JPH01120906A - Two-dimension phased array antenna - Google Patents

Abstract

PURPOSE:To improve the economy being a problem in the comparison of the cost-performance by eliminating the need for a variable attenuator and providing a switch applying on/off control to supply power to an antenna element located at an apex of a square so as to attain simple constitution as a whole. CONSTITUTION:While variable phase shifters 2 of eight antenna elements 1 not located on the apexes of a square are connected directly to each distributer 3 respectively, a switch 5 is interposed respectively between a variable phase shifter 2 and a distributer 3 of each of four antenna element 1 located on the apexes (1, 1), (1, 4), (4, 4) and (4, 1) of the square, the four switches 5 are subjected to on/off control in response to the beam scanning direction thereby controlling the power supply to the four antenna elements. That is, the antenna element 1 on the apex in a direction orthogonal to the beam scanning direction is set in the non-feeding state so as to obtain a proper tilt characteristic in the electric field strength distribution at both sides orthogonal to the beam scanning direction thereby obtaining a radiation pattern whose side lobe level is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a two-dimensional phased array antenna, and particularly to sidelobe reduction technology.

(Prior Art) As a conventional two-dimensional phased array antenna, for example, the one shown in FIG. 4 is known.

This two-dimensional phased array antenna consists of 16 antenna elements 1 arranged two-dimensionally with a square outer circumferential shape, an associated variable phase shifter 2, and each antenna element 1.
It basically consists of a divider 3 for distributing and supplying power to the antenna elements 1 and a variable attenuator 4 provided between the variable phase shifter 2 and the divider 3. Dolph-Chebyshev distribution and Ta
This is to apply weighting based on the Ylor distribution or the like to obtain desired low sidelobe characteristics.

(Problem to be solved by the invention) However, although the conventional two-dimensional phased array antenna has the advantage of being able to obtain desired low sidelobe characteristics using a variable attenuator, it is provided for each antenna element, so it cannot be controlled. The configuration including the circuit becomes extremely complicated. In particular, a variable attenuator is an effective means to significantly reduce side lobes, but it can reduce the side lobe level by about 4 to 5 dB.
In cases where it is sufficient to improve the level of improvement, there is a problem that it is uneconomical when comparing cost-effectiveness.

The present invention has been made in view of these conventional problems, and an object thereof is to provide a two-dimensional phased array antenna that can reduce side lobes with a simple configuration.

(Means for Solving the Problems) In order to achieve the above object, the two-dimensional phased array antenna of the present invention has the following configuration.

That is, the two-dimensional phased array antenna of the present invention includes a group of antenna elements arranged two-dimensionally with a rectangular outer circumferential shape and a group of phase shifters accompanying the antenna elements; power is distributed and supplied to each antenna element; a distributor to which phase shifters of antenna elements not located at the apex of the antenna element are directly connected;
A switch provided between the phase shifter and the divider of the antenna element located at the apex of the rectangle for controlling on/off power supply to the antenna element in accordance with the beam scanning direction;
It is characterized by having the following.

(Function) Next, the function of the two-dimensional phased array antenna of the present invention configured as described above will be explained.

For example, when the outer circumferential shape of a two-dimensionally arranged antenna element group, that is, the shape of the antenna aperture is a square, and beam scanning is performed in a direction parallel to one diagonal of the square, two Put two antenna elements into a parasitic state.

As a result, the electric field strength distribution on both sides perpendicular to the beam scanning direction has an appropriate slope characteristic, and as a result, the radiation has sidelobe characteristics that are several dB lower than the sidelobe level obtained when all antenna elements are excited with the same amplitude. You can get the pattern.

As described above, according to the two-dimensional phased array antenna of the present invention, a variable attenuator is eliminated, and a switch is provided to control on/off the power supplied to the antenna elements located at the vertices of the rectangle. Because the predetermined antenna elements are set to a parasitic state, we cannot expect a sidelobe reduction effect as large as that of a variable attenuator, but a small sidelobe reduction effect of about 4 to 5 dB can be expected. can be obtained. Therefore, the required number of switches is equal to the number of vertices of the rectangle, and the control circuit thereof has a simpler configuration than the control circuit of the variable attenuator, so the overall configuration can be simplified and cost-effective. It has the effect of improving the economical efficiency, which is a problem from comparative considerations. (Example) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows a two-dimensional phased array antenna according to an embodiment of the present invention, the antenna opening is square like the conventional example, and the antenna element 1 has a total of 16 antenna elements (4 vertical elements x 4 horizontal elements). The case is shown below.

Each of the 16 antenna elements 1 is set to (1, 1) to (4
, 4), the phased array antenna of the present invention eliminates the variable attenuator 4 in the conventional example and uses the variable attenuator 4 of the eight antenna elements 1 that are not located at the vertices of the square. The phase shifters 2 are each directly connected to the distributor 3, while the vertices of the square <1.1), the same (1,
4) A switch (a so-called high frequency switch) 5 is interposed between the variable phase shifter 2 and the distributor 3 of the four antenna elements 1 located at (4,4) and (4,1), respectively. These four switches 5 are turned on and off according to the beam scanning direction, thereby controlling the power supply to the four antenna elements.

Figure 2 shows the power feeding state in the beam scanning direction. When the antenna aperture is square, the beam scanning direction is parallel to the sides of the square (Figure 2 (a)) and +45 degrees (
In the case shown in FIG. 2(a), the vertex (1, 1),
4 in (1, 4) (4, 4) and (4, 1)
All of the antenna elements 1 are set to a parasitic state. As shown in Fig. 2(b), when the beam scanning direction is +45 degrees, the two antenna elements 1 at the apex <1.1) and the apex (4,4) are set to a parasitic state, and vice versa. Figure 2(c)
As shown in , when the beam scanning direction is 145 degrees, the vertex (
Two antenna elements 1, 1, 4) and (4, 1>), are set to a parasitic state.

In other words, the antenna element 1 located at the apex position in the direction orthogonal to the beam scanning direction is set to a non-powered state, and as a result, an appropriate slope characteristic is obtained in the electric field intensity distribution on both sides orthogonal to the beam scanning direction. As shown in FIG. 3, it is possible to obtain a radiation pattern with a reduced sidelobe level compared to when all antenna elements 1 are excited with equal amplitude.

Figure 3 shows the measured radiation pattern when the beam scanning direction is parallel to the sides of the square.The radiation pattern when all antenna elements are fed is as shown by the solid line, and the sidelobe level is approximately -13 dB. . On the other hand, as shown in FIG. 2(a), the vertex (1, 1).

The radiation pattern when the antenna elements located at (1, 4), (4, 1), and (4, 4) are placed in a parasitic state is as shown by the broken line, and the sidelobe level is approximately 4 to 4.
This is an improvement of about 5 dB.

Although this embodiment shows a case where the antenna opening is square, the present invention is not limited to this, and it goes without saying that it may be, for example, a regular hexagon.

(Effects of the Invention) As explained above, according to the two-dimensional phased array antenna of the present invention, a variable attenuator is eliminated and a switch for controlling on/off the power supplied to the antenna elements located at the vertices of the rectangle is provided. Since the predetermined antenna element determined according to the beam scanning direction is set to a parasitic state, we cannot expect a sidelobe reduction effect as large as that of a variable attenuator, but it can reduce the sidelobe by about 4 to 5 dB. A small sidelobe reduction effect can be obtained. Therefore, the required number of switches is equal to the number of vertices of the rectangle, and the control circuit thereof has a simpler configuration than the control circuit of the variable attenuator, so the overall configuration can be simplified and cost-effective. This has the effect of improving economic efficiency, which is a problem from a comparative perspective.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a two-dimensional phased array antenna according to an embodiment of the present invention, Figure 2 is a diagram of the relationship between the beam scanning direction and antenna element feeding, Figure 3 is a characteristic diagram of the radiation pattern, and Figure 4 is a configuration diagram of a conventional example. 1...Antenna element, 2...Variable phase shifter, 3...Distributor, 4...Variable attenuator, 5...... switch. Agent Patent Attorney Yoshihiro Yahata (a) ○ mt-t+, ('2) Oomachi Chigupihi → 1tozu! 2nd picture of the direction of the beam dog) and the antenna element 4

Claims (1)

[Claims] A group of antenna elements arranged two-dimensionally with a rectangular outer circumferential shape and a group of phase shifters associated therewith; phase shifting of antenna elements that distribute and supply power to each antenna element and are not located at the vertices of the rectangle. a distributor to which the device is directly connected;
a switch provided between the phase shifter and the distributor of the antenna element located at the apex of the rectangle for controlling on/off power supply to the antenna element in accordance with the beam scanning direction;
A two-dimensional phased array antenna characterized by being equipped with.