and a fourth receiving antenna.

[0014] In the context of the present invention proposed herein, a "lobe" should be understood as a curve of values that corresponds to a fluctuation (Ausschlag), i.e., to a sharp rise and fall of numerical values.

[0015] The proposed antenna assembly includes a configuration of three transmitting antennas and four receiving antennas that are oriented relative to each other or arranged relative to each other in an azimuth plane.

[0016] The proposed antenna assembly is particularly used for transmitting and receiving radar radiation, so that based on the flight time of the radar radiation, an object located in the environment of the antenna assembly or the orientation of the object relative to the antenna assembly can be inferred.

[0017] A radiation pattern with particularly small side lobes is achieved through the configuration of the proposed antenna assembly, which suppresses the intensity of the side lobes to below 10 -3 dBi, and accordingly reduces false identifications in the region of the side lobes.

[0018] It can be stipulated that the plurality of antennas are arranged in a grid along an azimuth plane, the grid extending at grid points from 0 to 16, the grid being divided into multiples of an azimuth coefficient that corresponds to a value between 0.8 and 2 multiplied by half of the respective wavelength at which the antenna assembly operates.

[0019] The positioning of the respective antennas of the proposed antenna assembly can be given particularly precisely with respect to the respective wavelength (Lambda) used during operation of the antenna device.

[0020] Dividing an azimuth plane into a grid with 16 grid points divides the azimuth plane into 16 parts, where one part corresponds to a value between 0.8 and 2 multiplied by half of the respective wavelength.

[0021] It can be stipulated that in the first configuration, the first transmitting antenna is arranged at grid point 0, the second transmitting antenna is arranged at grid point 6 and the third transmitting antenna is arranged at grid point 16, the first receiving antenna is arranged at grid point 0, the second receiving antenna (Rx1) is arranged at grid point 4 or 5, the third receiving antenna (Rx2) is arranged at grid point 7 or 8 and the fourth receiving antenna (Rx3) is arranged at grid point 12.

[0022] It has been demonstrated in experiments that the following configuration produces particularly small side lobes: in this configuration, one transmitting antenna each is arranged at the poles or ends of the azimuth plane, and the additional transmitting antennas are arranged between each of said ends and relative to the corresponding receiving antennas. It has been confirmed here that the following configuration is particularly suitable for generating a radiation field with weak or small side lobes: in this configuration, the additional transmitting antennas arranged between each of said ends are arranged in a region that is adjacent to two intermediate receiving antennas on the plane of the receiving antennas.

[0023] Furthermore, it can be stipulated that in the second configuration, the first transmitting antenna is arranged at grid point 0, the second transmitting antenna is arranged at grid point 10 and the third transmitting antenna is arranged at grid point 16, the first receiving antenna is arranged at grid point 0, the second receiving antenna is arranged at grid point 4 or 5, the third receiving antenna is arranged at grid point 7 or 8, and the fourth receiving antenna is arranged at grid point 12.

[0024] The second configuration corresponds essentially to the mirror image of the first configuration of the proposed antenna assembly and has also been confirmed to be particularly suitable for generating a radiation field with weak or small side lobes.

[0025] It can be stipulated that the antenna assembly is a multiple-input multiple-output (MIMO) assembly and includes a controller that is configured to determine the orientation of the antenna assembly relative to a corresponding object in the environment of the antenna assembly based on the radiation transmitted by the plurality of transmitting antennas and received by the plurality of receiving antennas.

[0026] Since the proposed antenna assembly exhibits particularly small side lobes and correspondingly few misidentifications of radiation, it is suitable for particularly precisely determining the orientation of the antenna assembly or a corresponding system including the antenna assembly relative to a corresponding object in the environment of the antenna assembly.

[0027] Furthermore, it can be stipulated that the controller is configured to perform beamforming based on the Fourier transform of the signals determined by the plurality of antennas.

[0028] With the aid of so-called "beamforming", i.e., by means of a process for directing the emitted radiation (the process is evaluated based on the Fourier transform), the orientation of the antenna assembly relative to a corresponding object in the environment of the antenna assembly can be determined particularly efficiently computationally.

[0029] Furthermore, it can be provided that the plurality of transmit antennas are arranged distributed over a first plurality of elevation planes.

[0030] It has been confirmed in experiments that transmit antennas distributed over the height of the antenna assembly, i.e., in the elevation plane of the antenna assembly, are particularly advantageous in generating a radiation field with particularly small or weak side lobes.

[0031] Furthermore, it can be provided that the plurality of receive antennas are arranged distributed over a second plurality of elevation planes.

[0032] It has been confirmed in experiments that receive antennas distributed over the height of the antenna assembly, i.e., in the elevation plane of the antenna assembly, are particularly advantageous in generating a radiation field with particularly small or weak side lobes. Here, the height or elevation plane in which the receive antennas are distributed can be different from the height or elevation plane in which the transmit antenna assembly is arranged.

[0033] Furthermore, it can be provided that the plurality of antennas are radar antennas.

[0034] It has been confirmed in experiments that radar antennas, i.e., antennas configured to transmit or receive radar waves, are particularly suitable for determining the position of the antenna assembly relative to an object located in the environment of the antenna assembly. Furthermore, radar antennas have proven to be particularly suitable for use in road traffic, for example for vehicle control.

[0035] According to a second aspect, the present invention proposed relates to a vehicle which includes a feasible configuration of the proposed antenna assembly.

[0036] According to another aspect, the present invention relates to a radar sensor having an antenna assembly according to the above description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be explained in more detail below with the aid of the drawings. In the figures:

[0038] Figure 1 shows a feasible configuration of the proposed antenna assembly,

[0039] Figure 2 shows the radiation pattern determined by the antenna assembly according to Figure 2 and

[0040] Figure 3 shows a feasible design of the proposed vehicle. DETAILED DESCRIPTION

[0041] Figure 1 A grid 100 is shown, which extends in the longitudinal direction on the azimuth plane of the antenna assembly and in the transverse direction on the elevation plane of the antenna assembly. Marked in the grid 100 are:

[0042] The first transmitting antenna (Tx0), the second transmitting antenna (Tx1), the third transmitting antenna (Tx2), the first receiving antenna (Rx0), the second receiving antenna (Rx1), the third receiving antenna (Rx2), and the fourth receiving antenna (Rx3).

[0043] In Figure 2 a chart 200 is shown, which unfolds over time on its abscissa and has directivity in dBi on its ordinate.

[0044] It can be well seen with the aid of the curve 201 that the main lobe 203 fluctuates significantly higher compared to the respective side lobes 205, so that the main lobe is particularly reliably identified as the main lobe and misidentification caused by the side lobes 205 is reduced.

[0045] In Figure 3 a vehicle 300 is shown. The vehicle 300 includes a distance measurement system 301 having an antenna assembly 303 according to Figure 1 ...

[0046] List of reference numerals

[0047] 100 Grid

[0048] Tx0 First transmitting antenna

[0049] Tx1 Second transmitting antenna

[0050] Tx2 Third transmitting antenna

[0051] Rx0 First receiving antenna

[0052] Rx1 Second receiving antenna

[0053] Rx2 Third receiving antenna

[0054] Rx3 Fourth receiving antenna

[0055] 200 Chart

[0056] 201 Curve

[0057] 203 Main lobe

[0058] 205 Side lobe

[0059] 300 Vehicle

[0060] 301 Distance measurement system

[0061] 303 Antenna Assembly

Claims

1. An antenna assembly (303) for a vehicle (300), wherein, the antenna assembly (303) includes a plurality of antennas, wherein the plurality of antennas includes a plurality of transmitting antennas for emitting radiation and a plurality of receiving antennas for receiving the radiation emitted by the corresponding transmitting antennas, the plurality of transmitting antennas includes: - a first transmitting antenna (Tx0), - a second transmitting antenna (Tx1), - a third transmitting antenna (Tx2), the antenna assembly (303) includes a plurality of receiving antennas, the plurality of receiving antennas includes: - a first receiving antenna (Rx0), - a second receiving antenna (Rx1), - a third receiving antenna (Rx2), - a fourth receiving antenna (Rx3).

2. The antenna assembly (303) according to claim 1, wherein, the plurality of antennas are arranged in a grid (100) along an azimuth plane, the grid extends at grid points from 0 to 16, the grid (100) is divided into multiples of an azimuth coefficient, the azimuth coefficient corresponding to a value between 0.8 and 2 multiplied by half of the corresponding wavelength at which the antenna assembly (303) operates.

3. The antenna assembly (303) according to claim 2, wherein, in a first configuration, the first transmitting antenna (Tx0) is arranged at grid point 0, the second transmitting antenna (Tx1) is arranged at grid point 6 and the third transmitting antenna (Tx2) is arranged at grid point 16, the first receiving antenna (Rx0) is arranged at grid point 0, the second receiving antenna (Rx1) is arranged at grid point 4 or 5, the third receiving antenna (Rx2) is arranged at grid point 7 or 8 and the fourth receiving antenna (Rx3) is arranged at grid point 12.

4. The antenna assembly (303) according to claim 2, wherein, in a second configuration, the first transmitting antenna (Tx0) is arranged at grid point 0, the second transmitting antenna (Tx1) is arranged at grid point 10 and the third transmitting antenna (Tx2) is arranged at grid point 16, the first receiving antenna (Rx0) is arranged at grid point 0, the second receiving antenna (Rx1) is arranged at grid point 4 or 5, the third receiving antenna (Rx2) is arranged at grid point 7 or 8 and the fourth receiving antenna (Rx3) is arranged at grid point 12.

5. The antenna assembly (303) according to any one of the preceding claims, wherein, the antenna assembly (303) is a multiple-input multiple-output (MIMO) assembly and includes a controller configured to determine the orientation of the antenna assembly (303) relative to a corresponding object in the environment of the antenna assembly (303) based on the radiation transmitted by the plurality of transmitting antennas and received by the plurality of receiving antennas.

6. The antenna assembly (303) according to claim 5, wherein, the controller is configured to perform beamforming based on a Fourier transform of the signals determined by the plurality of antennas.

7. The antenna assembly (303) according to any one of the preceding claims, wherein, The plurality of transmit antennas are arranged distributively in a first plurality of elevation planes.

8. The antenna assembly (303) according to any one of the preceding claims, characterized in that the plurality of receive antennas are arranged distributively in a second plurality of elevation planes.

9. The antenna assembly (303) according to any one of the preceding claims, wherein the plurality of antennas are radar antennas.

10. A radar sensor comprising the antenna assembly according to any one of the preceding claims.

11. A vehicle (300), wherein the vehicle (300) comprises the antenna assembly (303) according to any one of claims 1 to 9.

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