JPH10190337A - Phased array antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute the scanning of a wide range without increasing the number of phased array antennas by combining the electronic scanning and the mechanical scanning of the phased array antenna. SOLUTION: A cylindrical structure 1, the plural phased array antennas 2 and 2a-2c arranged on the surface of the cylindrical structure 1 and a rotary shaft 3 connected with a rotary mechanism loading an artificial satellite are provided. Namely, the plural phased array antennas 2 and 2a-2c are arranged on the cylindrical structure 1 in a row and they are rotated around the rotary shaft 3 with the rotary mechanism. Thus, the plural phased array antennas 2 and 2a-2c are also rotated and the plural beams can mechanically be scanned. Furthermore, the respective phased array antennas are electronically scanned. Thus, a global coverage being a communication object can be scanned for the wide range by combining mechanical scanning and electronic scanning.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phased array antenna device, and more particularly to a phased array antenna arranged on the surface of a tubular structure, and rotating them to perform mechanical scanning and electronic scanning by the phased array antenna. The present invention relates to a phased array antenna device.

[0002]

2. Description of the Related Art Generally, when simultaneously communicating or broadcasting to a plurality of service areas allocated on the ground surface, simultaneous communication by a plurality of beams is required, so that a plurality of phased array antennas must be mounted on a satellite. Occurs.

That is, since the beam scanning range of the phased array antenna is narrow, a large number of phased array antennas are required to cover a wide service area.

Here, the phased array antenna is composed of a plurality of antenna elements, and a variable phase shifter is connected to each of the antenna elements to control the excitation phase of each antenna element, so that the antenna element is planarly arranged in an arbitrary direction. Shows an antenna capable of beam scanning.

[0005] In recent years, a phased array antenna characterized by combining electronic scanning of the phased array antenna with mechanical scanning has been known.

As an example of such a phased array antenna, a "phased array antenna" described in Japanese Patent Application Laid-Open No. 58-53202 is known. This publication describes a technique in which a plurality of antenna elements are arranged along a plane or a rotationally symmetric curved surface, and are mechanically rotated with the normal direction of the plane or the rotationally symmetric axis direction of the curved surface as a rotation axis. Have been.

An "antenna device" described in Japanese Patent Application Laid-Open No. 4-196904 is also known.

In this publication, there is provided a movable mechanism comprising a plurality of sub-arrays for rotating the sub-arrays in association with the rotation axes of the respective sub-arrays in the same direction, and for changing the arrangement intervals of these sub-arrays. Therefore, there is described a technique in which a main beam is continuously scanned in an azimuthal direction without using a phase shifter.

[0009] All of them aim at controlling one beam and do not have a function of simultaneously scanning a plurality of beams.

FIG. 6 is an explanatory diagram showing the operation of a conventional phased array antenna device.

FIG. 6A is a diagram for explaining a coverage area, and FIG. 6B is a diagram for explaining operation by artificial satellites. Referring to FIG. 6A, assuming that the service area on the ground surface has a spread of 120 degrees from the artificial satellite 6 as a base point, a wide area of the coverage area 4 is simultaneously beamed by one phased array antenna. Cannot scan. Here, the coverage area indicates an area that can be simultaneously scanned by the beam of the phased array antenna.

Since the phased array antenna has a narrow beam electronic scanning range and cannot scan a wide coverage area 4 of 120 degrees by one unit, for example, the scanning range of 120 degrees is divided into four and the scanning beam of one phased array is divided. With a width of 30 degrees, it is necessary to allocate a total of four phased array antennas to each divided range.

Further, as the artificial satellite 6 moves, FIG.
Since the angle changes as shown in (b), another phased array antenna is required. When the artificial satellite 6 moves, since the point on the coverage area is fixed, the angle of the scanning beam needs to be changed every time the phased array antenna moves.

Therefore, it is necessary to divide the angle change accompanying the movement of the artificial satellite 6 into, for example, three, to provide a group of phased array antennas corresponding to the division, and to share the angle change accompanying the movement among the phased array antenna groups. . In other words, the coverage area 4 can be scanned by using the first, second, and third three phased array antenna groups and sequentially switching and controlling the three phased array antenna groups as the artificial satellite 6 moves. it can.

As a method of switching the group of phased array antennas, for example, when the artificial satellite 6 is moving from the right end to the left end, the first phased array antenna group is used in an area 1/3 from the right side. Furthermore, when the artificial satellite 6 moves to the left end, it is switched to the second phased array antenna group, and the area of ／ from the right is shared. Further, when the artificial satellite 6 moves to the left end, the entire area is covered by switching to the third phased array antenna group and sharing 3/3 of the area from the right.

In this case, the total number of phased array antennas is 4 × 3 groups = 12, and twelve phased array antennas are required to simultaneously and continuously scan the 120 ° coverage area 4.

[0017]

In the above-mentioned conventional phased array antenna device, the scanning beam width is narrow in the electronic scanning by the phased array antenna, and the number of phased array antennas increases when a wide coverage is secured. It has the disadvantage that it leads to an increase in the size and weight of the satellite.

Further, when a large structure such as a phased array antenna is mounted on an artificial satellite, there is a disadvantage that an attitude stabilizing device is required for attitude control of the satellite.

An object of the present invention is to provide a phased array antenna device capable of performing a wide range of scanning without increasing the number of phased array antennas by combining electronic scanning and mechanical scanning of the phased array antenna. Is to do.

[0020]

According to the phased array antenna device of the present invention, in a phased array antenna device mounted on a flying object, n (n is an integer of 1 or more) number of the phased array antennas are provided on the surface of a cylindrical structure. One array antenna
A mechanical beam scanning unit generated by rotating the structure, and electronic scanning of each of the n × m phased array antennas And scanning means for scanning a predetermined communication area.

The phased array antenna is arranged in one row (m
= 1).

It is characterized in that the tubular structure is a triangular prism.

The angular momentum generated by the rotation of the structure and the phased array antenna mounted on the surface of the structure is used for stabilizing the attitude of the flying object.

Also, in the phased array antenna device mounted on a flying object, a rotating shaft driven by a rotating mechanism of the flying object; a cylindrical structure rotating around the rotating axis; And m (where m is an integer equal to or greater than 1) m (where m is an integer equal to or greater than 1) arrayed phased array antennas.

The phased array antenna is arranged in one row (m
= 1).

The structure is characterized in that the structure is a triangular prism.

The angular momentum generated by the rotation of the structure and the phased array antenna mounted on the surface of the structure is used for stabilizing the attitude of the flying object.

[0028]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing one embodiment of the phased array antenna device of the present invention.

The present embodiment shown in FIG.
And a plurality of phased array antennas 2, 2a, 2b, 2c arranged on the surface of the cylindrical structure 1, and a rotating shaft 3 connected to a rotating mechanism (not shown) mounted on an artificial satellite. .

A plurality of phased array antennas 2, 2 a, 2 b, and 2 c are arranged in a row on the cylindrical structure 1 and rotated around a rotation axis 3 by a rotating mechanism, whereby a plurality of phased array antennas 2, 2 a , 2b, and 2c rotate in the same manner, so that a plurality of beams can be mechanically scanned.

Further, each phased array antenna is itself electronically beam scanned. By combining and using the mechanical scanning and the electronic scanning described above, it is possible to scan a coverage on the earth to be communicated over a wide range.

FIG. 2 is an explanatory diagram showing a communication system using the embodiment of FIG.

Referring to FIG. 2, the cylindrical structure 1 is mounted on an artificial satellite 6, and the coverage area on the ground has an elevation angle as viewed from the communication point 7 on the ground even when the artificial satellite 6 orbits. The system is fixed within the range (elevation angle of θ degrees or more). Here, it is assumed that the coverage area is further subdivided into a grid pattern. When such a coverage area is communicated with a conventional phased array antenna, a large number of phased array antennas are required. However, according to the present embodiment, a phased array antenna corresponding to one row of a grid is used. By mechanical scanning generated by rotating the cylindrical structure 1 disposed on the cylindrical structure, beam scanning in the traveling direction of the coverage area can be performed, and electronic scanning of the phased array antenna itself can be performed. The combined use with the mechanical scanning by the rotation of the linear structure 1 makes it possible to scan the entire row area of the coverage area with the phased array antenna for one row.

Since the angular momentum is generated by rotating the cylindrical structure 1, the effect of stabilizing the rotation axis of the cylindrical structure 1 is generated in the same manner as the stabilization of the axis of the rotating frame. I do. The phased array antenna arranged in the tubular structure 1 needs to be fixed to a grid-like area of a grid in a coverage area for a certain period of time because of communication with the ground. Communication between the satellite and the ground must take place during this fixed time,
With only mechanical scanning, the scanning beam continuously runs through the coverage area to the front row, so that the scanning beam cannot be fixed to the target area of the grid on the grid.

This can be dealt with by electronically scanning the phased array antenna itself in a direction opposite to the mechanical scanning of the tubular structure 1. The beam scanned in the reverse direction by electronic scanning for a certain period of time is electronically returned to the scanning start point again. During this time, the scanning beam is moved to the next row of the grid by mechanical scanning. Then, the beam can be fixed to the next row of the grid in the grid again.

By repeating the above operation, the scanning beam can be fixed on all the cells in the coverage area for a certain time.

The method of performing the electronic scanning linearly in the direction opposite to the rotation direction has been described. This is the case where one scanning beam fixes the beam on one column. As another application, it is possible to fix beams on a plurality of rows with one beam.

FIG. 3 is a diagram for explaining an example of a beam scanning fixing method.

In the case where the scanning beam is fixed to the four cells in the coverage area, the scanning beam from the phased array antenna scans the four cells electronically while skipping each cell. Scanning is performed while canceling mechanical scanning by rotation. That is, the scanning beam needs to scan a coverage area fixed on the ground as shown in FIG. Because the phased array antenna is rotating mechanically,
In order to scan a fixed point on the ground in this way, it is necessary to electronically rotate the scanning beam in a direction opposite to the mechanical rotation to correct the displacement of the scanning beam caused by the mechanical rotation.

FIG. 4 is an explanatory diagram showing an operation example of the embodiment of FIG.

FIG. 4A is a bird's-eye view, and FIG. 4B is a three-dimensional perspective view of the same.

The ground coverage area 4 is divided into a grid pattern of n rows and m columns, and is set as an area of n × m squares. To cover this coverage area 4, n
The two phased array antennas 2 to 2c are arranged in the tubular structure 1 for one row. The tubular structure 1 is rotated once every T seconds.

Assuming that the angle of the coverage area 4 as viewed from the cylindrical structure 1 mounted on the artificial satellite 6 is θ degrees, the time t for fixing the scanning beam on one row of each cell every T seconds is:
t = (T / 360) · (θ / m). During this time, communication can be performed between the artificial satellite 6 and the grid area of n rows and 1 column between the ground.

The cylindrical structure 1 is provided with n phased array antennas, and scans an n-row area of the coverage area 4 on the ground by rotation (spin) of the cylindrical structure 1. With this mechanical scanning alone, the scanning beam continuously travels through the m rows of coverage areas, so that scanning is performed on one grid-shaped area of the target grid (in this case, any one of the m rows). The beam cannot be fixed.

For this purpose, n phased array antennas themselves are electronically scanned in the direction opposite to the mechanical scanning of the tubular structure 1. The beam scanned in the reverse direction of the electronic scanning of an arbitrary row is electronically returned to the scanning start point again. During the predetermined time t, the scanning beam is moved to the next row by mechanical scanning. Therefore, the beam can be fixed again in the next one row area for the predetermined time t. That is, the time during which the beam is fixed to each column is indicated by t seconds.

As described above, conventionally, a large number of phased array antennas are required, but the minimum required number of phased array antennas can cover the entire coverage area.

FIG. 5 is a block diagram showing a second embodiment of the present invention.

FIG. 5A is a perspective view, and FIG. 5B is a side view as viewed from the direction of the rotation axis.

In FIG. 5, components corresponding to those shown in FIG. 1 are denoted by the same reference numerals or symbols, and description thereof is omitted.

There is no particular limitation on the shape of the cylindrical structure, and the structure can be freely formed. The number of rows in which the phased array antennas are arranged, that is, the number of rows per column may be one row, two rows, or three rows, and the number of columns m
Increases, the time t during which the scanning beam passes through one row can be shortened.

In the case of three rows, the cylindrical structure 5 has a triangular prism shape. The phased array antenna 2 is arranged on each of the three surfaces of the tubular structure 5. Therefore, the cycle for one row is T
What is once every second becomes a cycle every T / 3 seconds, so that the communication frequency can be increased. However, even in the case of the cylindrical structure 5 having a triangular prism, it is not always necessary to arrange it on all three surfaces.
They can be arranged in rows, that is, on one surface.

As described above, in the conventional system, the scanning beam range of the phased array antenna is narrow, so that 12 units are required. However, by using together with the mechanical rotation, one unit can cover the scanning range. It becomes possible. That is, the number n of phased array antennas required for one row is determined by the required value of the width of the coverage area 4. If the horizontal beam scanning range is required to be 30 degrees,
The 120-degree coverage area 4 associated with the movement of the artificial satellite 6 in FIG. 6A can be covered by one phased array antenna instead of twelve.

When a large structure such as the cylindrical structure 1 on which the array antenna is arranged is spun, an angular momentum is generated along with the spinning. Can be used as part of control.

[0055]

As described above, the phased array antenna device of the present invention uses a combination of mechanical scanning by rotation of a tubular structure and electronic scanning by a phased array antenna arranged on the present structure. Since the beam can be scanned over a wide range, the number of phased array antennas can be reduced.

Further, since an angular momentum is generated by rotating the cylindrical structure, the satellite has a function of stabilizing the attitude of the artificial satellite, and thus has an effect of providing an attitude stabilizing effect.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a phased array antenna device of the present invention.

FIG. 2 is an explanatory diagram showing a communication system using the embodiment of FIG. 1;

FIG. 3 is a diagram illustrating an example of a beam scanning fixing method.

FIG. 4 is an explanatory diagram showing an operation example of the embodiment of FIG. 1;

FIG. 5 is a configuration diagram showing a second embodiment of the present invention.

FIG. 6 is an explanatory diagram showing operation by a conventional phased array antenna device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical structure 2, 2a, 2b, 2c Phased array antenna 3 Rotation axis 4 Coverage area 5 Cylindrical structure 6 Artificial satellite 7 Communication point

Claims (8)

[Claims] 1. A phased array antenna device mounted on a flying object, wherein n (n is an integer of 1 or more) phased array antennas are arranged in a row on the surface of a cylindrical structure, and m (m is 1 or more) ), A mechanical beam scanning unit generated by rotating the structure, and an electronic beam scanning unit of each of the (n × m) phased array antennas are used in combination. A phased array antenna device, which scans a communication area of the antenna. 2. The phased array antenna device according to claim 1, wherein said phased array antenna is mounted in one row (m = 1). 3. The phased array antenna device according to claim 1, wherein the cylindrical structure is a triangular prism. 4. The flying object according to claim 1, wherein angular momentum generated by rotation of the structure and a phased array antenna mounted on a surface of the structure is used for stabilizing the attitude of the flying object. 3. The phased array antenna device according to 3. 5. A phased array antenna device mounted on a flying object, a rotating shaft driven by a rotating mechanism of the flying object; a cylindrical structure rotating around the rotating axis; A phased array antenna having an array of m (m is an integer of 1 or more) m columns (m is an integer of 1 or more) mounted in one column. 6. The phased array antenna device according to claim 5, wherein said phased array antenna is mounted in one row (m = 1). 7. The phased array antenna device according to claim 5, wherein the shape of the structure is a triangular prism. 8. The method according to claim 5, wherein angular momentum generated by rotation of the structure and a phased array antenna mounted on the surface of the structure is used for stabilizing the attitude of the flying object. 8. The phased array antenna device according to 7.