JPH01129509A - Array antenna device - Google Patents

Abstract

PURPOSE:To simplify the whole device and to make it small in size and light in weight by constituting said device so that at least plural pieces of branching circuits to which plural pieces of antenna element have been connected are provided, and also, to each of these branching circuit, a distributing and synthesizing circuit is connected through a transmitting and receiving circuit. CONSTITUTION:Each antenna element 1 is connected to a branching circuit 2, respectively and constitutes one antenna circuit 10. The branching circuit 2 consists of plural pieces in accordance with the number of branches, but these branching circuits can be constituted, for instance, of a 3dB Wilkinson type branching circuit. As for a transmitting and receiving circuit 3, a circulator 31 connected to an antenna circuit is connected to a high frequency transmitting/ receiving switch 34 through transmitting use/receiving use amplifying circuits 32, 33, and connected to a distributing and synthesizing circuit 4 through a phase shifter 35. A control terminal 36 receives a signal from a control circuit which is not shown in the figure in accordance with switching of transmission and reception, and controls the switch 34 and the phase shifter 35. The transmitting and receiving circuit 3 can be constituted by converting it to a module.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement in an array antenna device that makes it possible to equalize the functions of transmitting and receiving circuits connected to many antenna elements. .

(Conventional technology) For example, in the active phased array radar system,
An array antenna device shown in FIG. 4 is used. That is,
In the conventional device, a plurality of antenna elements (1) are directly connected to corresponding transmitter/receiver circuits (3) each consisting of a transmitter/receiver module, etc., and these transmitter/receiver circuits (3) perform a distribution/synthesis system that distributes and combines the transmitted and received signals respectively. It is configured to be connected to a radar device main body (not shown) via a circuit (4).

In such an array antenna device, each transmitter/receiver circuit (3
), the amplitude and phase of the power radiated from each antenna element are adjusted and controlled, and beam steering is performed to obtain the required antenna radiation characteristics. Generally, the feeding phase to each antenna element (1) is controlled by a phase shifter in the transmitter/receiver circuit (3), but the amplitude is rarely controlled and is fixed based on prespecified amplification operating characteristics. It is often used as The reason for this is that the transmission amplification semiconductor element in the transmitter/receiver circuit (3) is always required to be used in a stable operating state and in a state with high power usage efficiency, so both output power and power usage efficiency are maximized and i& This is because it is set to operate at an appropriate specific operating point. For example, the maximum output of the transmitter/receiver circuit (3) is 3 dB each.
Like step 100W, 50W, 25W...
Several types of amplifying semiconductor elements having different output characteristics are prepared in advance, and these are made to correspond to each antenna element and used in selected combinations. As shown in FIG. 5, the relationship between each antenna element (1) and each transmitting/receiving circuit (3) in one-to-one correspondence is, for example, as shown in FIG. When (1) is arranged, 4 transmitter/receiver circuit groups (301) with a maximum output of 100W, 50W1 sequentially from the center.
It is divided into two transmitting/receiving circuit groups (302) and 25W and 48 transmitting/receiving circuit groups (303) to obtain desired antenna beam amplitude characteristics with a small sidelobe level.

(Problems to be Solved by the Invention) By the way, since the transmitting/receiving circuit can be said to be the heart that determines the performance and functions of the radar device itself, it is especially important when it includes active elements such as amplifiers and phase shifters. High functionality and stable performance are required. The requirements for high-performance, high-stability elements themselves are accompanied by difficulties in designing and manufacturing, so preparing a large number of such high-quality transmitter/receiver circuits in large numbers in order to obtain the desired amplitude distribution is difficult in terms of design. This was a major manufacturing hurdle. In addition, it is difficult to maintain stable operation with amplification control, especially in semiconductor amplifier circuits for transmission.
Overloading to increase output leads to destruction of semiconductor elements, while light loading reduces power usage efficiency, which is a practical problem.

[Structure of the Invention] (Means for Solving the Problems) The array antenna device of the present invention includes at least a plurality of branch circuits to which a plurality of antenna elements are connected, and a transmission/reception circuit is connected to each of the branch circuits. It was constructed by connecting a distribution and synthesis circuit.

(Function) The array antenna device of the present invention takes advantage of the fact that the amplitude level at each output terminal differs depending on the number of branches of the branch circuit, and provides this signal branch circuit between the antenna element and the transmitting/receiving circuit. The necessary amplitude distribution on the antenna aperture plane is obtained by introducing these antenna elements. That is,
Even if the amplification characteristics of the transmitter/receiver circuit are all constant, for example, if the required amplitude is 1/J2, the number of branches in the branch circuit should be 2 degrees, and similarly, if the required amplitude is 1/f3, the number of branches should be 3 degrees. The amplitude below is 1/J
When the number of branches is N, the array antenna is constructed by selectively arranging the number of branches to N (plurality).

A combination of such an antenna element and a branch circuit is connected to a distribution/synthesis circuit to obtain a desired amplitude distribution on the antenna aperture surface.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the array antenna device of the present invention, in which each antenna element (1) is connected to a branch circuit (2).
are connected to constitute one antenna circuit (10).

The branch circuit (2) is composed of a plurality of types depending on the number of branches, and these branch circuits can be configured, for example, by a 3 dB Wilkinson type branch circuit. Note that a part of the antenna circuit (10) may include one that is directly connected to the antenna element without being branched. The antenna circuits (10) are each connected to a transmitting/receiving circuit (3). In the transmitting/receiving circuit (3), as shown in FIG.
3) to a high frequency transmission/reception switch (34), and a phase shifter (35) to the distribution/synthesis circuit (4) shown in FIG.

In FIG. 2, a control terminal (36) receives a signal from a control circuit (not shown) in response to switching between transmission and reception, and a switch (34)
The phase shifter (35) is controlled by a transmitting/receiving circuit (3) like this.
) can be configured modularly. Figure 3 shows an antenna circuit arranged in an array (similar to Figure 5).
10) is shown, and the arrangement state from the central part will be sequentially explained.

In the center are four antenna elements (1) each marked with a cross.
are directly connected to the transmitter/receiver circuit in a one-to-one correspondence, forming a first circuit group (301).

Next, the 12 antenna elements (1) are divided into 6 unit sections, 2 of each are paired to form a branch circuit (
21). Similarly, on the outside thereof, 48 antenna elements (1) are divided into 12 unit sections and arranged in groups of 4 in each section connected to a branch circuit (22) forming 4 branches.

As a result of this arrangement, the number of transmitting and receiving circuits is reduced to 22 in total.

Since the array antenna device of the present invention is configured as described above, the radar signal supplied from the main body of the radar device is distributed to each transmitting/receiving port R (3) via the distribution/synthesizing circuit (4), where the phase is shifted. It is supplied to the rear antenna circuit (10) under control. If a 3 dB Wilson type branch circuit is used here, each of the two branched outputs will be 1/2 as described above, so the amplitude will be 1/2 compared to when no branch circuit is provided.
/f2. Similarly, in the antenna circuit, the signal power supplied to each antenna element is adjusted to 100 W, 50 W, etc. in 3 dB steps as described above, depending on the number of branches of the branch circuit.
, 25W, etc. Therefore, a desired amplitude pattern similar to that shown in FIG. 5 can be obtained based on the arrangement shown in FIG. 3.

Note that the array antenna element is of course not limited to the planar shape, but also the line (
The antenna elements may be arranged in a line shape, and the antenna elements may not be connected to all terminals of the branch circuit.

[Effects of the Invention] This invention is configured as described above and has a particularly simple branch circuit, so it is not necessary to have many high-performance, multi-model transmitter/receiver circuits that have amplitude modulation N functions, and it is possible to achieve uniformity or unification. It is possible to easily obtain a desired antenna amplitude distribution with a standardized transmitting/receiving circuit, and it is possible to provide an array antenna device particularly suitable for an active phased array radar.

Further, according to the present invention, since several antenna elements are combined by branching the branch circuit, there is an advantage that the number of used transmitting/receiving circuits can be significantly reduced.

Furthermore, in conjunction with the above, control means for each circuit.

Since it is also possible to reduce the number of distributions in the synthesis distribution circuit,
This has great practical effects, such as simplifying the entire device, making it smaller and lighter, and increasing the reliability of the device itself.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the array antenna device of the present invention, FIG. 2 is a block diagram showing a transmitting/receiving circuit of the device shown in FIG. 1, and FIG. 3 is a plan view showing the antenna circuit of FIG. 1. FIG. 4 is a configuration diagram showing a conventional array antenna device, and FIG. 5 is a plan configuration diagram showing an antenna circuit of the device shown in FIG. 4. (1) Antenna element (2) Branch circuit (3) Transmission/reception circuit (4) Distribution and synthesis circuit

Claims (1)

[Claims] An array antenna having a plurality of unit sections in which a plurality of antenna elements are arranged and the number of antenna elements differs as the distance from the center of the array increases; and at least one antenna element connected to the plurality of antenna elements included in the unit section. An array antenna device comprising a plurality of branch circuits, a plurality of transmitting/receiving circuits respectively connected to the plurality of branch circuits, and a distribution/combining circuit connected to the plurality of transmitting/receiving circuits.