JP2001119229A - Array antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an array antenna capable of two-dimensionally expanding antenna open surfaces and also suppressing a side lobe. SOLUTION: This array antenna device 1 has a plurality of sub arrays 2 and houses and stores the plurality of sub arrays 2 in a structure 3. The arrays 2 have an element antenna composed of vertical/horizontal polarization element antennas. Then, the arrays 2 can be housed in the structure in square shape. Therefore, the antenna open surfaces 4 can be two-dimensionally expanded. Because the structure 3 has strength on behalf of the device 1, it is possible to make narrow intervals of the element antennas facing each other interposing a boundary of sub arrays between them. The element intervals of the element antennas can be made close in a uniform way with the antenna open surfaces 4 as a whole. Therefore, a side lobe level can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an array antenna device for detecting a target such as an airplane.

[0002]

2. Description of the Related Art Conventionally, there has been known an array antenna device for detecting a target such as an airplane by arranging a plurality of element antennas in an array to form a beam. The array antenna device is installed, for example, in a building constructed in a position where the detection direction can be seen, or installed on a dedicated antenna installation stand provided in a position where the detection direction can be seen.

[0003] On the other hand, the detection direction is not invariable but changes according to a user's request or the like, and it is necessary to change a test site in order to test antenna performance before actual operation. Therefore, the conventional array antenna device is configured to be easily carried by a transport truck or the like.

FIG. 19 is a perspective view showing a configuration of a conventional array antenna device. This array antenna device 90
Is constructed by connecting a plurality of sub-arrays 91 via connection fittings 92 so that they can be disassembled during transportation. The sub-array 91 has an array antenna surface 94 in which a plurality of element antennas (for example, vertically polarized element antennas) 93 that form a beam of a single polarized wave (for example, vertically polarized wave) are mounted in an array at predetermined element intervals.
have. The plurality of sub-arrays 91 are connected with the array antenna surfaces 94 all facing in the same direction, and constitute an antenna aperture surface 95 as a whole. Reference numeral 96 denotes a radome for protecting the array antenna surface 94.

[0005]

In the array antenna device 90, the side surface 91a of the subarray 91 is provided.
Can secure the strength as an array antenna device. Therefore, the sub-array 91 cannot be assembled in the vertical direction. On the other hand, in order to improve the antenna gain, it is necessary to connect the sub-arrays 91 in the vertical and horizontal directions, and to expand the antenna aperture 95 in the vertical and horizontal directions.

On the other hand, in the array antenna device 90,
In consideration of the strength of the array antenna device, the sub-arrays 91 can be connected only in the horizontal direction, and cannot be connected in both the vertical and horizontal directions. That is, the antenna opening surface 95 cannot be expanded in the vertical and horizontal directions. Therefore, it is difficult to improve the antenna gain. Therefore, there is a problem that it is difficult to increase the detection distance of the target and to properly detect a small target.

In the above array antenna device 90,
There is also a problem that it is difficult to improve the ability to detect a target because the configuration only connects a plurality of sub-arrays 91.

More specifically, the array antenna device 90
Must be secured by the sub-array 91 itself. Therefore, the partition of the sub-array 91 is necessarily thick. On the other hand, in order to secure the intended detection capability, the number of element antennas 93 cannot be reduced unnecessarily, and the element spacing cannot be easily widened according to the thickness of the partition wall of the sub-array 91.

Therefore, the spacing between element antennas 93 in the entire array antenna device 90 is not uniform. More specifically, as shown in FIG. 20, for example, an element interval k1 (for example, k1 = 200 (m)) between element antennas 93 opposed to each other across a partition wall 91b between two sub-arrays 91.
m)) is wider than the interval k2 between the element antennas 93 in the same sub-array 91 (for example, k2 = 110 (mm)).

If the element spacing becomes non-uniform as a whole,
The side lobe level of the array antenna device 90 increases. More specifically, when the element spacing is uniform, the difference between the main lobe level and the side lobe level is R1 (for example, R1 = 30 dB) as shown in FIG. If different, the difference between the main lobe level and the side lobe level is R1 as shown in FIG.
R2 (for example, R2 = 20 dB).

Thus, if the element spacing is not uniform,
Since the side lobe level increases, there is a problem that it is difficult to improve the target detection ability.

It is an object of the present invention to solve the above-mentioned technical problems and to provide an array antenna device capable of two-dimensionally widening an antenna aperture surface and suppressing a side lobe level. .

[0013]

According to the present invention, there is provided an array antenna apparatus comprising: a plurality of element antennas each including a vertical polarization element antenna and a horizontal polarization element antenna; A plurality of sub-arrays each having an array antenna surface mounted in an array shape, and a plurality of compartments are defined in a frame having an outer shape corresponding to an antenna opening surface of a predetermined shape, and each sub-array is formed in each compartment. And a structure for accommodating and holding each.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a perspective view showing an external configuration of an array antenna device according to Embodiment 1 of the present invention. The array antenna device 1 is for detecting a target such as an airplane, and includes a plurality (nine in the first embodiment) of sub-arrays 2.
Is accommodated in one structure 3 and attached. More specifically, the array antenna device 1 has a rectangular parallelepiped shape. One surface of the array antenna device 1 is an antenna opening surface 4. The antenna aperture surface 4 is configured by two-dimensionally arranging an array antenna surface (not shown) of the plurality of sub-arrays 1, and extends in a horizontal direction h and a vertical direction v when viewed from the front direction z. It has a square shape along. That is, the array antenna device 1 has a square antenna opening surface 4, and detects a target by forming a pencil beam having a desired shape in a predetermined direction from the antenna opening surface 4.

FIG. 2 is a perspective view showing the structure of the structure 3. The structure 3 is a rectangular parallelepiped that constitutes the appearance of the array antenna device 1 shown in FIG. 1 and has a square shape along the horizontal direction h and the vertical direction v when viewed from the front direction z. The structure 3 is made of a material such as an aluminum alloy, and is configured to have sufficient strength against earthquake, rain, snow, and the like.

The structure 3 includes a plurality of sub arrays 2
Is stored and held in a predetermined two-dimensional pattern,
This is commonly used for a plurality of sub-arrays 2. More specifically, the structure 3 includes a frame 10. The frame body 10 has an outer shape having a shape corresponding to the antenna opening surface 4. More specifically, the frame 10
Has a square outer shape along the vertical direction v and the horizontal direction h in a front view.

In the frame 10, a plurality (the first embodiment)
9 compartments 11 are defined. Compartment 11
Is for accommodating the sub-array 2. The plurality of compartments 10 are rectangular parallelepiped spaces of the same size, and have a square shape when viewed from the front direction z. The plurality of compartments 11 are partitioned and formed in a square shape (matrix shape) along a vertical direction v and a horizontal direction h with a partition wall 12 interposed therebetween. The end surface 13 of the partition wall 12 is a mounting surface of the sub-array 2 housed in the compartment 11 and has a plurality of bolt holes (not shown).

FIG. 3 is a perspective view showing the structure of the sub-array 2. The subarray 2 has a rectangular parallelepiped shape, one surface of which is an array antenna surface 20. More specifically, the sub-array 2 includes a frame 21, an antenna 22 provided on the frame 21, a mounting member 23 for mounting the sub-array 2 to the structure 3, and an antenna 22.
And a radome 24 for protecting the

The frame 21 is a rectangular parallelepiped having a space inside, and is made of, for example, an aluminum alloy.
The frame 21 has a square shape in a front view. The antenna section 22 has an array antenna surface 20 on which a plurality of element antennas 25 are arranged in an array. The array antenna surface 20 has a square shape along the horizontal direction h and the vertical direction v when viewed from the front direction z,
It is formed along the opening surface of the frame 21. The element antenna 25 includes a vertical polarization element antenna 25a and a horizontal polarization element antenna 25b. More specifically, the vertical polarization element antenna 25a is arranged along the vertical direction v, and the horizontal polarization element antenna 25b is arranged along the horizontal direction h. The vertical polarization element antenna 25a and the horizontal polarization element antenna 25b are arranged so as to be orthogonal at the center of each other. Accordingly, when viewed from the front direction z, the element antenna 25 has a cross shape.

Module 2 for feeding power to element antenna 25
6 is a perspective view showing the configuration of the sub-array 2 with the element antenna 25 removed, and is provided on the sub-array inner side of the element antenna 25 as shown in FIG.
The module 26 amplifies the transmission signal and modulates the element antenna 25
Power. As a result, the element antenna 25 forms the transmission signal into two polarizations, that is, a vertically polarized wave and a horizontally polarized wave, and radiates it to space.

Returning to FIG. 3, the mounting member 23 has a square frame shape, and is mounted on the frame body 21 so as to surround the square array antenna surface 20. More specifically, a portion corresponding to each side of the mounting member 23 has a linear shape. The mounting member 23 has bolt holes 23a formed at predetermined intervals.

The radome 24 is attached to the frame 21 in a state of being fitted from the front of the frame 21 so as to shield the array antenna surface 20 from the outside. Transmits horizontally polarized waves.

The array antenna device 1 is assembled as follows. First, the subarray 2 is assembled. The sub-array 2 is assembled by housing the antenna unit 22 including the module 26 and the element antenna 25 in the frame 21 to which the mounting member 23 is mounted, and then mounting the radome 24 from the front.

Next, the sub-array 2 is mounted on the structure 3. More specifically, the sub-array 2 is housed in the compartment 11, and the mounting member 23 is brought into contact with the mounting surface 13 in a state where the bolt holes 23a of the mounting member 23 and the bolt holes of the mounting surface 13 are aligned. Next, the bolts are screwed into the bolt holes 23 a of the mounting member 23 and the bolt holes of the mounting surface 13. By doing so, the subarray 2 can be attached to the structure 3, and the array antenna device 1 is assembled.

The disassembly of the array antenna device 1 is achieved by reversing the above assembly procedure. That is, this is achieved by removing the bolts and extracting the sub-array 2 from the structure 3.

FIG. 5 is a front view showing the configuration near the boundary of subarray 2 after assembling array antenna device 1. However, FIG. 5 shows a state in which the radome 24 is removed for convenience.

The adjacent sub-array 2 is provided with
Is attached to the structure 3 in a state where the outer peripheral edges thereof are in contact. On the other hand, the element antennas 25 are arranged in a grid along the horizontal direction h and the vertical direction v at every predetermined element interval d1. In this case, the element interval d1 is defined as the intersection 30A between the vertical polarization element antenna 25a and the horizontal polarization element antenna 25b of a certain element antenna 25, and the vertical polarization element antenna 25a of the element antenna 25 adjacent to the element antenna 25. And the intersection 30B between the horizontal polarization element antenna 25b and the horizontal polarization element antenna 25b. Embodiment 1
Then, the element interval d1 is, for example, 110 (mm).

On the other hand, in the first embodiment, a plurality of sub-arrays 2
And the structure 3 has the strength as the array antenna device 1. Therefore, the first embodiment
In the example, the thickness of the sub-array 2 is set to be thin. For example, the thickness of the sub-array 2 is 10 (mm). In the first embodiment, the thickness of the partition wall 12 is set to be thin. For example, the thickness of the partition 12 is 40 (mm). Therefore, the distance d2 between two element antennas (hereinafter, referred to as “boundary element antennas”) 25 opposed to each other with the partition wall 12 interposed therebetween, that is, the distance d2 between the intersections 30B and 30C.
Is smaller than before, for example, 150
(mm).

As described above, according to the first embodiment, since the vertical polarization element antenna 25a and the horizontal polarization element antenna 25b are configured as one element antenna 25, a plurality of sub-arrays 2 are And can be assembled along the horizontal direction h. Therefore, a plurality of sub-arrays 2 can be assembled in a square shape,
As a result, a square antenna opening surface 4 can be formed.
That is, the antenna opening surface 4 can be expanded in the vertical direction v and the horizontal direction h.

Therefore, the antenna opening surface 4 can be expanded to an arbitrary size. Therefore, the antenna gain can be improved. For example, if the area of the antenna aperture 4 is increased from S1 to S2, the antenna gain is 10 log (S
1 / S2) Increase in dB. That is, if the area of the antenna aperture 4 is doubled, the antenna gain increases by 3 dB. In this case, if the number of modules 26 is also doubled, the transmission power can be increased by 3 dB, and as a result, the gain of the array antenna device 1 is increased by 6 dB. Therefore, a relatively small target such as a target moving at high speed can be detected well. In addition, the detection distance of the target can be increased, and a distant target can be detected well.

Further, since a plurality of sub-arrays 2 constituting the antenna aperture surface 4 are accommodated in the structure 3 and the structure 3 has the strength as the array antenna device 1, the distance d2 between the boundary element antennas 25 is reduced. It can be smaller than before. Therefore, it is possible to make the element spacing of the element antenna 25 close to a uniform one as the whole antenna opening surface 4. Therefore, the side lobe level can be suppressed. Therefore, the target detection ability can be improved.

More specifically, as shown in FIG. 6, when the difference between the main lobe level and the side lobe level is R3 (for example, R3 = 20 dB) in the conventional case, the configuration as in the first embodiment is used. Is adopted, the difference can be increased to R4 (for example, R4 = 25 dB) larger than R3. In this case, assuming that the target can be detected at the level indicated by the two-dot chain line, the target cannot be detected well because the side lobe level is conventionally equal to or higher than the level of the two-dot chain line. In the first embodiment, since the side lobe level is lower than the level indicated by the two-dot chain line, the target can be detected well.

Further, the sub-arrays 2 can be individually removed from the structure 3 to maintain the antenna section 22. Therefore, maintenance and inspection of the antenna unit 22 can be easily performed. Therefore, the maintenance of the entire array antenna device 1 can be improved.

Embodiment 2 FIG. 7 is a perspective view showing a configuration of a sub-array according to Embodiment 2 of the present invention. 7, the same reference numerals are used for the same functional parts as in FIG.

In the first embodiment, the portion corresponding to each side of the mounting member 23 is formed in a straight line. On the other hand, in the second embodiment, a portion corresponding to each side of the mounting member 23 is formed in a stepped shape. More specifically, the mounting member 23 according to the second embodiment includes a trapezoidal concave portion 41 a and a trapezoidal convex portion 41 between each of the four vertexes 40.
b are alternately arranged. More specifically, when the sub-array 2 is housed in the structure 3, the mounting member 23 according to the second embodiment includes the recess 41 a of the mounting member 23 of a certain sub-array 2 and the mounting member of the sub-array 2 adjacent to the sub-array 2. 23 convex portions 41
b are engaged with each other.

As described above, according to the second embodiment, the mounting members 23 of two adjacent sub-arrays 2 can be engaged with each other in the housed state in the structure 3. Therefore, the thickness of the partition wall 12 can be reduced as compared with the first embodiment. Therefore, the boundary element antenna 2
5 can be reduced to, for example, 125 (mm). Therefore, the element spacing as the whole antenna aperture surface 4 can be made uniform. Therefore, the side lobe level can be favorably suppressed, and the ability to detect a target can be improved.

As the stepped shape, any shape other than the trapezoidal shape, such as a semicircle, a square, a triangle, and a polygon, can be adopted. In short, a certain subarray 2
Any shape can be used as long as the concave portion 41a of the mounting member 23 and the convex portion 41b of the mounting member 23 of the adjacent subarray 2 can be engaged.

Third Embodiment FIG. 8 is a front view showing a configuration of a subarray according to a third embodiment of the present invention. 8, the same reference numerals are used for the same functional parts as in FIG.

In the first and second embodiments, the element antenna 25 is formed in a cross shape when viewed from the front. On the other hand, in the third embodiment, the element antenna 25 is formed in a cross shape in a front view.

More specifically, the element antenna 25 according to the third embodiment is in a state where the cross-shaped element antenna 25 according to the first embodiment is rotated by 45 degrees around the intersection. In other words, the element antenna 25 is formed in a cross shape with respect to the peripheral edge 20a of the array antenna surface.

Accordingly, the width of the element antenna 25 along the horizontal direction h and the height along the vertical direction v are shorter than in the case of the cross shape. More specifically, for example, as shown in FIG. 9, when the width along the horizontal direction h in the case of a cross is K3 (for example, K3 = 100 (mm)), the horizontal direction h in the case of an x-shape The width along is K3
K4 (for example, K4 = 71 (mm)).

Therefore, the x-shaped element antenna 25 is
It can be arranged at a position closer to the periphery of the array antenna surface 20 than in the case of the cross shape. On the other hand, the element interval d1 is 2
Since the distance between the intersections of the two element antennas 25 is provided, by disposing the boundary element antenna 25 near the periphery of the array antenna surface 20, the interval between the boundary element antennas 25 can be reduced. Therefore, it is possible to make the element spacing closer to the entire antenna aperture surface 4.
Therefore, the side lobe level can be further suppressed, and the ability to detect a target can be further improved.

By configuring the element antenna 25 in an x-shape, it is possible to transmit not only vertically polarized waves and horizontally polarized waves but also circularly polarized waves. Therefore, it is possible to provide an array antenna device that can appropriately respond to a user's request.

Fourth Embodiment FIG. 10 is a front view showing a configuration of a subarray according to a fourth embodiment of the present invention. 10, the same reference numerals are used for the same functional parts as in FIG.

In the first or second embodiment, all the element antennas 25 are formed in a cross shape. On the other hand, in the fourth embodiment, the vertical polarization element antenna 25a and / or the horizontal polarization element antenna 25b of the boundary element antenna 25 are offset toward the periphery of the array antenna surface 20, so that the boundary element antenna 25 is It has a shape other than a cross.

More specifically, in the subarray 2 according to the fourth embodiment, the boundary element antennas 25 except for those arranged at the four corners are arranged such that the vertical polarization element antenna 25a is located at the center position of the horizontal polarization element antenna 25b. And a predetermined offset value (for example, 35 (mm)) at a position closer to the peripheral edge 20a of the array antenna surface 20. Embodiment 4
Then, the offset value is set to the horizontal polarization element antenna 25b.
, And thus the boundary element antenna 25 is T-shaped.

Further, in the boundary element antennas 25 arranged at the four corners, the horizontal polarization element antenna 25b in addition to the vertical polarization element antenna 25a has a predetermined offset value (for example, 35 (mm))
In the fourth embodiment, the offset value is set to half the length of the vertical polarization element antenna 25a. Therefore, the boundary element antennas 25 arranged at the four corners are L-shaped.

As described above, according to the fourth embodiment, the intersection of the vertical / horizontal polarization element antennas 25a and 25b in the boundary element antenna 25 is shifted toward the peripheral edge 20a of the array antenna surface 20. Therefore, the interval between the boundary element antennas 25 can be reduced as compared with the case where they are arranged in a cross shape as in the first embodiment. More specifically, for example, as shown in FIG. 11A, the interval between the cross-shaped boundary element antennas 25 is d2 (for example, d2 = 2).
00 (mm)), assuming that the offset value is Δd (for example, Δd = 35 (mm)), the distance d4 between the boundary element antennas 25 when the offset is performed is as shown in FIG.
As shown in (b), d2-2Δd (for example, d4 = 13
0 (mm)).

Therefore, the distance between the boundary element antennas 25 can be made closer to the element distance between the two element antennas 25 arranged in the same subarray 2. therefore,
The side lobe level can be further suppressed, and the ability to detect a target can be further improved.

By offsetting the boundary element antenna 25, the element distance d5 between the boundary element antenna 25 and the adjacent element antenna 25 is reduced to another element distance d.
May be wider than one. However, even in this case, its spread is sufficiently allowable as compared with the case where the partition wall is sandwiched, so that the influence on the antenna characteristics can be ignored.

Fifth Embodiment FIG. 12 is a front view showing a configuration of a subarray according to a fifth embodiment of the present invention. 12, the same reference numerals are used for the same functional parts as in FIG.

In the first to fourth embodiments, the case where sub-arrays 2 having the same shape and the same size are applied is taken as an example. On the other hand, in the fifth embodiment, as the subarray 2, the subarrays 5 having different shapes and sizes are used.
0, 51 and 52 are applied.

More specifically, the array antenna device 1 according to the fifth embodiment includes a subarray 50 having an array antenna surface 50a and a subarray 51 having an array antenna surface 51a having an area smaller than the array antenna surface 50a. And a sub-array 52 having an array antenna surface 52a having a smaller area than the array antenna surface 51a.

In the fifth embodiment, three sub-arrays 5
0, 51, 52, the subarray 50 having the largest area.
Is accommodated in the center of the structure 3, and the remaining two types of sub-arrays 51 and 52 are accommodated around the sub-array 50. Therefore, in the following, for convenience, sub-array 50 is referred to as central sub-array 50 and sub-array 51
Are referred to as a first peripheral sub-array 51, and the sub-array 52 is referred to as a second peripheral sub-array 52.

More specifically, the central sub-array 50
Has a square array antenna surface 50a.
The length of each side portion 50b of the array antenna surface 50a is longer than that of the first embodiment by K5 (for example, K5 = 1 (m)). The maximum length of each side 50b of the central sub-array 50 is set to the maximum length that satisfies the traffic restrictions of the Road Traffic Law. Specifically, the Road Traffic Law stipulates that the height of the transported luggage from the ground is 3.8 m at the maximum. Therefore, taking into account the height of the carrier of the transport truck, the length obtained by adding the height to the length of each side 50b of the central sub-array 50 is 3.8 (m). The maximum length is 50b. Of course, if the maximum length from the ground becomes less than 3.8 (m) or more due to the revision of the Road Traffic Law, each side of the central sub-array 50 will be set to a value that complies with it. Set the maximum length of 50b.

The first peripheral sub-array 51 has a rectangular array antenna surface 51a. The array antenna surface 51a has a long side 51b having substantially the same length as each side 50b of the central sub-array 50, and a short side perpendicular to the long side 51b and shorter than the long side 51b. Side 51
c. The second peripheral sub-array 52 has a square array antenna surface 52a. Array antenna surface 5
The length of each side portion 52b of the first peripheral sub-array 51
Are set to have substantially the same length as the short side portion 51c.

FIG. 13 is a front view showing the structure of the structure 3 according to the fifth embodiment. Structure 3
In the frame 10, compartments 53, 5 having three kinds of opening areas are provided.
4 and 55 are defined by partition walls 12. Compartment 5
Numeral 3 is for accommodating the central sub-array 50 and has an opening 53a having the largest area. The opening 53a has a square shape in a front view. The compartment 54 accommodates the first peripheral sub-array 51 and has an opening 54a having an area smaller than the opening 53a. The opening 54a has a rectangular shape in a front view. The compartment 55 is for accommodating the second peripheral sub-array 52, and has an opening 55a having an area smaller than the opening 54a. The opening 55a has a square shape in a front view.

In this configuration, one compartment 53 is arranged at the center, and four compartments 54 and 55 are arranged around the compartment 53 with the partition wall 12 interposed therebetween. Therefore, hereinafter, for convenience, the compartment 53 is referred to as the central compartment 53, the compartment 54 is referred to as the first peripheral compartment 54, and the compartment 55 is referred to as the second peripheral compartment 55.

More specifically, the four first peripheral compartments 54
Are arranged such that their long sides 54b are along each side 53b of the central compartment 53, respectively. Further, the second peripheral compartment 55 is arranged such that two continuous sides 55b are along each short side 54c of the two first peripheral compartments 54. The entire opening 53a, 54a, 55a has a square shape when viewed from the front direction z.

As described above, according to the fifth embodiment, the central sub-array 50 and the first and second peripheral sub-arrays 5
The partition wall 12 corresponding to the boundary surface between the antenna apertures 1 and 52 can be located on the peripheral side of the antenna opening surface 4 as compared with the case of the first embodiment. Therefore, the main lobe level can be increased and the side lobe level can be reduced. Therefore, the antenna gain of the array antenna device 1 can be improved. For example, the antenna gain of the array antenna device 1 is 1d as compared with the case of the first embodiment.
B or more can be improved. Therefore, it is possible to improve the ability to detect a target.

As shown by a two-dot chain line in FIG. 13, the second peripheral compartment 54 is further divided into two and the first peripheral compartment 5 is divided into two.
3, the second peripheral sub-array 52 may be the same size as the first peripheral sub-array 51.

Sixth Embodiment FIG. 14 is a front view showing a configuration of a sub-array according to a sixth embodiment of the present invention. 14, the same reference numerals are used for the same functional parts as in FIG.

In the fifth embodiment, the central sub-array 50
Partition wall 1 between first and second peripheral sub-arrays 51 and 52
2 closer to the peripheral side of the antenna aperture 4,
The side lobe level is suppressed. On the other hand, in the sixth embodiment, the side lobe level is suppressed by reducing the area of the mounting surface 13 which is the boundary surface between the central sub-array and the peripheral sub-array.

More specifically, the array antenna device 1 according to the sixth embodiment has one sub-array 60 and four sub-arrays 61. One subarray 60
Is a square array antenna surface 60a in a front view.
It has. The other sub-array 61 has a trapezoidal array antenna surface 61a in a front view. In the sixth embodiment, the sub-array 60 is arranged at the center of the structure 3, and the four sub-arrays 61 are arranged around the sub-array 60. Therefore, hereinafter, for convenience, the sub-array 60 is referred to as a central sub-array 60, and the sub-array 61 is referred to as a peripheral sub-array 61.

More specifically, the array antenna surface 60a of the central sub-array 60 has four sides 60b. The array antenna surface 61a of the peripheral sub-array 61 is
Side 6 of array antenna surface 60a of central subarray 60
0b, a lower side 61c provided at a position facing the upper side 61b, and a hypotenuse 6 connecting each vertex of the upper side 61 and each vertex of the lower side 61c.
1d.

FIG. 15 is a front view showing the structure of the structure 3 according to the sixth embodiment. Structure 3
One compartment 62 and four compartments 63 are formed in the frame body 10 with the partition walls 12 interposed therebetween. One compartment 62
Is provided at the center of the structure 3 when viewed from the front and has a square opening 62a. The other compartment 63 is for accommodating the peripheral sub-array 61 and is disposed around the compartment 62 in a front view, and has a trapezoidal opening 63a.
Therefore, hereinafter, for convenience, the compartment 62 is referred to as the central compartment 6.
2, and the compartment 63 is referred to as a peripheral compartment 63.

More specifically, the four peripheral compartments 63
Have an upper side 63b and a lower side 63c, respectively. The upper side 63b is provided along each side 62b of the central compartment 62. The lower side 63c is provided along each side 10a of the frame 10. Each of these accommodation spaces 6
The mounting surface 13 is provided between the openings 62a and 63a of the second and third openings 63a. The entire opening including the opening 62a of the central compartment 62 and the opening 63a of the peripheral compartment 63 is located in the front direction z.
It has a square shape when viewed from above.

The peripheral sub-array 61 has an upper side 61
b and the lower side 61c are accommodated in the peripheral compartment 63 along the upper side 63b and the lower side 63c, respectively.
The structure 3 is attached to the structure 3 by attaching the attachment member 23 to the attachment surface 13.

As described above, according to the sixth embodiment, the ratio of the mounting surface 13 to the entire antenna opening surface 4 can be reduced as compared with the case of the first embodiment. Therefore, the side lobe level can be suppressed. Therefore, the ability to detect a target can be improved.

It is needless to say that the size of the central sub-array 60 may be larger than the size according to the first embodiment. In this case, since the position of the mounting surface 13 is closer to the peripheral edge of the structure 3, the side lobe level can be further reduced. Therefore, the ability to detect the target can be further improved.

Seventh Embodiment FIG. 16 is a front view showing a configuration of a subarray according to a seventh embodiment of the present invention. In FIG. 16, the same reference numerals are used for the same functional parts as in FIG.

In the sixth embodiment, the case where the central sub-array 60 is square and the peripheral sub-array 61 is trapezoidal when accommodated in the structure 3 is described as an example. On the other hand, in the seventh embodiment, the central sub-array has a rhombic shape when housed in the structure 3,
Four peripheral sub-arrays are arranged so as to surround the periphery of the central sub-array.

More specifically, the array antenna device 1 according to the seventh embodiment includes one sub-array 70 and four sub-arrays 71. One sub-array 70
Is a square array antenna surface 70a in a front view.
It has. The other sub-array 71 has a pentagonal array antenna surface 71a in a front view. In the seventh embodiment, the sub-array 70 is arranged at the center of the structure 3, and four sub-arrays 71 are arranged around the sub-array 70. Therefore, in the following, the sub-array 70 will be referred to as a central sub-array 70 and the sub-array 71 will be referred to as a peripheral sub-array 71 for convenience.

More specifically, the array antenna surface 70a of the central sub-array 70 has four sides 70b. The array antenna surface 71a of the peripheral sub-array 71 is
Side 7 of array antenna surface 70a of central sub-array 70
0b, two oblique sides 71b having the same length as 0b, and two first linear portions 71c continuous from each vertex of the oblique side 71,
One end extends perpendicularly from the vertex of the first straight portion 71c, and the other end has two second straight portions 71d connected to each other.

FIG. 17 is a front view showing the structure of the structure 3 according to the seventh embodiment. Structure 3
One compartment 72 and four compartments 73 are formed in the frame body 10 with the partition walls 12 interposed therebetween. One compartment 72
Is for accommodating the central sub-array 70, is disposed at the center of the structure 3 when viewed from the front, and has a rhombic opening 72a. The other compartment 73 is for accommodating the peripheral sub-array 71, and the compartment 7 is viewed from the front.
2, and has a pentagonal opening 73a.
Therefore, hereinafter, for convenience, the compartment 72 will be referred to as the central compartment 7.
2 and the compartment 73 is referred to as a peripheral compartment 73.

More specifically, the four peripheral compartments 73
Is a hypotenuse portion 73b, and two first straight portions 73c that are continuous from the vertices of the hypotenuse portion 73b.
One end extends at a right angle from the vertex of the first straight portion 73c and has two second straight portions 73d connected at the other end. The hypotenuse 73 b is provided along each side 72 b of the central compartment 72. The first straight portion 73c is provided in the central compartment 7
2 are provided so as to be orthogonal to each side 10a of the frame 10 from each vertex. The second straight portion 73d is provided along each side 10a of the frame 10. A mounting surface 13 is provided between the openings 62a and 63a of the housing spaces 62 and 63. The opening 62 of the central compartment 62
a and the opening 63a of the peripheral compartment 63
It has a square shape when viewed from the front direction z.

Note that the peripheral sub-array 71 is
b, the first straight portion 71c and the second straight portion 71d are respectively replaced by the oblique side 73b, the first straight portion 73c and the second straight portion 7
It is accommodated in the peripheral compartment 63 along 3d, and is attached to the structure 3 by attaching the attachment member 23 to the attachment surface 13.

As described above, according to the seventh embodiment, the ratio of the mounting surface 13 to the entire antenna opening surface 4 can be reduced as compared with the case of the first embodiment. Therefore, the side lobe level can be suppressed. Therefore,
The ability to detect a target can be improved.

Other Embodiments Embodiments of the present invention have been described above.
It goes without saying that the present invention can take other embodiments. For example, in the above embodiment, the element antenna 25 corresponding to one type of frequency is taken as an example. However, the present invention can be easily applied to a case where a plurality of frequencies are supported.

FIG. 18 is a front view showing the structure of the sub-array 2 in a case where a plurality of frequencies are supported. This sub-array 2 includes two types of first element antennas 80 and second element antennas 81 corresponding to two frequencies. The first element antenna 80 has a cross shape in which the size of the element antenna itself is relatively large, and forms a beam of the first frequency. The second element antenna 81 has a cross shape in which the size of the element antenna itself is relatively small, and forms a beam of a second frequency different from the first frequency. The second element antenna 81 is arranged at an empty position after the arrangement of the first element antenna 80 with an element interval shorter than the element interval of the first element antenna 80.

As described above, according to the subarray 2 corresponding to a plurality of types of frequencies, it is possible to detect even a target that is difficult to detect with one type of frequency. Therefore, a high-performance array antenna device 1 can be provided.

Further, by accommodating and attaching the sub-array 2 to the structure 3, the element spacing as a whole of the antenna aperture 4 can be made uniform, and as a result, the ability to detect a target can be improved. .

In each of the above embodiments, the case where the shape of the antenna opening surface 4 is square is described. However, the antenna opening surface 4 may have another rectangular shape such as a rectangular shape. In this case, the shape of the opening of the structure 3 naturally becomes another rectangular shape such as a rectangular shape.

[0085]

As described above, according to the present invention, since the element antennas provided in the sub-array are composed of the vertical polarization element antenna and the horizontal polarization element antenna, the sub-arrays are arranged in the vertical and horizontal directions. can do. Therefore, the antenna opening surface can be expanded in the vertical and horizontal directions.

Therefore, the antenna gain of the array antenna device can be improved. Therefore, since the beam width of the main lobe can be reduced, a small target can be satisfactorily detected, and the detection distance can be extended.

Further, since a plurality of sub-arrays are housed and held in the compartments provided in the structure, the strength of the array antenna device can be ensured by the structure. Therefore, the frame of the sub-array can be made thin. As a result, the interval between the element antennas facing each other between two adjacent subarrays can be made smaller than in the related art. Therefore, it is possible to make the element spacing of the element antenna close to a uniform one over the entire antenna aperture surface. Therefore, the side lobe level can be suppressed. Therefore, it is possible to improve the target detection ability.

When each array antenna surface of the sub-array is formed in the same rectangular shape, the sub-array can be manufactured by one manufacturing apparatus. Therefore, equipment costs can be reduced.

Further, when the sub-array is attached to the structure using the attaching member, the attaching operation can be facilitated.

Further, when the mounting members are formed in a stepped shape so that the mounting members of the adjacent subarrays are alternately combined with each other, compared with the case where the outer peripheral edges of the mounting members are brought into contact with each other, the space of the compartments is reduced. The interval can be reduced. Therefore, the interval between the element antennas at the boundary can be reduced. Therefore, the element spacing of the element antenna can be made more uniform over the entire antenna aperture surface. Therefore, the side lobe level can be further suppressed, and the target detection ability can be further improved.

Further, when the element antenna is formed in a cross shape, the element antenna can be arranged closer to the periphery of the array antenna surface than when it is formed in a cross shape. Therefore, compared to the case where the element antenna is configured in a cross shape,
The distance between the element antennas at the boundary can be reduced.
Therefore, the element spacing of the element antenna can be made more uniform over the entire antenna aperture surface.
Therefore, the side lobe level can be further suppressed, and the target detection ability can be further improved.

Further, when the element antennas are offset, the distance between the element antennas at the boundary can be further reduced. Therefore, the element spacing of the element antenna can be made closer to a uniform one as a whole of the antenna opening surface. Therefore, the side lobe level can be further suppressed, and the target detection ability can be further improved.

Further, when a sub-array is composed of one central sub-array having an array antenna surface having a relatively large area and a plurality of peripheral sub-arrays having an array antenna surface having a relatively small area, The boundary between the sub-array and the peripheral sub-array can be located on the peripheral side of the antenna opening surface. Therefore, the side lobe level can be suppressed. Therefore, it is possible to improve the ability to detect a target.

Furthermore, when a sub-array is composed of one central sub-array having a rectangular array antenna surface and four peripheral sub-arrays having a trapezoidal array antenna surface, the sub-array is arranged with respect to the antenna aperture surface. The proportion occupied by the interface between them can be reduced. Therefore, the side lobe level can be suppressed, and the ability to detect a target can be improved.

Further, when a sub-array is composed of one central sub-array having a diamond-shaped array antenna surface and four peripheral sub-arrays having a pentagonal array antenna surface, the distance between the sub-arrays with respect to the antenna aperture surface is also reduced. The ratio occupied by the boundary surface can be reduced. Therefore, the side lobe level can be suppressed, and the ability to detect a target can be improved.

Further, when a plurality of element antennas forming beams of different frequencies are provided, it is possible to detect a target that is difficult to detect with one type of frequency. Therefore, a high-performance array antenna device can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of an array antenna device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a structure of a structure.

FIG. 3 is a perspective view showing a configuration of a sub-array.

FIG. 4 is a perspective view showing a configuration of a subarray in a state where an array antenna surface is removed.

FIG. 5 is a front view showing a configuration near a boundary of an array antenna surface.

FIG. 6 is a diagram for explaining a level difference between a main lobe and a side lobe between the related art and the first embodiment.

FIG. 7 is a perspective view illustrating a configuration of a sub-array according to Embodiment 2 of the present invention.

FIG. 8 is a front view showing a configuration of a sub-array according to Embodiment 3 of the present invention.

FIG. 9 is a diagram for explaining a difference in horizontal width between a cross-shaped element antenna and an X-shaped element antenna.

FIG. 10 is a front view showing a configuration of a sub-array according to Embodiment 4 of the present invention.

FIG. 11 is a diagram for explaining a difference in an interval between boundary element antennas of an element antenna without an offset and an element antenna with an offset.

FIG. 12 is a front view showing a configuration of a sub-array according to Embodiment 5 of the present invention.

FIG. 13 is a front view showing a structure of a structure according to a fifth embodiment of the present invention.

FIG. 14 is a front view showing a configuration of a subarray according to Embodiment 6 of the present invention.

FIG. 15 is a front view showing a structure of a structure according to a sixth embodiment of the present invention.

FIG. 16 is a front view showing a configuration of a subarray according to Embodiment 7 of the present invention.

FIG. 17 is a front view showing a structure of a structure according to a seventh embodiment of the present invention.

FIG. 18 is a front view showing a configuration of a sub-array according to another embodiment of the present invention.

FIG. 19 is a perspective view showing a configuration of a conventional array antenna device.

FIG. 20 is a diagram for explaining a distance between element antennas at a boundary in a conventional array antenna device.

FIG. 21 is a diagram for explaining a level difference between a main lobe and a side lobe in a conventional array antenna device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Array antenna apparatus, 2 subarrays, 3 structures, 4 antenna aperture surfaces, 10 frame bodies, 11 compartments, 12 partition walls, 20, 50a, 51a, 51a, 60
a, 61a, 70a, 71a Array antenna surface, 23
Mounting member, 25-element antenna, 25a vertical polarization element antenna, 25b horizontal polarization element antenna, 41a recess, 41b projection, 50, 60, 70 central sub-array, 51, 52, 61, 71 peripheral sub-array, 53
a, 54a, 55a, 62a, 63a, 72a, 73a
Opening.

Claims (10)

[Claims] 1. A plurality of sub-arrays each having an array antenna surface in which a plurality of element antennas each including a vertical polarization element antenna and a horizontal polarization element antenna are mounted in an array at predetermined element intervals, and a predetermined shape. A plurality of compartments are defined in a frame having an outer shape corresponding to the antenna opening surface, and each sub-array is accommodated and held in each compartment. 2. The plurality of sub-arrays according to claim 1, wherein the plurality of sub-arrays have the same size and have a square shape in a front view, and the plurality of compartments have the same size and a square shape in a front view. , Wherein the array antenna device is partitioned in a matrix. 3. The sub-array according to claim 1, further comprising a frame-shaped mounting member provided along a peripheral portion of the array antenna surface and mounting the sub-array in a housed state to the structure. Characteristic array antenna device. 4. The array antenna device according to claim 3, wherein the mounting member is stepped so as to be alternately meshed with mounting members of an adjacent sub-array when the sub-array is housed. . 5. The method according to claim 1, wherein
The above element antenna has a vertical polarization element antenna and a horizontal polarization element antenna with respect to the periphery of the array antenna surface.
An array antenna device characterized by being arranged in a letter shape. 6. The method according to claim 1, wherein
The vertical polarization element antenna and / or the horizontal polarization element antenna of the boundary element antenna, which is the element antenna disposed at the position closest to the peripheral edge of the array antenna surface, is moved from the center position of the element antenna to be crossed to the array antenna surface. An array antenna device characterized in that the array antenna device is offset toward the periphery of the antenna. 7. The sub-array according to claim 1, wherein the plurality of sub-arrays have one central sub-array and a plurality of peripheral sub-arrays, and the central sub-array is relatively The peripheral sub-array has an array antenna surface with a relatively small area, and the plurality of compartments are for accommodating the central sub-array. A central compartment having a relatively large area opening centrally disposed therein and disposed around the central compartment for accommodating the peripheral sub-array;
An array antenna device comprising: a plurality of peripheral compartments each having an opening having a relatively small area. 8. The method according to claim 1, wherein the plurality of sub-arrays include one central sub-array and four peripheral sub-arrays, and the central sub-array includes the compartment. The peripheral sub-arrays have a rectangular array antenna surface in a housed state, and each of the peripheral sub-arrays has an upper side portion substantially equal to a side portion of the array antenna surface of the central sub-array and a side portion of the structure. It has a trapezoidal array antenna surface having a lower side of equal length, and the plurality of compartments are for accommodating the central sub-array, and have a square shape in a centrally disposed front view. One central compartment having an opening, and for accommodating the peripheral sub-array, each having a trapezoidal opening disposed around the central compartment. An array antenna device having four peripheral compartments. 9. The method according to claim 1, wherein the plurality of sub-arrays include one central sub-array and four peripheral sub-arrays, and the central sub-array includes the compartment. The peripheral sub-array has a pentagonal shape having an oblique side along each side of the central sub-array in the accommodation state in the compartment, respectively. The plurality of compartments are for accommodating the central sub-array, and one central compartment having a diamond-shaped opening as viewed from the front, which is disposed at the center, For accommodating the peripheral sub-array, comprising four peripheral compartments each having a pentagonal opening arranged around the central compartment. Characteristic array antenna device. 10. The element antenna according to claim 1, wherein the element antenna forms a beam of a first frequency and a second element forms a beam of a second frequency different from the first frequency. An array antenna device comprising an antenna.