JP7023564B2 - Antenna device - Google Patents

Description

The present invention relates to an antenna device in which a plurality of antenna elements (radiating elements) are arranged in the horizontal direction and the vertical direction.

In a radar array antenna device, it is effective to increase the opening length of the antenna in order to improve the resolution. However, if a large number of antenna elements are arranged, not only the cost increases, but also the circuit scale and the calculation scale become large, which may make it difficult to put into practical use. On the other hand, if a small number of antenna elements are arranged in a long opening, a grating lobe is generated and the angle range that can be measured becomes narrow, and the true direction cannot be estimated.

Therefore, as a method for obtaining the same performance as a large aperture with a small number of antenna elements, a patent-Rao product (hereinafter referred to as "KR product") extended array using a covariance matrix has been proposed (for example, non-). See Patent Document 1). Although the details will be described later, in this KR product expansion array, the virtual antenna elements are arranged at some positions of the existing antenna elements that should be linearly arranged at predetermined intervals and satisfy the predetermined conditions (existing). By not arranging the antenna element), it can be regarded as if the existing antenna element is arranged at all the positions.

W. K. Ma, et al. , IEEE Transitions on Signal Processing, vol. 58, no. 4, pp. 2168-2180, April 2010

By the way, in order to detect the azimuth and height, it is necessary to arrange a plurality of existing antenna elements in a two-dimensional and grid pattern in the horizontal direction (horizontal direction) and the vertical direction (vertical direction), but many existing antenna elements are used. Requires an element. Moreover, due to restrictions such as the size of the existing antenna element and the size of the feeding port, the actual antenna element may not be ideally arranged. Further, in the technique as shown in Non-Patent Document 1, only the antenna in which the real antenna element is arranged linearly is targeted, and the case where the real antenna element is arranged two-dimensionally is not disclosed.

Therefore, an object of the present invention is to provide an antenna device capable of detecting the direction and height with a small number of existing antenna elements.

In order to solve the above problem, the invention according to claim 1 is provided with a plurality of arrangement positions in the horizontal direction, and an existing antenna element is arranged at a part of the arrangement positions. A plurality of horizontal antenna element groups in which the virtual antenna element in which the existing antenna element is not arranged are arranged at other arrangement positions, and the ends are arranged so as to be displaced in the horizontal direction. Each of the horizontal antenna element groups includes a dimensional array antenna and a processing unit, and the existing antenna element is arranged so that the signal of the virtual antenna element can be interpolated by utilizing the phase difference between the existing antenna elements. , The numerical values corresponding to the arrangement positions of the existing antenna elements are arranged in the top row, and the numerical values corresponding to the arrangement positions of the actual antenna elements are arranged in the leftmost column and these numerical values are added vertically and horizontally. In the horizontal direction, the independent components of the co-dispersion matrix, which are numerical values in the matrix, are serial numbers, and the independent components of the co-dispersion matrix of the existing antenna element in any of the columns arranged in the vertical direction are serial numbers. The processing unit arranges the independent components of the co-dispersion matrix for all the existing antenna elements in the vertical direction for each horizontal independent component group corresponding to the horizontal antenna element group, and the processing unit arranges the independent components in the horizontal independent component group. A Fourier transform is performed for each, and based on the result of the Fourier transform, the horizontally independent component groups are horizontally shifted so that the overlap of the horizontally independent component groups in the vertical direction increases, and the horizontally shifted component groups are shifted. It is an antenna device characterized by performing a Fourier transformation of a group of horizontally independent components in the vertical direction .

The invention according to claim 2 utilizes the phase difference determined by the relative position of another real antenna element from the reference point with the position of a specific real antenna element as a reference point in the antenna device according to claim 1. Based on the calculation rule for generating the signal of the virtual antenna element, the correspondence between the existing antenna elements for generating the signal of the virtual antenna element at an arbitrary arrangement position is maintained, and the correspondence is based on the held correspondence. It is characterized by generating a signal of a virtual antenna element.

According to the third aspect of the present invention, in the antenna device according to the first or second aspect, the processing unit applies phase rotation based on each arrangement position to the result of the Fourier transformation in the horizontal direction, and in the vertical direction. It is characterized in that the horizontally independent component group is shifted in the horizontal direction so that the overlap of the horizontally independent component group is increased .

The invention according to claim 4 is the antenna device according to any one of claims 1 to 3 , wherein the processing unit can carry out the processing in the order of the horizontal direction and the vertical direction. It is characterized by that.

According to the first aspect of the present invention, the phase difference between the existing antenna elements can be used to form a virtual antenna element in which the real antenna element is not arranged and is continuously arranged in the vertical direction and the horizontal direction. Since the existing antenna elements are arranged, it is possible to detect the direction and height with a small number of existing antenna elements.

According to the second aspect of the present invention, a correspondence relationship between existing antenna elements for generating a signal of a virtual antenna element at an arbitrary arrangement position is maintained based on a predetermined calculation rule, and the correspondence relationship is maintained. Since the signal of the virtual antenna element is generated based on this , it is possible to detect the orientation and the height with a small number of existing antenna elements.

According to the invention of claim 1 , by performing a Fourier transform in the horizontal direction of each row and a Fourier transform in the vertical direction of each column, a two-dimensional array equivalent to the arrangement of wide existing antenna elements in the vertical and horizontal directions is performed. It is possible to configure an antenna.

According to the third aspect of the present invention, since a larger region is subject to the Fourier transform, it is possible to construct a two-dimensional array antenna equivalent to a real antenna element arranged more widely in the vertical and horizontal directions. It becomes.

According to the fourth aspect of the present invention, since the processing in the horizontal direction and the processing in the vertical direction can be exchanged in order, the degree of freedom in processing and design is increased.

It is a schematic block diagram which shows the antenna device which concerns on embodiment of this invention. It is a schematic block diagram which shows the radar apparatus provided with the antenna apparatus of FIG. It is a figure which shows the covariance matrix for demonstrating the KR product expansion array in embodiment of this invention, and is the figure when all the arrays are present. It is a figure which shows the case where a part array is missing in the covariance matrix of FIG. It is a figure which shows the example of the interpolation state of the antenna element for demonstrating the KR product expansion array in embodiment of this invention. It is a figure which shows only the exponential of the covariance matrix in the case of FIG. It is a figure (a) which shows an example of the horizontal antenna element group of the two-dimensional array antenna of the antenna device of FIG. 1, and the figure (b) which shows an example of a two-dimensional array antenna. In the antenna device of FIG. 1, it is a conceptual diagram (a) showing a state in which a plurality of horizontally independent component groups are arranged in the vertical direction, and a conceptual diagram (b) showing a state in which the horizontally independent component groups are shifted in the horizontal direction. It is a conceptual diagram which shows the state which changed the furia from the state of FIG. 8A. It is explanatory drawing which shows the phase state of each element component in the state of FIG. It is explanatory drawing which shows the method of shifting each element component from the state of FIG. It is explanatory drawing which shows the 2D array antenna for demonstrating the processing part of the antenna apparatus of FIG. It is a figure which shows only the exponential of the covariance matrix with respect to the 2D array antenna of FIG. It is a figure which shows the state which arranged the horizontally independent component group in the vertical direction based on the covariance matrix of FIG. It is a figure which shows an example of the antenna for the MIMO radar to which the antenna device of FIG. 1 is applied. It is a figure which shows the virtual array antenna configuration by the antenna for the MIMO radar of FIG. It is a figure which shows the result of applying the virtual array antenna of FIG. 16 to the antenna device of FIG.

Hereinafter, the present invention will be described based on the illustrated embodiment.

1 to 17 show an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram showing a radar device 1 provided with an antenna device 2 according to the embodiment. The radar device 1 mainly includes an antenna device 2 including a two-dimensional array antenna 4 and a processing unit 5, and a signal processing device 3 that processes a received signal by digital beamforming or the like and converts it into a radar image.

Here, first, the KR product expansion array will be described. When the existing antenna elements are linearly arranged at predetermined intervals, for example, as shown in FIG. 3, the covariance matrix of the received signal of the antenna and the complex conjugate of the received signal has continuous independent components (continuous). Turn). Further, when the real antenna element is not arranged at the position where the real antenna element should be arranged, that is, when the components of the covariance matrix have redundancy, for example, as shown in FIG. 4, the received signal and the received signal Even if there is a gap with the complex conjugate of, the independent components in the covariance matrix may be continuous. In this way, even if the virtual antenna element (missing) is arranged without arranging the real antenna element at a part of the positions satisfying the predetermined conditions, the real antenna element is arranged at all the positions. It may be considered. That is, there are cases where the missing signal can be interpolated by the KR product.

Specifically, for example, as shown in FIG. 5, a plurality of arrangement positions P ₀ to P ₇ are provided at predetermined intervals d, and some of the arrangement positions P ₀ to P ₇ are arranged. The existing antenna elements F ₀ , F ₁ , F ₂ , F ₄ , and F ₇ are arranged at P ₀ , P ₁ , P ₂ , P ₄ , and P ₇ , and other arrangement positions P ₃ , P ₅ , and P ₆ are arranged. It is assumed that the virtual antenna elements F ₃ , F ₅ , and F ₆ to which the actual antenna element is not arranged are arranged in. In this case, the signals of the virtual antenna elements F ₃ , F ₅ , and F ₆ can be interpolated by the signals of the real antenna elements F ₀ , F ₁ , F ₂ , F ₄ , and F ₇ using the interval d.

That is, since the virtual antenna element F ₃ is separated from the real antenna element F ₇ by an interval of 4d, the signal difference (phase rotation) S4 between the real antenna elements F ₀ and F ₄ is used for interpolation. Similarly, since the virtual antenna element F ₅ is separated from the real antenna element F ₇ by an interval of 2d, the signal difference S2 between the real antenna elements F ₀ and F ₂ is used for interpolation. Further, since the virtual antenna element F ₆ is separated from the real antenna element F ₇ by an interval d, the signal difference S1 between the real antenna elements F ₀ and F ₁ is used for interpolation.

Further, similarly, the complex conjugate virtual antenna elements F _{-1 to} F- ₇ can be arranged at the arrangement positions P _-1 to P- ₇ in the opposite direction with the real antenna element F0 as the origin. .. In this way, it is possible to configure an antenna equivalent to the arrangement of 15 antenna elements F- ₇ to _F7 with five existing antenna elements F ₀ , F ₁ , F ₂ , F ₄ , and F ₇ . It becomes.

Then, in order for such a KR product expansion array to be established, the independent components in the covariance matrix need to be continuous. That is, when looking only at the exponents of the independent components in the covariance matrix e ^inα (n: 0, ± 1, ± 2 ...), the array shown in FIG. 5 becomes the matrix shown in FIG. 6, which is -7. Serial numbers are obtained from ~ +7, and the KR product expansion array is established. In other words, it is necessary to dispose the real antenna element, that is, the virtual antenna element so that the independent components are continuous in this way. Here, in FIG. 6, numerical values (0, 1, 2, 4, 7) corresponding to the arrangement positions of the existing antenna elements F ₀ , F ₁ , F ₂ , F ₄ , and F ₇ are shown in the uppermost row of the figure. In the leftmost column of the figure, the complex conjugate values (-0, -1, -2, -4,-corresponding to the arrangement positions of the existing antenna elements F ₀ , F ₁ , F ₂ , F ₄ , F ₇ 7) is described, and the numerical value obtained by adding these numerical values vertically and horizontally corresponds to the numerical value described in the form of matrix.

The two-dimensional array antenna 4 of the antenna device 2 is configured on the premise of such a KR product expansion array. Specifically, the antenna device 2 has the following configuration.
A virtual antenna in which a plurality of arrangement positions are provided in the horizontal direction, the real antenna element is arranged in a part of the arrangement positions, and the real antenna element is not arranged in the other arrangement positions. A group of horizontal antenna elements in which the elements are arranged are arranged so that a plurality of horizontal antenna elements are arranged in the vertical direction and their ends are displaced in the horizontal direction.
The existing antenna elements of each of the horizontal antenna element groups are arranged so that the independent components in the covariance matrix are continuous, and the existing antenna elements in any of the rows arranged in the vertical direction are arranged in the covariance matrix. The horizontal antenna element groups are arranged so as to be continuous so that the independent components are continuous.
The independent components of the codispersion matrix for all the existing antenna elements are arranged in the vertical direction for each horizontal independent component group corresponding to the horizontal antenna element group, Fourier transformed for each horizontal independent component group, and based on the result. An antenna device comprising a processing unit that shifts the horizontally independent component group in the horizontal direction so that the horizontal independent component group overlaps more in the vertical direction.

First, for example, as shown in FIG. 7A, a plurality of arrangement positions P0 to P14 are provided in the horizontal direction (horizontal direction), and some of the arrangement positions P0 and P1 of the arrangement positions P0 and P1 , P3, P4, P6, P7, P10, P11, P13, P14 are arranged with the real antenna element RF, and the other arrangement positions P2, P5, P8, P9, P12 are not arranged with the real antenna element RF. The antenna element group in which the virtual antenna element VF is arranged is referred to as a horizontal antenna element group HA.

As shown in FIG. 7 (b), such horizontal antenna element group HA is arranged so as to be displaced in a plurality of vertical directions and laterally (viewed from the vertical direction) at the ends, and is two-dimensional. The array antenna 4 is configured. That is, in a state where a plurality of horizontal antenna element groups HA are arranged in the vertical direction, the whole is not rectangular, and a plurality of horizontal antenna elements are arranged so that both sides do not extend straight and vertically (unevenly or inclined). Group HA is arranged.

Here, the existing antenna element RF of each horizontal antenna element group HA is arranged so that the independent components in the covariance matrix are continuous. That is, the real antenna element RF and the virtual antenna element VF are provided so that each horizontal antenna element group HA forms the KR product expansion array as described above. If this requirement is satisfied, the arrangement of the real antenna element RF and the virtual antenna element VF of each horizontal antenna element group HA may be the same or different.

Further, the horizontal antenna element groups HA are arranged so as to be continuous with respect to the existing antenna element RF in any of the rows L arranged in the vertical direction so that the independent components in the covariance matrix are continuous. That is, the set in which the antenna elements RF and VF of the plurality of horizontal antenna element groups HA are arranged and connected in the vertical direction is referred to as a column L. Then, each horizontal antenna element group HA is displaced so as to form the above-mentioned KR product expansion array in any of the columns L, that is, so that the independent components in the covariance matrix in the column L are continuous. Are arranged.

For example, in the column L7 of FIG. 7B, the real antenna element RF, the real antenna element RF, the virtual antenna element VF, the virtual antenna element VF, and the real antenna element RF are arranged in order from the top in the vertical direction. The independent components in the variance matrix are arranged so as to be continuous. In other words, as long as these requirements are satisfied, the existing antenna element RF may be arranged according to the size, shape, size, and the like of the space for arranging the two-dimensional array antenna 4. , High degree of freedom of arrangement.

Next, the processing unit 5 arranges the independent component IFs of the codispersion matrix for all the existing antenna element RF in the vertical direction for each horizontal independent component group HF corresponding to the horizontal antenna element group HA, and arranges them vertically for each horizontal independent component group HF. Based on the result of Fourier transformation, the horizontal independent component group HF is shifted horizontally so that the horizontal independent component group HF overlaps more in the vertical direction, and the independent component IFs connected in the vertical direction are vertically (column). ) Is a Fourier transform.

That is, conceptually, for example, as shown in FIG. 7 (b), a covariance matrix is calculated for all of the existing antenna elements RF (0, 1, 2 ... 14 ...), and FIG. 8 (a) shows. As shown, the independent component IFs are arranged in the vertical direction for each horizontal independent component group HF corresponding to the horizontal antenna element group HA. At this time, the ends of the horizontally independent component groups HF are laterally displaced (when viewed from the vertical direction), and the horizontally independent component groups HF overlap in the vertical direction, that is, the region where all the horizontally independent component groups HF overlap. SF is small.

Next, a Fourier transform is performed for each horizontal independent component group HF, and based on the result, as shown in FIG. 8B, the overlap of the horizontal independent component group HF in the vertical direction is increased, that is, each horizontal. The horizontal independent component group HF is shifted in the horizontal direction so that the lateral deviation of the end portion of the independent component group HF is small. As a result, the region SF in which all the horizontally independent component groups HF overlap is increased. Further, the independent component IFs connected in the vertical direction are Fourier transformed for each vertical direction (column).

Such processing will be specifically described with reference to the example shown in FIG. In FIG. 9, after the horizontal Fourier transform (FFT) 51 shown in FIG. 1 performs a Fourier transform for each horizontal independent component group HF, the first horizontal with respect to the 0th (reference) horizontal independent component group HF ₀ . The independent component group HF ₁ is shifted to the right by one antenna element, the second horizontal independent component group HF ₂ is shifted to the right by two antenna elements, and the kth horizontal independent component group HF _k is shifted to the right by k antenna elements. It is assumed that there is. Further, the number of element components in each horizontal independent component group HF is N of "0", "1", "2" ... "m" ... "N-1". Then, in each of the horizontally independent component groups HF _{0 to k} , as shown in FIG. 10, the 0th (reference) element component (“0” in the figure) is rotated in 0 phase (not rotated), and the first The phase of the element component (“1” in the figure) is rotated by λ / dN (λ: wavelength, d: element spacing, N: number of elements), and the second element component (“2” in the figure) is 2λ /. The phase is rotated by dN, and the phase of the mth element component (“m” in the figure) is rotated by mλ / dN.

Then, in order to shift the horizontal independent component group HF _{0 to k} in the horizontal direction so that the horizontal independent component group HF _{0 to k} overlap more in the vertical direction, for example, the left end of the 0th horizontal independent component group HF ₀ is used. The left end of the other horizontal independent component groups HF _{1 to k} may be aligned with. That is, the first horizontal independent component group HF ₁ is shifted to the left by one antenna element, the second horizontal independent component group HF ₂ is shifted to the left by two antenna elements, and the kth horizontal independent component group HF _k is shifted to the left by the k antenna. Move it to the left by the element.

In order to perform such movement, since the phase of each element component is rotated as described above, exp (-ikλm / dN) is applied to each element component by the multiplier (phase rotation unit) 52 shown in FIG. ). Specifically, as shown in FIG. 11, since exp (−i0λm / dN) = 1 is multiplied by each element component of the 0th horizontal independent component group HF ₀ , the value remains as it is. Next, for each element component of the first horizontal independent component group HF ₁ ,
exp (-iλm / dN)
m: 0 ~ (N-1)
You just have to ride. For example, the first element component is multiplied by exp (-iλ / dN), the second element component is multiplied by exp (-i2λ / dN), and the mth element component is multiplied by exp (-imλ / dN).

Similarly, each element component of the second horizontal independent component group HF ₂ is multiplied by exp (-i2λm / dN), and each element component of the kth horizontal independent component group HF _k is multiplied by exp (-ikλm / dN). Multiply. Specifically, in the case of the kth horizontal independent component group HF _k , the first element component is multiplied by exp (-ikλ / dN), the second element component is multiplied by exp (-i2kλ / dN), and the m. The element component of is multiplied by exp (-imkλ / dN).

By shifting the horizontal independent component groups HF _{1 to k} in this way, as shown in FIG. 1, all the horizontal independent component groups HF _{0 to k} are overlapped in the vertical direction, that is, the horizontal independent components in the vertical direction. The overlap of groups HF _{0 to k} is increased. After that, the element components (independent components) connected in the vertical direction are Fourier-transformed column by column ("0", "1", "m", etc.) by the vertical Fourier transform (FFT) 53.

A process when such a process is actually performed will be described with reference to a simple example shown in FIG. Here, the existing antenna element RFs of the horizontal antenna element groups HA ₀ and HA ₁ are arranged so that the independent components in the covariance matrix are continuous, and some columns L (for example, the column “1”) are arranged. The horizontal antenna element groups HA ₀ and HA ₁ are displaced from each other so that the independent components in the covariance matrix are continuous with respect to the existing antenna element RF. Further, the phase is shifted by α (corresponding to mλ / dN in the above example) between the antenna elements in the horizontal direction, and the phase is shifted by β (corresponding to kλ / dN in the above example) between the antenna elements in the vertical direction. Suppose you are.

In the case of such an antenna configuration, the index of the independent component of the covariance matrix for all the existing antenna elements RF is the matrix as shown in FIG. Here, the value (number of α, β) corresponding to the arrangement position of the real antenna element RF is described in the uppermost row in the figure. That is, "0" for the real antenna element RF ₀₀ , "α" for the real antenna element RF ₁₀ , "3α" for the real antenna element RF ₃₀ , "α + β" for the real antenna element RF ₁₁ , and "2α + β" for the real antenna element RF ₂₁ . , "4α + β" for the existing antenna element RF ₄₁ is described. Further, the value (minus value) of the complex conjugate corresponding to the value corresponding to the arrangement position of the real antenna element RF is described in the leftmost column in the figure. The matrix of FIG. 13 corresponds to a numerical value (independent component exponent) obtained by vertically and horizontally adding these values described in a matrix.

Then, when these independent components are arranged in the vertical direction for each of the horizontal independent component groups HF _{-1 to 1} corresponding to the horizontal antenna element group HA ₀ and HA ₁ , the arrangement is as shown in FIG. Here, the horizontal independent component group HF ₀ corresponds to the horizontal antenna element group HA ₀ , the horizontal independent component group HF ₁ corresponds to the horizontal antenna element group HA ₁ , and the horizontal independent component group HF _-1 corresponds to the horizontal antenna element group HA. Corresponds to the complex conjugate of ₁ .

In this way, the six existing antenna elements RF form a two-dimensional array antenna in which 21 antenna elements are arranged in a grid pattern in the vertical and horizontal directions. Further, for each antenna element, the element component of each antenna element can be calculated by shifting the phase by the value of the corresponding position (the number of α and β). That is, a table showing the amount of deviation as shown in FIG. 14 is created and stored in advance, and when a signal is received, each element component is Fourier-transformed laterally by the horizontal Fourier transformer 51, and the phase of each element component is phased according to this table. Then, each element component may be Fourier-transformed in the vertical direction by the vertical Fourier transformer 53.

As described above, according to the antenna device 2, the real antenna element RF is arranged only in a part of the arrangement positions P in each horizontal antenna element group HA, and the virtual antenna element VF is arranged in the other arrangement positions P. And a plurality of horizontal antenna element group HAs are arranged in the vertical direction so that the ends are displaced in the horizontal direction, so that the orientation and height can be detected with a small number of existing antenna element RFs. In addition, it is possible to cope with a larger opening with a small number of existing antenna element RFs.

That is, even if there is a virtual antenna element VF in which the real antenna element RF is not arranged in each horizontal antenna element group HA, the real antenna element RF (in other words, the virtual antenna element VF) has a continuous independent component in the covariance matrix. If they are arranged, the KR product expansion array is formed, which is equivalent to the one in which the real antenna element RF is arranged at all the arrangement positions P, and the number of arrangements of the real antenna element RF can be reduced. .. Similarly, for the real antenna element RF in any of the rows, if the real antenna element RF is arranged so that the independent components in the covariance matrix are continuous, a KR product expansion array is formed and the real antenna is formed. The number of arrangements of the element RF can be reduced.

Further, the independent components of the codispersion matrix for all the existing antenna elements RF are arranged in the vertical direction for each horizontal independent component group HF, and the horizontal independent component group HF is horizontally arranged so that the overlap of the horizontal independent component group HF in the vertical direction increases. By shifting in the direction, it is possible to construct a two-dimensional array antenna equivalent to the arrangement of wide existing antenna elements RF in the vertical and horizontal directions. Then, even if the real antenna element RF cannot be ideally arranged due to restrictions such as the size of the real antenna element RF, the real antenna element RF can be arranged so as to satisfy the above requirements. It is possible to construct a desired two-dimensional array antenna.

Here, the effect when the antenna device 2 is applied to the MIMO radar will be described. Due to restrictions such as the size and shape of the arrangement space, the size of the existing antenna element RF, and the size of the feeding port, for example, as shown in FIG. 15, 6 existing antenna elements for transmission RF1 and 8 existing antenna elements for reception are used. It is assumed that the antenna element RF2 is arranged. In this case, as shown in FIG. 16, 48 (= 6 × 8) antenna elements are produced by receiving the transmission signal from each transmission real antenna element RF1 by each reception real antenna element RF2 and processing the signal. A virtual array antenna to have is formed. In FIG. 16, only the representative position is shown, ignoring the size of the antenna element.

Further, when the above processing in the present embodiment is applied to this virtual array antenna, as shown in FIG. 17, a virtual array antenna having a 385 (= 11 × 35) antenna element is formed. Can be done. Here, reference numeral SZ1 in FIG. 17 indicates a limit size (= 48 elements) of the MIMO radar alone, and SZ2 indicates a hardware mounting size (= 6 × 18 elements). As is clear from this, even if the hardware mounting size SZ2 in which the antenna element is arranged is small, a larger two-dimensional array antenna 4 can be configured.

Although the embodiment of the present invention has been described above, the specific configuration is not limited to the above-described embodiment, and even if there is a design change or the like within a range that does not deviate from the gist of the present invention. Included in the invention.

1 Radar device 2 Antenna device 3 Signal processing device 4 Two-dimensional array antenna 5 Processing unit 51 Horizontal Fourier transformer 52 Multiplier (phase rotation unit)
53 Vertical Fourier Transformer P0 to P14 Arrangement position RF Real antenna element VF Virtual antenna element HA Horizontal antenna element group HF Horizontal independent component group

Claims (4)

A virtual antenna in which a plurality of arrangement positions are provided in the horizontal direction, the real antenna element is arranged in a part of the arrangement positions, and the real antenna element is not arranged in the other arrangement positions. A group of horizontal antenna elements in which elements are arranged is provided with a two-dimensional array antenna in which a plurality of elements are arranged in the vertical direction and whose ends are arranged so as to be displaced in the horizontal direction, and a processing unit.
Each of the horizontal antenna element groups is
The real antenna element is arranged so that the signal of the virtual antenna element can be interpolated by utilizing the phase difference between the real antenna elements .
A matrix in which the numerical values corresponding to the arrangement positions of the existing antenna elements are arranged in the top row, and the numerical values corresponding to the arrangement positions of the actual antenna elements are arranged in the leftmost column and these numerical values are vertically and horizontally added. The independent components of the covariance matrix, which are the numerical values in, are serial numbers.
In addition, the independent components of the covariance matrix of the existing antenna elements in any of the columns arranged in the vertical direction are arranged so as to be sequentially numbered in the horizontal direction.
The processing unit
The independent components of the covariance matrix for all the existing antenna elements are arranged in the vertical direction for each horizontal independent component group corresponding to the horizontal antenna element group, and a Fourier transform is performed for each horizontal independent component group.
Based on the result of the Fourier transform, the horizontally independent component groups are shifted in the horizontal direction so that the horizontal independent component groups overlap in the vertical direction.
Fourier transform the horizontally independent component group shifted in the horizontal direction in the vertical direction.
An antenna device characterized by that. Arbitrary arrangement based on a calculation rule that uses the position of a specific real antenna element as a reference point and generates a signal of a virtual antenna element using the phase difference determined by the relative position of another real antenna element from that reference point. The first aspect of claim 1 is to maintain a correspondence between existing antenna elements for generating a signal of a virtual antenna element at a position and generate a signal of the virtual antenna element based on the held correspondence. The antenna device described. The processing unit performs phase rotation based on each arrangement position on the result of the horizontal Fourier transform, and sets the horizontally independent component group in the horizontal direction so that the overlap of the horizontally independent component group in the vertical direction increases. The antenna device according to claim 1 or 2 , wherein the antenna device is shifted to a horizontal position. The antenna device according to any one of claims 1 to 3 , wherein the processing unit can perform processing in which the order of processing in the horizontal direction and the processing in the vertical direction is exchanged.

Images