Multi-input multi-output imaging array and corresponding imaging method

Abstract

The present invention relates to a multi-input, multi-output (MIMO) imaging array and a corresponding imaging method. A MIMO imaging array for generating incident angle-resolved images of a device under test is provided. The MIMO imaging array includes redundant arrays of transmit and receive antennas and a controller. In this case, the controller is configured to implement a selection mode that selects individual transmit and receive antenna pairs for creating corresponding images.

Description

Technical Field

[0001] The present invention relates to a multi-input multi-output imaging array for incident angle resolved images of a device under test and a multi-input multi-output imaging method for incident angle resolved images of a device under test. Background Art

[0002] In general, and particularly in the context of autonomous vehicles, as the number of automotive radar integrated components increases, there is a growing demand for multi-input multi-output imaging arrays and multi-input multi-output imaging methods for incident angle-resolved images, in order to verify the correct functionality of the automotive radar integrated components in a highly accurate and efficient manner. This is described, for example, in US 2017 / 0363719A1.

[0003] Unfortunately, neither a multiple-input multiple-output imaging array for incident angle resolved images of a device under test (such as the automotive radar integrated component) nor a multiple-input multiple-output imaging method for incident angle resolved images of a device under test is known. Summary of the Invention

[0004] Therefore, it is necessary to provide a multi-input multi-output imaging array for incident angle resolved images of a device under test and a multi-input multi-output imaging method for incident angle resolved images of a device under test, thereby ensuring high accuracy and high efficiency.

[0005] According to a first aspect of the present invention, a multi-input, multi-output (MIMO) imaging array for generating incident angle-resolved images of a device under test (DUT) is provided. The MIMO imaging array comprises redundant arrays of transmit and receive antennas and a controller. In this case, the controller is configured to implement a selection mode that selects the respective transmit and receive antenna pairs used to create the corresponding images. Advantageously, this ensures both high accuracy and high efficiency.

[0006] According to a first preferred implementation form of the first aspect of the present invention, the selection mode is based on the incident angle required for creating the corresponding image. Advantageously, for example, efficiency can be further improved.

[0007] According to a second preferred implementation form of the first aspect of the present invention, the transmitting antenna and the receiving antenna are arranged so that they are approximately located at the incident angle to each other with respect to their respective specular reflection points. Advantageously, for example, accuracy can be further improved.

[0008] According to another preferred implementation form of the first aspect of the present invention, the set of the respective transmit and receive antenna pairs forms an array that creates a distorted image and / or an aliasing-minimized image. Advantageously, for example, accuracy and efficiency can be further improved.

[0009] According to another preferred implementation form of the first aspect of the present invention, the controller is configured to reconstruct the corresponding image based on a densely sampled array. Advantageously, the reconstruction can be performed in a highly accurate and efficient manner, for example.

[0010] According to another preferred implementation form of the first aspect of the present invention, based on the set of transmit and receive antenna pairs forming an array that creates a distorted image and / or an aliasing-minimized image, the controller is configured to reconstruct the corresponding image based on the corresponding densely sampled array. Advantageously, for example, accuracy and efficiency can be further improved.

[0011] According to another preferred implementation form of the first aspect of the present invention, the redundant array is redundant with respect to one dimension. Advantageously, for example, complexity can be reduced, thereby improving efficiency.

[0012] According to another preferred implementation form of the first aspect of the present invention, the redundant array is redundant with respect to at least one dimension, preferably redundant with respect to two dimensions. Advantageously, for example, the accuracy can be further improved.

[0013] According to another preferred implementation form of the first aspect of the present invention, the device under test and / or the redundant array are mechanically moved to create a synthetic two-dimensional redundant array over time. Advantageously, for example, costs can be reduced, which leads to improved efficiency.

[0014] According to another preferred implementation form of the first aspect of the present invention, the device under test includes a radar cover, preferably an automobile radar cover. Advantageously, for example, an automobile radar integrated component can be tested.

[0015] According to another preferred implementation form of the first aspect of the present invention, the redundant array includes at least one sparsity. Advantageously, for example, accuracy can be improved.

[0016] According to another preferred implementation form of the first aspect of the present invention, the controller is configured to create the precise incident angle by interpolation between nearby incident angles. Advantageously, for example, the accuracy can be further improved.

[0017] According to another preferred implementation form of the first aspect of the present invention, the controller is configured to address the at least one sparsity. Advantageously, for example, both efficiency and accuracy can be improved.

[0018] According to another preferred implementation form of the first aspect of the present invention, the controller is configured to average between nearby incident angles. Advantageously, for example, the accuracy can be further improved.

[0019] According to another preferred implementation form of the first aspect of the present invention, the controller is configured to resolve the at least one sparsity by averaging between nearby incident angles. Advantageously, for example, not only the accuracy but also the efficiency can be further improved.

[0020] According to a second aspect of the present invention, a multi-input, multi-output (MIMO) imaging method for generating incident angle-resolved images of a device under test is provided. The MIMO imaging method includes the steps of providing redundant arrays of transmit and receive antennas and implementing a selection mode that selects each transmit and receive antenna pair used to create a corresponding image. Advantageously, this method ensures both high accuracy and high efficiency.

[0021] According to a first preferred implementation form of the second aspect of the present invention, the selection mode is based on the incident angle required for creating the corresponding image. Advantageously, for example, efficiency can be further improved.

[0022] According to a second preferred implementation form of the second aspect of the present invention, the method further comprises the step of arranging the transmitting antenna and the receiving antenna so that the transmitting antenna and the receiving antenna are approximately located at the incident angle with respect to their respective specular reflection points. Advantageously, for example, accuracy can be further improved.

[0023] According to another preferred implementation form of the second aspect of the present invention, the method further comprises the step of forming an array for creating a distorted image and / or an aliasing-minimized image by means of a set of the respective transmitting and receiving antenna pairs. Advantageously, for example, accuracy and efficiency can be further improved.

[0024] According to another preferred implementation form of the second aspect of the present invention, the method further comprises the step of reconstructing the corresponding image based on a densely sampled array. Advantageously, the reconstruction can be performed in a highly accurate and efficient manner, for example. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Exemplary embodiments of the present invention will now be further described with reference to the accompanying drawings, by way of example only and not limitation. In the drawings:

[0026] Figure 1 An exemplary embodiment of the first aspect of the present invention is shown;

[0027] Figure 2 A first exemplary case regarding a specular reflection point is shown;

[0028] Figure 3 A second exemplary case regarding a specular reflection point is shown;

[0029] Figure 4 A third exemplary case regarding a specular reflection point is shown;

[0030] Figure 5 A fourth exemplary case regarding a specular reflection point is shown;

[0031] Figure 6 A fifth exemplary case regarding a specular reflection point is shown;

[0032] Figure 7 Another exemplary embodiment of the first aspect of the present invention is shown;

[0033] Figure 8 An exemplary array sparsity concept is shown;

[0034] Figure 9 A flow chart illustrating an exemplary embodiment of the second aspect of the present invention;

[0035] Figure 10 a flow chart illustrating another exemplary embodiment of the second aspect of the present invention; and

[0036] Figure 11 A flow chart illustrating another exemplary embodiment of the second aspect of the present invention is shown. DETAILED DESCRIPTION

[0037] first, Figure 1 An exemplary embodiment of the present invention is shown of a multiple-input multiple-output imaging array 10 for capturing incident angle resolved images of a device under test 15. The multiple-input multiple-output imaging array 10 includes redundant arrays of transmit and receive antennas (exemplarily, four pairs of transmit antennas 11a, 12a, 13a, 14a and corresponding receive antennas 11b, 12b, 13b, 14b) and a controller 17.

[0038] In this case, the controller 17 implements a selection mode which selects the respective transmit and receive antenna pairs for creating the respective images. It is noted that it may be particularly advantageous if the selection mode is based on the angle of incidence required to create said respective images.

[0039] Furthermore, the transmitting antennas 11a, 12a, 13a, 14a and the receiving antennas 11b, 12b, 13b, 14b may be arranged such that the transmitting antennas 11a, 12a, 13a, 14a and the receiving antennas 11b, 12b, 13b, 14b are located approximately at said angle of incidence to each other with respect to the respective specular reflection points.

[0040] Additionally or alternatively, the set of respective transmit and receive antenna pairs may form an array that creates a distorted image and / or an aliasing minimized image.Furthermore, it may be particularly advantageous if the controller reconstructs the respective image based on a densely sampled array.

[0041] Additionally or alternatively, based on the collection of respective transmit and receive antenna pairs forming an array that creates a distorted image and / or an aliasing-minimized image, the controller can reconstruct the corresponding image based on a corresponding densely sampled array. Furthermore, it is noted that it can be particularly advantageous if the redundant array is redundant with respect to one dimension.

[0042] Alternatively, the redundant array may be redundant in at least one dimension, preferably in two dimensions. In addition, in particular where the redundant array is redundant in one dimension, the device under test 15 and / or the redundant array may be mechanically moved to create a synthetic two-dimensional redundant array over time.

[0043] Regarding the device under test 15, according to Figure 1 It should be noted that the device under test 15 comprises a radome 16, preferably an automotive radome. In this case, it should also be noted that the radome is in particular a radome.

[0044] Regarding the redundant array, it is noted that the redundant array can include, in particular, at least one sparsity. Furthermore, the controller 17 can create the precise angle of incidence by interpolating between nearby angles of incidence. In particular, regarding the at least one sparsity, it is noted that the controller 17 can account for the at least one sparsity.

[0045] Note also that it may be particularly advantageous if the controller 17 may average between nearby angles of incidence.Furthermore, the controller 17 may in particular account for the at least one sparsity by averaging between nearby angles of incidence.

[0046] Now refer to Figure 2 A first exemplary situation 20 is shown regarding a specular reflection point.

[0047] according to Figure 2 , showing an exemplary specular reflection point. Furthermore, multiple transmit and receive antenna pairs 21 are shown. In this case, a single transmit and receive antenna pair typically comprises a co-located independent transmitter and receiver. Furthermore, the multiple transmit and receive antenna pairs 21 typically form an array, preferably a one-dimensional array.

[0048] It can also be seen that, for a particular specular reflection point, there are a large number of transmitter and receiver pairs, each with its own angle of incidence or reflection. In other words, a multiple-input multiple-output (MIMO) array with high redundancy is provided. Depending on the size of the MIMO array, the exact antenna distribution in the array, the location of the specular reflection points, and the number of transmitter and receiver pairs can vary.

[0049] In order to capture the angle-dependent reflections of reflection points over a wide range of angles without excessive gaps, the antenna distribution of the corresponding receiver array and the antenna distribution of the corresponding transmitter array should not contain large gaps. However, at the same time, it is not necessary to have a completely dense arrangement of the receiver and transmitter arrays. Advantageously, averaging over a small range of angles of incidence to reduce gaps can, in return, allow for smaller gaps.

[0050] For example, according to Figure 2 At the mirror reflection points, there are a large number of transmitter and receiver pairs. Because the mirror reflection points are concentrated at the front of the symmetric MIMO array, the number of transmitter and receiver pairs is particularly large. Each adjacent mirror reflection point still has a large number of transmitter and receiver pairs, although not as many due to the finite length of the array.

[0051] Note that due to Figure 2 Each transmitter-receiver pair is symmetrical, so the same signal path exists in the other direction. To keep the figures clear, the signal paths have been omitted. This also applies to the following figures.

[0052] also, Figure 3 A second exemplary case 30 regarding specular reflection points is shown. In this case, a plurality of emitter and receiver pairs 31 are shown, in particular in the form of a one-dimensional array. Furthermore, a virtual array 32 is shown. Virtual array 32 in particular only includes the individual contributions of the specular reflection components for the individual devices under test. Virtual array 32 is preferably a one-dimensional virtual array.

[0053] Furthermore, reference numeral 33 denotes a situation in which the corresponding transmitter and receiver pair does not have a valid signal path, since, in this example, there are no specular reflection points for this transmitter and receiver pair. Furthermore, specular reflection points are still taken into account in each measurement, but in the case shown, they do not contribute to the result. Furthermore, specular reflection points still contribute to scattering at reflectors in the scene (i.e., the edges of the corresponding device under test). This also applies in particular to the following figures.

[0054] Also note that the use of Figure 2The transmitter and receiver pairs 21 shown cannot create an image, in particular a millimeter wave image, because they all have the same virtual antenna. In order to be able to create an image, preferably a millimeter wave image, in particular a virtual array must be formed.

[0055] For each specular reflection point in front of the array, one must in particular pick the right emitter and receiver pair to create a virtual array, which preferably consists only of emitter and receiver pairs having the required angle of incidence with respect to the specular reflection point.

[0056] Furthermore, the angle of incidence does not necessarily have to be the same for every emitter and receiver pair (especially for emitter and receiver pairs that form a virtual array). For example, for a potential device under test, it may be relevant to have a larger angle of incidence at the sides and a smaller angle of incidence at the center. Generally, the angle of incidence and the angle of reflection are given by, among other things, the angle between the respective surface normals at the point of specular reflection, and the incident and reflected vectors, respectively.

[0057] Furthermore, the emitter and receiver pairs are preferably selected according to the following constraints. First, for each specular reflection point in front of the respective physical aperture, an emitter and receiver pair must be selected with the desired angle of incidence. Second, the virtual arrays formed by each must be densely sampled to enable image reconstruction.

[0058] Note also that any number of virtual arrays can be created and for each virtual array an image, preferably a millimeter wave image, can be reconstructed.

[0059] according to Figure 4 , shows another exemplary case 40 regarding specular reflection points. In this case, a physical array 41 (preferably a one-dimensional physical array) and a virtual array 42 (preferably a one-dimensional virtual array) are shown. As an example, it can be seen that a transmitter and receiver pair with a very low angle of incidence is selected. Furthermore, for each reflection point, the angle of incidence is the same.

[0060] Note also that the individual virtual apertures are still densely packed and especially Figure 3 Same size in .

[0061] also, Figure 5 Another exemplary situation regarding specular reflection points is shown 50. In this case, a physical array 51 (preferably a one-dimensional physical array) and a virtual array 52 (preferably a one-dimensional virtual array) are shown.

[0062] By way of example, it can be seen that the emitter and receiver pairs with very high angles of incidence are selected. In addition, for each reflection point, the angle of incidence is the same. It is also noted that the individual virtual apertures are still densely arranged and, in particular, Figure 3 and Figure 4 Same size in .

[0063] also, Figure 6 Another exemplary case 60 regarding specular reflection points is shown. In this case, a physical array 61 (preferably a one-dimensional physical array) and a virtual array 62 (preferably a one-dimensional virtual array) are shown. As an example, it can be seen that emitter and receiver pairs with mixed incidence angles are selected. In addition, the high incidence angles are at the sides, while the lower incidence angles are closer to the center. It is also noted that the individual virtual apertures are still densely arranged and, in particular, with Figure 3 、 Figure 4 and Figure 5 Same size in .

[0064] In general, and particularly with regard to the shape of the individual devices under test, it should be noted that the target devices under test of the present invention are particularly automotive radar covers, such as emblems, logos, bumpers, plastic covers, and the like. The vast majority of these components have no or very little curvature. Furthermore, these components particularly have smooth surfaces.

[0065] It is also noted that for the vast majority of devices under test the invention can be applied regardless of the shape.Furthermore, significant curvatures of the devices under test can be taken into account, inter alia, by selecting corresponding transmitter and receiver pairs according to the shape of the respective device under test.

[0066] Now, refer to Figure 7 , shows another embodiment of the first aspect of the present invention. In this case, a physical array 71 (preferably a one-dimensional physical array) comprising a plurality of emitter and receiver pairs is mechanically moved from bottom to top.

[0067] It is generally noted that it can be particularly advantageous if the physical array is highly redundant in at least one dimension. Furthermore, the physical array can be implemented as an all-electronic array, a technology-scan array (which simulates the physical array through a series of individual measurements), or a combination of both.

[0068] Note also that the physical array 71 can be extended in at least one dimension by means of mechanical movement, in particular by means of synthetic aperture methods. For example, a one-dimensional highly redundant physical array can be moved along an arbitrary trajectory to extend the array in the dimension given by the trajectory.

[0069] Furthermore, each device under test can be moved mechanically to expand the physical array in at least one dimension, in particular by an inverse synthetic aperture method. For example, the device under test can be moved along an arbitrary trajectory to expand the array into a dimension given by the trajectory.

[0070] Furthermore, the following points should be noted. First, because a MIMO array can be highly redundant in one direction, a fully electronic implementation in two dimensions may not be feasible. Second, a two-dimensional array can be synthesized by moving the MIMO array or the device under test in at least one other direction. Third, a two-dimensional, highly redundant MIMO array of sufficient size may not be feasible, particularly from a technical and economic perspective. Fourth, the direction in which the redundant MIMO array or the device under test moves, and the direction in which it is highly redundant, can be freely selected based on the application, mechanical constraints, and the like. This does not affect the essence of the present invention in particular.

[0071] according to Figure 8 , shows an exemplary array sparsity concept. In this exemplary case, with respect to an array 81 comprising a plurality of transmitter and receiver pairs, a physical separation of the respective transmitter array 82b and the respective receiver array 82a is performed. In this case, Figure 8 It can also be seen that the separation results in a lateral translation between the receiver array 82a and the transmitter array 82b.

[0072] According to this exemplary sparsity concept, a receiver array 83a including some gaps and a transmitter array 83b including some gaps are provided. It should be noted that it can be particularly advantageous if the gaps between the antennas are kept small, preferably less than three times the wavelength of the respective radiation. In particular, in order to create a densely sampled virtual array, the gaps should be reduced by introducing averaging of the incident angles.

[0073] Note also that the positions of the individual transmitter and receiver arrays in the physically separate arrays can be freely chosen (especially as long as the arrays maintain a high degree of redundancy in at least one dimension) and that virtual arrays with different incidence angle characteristics can be created.

[0074] at last, Figure 9 A flow chart illustrating an exemplary embodiment of the present invention's multi-input, multi-output imaging method for generating incident angle-resolved images of a device under test. In a first step 100, redundant arrays of transmit and receive antennas are provided. Then, in a second step 101, a selection mode is implemented, wherein the selection mode selects individual transmit and receive antenna pairs for creating corresponding images.

[0075] It may be particularly advantageous if the selection mode is based on the angle of incidence required to create the respective image.

[0076] Additionally or alternatively, according to Figure 10 The method may further comprise the step of arranging the transmitting antenna and the receiving antenna such that the transmitting antenna and the receiving antenna are substantially located at an angle of incidence to each other with respect to their respective specular reflection points.

[0077] Additionally or alternatively, the method may further comprise the step of forming an array for creating a distorted image and / or an aliasing-minimized image by means of a set of respective transmit and receive antenna pairs. Furthermore, additionally or alternatively, the method may in particular comprise the step of reconstructing the respective image based on a densely sampled array.

[0078] Furthermore, based on the set of respective transmit and receive antenna pairs forming an array creating a distorted image and / or an aliasing minimized image, the method may additionally or alternatively comprise the step of reconstructing the respective image based on the respective densely sampled array.

[0079] With respect to the redundant array described above, it should be noted that the redundant array can be redundant in particular with respect to one dimension. In addition, the redundant array can be redundant with respect to at least one dimension, preferably redundant with respect to two dimensions.

[0080] Furthermore, the method may include mechanically moving the device under test and / or the redundant array to create a composite two-dimensional redundant array over time. Regarding the device under test, it is noted that the device under test may in particular include a radome, preferably an automotive radome. It is also noted that the redundant array may in particular include at least one sparsity characteristic.

[0081] according to Figure 11 It may be particularly advantageous if the method further comprises the step of creating an accurate angle of incidence by interpolating between nearby angles of incidence. Additionally or alternatively, the method may further comprise the step of resolving the at least one sparsity. Additionally or alternatively, the method may further comprise the step of averaging nearby angles of incidence.

[0082] Additionally or alternatively, the method may comprise the step of resolving the at least one sparsity by averaging nearby angles of incidence.

[0083] Although various embodiments of the present invention have been described above, it should be understood that these embodiments are presented by way of example only and not limitation. Various modifications may be made to the disclosed embodiments based on the disclosure herein without departing from the spirit or scope of the present invention. Therefore, the breadth and scope of the present invention should not be limited by any of the above-described embodiments. Rather, the scope of the present invention should be defined in accordance with the appended claims and their equivalents.

[0084] Although the present invention has been shown and described with respect to one or more implementations, equivalent changes and modifications will occur to those skilled in the art upon reading and understanding this specification and the accompanying drawings. In addition, although particular features of the present invention may be disclosed with respect to only one of a plurality of implementations, such features may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application.

Claims

1. A multi-input multi-output imaging array for generating incident angle resolved images of a device under test, the multi-input multi-output imaging array comprising: redundant arrays of transmit and receive antennas, and controller, wherein the controller is configured to implement a selection mode, wherein the selection mode selects respective transmit and receive antenna pairs for creating the millimeter wave image based on the incident angle required to create the millimeter wave image, wherein, for each specular reflection point in front of the respective physical aperture, a transmit and receive antenna pair with said desired angle of incidence is selected to create a virtual array, and The formed virtual array is densely sampled to reconstruct the millimeter wave image.

2. The multi-input multi-output imaging array according to claim 1, in, The redundant arrays of the transmit antennas and the receive antennas are arranged such that the transmit antennas and the receive antennas are located substantially at the angle of incidence to each other with respect to respective specular reflection points.

3. The multi-input multi-output imaging array according to claim 1, in, The collection of the various transmit and receive antenna pairs forms an array that creates a distorted image and / or an aliasing-minimized image.

4. The multi-input multi-output imaging array according to claim 1, in, The redundant array is redundant with respect to one dimension.

5. The multi-input multi-output imaging array according to claim 1, in, The redundant array is redundant with respect to two dimensions.

6. The multi-input multi-output imaging array according to claim 4, in, The device under test and / or the redundant array are mechanically moved to create a synthetic two-dimensional redundant array over time.

7. The multi-input multi-output imaging array according to claim 1, in, The device under test includes a radome.

8. The multi-input multi-output imaging array according to claim 1, in, The redundant array includes at least one sparsity.

9. The multi-input multi-output imaging array according to claim 1, in, The controller is configured to create a precise angle of incidence by interpolating between nearby angles of incidence.

10. The multi-input multi-output imaging array according to claim 8, in, The controller is configured to account for the at least one sparsity.

11. The multi-input multi-output imaging array according to claim 1, in, The controller is configured to average between nearby angles of incidence.

12. The multi-input multi-output imaging array according to claim 8, in, The controller is configured to account for the at least one sparsity by averaging among nearby angles of incidence.

13. A multi-input multi-output imaging method for generating incident angle resolved images of a device under test, the multi-input multi-output imaging method comprising the following steps: providing redundant arrays of transmit and receive antennas, and Implementing selection mode, in, The selection mode selects respective transmit and receive antenna pairs for creating the millimeter wave image based on the angle of incidence required to create the millimeter wave image, wherein, for each specular reflection point in front of the respective physical aperture, a transmit and receive antenna pair with said desired angle of incidence is selected to create a virtual array, and The formed virtual array is densely sampled to reconstruct the millimeter wave image.

14. The multi-input multi-output imaging method according to claim 13, in, The method further comprises the step of arranging the redundant arrays of the transmit antennas and the receive antennas such that the transmit antennas and the receive antennas are located substantially at the angle of incidence to each other with respect to respective specular reflection points.

15. The multi-input multi-output imaging method according to claim 13, in, The method further comprises the step of forming an array for creating a distorted image and / or an aliasing-minimized image by means of a collection of said respective transmit and receive antenna pairs.

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