JPS5853202A - Phased array antenna - Google Patents

Abstract

PURPOSE:To obtain a phased array antenna which needs no space for revolution, by arraying element antennas along the symmetric faces in terms of revolution and then rotating these elements mechanically with the revolution symmetric axis direction of the symmetric face defined as a revolving axis. CONSTITUTION:A phased array antenna 6 is provided with numbers of element antennas 31, 32, 33- which are arrayed on a circular open face 2. An electronic beam scan is carried out within a vertical face including a vertical axis 4. Then the element antennas are rotated mechanically around an axis 7. This revolution around the axis 7 eliminantes an excessive space for revolution of a phased antenna.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention arranges a plurality of element antennas in a plane, uses a variable phase shifter to electronically scan a beam within one plane of space, and scans a beam that is different from the above one plane. Regarding other aspects, a hybrid scanning phased array antenna (phased array antenna) that mechanically scans the beam is used.
enna). Generally, by connecting a variable phase shifter to each of the element antennas that make up a phased array antenna and controlling the excitation phase of each element antenna, it is possible to scan the beam two-dimensionally in any direction in space. Since a large number of element antennas are required, if the number of element antennas is 102 to 108, it becomes extremely expensive and poses a serious economic problem. Therefore, conventionally, for example, a variable phase shifter is connected to only one row in the vertical direction to electronically scan the beam in the vertical plane, and to scan the beam in the horizontal plane by mechanically rotating the antenna. Antenna is also used in practice.

Here, a conventional hybrid scanning phased array will be explained with reference to FIG. In Fig. 1, (1) is a phased array antenna, in which a large number of element antennas C30°C3L (C), . . . are arranged on a circular aperture (2), and the phased array antenna ( 1
) rotates mechanically around a vertical axis (4). Also,
Phased array antenna (11 contains a variable phase shifter, includes a vertical plane, i.e. vertical axis (4), 9 circular aperture planes (
2) The beam is electronically scanned in a plane perpendicular to the plane. In FIG.

(a) is a front view of the phased array antenna (11), and (b) is a side view.

The conventional phased array antenna uses the above configuration to perform beam scanning in the vertical and horizontal planes, so as the mechanical rotation in the horizontal plane occurs, the phased array antenna (1) moves directly above it (in the vertical direction). ), it moves as shown in Figure 2. That is, the vertical axis (4
), and if it rotates once, the circle (5
) is required for rotation.

Therefore, such a phased array antenna +1
1 in a narrow space such as the nose of an aircraft, the mechanical rotation of the antenna uses more valuable space than the volume occupied by the antenna itself.

A hybrid phased array antenna according to the present invention was developed to eliminate the drawbacks of the conventional method, and will be explained below with reference to the drawings.

FIG. 3 is a schematic configuration diagram of an embodiment of the present invention, in which a phased array antenna (6) has a large number of element antennas c+a, oa, n, . . . arranged on its circular aperture surface (2). The beam is scanned electronically in a vertical plane including the vertical axis (4), while mechanically rotating around the axis (b) of FIG. By electronic and mechanical scanning, the beam can be scanned within a conical spatial region at an angle θ.Moreover, since it rotates around the axis (7), extra space is required for one rotation. It is clear that there is nothing to be done, viz.

Even when it rotates, the phased array antenna (6) always occupies space equal to its own volume. Note that the polarization of the radio waves of the phased array antenna (6) rotates with the mechanical rotation, but as long as the phased array antenna according to the present invention is used for applications such as ordinary radar that transmits and receives itself, the polarization will not change. The rotation of the waves is not a problem.

In addition, in the above nine embodiments, the case where the element antennas are arranged in a planar shape has been described, but the present invention is not limited to this, and can be implemented in the same way when the element antennas are arranged in a curved shape.
A similar effect can be obtained.

As described above, by using the hybrid type phased array antenna that uses both electronic scanning and mechanical scanning according to the present invention, the space occupied by rotation can be kept to a minimum, and this can be used for aircraft-mounted radar. The practical effect when used as a commercial antenna is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a conventional phased array antenna, FIG. 2 is an explanatory diagram of mechanical rotation of a conventional phased array antenna, FIG. 3 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 4 is a diagram of the present invention. FIG. 3 is an explanatory diagram of a beam scanning range in an embodiment of the invention. In the figure, (1) is a phased array antenna, (2) is a circular aperture, t31L C33C (3,... is an element antenna. (4) is a vertical axis, (6) is a phased array antenna. (7) is a phased array antenna. The same or equivalent parts in Figure 9 are indicated by the same reference numerals. @Figure 3 @ Figure 7

Claims (1)

[Claims] In a phased array antenna that is composed of a plurality of element antennas and that electronically scans a beam in a plane, the element antennas are arranged along a plane or a rotationally symmetrical curved surface, and the element antennas are arranged in the normal direction of the plane or along the curved surface. A phased array antenna characterized in that it is configured to be mechanically rotated with a rotational symmetry axis direction as a rotation axis.