Antenna, radar system and vehicle

Abstract

The utility model discloses an antenna, a radar system and a vehicle, and the antenna comprises a transmitting antenna array which is used for transmitting a radar signal; the receiving antenna array is used for receiving an echo signal after the radar signal is reflected by a target; wherein the transmitting antenna array and the receiving antenna array are used for forming a virtual plane array, virtual array elements of the virtual plane array are uniformly distributed at a first array element interval in a first direction, and virtual array elements of the virtual plane array are uniformly distributed at a second array element interval in a second direction, the first direction is perpendicular to the second direction; the position of a transmitting array element in the transmitting antenna array is related to the first array element spacing; and the position of a receiving array element in the receiving antenna array is related to the second array element spacing. According to the invention, a hole-free high-gain equivalent uniform virtual plane array can be obtained, so that the performances of angle resolution, degree of freedom and the like are further improved.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to an antenna, a radar system and a vehicle. Background Art

[0002] MIMO radar (Multiple-Input Multiple-Output Radar) is a radar system that uses multiple transmitting and receiving antennas to improve radar performance. The traditional MIMO radar antenna layout is limited by half the wavelength, which limits the antenna aperture. The smaller array element spacing will also lead to stronger mutual coupling effects between antenna elements. In addition, the number of targets that can be identified by the traditional direction of arrival estimation (DOA) algorithm is also limited by the number of antenna elements in the physical array, affecting the degree of freedom, and when the number of identified targets exceeds the number of antenna elements, many DOA algorithms will fail.

[0003] In order to solve the problems caused by the half-wavelength limitation and the limitation on the number of physical array elements, the MIMO array is laid out in a sparse array, so that the array element spacing breaks through the half-wavelength limitation and the antenna aperture is greatly expanded with the same number of antennas, which greatly weakens the mutual coupling effect between antenna units, obtains good direction of arrival (DOA) estimation performance, and ensures an increase in the number of identifiable targets.

[0004] However, the current MIMO radar array element position is not designed to be optimized, and the number of corresponding virtual array elements is small, which results in holes between the equivalent virtual array elements corresponding to the physical array elements of the sparse array. The holes have a certain impact on the degree of freedom, angular resolution, etc. Therefore, how to construct a high-gain equivalent uniform virtual array without holes based on a limited number of array elements to improve the degree of freedom and angular resolution of the MIMO radar has become an urgent problem to be solved. Utility Model Content

[0005] The present application provides an antenna, a radar system and a vehicle, aiming to effectively solve the above-mentioned technical problem of constructing a high-gain equivalent uniform virtual array without holes when the number of array elements is limited.

[0006] According to a first aspect of the present application, the present application provides an antenna, comprising:

[0007] A transmitting antenna array for transmitting radar signals;

[0008] A receiving antenna array, used to receive an echo signal after the radar signal is reflected by a target;

[0009] The transmitting antenna array and the receiving antenna array are used to form a virtual plane array, in a first direction, the virtual array elements of the virtual plane array are evenly distributed with a first array element spacing, and in a second direction, the virtual array elements of the virtual plane array are evenly distributed with a second array element spacing, and the first direction is perpendicular to the second direction;

[0010] The position of the transmitting array element in the transmitting antenna array is related to the first array element spacing;

[0011] The positions of the receiving array elements in the receiving antenna array are related to the second array element spacing.

[0012] Furthermore, the transmitting antenna array includes a plurality of transmitting sub-arrays, the transmitting sub-arrays are coprime arrays and include a plurality of transmitting array elements arranged along a first direction, and the virtual array elements formed by the transmitting sub-arrays are evenly distributed at a first array element spacing.

[0013] Further, the value range of the first array element spacing is a first range determined by a range of a field of view angle in a first direction and a range of an angle blur value.

[0014] Furthermore, the first array element spacing is a maximum value in the first range.

[0015] Further, the multiple transmitting subarrays are subarrays with the same position, and the positions of the transmitting array elements in the transmitting subarrays are determined according to the intersection of the positions of the transmitting array elements in the first coproton subarray, the second coproton subarray, and the third subarray;

[0016] The array element spacing of the transmitting array elements in the first co-proton sub-array is M*d, and the array element spacing of the transmitting array elements in the second co-proton sub-array is N*d, where M and N are co-prime numbers, d is a unit spacing, and the value of M+N-1 is equal to the number of transmitting array elements of the transmitting sub-array;

[0017] The positions of the transmitting array elements in the third sub-array are used to fill the holes in the first co-proton sub-array and the second co-proton sub-array.

[0018] Furthermore, the positions of the transmitting array elements in the transmitting subarray are obtained by adjusting the positions of the transmitting array elements in the intersection according to a preset multiple;

[0019] The preset multiple is determined according to the ratio between the first array element spacing and the unit spacing.

[0020] Furthermore, the coordinates of the transmitting array element in the first direction are obtained by translating the transmitting array elements in the transmitting sub-array according to the hole positions of the virtual plane array.

[0021] Furthermore, the receiving antenna array includes a plurality of receiving sub-arrays, the receiving sub-arrays are minimum redundant arrays and include a plurality of receiving array elements arranged along a second direction, and the virtual array elements formed by the receiving sub-arrays are evenly distributed at a second array element spacing.

[0022] Furthermore, the positions of the receiving array elements in the receiving sub-array are determined based on the second array element spacing according to the characteristics of a minimum redundant array.

[0023] Furthermore, the coordinates of the receiving array elements in the second direction are obtained by translating the positions of the receiving array elements in the receiving sub-array according to the hole positions of the virtual plane array.

[0024] Furthermore, the multiple receiving sub-arrays and the multiple transmitting sub-arrays form a square shape.

[0025] Furthermore, the number of the receiving sub-array and the number of the transmitting sub-array are both 2.

[0026] Furthermore, the virtual planar array is a sum-difference co-array virtual array.

[0027] Furthermore, the total number of the transmitting array elements is 12, and the total number of the receiving array elements is 16.

[0028] Furthermore, the first array element spacing is a full wavelength, and the second array element spacing is a half wavelength.

[0029] According to a second aspect of the present application, the present application also provides a radar system, comprising: the antenna as described above, and a processing unit;

[0030] The processing unit is used to determine the angle information of the target according to the echo signal.

[0031] According to a second aspect of the present application, the present application also provides a vehicle, comprising the antenna as described above, and / or the radar system as described above.

[0032] Through one or more of the above-mentioned embodiments in the present application, at least the following technical effects can be achieved: without increasing the hardware cost and layout complexity (that is, when the number of antennas is limited), a high-gain equivalent uniform virtual planar array without holes is obtained by constructing a transmitting antenna array and a receiving antenna array, thereby further improving the performance of the MIMO radar such as angular resolution and degrees of freedom. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0034] Figure 1Shown is one of the schematic diagrams of the existing antenna;

[0035] Figure 2 Shown Figure 1 A schematic diagram of a virtual planar array of antennas shown;

[0036] Figure 3 Shown is a second schematic diagram of an existing antenna;

[0037] Figure 4 Shown Figure 3 A schematic diagram of a virtual planar array of antennas shown;

[0038] Figure 5 Shown is a schematic diagram of the antenna structure provided in an embodiment of the present application;

[0039] Figure 6 Shown is one of the schematic diagrams of a virtual plane array provided in an embodiment of the present application;

[0040] Figure 7 Shown is a schematic diagram of a transmitting sub-array and a corresponding virtual linear array provided in an embodiment of the present application;

[0041] Figure 8 The figure shows a schematic diagram of parallel arrangement of transmitting sub-arrays provided in an embodiment of the present application;

[0042] Fig. 9 The figure shows a schematic diagram of a translation front antenna provided in an embodiment of the present application;

[0043] Fig.10 The figure shows a schematic diagram of a translated antenna provided in an embodiment of the present application;

[0044] Fig.11 The example provided in the embodiment of the present application is shown as follows Fig. 9 A schematic diagram of a virtual planar array corresponding to the antenna shown;

[0045] Fig.12 The example provided in the embodiment of the present application is shown as follows Fig.10 A schematic diagram of a virtual planar array corresponding to the antenna shown;

[0046] Fig.13 Shown is a directional diagram in the horizontal direction provided by an embodiment of the present application;

[0047] Fig.14 Shown is a directional diagram in the vertical direction provided by an embodiment of the present application. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0049] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article, unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0050] There are holes between the equivalent virtual array elements of the existing MIMO radar antenna array designed with sparse arrays. For example, a 12-transmit 16-receive antenna layout is as follows: Figure 1 As shown, the red one is the transmitting antenna, which has 12 channels in total, and the blue one is the receiving antenna, which has 16 channels in total. Figure 1 The corresponding equivalent virtual array is Figure 2 As shown in the figure, when the number of antennas is constant, the holes in the vertical direction are larger and more numerous, and the angular resolution in the vertical direction is lower, so that the performance of the radar does not reach the optimal state.

[0051] For example, another 12-transmit 16-receive antenna layout is as follows Figure 3 As shown, Figure 3 The corresponding equivalent virtual array is Figure 4 As shown in the figure, when the number of antennas is constant, although the vertical holes are smaller than those in the Figure 2 As shown, it becomes smaller and less, but there is still room for further optimization of the angular resolution.

[0052] against Figure 1 and Figure 2 The MIMO radar array shown corresponds to Figure 3 and Figure 4 There is a problem of low angular resolution in the equivalent virtual array. The present application provides an antenna, a radar system and a vehicle, which are described in detail below with reference to the accompanying drawings.

[0053] See also Figure 5 , an embodiment of the present application provides an antenna, the antenna 500 includes a transmitting antenna array 501 and a receiving antenna array 502. The transmitting antenna array 501 is used to transmit a radar signal, and the receiving antenna array 502 is used to receive an echo signal after the radar signal is reflected by a target.

[0054] The echo signal can be used to determine the horizontal azimuth and vertical azimuth of the target. The radar signal can be a frequency modulated continuous wave (FMCW), multiple frequency-shift keying (MFSK), phase modulated continuous wave (PMCW) or other waveforms used by radars, without limitation.

[0055] The transmitting antenna array 501 and the receiving antenna array 502 are used to form a virtual plane array (also referred to as a virtual area array). In a first direction, the virtual array elements of the virtual plane array are evenly distributed at a first array element spacing. In a second direction, the virtual array elements of the virtual plane array are evenly distributed at a second array element spacing. The first direction is perpendicular to the second direction.

[0056] The first direction may be a horizontal direction or a vertical direction; correspondingly, the second direction may be a vertical direction or a horizontal direction. If the first direction is a horizontal direction, the virtual array elements in the first direction are used to determine the horizontal azimuth measurement value of the target, and the virtual array elements in the second direction are used to determine the vertical azimuth measurement value of the target. In the drawings and examples of the present application, the first direction is taken as an example for schematic description.

[0057] The positions of the transmitting array elements in the transmitting antenna array 501 are determined according to the first array element spacing, and the positions of the receiving array elements in the receiving antenna array 502 are related to the second array element spacing.

[0058] It should be noted that the horizontal direction and the vertical direction described in the embodiment of the present application are related to the position of the virtual plane array formed by the transmitting antenna array 501 and the receiving antenna array 502.

[0059] The number of array elements in the receiving antenna array 502 and the transmitting antenna array 501 will be affected by the hardware cost, the complexity of the layout and installation, the size and volume constraints of the antenna, etc. The number of array elements is limited differently in different antenna application scenarios. For example, in a vehicle-mounted radar system, the number of array elements in the receiving antenna array 502 and the transmitting antenna array 501 is limited to a few to a dozen, while in an aviation radar system, the number of array elements is at least dozens.

[0060] The embodiment of the present application constructs a high-gain equivalent uniform virtual planar array without holes without increasing the hardware cost and layout complexity (that is, when the number of antennas is limited), thereby further improving the performance of the MIMO radar such as angular resolution and degrees of freedom.

[0061] In addition, the first array element spacing refers to the spacing between adjacent virtual array elements in the first direction in the virtual plane array, and correspondingly, the second array element spacing refers to the spacing between adjacent virtual array elements in the second direction in the virtual plane array. The first array element spacing may be the same as or different from the second array element spacing. The values ​​of the first array element spacing and the second array element spacing may be determined according to the requirements of the vertical angular resolution and the horizontal angular resolution.

[0062] Schematically, the distribution of the virtual plane array is as follows Figure 6 As shown, taking the first direction as the vertical direction as an example, a first array element spacing between virtual array elements in the first direction is greater than a second array element spacing between virtual array elements in the second direction.

[0063] Different from the prior art, in the embodiment of the present application, a uniformly distributed virtual plane array without holes can be virtualized through the transmitting antenna array 501 and the receiving antenna array 502 to improve the performance such as angular resolution and degree of freedom.

[0064] In some embodiments of the present application, the transmitting antenna array 501 includes a plurality of transmitting subarrays, the transmitting subarrays are coprime arrays and include a plurality of transmitting array elements arranged along a first direction, that is, the transmitting array elements in the transmitting subarrays are arranged in parallel in a straight line along the first direction, and the transmitting subarrays are sparse linear arrays. The virtual array elements formed by the transmitting subarrays are evenly distributed at the first array element spacing.

[0065] The transmitting subarray is a coprime array means that the transmitting subarray includes two or more different coprime subarrays, and the array element spacing between the coprime subarrays is a coprime number. Schematically, if the array element spacing in one subarray is 2*unit spacing d, and the array element spacing in the other subarray is 3*unit spacing d, then the two subarrays are coprime subarrays, and the transmitting subarray including the two coprime subarrays is a coprime array.

[0066] Since the transmitting subarray is a coprime array, the coprime subarrays it includes have unique antenna spacing and phase delay, which can form beams in different directions. Moreover, due to the differences between the subarrays, it can provide better angular resolution and more accurately determine the direction and angle of the target.

[0067] It should be noted that the number of transmitting sub-arrays is determined according to the layout shape of the physical array elements. There may be one transmitting sub-array, the physical array elements are linear, and the one transmitting sub-array includes all transmitting array elements. There may also be two transmitting sub-arrays, forming a square shape with the other two receiving sub-arrays. There may also be three transmitting sub-arrays, and forming three square shapes with the other three receiving sub-arrays, which are not limited.

[0068] In another embodiment of the present application, the value range of the first array element spacing is a first range determined by the range of the field of view angle in the first direction and the range of the angle ambiguity value. Schematically, if the range of the field of view angle θ in the first direction is [-30°, 30°], the angle ambiguity value f=2d1sin(θ) / λ∈[-1, 1], and then the value range of the first array element spacing d1 is determined to be d1∈(0, λ]. Within this range, the virtual plane array can avoid the problem of angle estimation ambiguity.

[0069] In order to further expand the array aperture in the vertical direction (in this embodiment, the first direction is the vertical direction), the maximum value is selected from the first range as the first array element spacing. Taking the above (0, λ] as an example, d1=λ.

[0070] In some other embodiments of the present application, the multiple transmitting subarrays are subarrays with the same position, and the positions of the transmitting array elements in the transmitting subarrays are determined according to the intersection of the positions of the transmitting array elements in the first coproton subarray, the second coproton subarray, and the third subarray.

[0071] The array element spacing of the transmitting array elements in the first coproton subarray is M*d, and the array element spacing of the transmitting array elements in the second coproton subarray is N*d, where M and N are coprime numbers, d is the unit spacing, and the value of M+N-1 is equal to the number of transmitting array elements in the transmitting subarray.

[0072] The positions of the transmitting array elements in the third sub-array are used to fill the holes in the first co-proton sub-array and the second co-proton sub-array.

[0073] Among them, the positions of the transmitting array elements between the transmitting sub-arrays are the same, that is, the elements of the transmitting sub-arrays are the same. Schematically, if one transmitting sub-array is {X1, X2, X3}, then the other transmitting sub-arrays are also {X1, X2, X3}, wherein X1, X2, X3 are all vector positions of the transmitting array elements.

[0074] More specifically, the vector positions of the transmitting array elements in the transmitting sub-array are determined based on the intersection of the vector positions of the transmitting array elements in the first coproton sub-array, the second coproton sub-array, and the third sub-array.

[0075] The first coproton matrix and the second coproton matrix are coprime. Specifically, the first coproton matrix can be {0:M:M(NM)}, and the second coproton matrix can be {M(NM):N:(M(NM)+N(M-1))}. Taking prime numbers M=3 and N=4 as an example, the first coproton matrix is ​​{0,3}, and the second coproton matrix is ​​{3,7,11}. If M=2 and N=3, the first coproton matrix is ​​{0,2}, and the second coproton matrix is ​​{2,5}.

[0076] Furthermore, since there will be holes in the virtual linear array formed by the coproton subarrays, in order to fill these holes, it is also necessary to design a third subarray to fill the holes in the virtual linear array corresponding to the first coproton subarray and the second coproton subarray. Based on the aforementioned first coproton subarray being {0:M:M(NM)}, the second coproton subarray being {M(NM):N:(M(NM)+N(M-1))}, the third subarray includes {NM, M(NM)+N(M-1)+1}, wherein {NM} is used to fill the holes of the virtual array elements corresponding to the first coproton subarray, and {M(NM)+N(M-1)+1} is used to fill the holes of the virtual array elements corresponding to the second coproton subarray. Taking the above M=3, N=4 as an example, the third subarray is {1,12}. For another example, taking the above M=2, N=3 as an example, the third subarray is {1,6}.

[0077] Furthermore, the intersection of the first coproton subarray, the second coproton subarray and the third subarray is taken as the vector position of the transmitting array element in the transmitting subarray. Schematically, taking the above M=3 and N=4 as an example, the transmitting subarray S=[0,1,3,7,11,12]×d.

[0078] Furthermore, in order to arrange the virtual array elements in the vertical direction at the first array element spacing, it is also necessary to adjust the positions of the transmitting array elements in the intersection according to a preset multiple, and the preset multiple here is determined according to the ratio between the first array element spacing and the unit spacing.

[0079] Taking the above transmitting subarray S = [0, 1, 3, 7, 11, 12] × d and d1 = λ = 2d as an example, the adjusted transmitting subarray S' = [0, 2, 6, 14, 22, 24] × λ / 2. The physical array of S' and its corresponding virtual linear array are as follows: Figure 7 As shown, the spacing between virtual array elements in the virtual linear array is 2d.

[0080] In other embodiments of the present application, in order to further expand the virtual plane array, the adjusted transmitting subarray S' is translated. The specific number of unit spacings required for translation is determined according to the total number of transmitting array elements. If the total number of transmitting array elements in the transmitting array is 12, the adjusted transmitting subarray S' is translated to the right by 4 unit spacings.

[0081] It should be noted that the translation of the transmitting subarray refers to the position translation of the transmitting array element along the first direction. When the first direction is a vertical direction, the vertical coordinate of the transmitting array element is translated.

[0082] The translation amount of the transmitting subarray is determined according to the hole situation of the virtual array. When the transmitting subarray S'=[0,2,6,14,22,24]×λ / 2, the hole situation in the virtual plane array needs to be filled by translating the transmitting subarray by 4 unit spacings.

[0083] After the adjusted transmitting subarray S' completes the translation, it is determined that all transmitting subarrays are obtained. Each transmitting subarray needs to be arranged in parallel, and the front and rear positions in the first direction are kept uniform. After the transmitting subarrays are arranged in parallel, the position information of all transmitting array elements is obtained. For example, if the number of transmitting subarrays is 3, the 3 transmitting subarrays are arranged in parallel, such as Figure 8 shown.

[0084] In some other embodiments of the present application, the receiving antenna array 502 includes multiple receiving sub-arrays, the receiving sub-arrays are minimum redundant arrays and include multiple receiving array elements arranged along the second direction, and the virtual array elements formed by the receiving sub-arrays are evenly distributed at the second array element spacing.

[0085] Among them, the position of the receiving array element is determined by the minimum redundant array concept, that is, under the condition that the number of receiving array elements in the receiving sub-array is certain and the spacing between the virtual array elements to be formed is the second array element spacing, the situation where the number of corresponding virtual array elements is the largest when the position of the receiving array element is continuously adjusted is found by traversal search, and the position of the receiving array element with the largest number of virtual array elements is used as the position of each receiving array element in the receiving sub-array, and then the number of receiving sub-arrays is calculated according to the total number of receiving sub-arrays and the number of receiving array elements in the receiving sub-array. The position of the receiving array element is the same between each receiving sub-array.

[0086] Table 1 Minimum redundant array traversal diagram

[0087]

[0088] As shown in Table 1, when the number of different receiving elements in the receiving sub-array is different, the traversal method is used to search for the maximum number of virtual elements. For example, when the number of receiving elements in the receiving sub-array is 3, the traversal method obtains the receiving element positions of [0, 1, 3], which corresponds to the maximum number of virtual elements.

[0089] In the receiving sub-array, the receiving array elements are arranged along the horizontal direction, which is opposite to the arrangement direction of the transmitting array elements. The interval between adjacent virtual array elements in the virtual linear array formed by the receiving sub-array is the second array element spacing.

[0090] In other embodiments of the present application, in order to expand the virtual plane array, the receiving sub-array is also translated, and the unit spacing of the receiving array element corresponding to the transmitting array element that needs to be translated also needs to be determined after testing, that is, after obtaining the initial position of the receiving array element, the existing holes are determined according to the virtual linear array formed by it, and then the number and direction of the unit spacing that need to be translated are determined. Schematically, taking the above-mentioned receiving array element position of [0, 1, 4, 10, 16, 18, 21, 23] × λ / 2 as an example, the virtual plane array formed by it and the transmitting array element requires the receiving array element to be translated by 4 unit spacings along the second direction to become [4, 5, 8, 14, 20, 22, 25, 27] × λ / 2.

[0091] It should be noted that the translation of the receiving array element is performed along the second direction. In an example where the second direction is a horizontal direction, the horizontal coordinate of the receiving array element is translated.

[0092] In other embodiments of the present application, in order to improve the space utilization of the antenna board, the parallel arranged transmitting sub-arrays and receiving sub-arrays are assembled into a U-shape, and the number of U-shapes can be multiple, which is determined according to the number of transmitting sub-arrays and receiving sub-arrays.

[0093] The antenna provided in the embodiment of the present application has a transmitting array element and a receiving array element in a U-shape, which improves the low space utilization rate of the antenna board and reduces mutual coupling interference.

[0094] The present application also provides an antenna, in which the number of transmitting array elements is 12 and the number of receiving array elements is 16. When the number of transmitting array elements and the number of receiving array elements are constant, a virtual plane array is obtained by the following design, in which in the first direction of the virtual plane array, the virtual array elements of the virtual plane array are evenly distributed with a first array element spacing; in the second direction, the virtual array elements of the virtual plane array are evenly distributed with a second array element spacing.

[0095] It should be noted that, in the specific description here, the first direction is taken as the vertical direction and the second direction is taken as the horizontal direction.

[0096] For the transmitting antenna array 501, according to the set range of the field of view angle θ of [-30°, 30°], and the angle ambiguity value f=2d1sin(θ) / λ∈[-1, 1], the value range of the unit spacing d1 between the virtual array elements d1∈(0,λ] (that is, the first range) can be calculated. That is to say, when there is no angle ambiguity, the maximum value of the first array element spacing d1 can be the full wavelength length of the signal, that is, the first array element spacing is λ. It should be noted that, in other embodiments, the range of the field of view angle and the value range of the angle ambiguity value are determined according to actual conditions, and the corresponding d1 value range also changes accordingly, and there is no limitation on this.

[0097] According to the ratio of the first array element spacing λ and the unit spacing λ / 2, the number of transmitting sub-arrays is 2. When there are 12 transmitting array elements in total, there are 6 elements in the transmitting sub-array. On this basis, the position of each transmitting array element in the transmitting sub-array needs to be determined in the following way.

[0098] S1 = {0:M:M(NM)};

[0099] S2 = {NM};

[0100] S3={M(NM):N:(M(NM)+N(M-1))};

[0101] S4 = {M (NM) + N (M-1) + 1};

[0102] Wherein, M and N are mutually prime numbers, S1 and S3 are two mutually prime first and second mutually prime subarrays, S2 and S4 are both third subarrays, S2 is used to fill the holes in the virtual linear array corresponding to the first mutually prime subarray, and S4 is used to fill the holes in the virtual linear array corresponding to the second mutually prime subarray. In the present application, the mutually prime numbers are set to M=3, N=4. It should be noted that the mutually prime numbers need to satisfy M+N-1=the number of transmitting array elements in the transmitting subarray. In other embodiments of the present application, the mutually prime numbers can be selected as M is 2, N is 5, or others, without limitation.

[0103] In addition, when the coprime numbers are closer, the aperture of the array is larger. Compared with other coprime arrays, the coprime numbers M=3 and N=4 set in this embodiment can make the aperture of the virtual array element larger.

[0104] In order to improve the space utilization of the antenna, in this embodiment, the transmitting sub-array and the receiving sub-array are assembled into a square shape, so the number of the transmitting sub-array and the number of the receiving sub-array are both set to 2.

[0105] Based on the mutually prime numbers M=3, N=4 determined above, two 6-element hole-free mutually prime transmitting subarrays are obtained, wherein the position of the transmitting element in each transmitting subarray is S=[0,1,3,7,11,12]×λ / 2, and the position in S is enlarged according to the direct ratio of the first element spacing and the unit spacing, and after doubling, the element position S'=[0,2,6,14,22,24]×λ / 2.

[0106] For the receiving antenna array 502, through the characteristic traversal search of the minimum redundant array, on the basis of the number of receiving array elements being 16 and the second array element spacing being λ / 2, a minimum redundant array with the largest number of continuous virtual array elements is obtained. The minimum redundant array includes 8 receiving array elements, and the receiving array element positions of the minimum redundant array are specifically [0, 1, 4, 10, 16, 18, 21, 23]×λ / 2.

[0107] Based on the above determination of the two transmitting subarrays as [0,2,6,14,22,24]×λ / 2 and the two receiving subarrays as [0,1,4,10,16,18,21,23]×λ / 2, the transmitting subarray and the receiving subarray are assembled in parallel to form the following: Fig. 9 The U-shaped antenna shown in the figure has a transmitting antenna array 501TX1={(tx1,ty1)|tx1=[0,31]×λ / 2,ty1=[0,2,6,14,22,24]×λ / 2}, where tx1 represents the horizontal position coordinate of the transmitting antenna array element, and ty1 represents the vertical position coordinate of the transmitting antenna array element. The receiving antenna array 502RX1={(rx1,ry1)|rx1=[0,1,4,10,16,18,21,23]×λ / 2;ry1=[0,32]×λ / 2}, where rx1 represents the horizontal position coordinate of the receiving antenna array element, and ry1 represents the vertical position coordinate of the receiving antenna array element.

[0108] It should be noted that the value of tx1 in the transmitting array and the value of ry1 in the receiving array are specifically determined according to the corresponding length of rx1 and ty1 and the corresponding translation distance. Specifically, tx1 = [0,31] × λ / 2 is due to the length of rx1 being 23, and the further translation distance being 4λ / 2, then 31 = 23 + 4*2, thereby determining the length of tx1. Similarly, the length of ry1 is determined according to the length of ty1, the length of ty1 being 24, and the translation distance being 4λ / 2, then 32 = 24 + 4*2. In summary, the horizontal coordinate of the transmitting array element in the transmitting array is determined according to the length of the receiving array element in the receiving array and the translation distance of the receiving array element. Similarly, the vertical coordinate of the receiving array element in the receiving array is determined according to the length of the transmitting array element in the transmitting array and the translation distance of the transmitting array element.

[0109] In addition, in order to further expand the virtual plane array, the vertical coordinate values ​​of the transmitting array element are translated, and the horizontal coordinate values ​​of the receiving array element are translated. Under the condition of 12 transmissions and 16 receptions, the transmitting array element is translated to the right by 4 unit spacings, and the receiving array element is translated upward by 4 unit spacings, so as to obtain the following after translation: Fig.10The antenna TX2 shown is: {(tx2, ty2)|tx2=[0,31]×λ / 2, ty2=[4,6,10,18,26,28]×λ / 2}, RX2={(rx2, ry2)|rx2=[4,5,8,14,20,22,25,27]×λ / 2; ry2=[0,32]×λ / 2}, wherein tx2 represents the horizontal position coordinate of the transmitting antenna element after translation, ty2 represents the vertical position coordinate of the transmitting antenna element after translation, rx2 represents the horizontal position coordinate of the receiving antenna element after translation, and ry2 represents the vertical position coordinate of the receiving antenna element after translation.

[0110] in, Fig. 9 The corresponding virtual plane array is as follows Fig.11 As shown, its virtual array aperture is 46λ×52λ, Fig.10 The corresponding virtual plane array is as follows Fig.12 As shown, the aperture of the virtual array is 54λ×56λ. It can be seen that after translation, the aperture of the virtual array increases and the virtual plane array becomes larger.

[0111] After obtaining the above-mentioned translated antenna, according to the working principle of the MIMO radar antenna array, after matched filtering, the transmitting and receiving antenna arrays 502 are equivalent to a co-array virtual array (that is, a virtual planar array), and the equivalent relationship of the virtual array element position set SX after matched filtering is:

[0112] SX={u x +v x |u x ∈TX2;v x ∈RX2};

[0113] Further, according to the principle of sum co-array, the transmit array element position set and the receive array element position set TX2 = {(tx2, ty2) | tx2 = [0, 31] × λ / 2, ty2 = [4, 6, 10, 18, 26, 28] × λ / 2} and RX2 = {(rx2, ry2) | rx2 = [4, 5, 8, 14, 20, 22, 25, 27] × λ / 2; ry2 = [0, 32] × λ / 2} are substituted into the above formula, and the sum co-array element position set of the MIMO radar antenna array can be expressed as:

[0114] SX={(sx,sy)|sx=[4,5,8,14,20,22,25,27,35,36,39,45,51,53,56,58]×

[0115] λ / 2; sy=[4,6,10,18,26,28,36,38,42,50,58,60]×λ / 2};

[0116] Among them, sx and sy are the horizontal position and vertical position respectively.

[0117] At the same time, according to the differential array principle, the received signal can also be equivalent to a sum-difference common array virtual array, and the equivalent relationship of its virtual array element position set SX is:

[0118] SDX={(u x -u y )+(v x -v y )|u x ,u y ∈TX2;v x ,v y ∈RX2}.

[0119] According to the sum-difference common array principle, the transmit array element position set TX and the receive array element position set RX2 are substituted into the above formula, and the sum-difference common array element position set of the MIMO radar antenna array (that is, the position of each virtual array element in the virtual plane array) can be expressed as:

[0120] SDX={(sdx,sdy)|sdx=(-54:1:54)×λ / 2; sdy=(-56:2:56)×λ / 2};

[0121] Among them, sdx and sdy are the horizontal and vertical positions respectively. It can be seen that the virtual array element spacing in the vertical direction is λ, the virtual array element spacing in the horizontal direction is λ / 2, and the virtual array aperture is 54λ×56λ. According to the Rayleigh criterion D is the virtual array aperture, ρ is the angular resolution, and the horizontal angular resolution is 0.0452° and the vertical angular resolution is 0.0436°. Based on the above virtual plane array, the corresponding horizontal directional pattern is as follows: Fig.13 As shown, the vertical direction diagram is as follows Fig.14 shown.

[0122] The sum-difference common array virtual array derived above is a hole-free uniform array. DFT, subspace algorithm and other parameter estimation can be directly applied to the hole-free uniform array. Figure 1 and Figure 2 Compared with the antenna array shown, the antenna provided in the embodiment of the present application can form a uniform virtual plane array without holes, which can improve the performance such as degree of freedom and angular resolution, and can also facilitate the subsequent application of DFT and subspace algorithms.

[0123] It should be noted that, in order to address the problem of low angular resolution in the vertical direction of the existing MIMO radar antenna array, in this embodiment, the first array element spacing is set to λ, and the second array element spacing is set to λ / 2, thereby expanding the virtual array element aperture in the vertical direction in the virtual plane array, thereby maintaining the angular resolution in the horizontal direction in an optimal state while improving the angular resolution in the vertical direction. In addition, based on the above-mentioned virtual plane array, a higher main-to-sidelobe ratio in both the horizontal and vertical directions is obtained.

[0124] Based on any of the above embodiments, another embodiment of the present application further provides a radar system, including an antenna and a processing unit. The antenna 500 includes a transmitting antenna array 501 and a receiving antenna array 502, and the transmitting antenna array 501 and the receiving antenna array 502 are used to form a virtual plane array, and in a first direction, the virtual array elements of the virtual plane array are evenly distributed with a first array element spacing, and in a second direction, the virtual array elements of the virtual plane array are evenly distributed with a second array element spacing. For details, please refer to the above description, which will not be repeated here.

[0125] The processing unit is used to determine the angle information of the target according to the echo signal.

[0126] Based on any of the above embodiments, another embodiment of the present application further provides a vehicle, which may include the above antenna, or include the above radar system, or include the above antenna and radar system, and the details will not be repeated here.

[0127] In summary, although the present application has been disclosed as above with preferred embodiments, the above preferred embodiments are not intended to limit the present application. Ordinary technicians in this field can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined in the claims.

Claims

1. An antenna, characterized in that: include: The antenna is characterized by comprising: A transmitting antenna array for transmitting radar signals; A receiving antenna array, used to receive an echo signal after the radar signal is reflected by a target; The transmitting antenna array and the receiving antenna array are used to form a virtual plane array, in a first direction, the virtual array elements of the virtual plane array are evenly distributed with a first array element spacing, and in a second direction, the virtual array elements of the virtual plane array are evenly distributed with a second array element spacing, and the first direction is perpendicular to the second direction; The position of the transmitting array element in the transmitting antenna array is related to the first array element spacing; The positions of the receiving array elements in the receiving antenna array are related to the second array element spacing.

2. The antenna according to claim 1, characterized in that The transmitting antenna array includes a plurality of transmitting sub-arrays, the transmitting sub-arrays are coprime arrays and include a plurality of transmitting array elements arranged along a first direction, and the virtual array elements formed by the transmitting sub-arrays are evenly distributed at a first array element spacing.

3. The antenna according to claim 2, characterized in that The value range of the first array element spacing is a first range determined by the range of the field of view angle in the first direction and the range of the angular blur value.

4. The antenna according to claim 3, characterized in that The first array element spacing is a maximum value in the first range.

5. The antenna according to claim 2, characterized in that The multiple transmitting subarrays are subarrays with the same position, and the positions of the transmitting array elements in the transmitting subarrays are determined according to the intersection of the positions of the transmitting array elements in the first coproton subarray, the second coproton subarray, and the third subarray; The array element spacing of the transmitting array elements in the first co-proton sub-array is M*d, and the array element spacing of the transmitting array elements in the second co-proton sub-array is N*d, where M and N are co-prime numbers, d is a unit spacing, and the value of M+N-1 is equal to the number of transmitting array elements of the transmitting sub-array; The positions of the transmitting array elements in the third sub-array are used to fill the holes in the first co-proton sub-array and the second co-proton sub-array.

6. The antenna according to claim 5, characterized in that The position of the transmitting array element in the transmitting subarray is obtained by adjusting the position of the transmitting array element in the intersection according to a preset multiple; The preset multiple is determined according to the ratio between the first array element spacing and the unit spacing.

7. The antenna according to claim 6, characterized in that The coordinates of the transmitting array element in the first direction are obtained by translating the transmitting array element in the transmitting sub-array according to the hole positions of the virtual plane array.

8. The antenna according to claim 2, characterized in that The receiving antenna array includes a plurality of receiving sub-arrays, the receiving sub-arrays are minimum redundant arrays and include a plurality of receiving array elements arranged along a second direction, and the virtual array elements formed by the receiving sub-arrays are evenly distributed at a second array element spacing.

9. The antenna according to claim 8, characterized in that The positions of the receiving array elements in the receiving sub-array are determined based on the second array element spacing according to the characteristics of the minimum redundant array.

10. The antenna according to claim 9, characterized in that The coordinates of the receiving array elements in the second direction are obtained by translating the positions of the receiving array elements in the receiving sub-array according to the hole positions of the virtual plane array.

11. The antenna according to claim 8, characterized in that The multiple receiving sub-arrays and the multiple transmitting sub-arrays form a square shape.

12. The antenna according to claim 11, characterized in that The number of the receiving sub-array and the number of the transmitting sub-array are both 2.

13. The antenna according to claim 1, wherein: The virtual planar array is a sum-difference co-matrix virtual array.

14. The antenna according to any one of claims 1 to 13, characterized in that The total number of the transmitting array elements is 12, and the total number of the receiving array elements is 16.

15. The antenna according to claim 14, characterized in that The first array element spacing is a full wavelength, and the second array element spacing is a half wavelength.

16. A radar system, characterized in that: include: The antenna according to any one of claims 1 to 15, and a processing unit; The processing unit is used to determine the angle information of the target according to the echo signal.

17. A vehicle, characterized in that: Comprising the antenna according to any one of claims 1 to 15, and / or the radar system according to claim 16.

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