JPH07151847A - Radar antenna equipment - Google Patents

Abstract

PURPOSE:To realize a radar system which can ensure the covering range with a minimum transmission power and is highly economical. CONSTITUTION:A vertical array 1 has a cosec<2> radiation characteristic of and is a waveguide slot array of which the loss is minimized by LP(linear programming). The ripple of a main beam is small and the effective gain of the array is equal to the one of a reflector antenna when a pattern loss is taken into consideration. A synthesizer-distributor 2, which executes a power distribution for giving a prescribed pattern of a horizontal plane, has a construction by which the number of transmission-reception modules 3 can be reduced. The transmission-reception module 3 is equipped with a power amplifier, a low-noise amplifier and a circulator. A distributor 4 supplies an exciting signal to each transmission-reception module 3 at the time of transmission. A synthesizer 5 synthesizes a reception signal of each transmission-reception module 3 at the time of reception.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar antenna apparatus using a solid-state transceiver.

[0002]

2. Description of the Related Art ASR (Airport Surveillance Radar) and ASSR
In a primary radar such as (airway monitoring radar), a radar antenna device is generally constructed by using a reflector antenna and a high-power transmitter. The aerial line is set on a steel tower (often 30 m in Japan) to secure the line of sight. On the other hand, the transceiver is installed in the station building under the tower to ensure maintainability. Therefore, since the antenna and the transceiver are connected by a long waveguide, a certain feeder loss occurs. For example, assuming that the antenna and the transceiver are connected by a waveguide of 40 m in the S band, the feeder loss is about 6 dB in a round trip.

Further, with the recent development of microwave semiconductor devices, solid-state transmitters can be applied to radar antenna systems, and maintenance and maintainability and reliability can be improved. In a radar antenna device using a solid-state transmitter, the power that can be handled by one semiconductor element is limited,
A medium output transmission module in which semiconductor elements are connected in parallel is further connected in parallel to obtain a desired high output.

Taking the S band as an example, a semiconductor device having a peak power of 100 W and a transmission module output of 700 W has been put into practical use. When a radar antenna device with a transmission output of 30 kW is realized by using this, 50 transmission modules are used in consideration of the synthetic loss.

[0005]

As described above, in the radar antenna apparatus using the solid-state transmitter, a large number of transmission modules are used. For example, if a feeder loss of 6 dB is expected, there is no feeder loss. Since a double transmission output is required, a 4-fold transmission module is required, which causes a problem of cost increase.

Further, since the design pattern of the reflector antenna is limited, so-called cut and cut is required for pattern analysis.
Due to the large number of trie elements, it is very difficult to optimize the desired vertical plane pattern. Therefore, in a radar antenna device using a reflector antenna, considerable vertical plane pattern loss must be expected, but this vertical plane pattern loss is also one of the major factors that raise the required power, so energy saving can be achieved. There is also the problem of difficulty.

An object of the present invention is to provide a radar antenna apparatus which can reduce the number of transmission modules and can construct a highly economical radar system.

[0008]

In order to achieve the above object, the radar antenna apparatus of the present invention has the following structure. That is, the radar antenna apparatus of the present invention includes: a plurality of vertical arrays forming a vertical radiation pattern; a plurality of transmitting / receiving modules for amplifying high frequency signals; and a transmitting high frequency signal output by the plurality of transmitting / receiving modules for the plurality of vertical arrays. Is a composite distributor for feeding high frequency signals of a plurality of vertical arrays to a plurality of transmitting / receiving modules, and a feeding distribution giving a low sidelobe horizontal plane radiation pattern at the connection end with the vertical array is obtained. And a distributor that distributes and outputs an excitation high-frequency signal to the plurality of transmission / reception modules; and a combination of reception high-frequency signals output from the plurality of transmission / reception modules. It is characterized by having a synthesizer and.

[0009]

Next, the operation of the radar antenna apparatus of the present invention constructed as described above will be described. The radar antenna apparatus of the present invention uses a vertical array antenna. As is well known, a vertical array antenna is a planar array antenna having a vertical plane radiation pattern with a cosec ² characteristic and a good sharp cutoff characteristic. Therefore, it is not necessary to consider the vertical plane pattern loss, which is a problem with the reflector antenna, and the transmission power can be reduced.

Further, the horizontal plane radiation pattern is desired to have a low side lobe, which is realized by the composite distributor by setting the horizontal feed distribution to the power excitation distribution required to obtain the low side lobe horizontal pattern.

Specifically, the power excitation distribution is a Taylor distribution, a Chebyshev distribution, etc., but these distributions have a distribution shape in which the level in the central portion is relatively constant and the attenuation is made toward both ends. ing. Therefore, in the case of transmission, the combiner / distributor receives a transmission high-frequency signal of constant power from the transceiver module, directly connects the power amplifier of the transceiver module for the vertical array near the center, and for the vertical array near both ends. The output of the power amplifier of one transceiver module is distributed to the vertical arrays so as to obtain the desired radiated power.

Since the distributor in the composite distributor can obtain a large distribution ratio with a small loss, the power supply loss can be minimized, and the electric power (output of the transceiver module) handled is relatively small. A power supply circuit can also be easily realized.

As a result of the synthesis distributor having such a configuration, the number of transmission / reception modules can be made smaller than the number of vertical arrays.

In short, it is possible to secure the radar coverage with the minimum transmission power, and to construct a low-cost and low-power radar system.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a radar antenna apparatus according to an embodiment of the present invention. The radar antenna apparatus of the present invention basically comprises a plurality of vertical arrays 1, one or a plurality of combiner / distributors 2, a plurality of transmitting / receiving modules 3, a distributor 4 and a combiner 5. Since transmission and reception are reversible, the operation at the time of transmission will be mainly described below.

The excitation signal applied to the input terminal 6 is distributed to the plurality of transmitting / receiving modules 3 by the distributor 4.
Since a class C amplifier is often used as the microwave amplifier from the viewpoint of improving efficiency, the distributor 4 is an equal power distributor.

As shown in FIG. 2, the transmission / reception module 3 includes a power amplifier 21 in the transmission system and a low noise amplifier 22 in the reception system. At the time of transmission, the excitation signal from the equal power distributor 4 is input to the power amplifier 21 via the input terminal 25, amplified to a predetermined power, passed through the circulator 23, and output from the input / output terminal 24 to the combiner distributor 2. It At the time of reception, the received signal from the combiner / distributor 2 is input from the input / output terminal 24 through the circulator 23 to the low noise amplifier 22, is amplified to a predetermined level, and is output to the combiner 5 via the output terminal 26. In principle, the input / output level and phase of the transmitting / receiving module 3 are the same regardless of the place where they are used.

The combiner / distributor 2 converts the input signals from the plurality of transmission / reception modules 3 into a plurality of vertical arrays 1 into a power excitation distribution (Taylor distribution, Chebyshev distribution, etc.) required for forming a horizontal radiation pattern of a low sidelobe. Supply power. For example, in the Taylor distribution, as shown in FIG. 3, the central portion has a relatively constant level and has a distribution shape that attenuates toward both ends, but the vertical array 1 is fed with such a Taylor distribution. FIG. 4 shows a configuration example of the combiner / distributor 2.

FIG. 4 shows 6 inputs 12 for simplicity of explanation.
The output distributor is shown. That is, the configuration is such that only six transmission / reception modules are required for twelve vertical arrays. In FIG. 4, the center 4 outputs of 12 outputs are connected to the vertical array corresponding to the vicinity of the center of the Taylor distribution, but the level difference is ±
Since it is about 0.5 dB, the outputs of the four transmission / reception modules 3 are passed through as they are. On the other hand, at the 4 output terminals at both ends,
The output of one transmission / reception module 3 is divided into four by a Wilkinson type distributor at a predetermined distribution ratio. Since the output of the transceiver module is relatively small, 1 kW or less, these distribution circuits can be easily configured and are used in the PWBs that are commonly used.
Can be realized with.

The vertical array 1 is, for example, a waveguide slot array, and it is possible to optimize a vertical plane radiation pattern which is difficult to realize with a reflector antenna. FIG. 5 shows an example of comparison between a vertical plane radiation pattern 13 required for ASR, a vertical plane radiation pattern 12 designed with a vertical array antenna, and a vertical plane radiation pattern 11 designed with a reflector antenna. . The vertical plane opening length is 2.2 m in the array antenna.
The aerial line of the reflector is 2.7 m.

It is difficult to optimize a desired vertical plane radiation pattern with a reflector antenna, and it is inevitable that vertical plane pattern loss will occur. However, when an array antenna is used, ripples are small in a small aperture and the coverage is close to the required range. The optimum vertical plane radiation pattern can be obtained. Particularly, when the waveguide slot array is used, the insertion loss (distribution ratio loss) can be suppressed by LP (linear programming) by about 1 dB.

Although the effective gain is 1 dB lower than that of the reflector antenna, the pattern loss is improved by 1 dB because the pattern ripple is small. Therefore, the antenna gain for the required coverage is considered to be equivalent to that of the reflector antenna.

According to this embodiment, in the radar system of 50 kW output, 90 transmission / reception modules of 700 W output were conventionally required, but this can be reduced to 1/4.

[0024]

As described above, in the radar antenna apparatus of the present invention, the vertical array which has a good radiation pattern on the vertical plane and can reduce the transmission power can be used, and the number of the transmitter / receiver modules can be reduced. Since the configuration is adopted, the radar coverage can be secured with the minimum transmission power, and there is an effect that a low cost and low power radar system can be constructed.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a radar antenna device according to an embodiment of the present invention.

FIG. 2 is a configuration block diagram of a transmission / reception module.

FIG. 3 is a characteristic diagram of Taylor distribution.

FIG. 4 is a block diagram showing a configuration example of a combining / distributing device.

FIG. 5 is a comparison diagram of vertical plane radiation patterns of ASR antennas (13: required value, 12: design value of vertical array antenna, 1
1: Design value of the reflector antenna.

[Explanation of symbols]

 1 Vertical Array 2 Combiner / Distributor 3 Transmitter / Receiver Module 4 Distributor 5 Combiner 21 Power Amplifier 22 Low Noise Amplifier 23 Circulator

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[Procedure amendment]

[Submission date] July 7, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

In order to achieve the above object, the radar antenna apparatus of the present invention has the following structure. That is, the radar antenna apparatus of the present invention comprises: a plurality of vertical arrays forming a vertical radiation pattern; a plurality of transmitting / receiving modules for amplifying high frequency signals; and a transmitting high frequency signal output from the plurality of transmitting / receiving modules for the plurality of vertical arrays. Is a composite distributor for feeding the received high-frequency signals of a plurality of vertical arrays to a plurality of transmission / reception modules, and a power distribution that gives a low sidelobe horizontal plane radiation pattern at the connection end with the vertical array is obtained. And a distributor that distributes and outputs an excitation high-frequency signal to the plurality of transmission / reception modules; and a combination of reception high-frequency signals output from the plurality of transmission / reception modules. It is characterized by having a synthesizer and. This
Here, the vertical array is specifically a waveguide slot array.
And the low side at the connection end with the vertical array
The feed distribution giving the lobe horizontal radiation pattern is the tailor
Distribution, Chebyshev distribution, etc. And a composite distributor
Specifically, the vertical array and the transmission / reception module are
1: 1 connection with the base, and multiple vertical arrays near both ends.
Configured to connect the transceiver with one transceiver module.
Be done.

Claims (1)

[Claims] 1. A plurality of vertical arrays forming a vertical radiation pattern; a plurality of transmitting / receiving modules for amplifying high frequency signals; a plurality of transmitting high frequency signals output from the plurality of transmitting / receiving modules for feeding to the plurality of vertical arrays; Is a composite distributor that distributes the received high-frequency signals of the vertical array to multiple transceiver modules, and a feed distribution that gives a low sidelobe horizontal plane radiation pattern at the connection end with the vertical array is obtained at the connection end with the transmission / reception module. A combiner having a configuration capable of obtaining a uniform power distribution; a distributor distributing and outputting an excitation high-frequency signal to the plurality of transmitting / receiving modules; and a combiner combining the received high-frequency signals output from the plurality of transmitting / receiving modules; A radar antenna device characterized by being provided.