JPH06140827A - Antenna system - Google Patents

Abstract

PURPOSE:To remove a disturbing wave component to be received by the side lobe of an antenna. CONSTITUTION:The main beam of a sub antenna 13 is scanned, and a maximum azimuth is specified by a product between the level of disturbing waves and the gain of the side lobe of a main antenna 11 previously stored in the memory of a computer inside a controller 17. The main beam of the sub antenna 12 is made coincident with this direction, and the input signal of the sub antenna 12 is calculated through an arithmetic circuit 16 and subtracted from the input signal of the main antenna 11. Thus, the disturbing wave component received by the side lobe of the main antenna is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device for removing the influence of interfering waves.

[0002]

2. Description of the Related Art FIG. 3 shows an example of the configuration of a conventional device of this type. In the figure, 1 is a main antenna, which is an antenna for receiving a desired wave and an interfering wave. Reference numeral 2 is an auxiliary antenna having omnidirectional gain, 3a and 3b are mixers, 4a and 4b are local oscillators, 5 is a side lobe canceller, and 6 is an arithmetic unit.

Next, the operation will be described. Main antenna 1
And the electromagnetic wave signals received by the auxiliary antenna 2 are converted into the intermediate frequency IF by the mixers 3a and 3b local oscillators 4a and 4b, respectively. The IF signal v of the reception signal of the auxiliary antenna 2 is input to the side lobe canceller 5,
The estimated signal y from the side lobe direction included in the IF signal u received by the main antenna 1 is output. Arithmetic unit 6
Outputs the estimated signal z of the desired signal by subtracting the estimated signal y from the received signal u of the main antenna 1. z
Is fed back and input to the sidelobe canceller 5.

[0004]

The conventional device of this type is configured as described above, and since the directivity pattern of the auxiliary antenna 2 is broad, the auxiliary antenna 2 has a reception gain in the desired wave direction. The component of the desired wave signal mixed in the signal v influences the output signal y of the sidelobe canceller 5, and this interferes with the desired signal component contained in the input signal u of the main antenna 1, and the desired signal in the residual output signal z. The reception gain in the wave direction decreases, which causes distortion in the residual output signal z.

The present invention has been made in order to solve the above-mentioned problems, and of the interference waves to the main antenna, the desired directivity wave of the desired wave is generated by the synergistic effect of the gain directivity characteristic of the main antenna and the level of the interference wave itself. An object of the present invention is to obtain a side lobe cancelable antenna device capable of removing a signal component that gives maximum interference to a desired wave without distorting the signal and appropriately corresponding to the generation and amount of the interference wave. .

[0006]

SUMMARY OF THE INVENTION An antenna device according to the present invention includes a first antenna for receiving a desired wave, a second antenna for detecting the arrival direction of an interference wave, and a main antenna for detecting the arrival direction of the interference wave. It is provided with a third antenna capable of making the beam directions coincident with each other, and a control device for controlling these beam directions and signal arithmetic processing.

Further, the above third antenna is an antenna having a plurality of lobes whose directional directions can be controlled.

Further, an antenna is used in which one antenna has the functions of the second antenna and the third antenna.

[0009]

In the present invention, the main beam direction of the second antenna is scanned to identify the arrival direction of the interfering wave. The main beam direction of the third antenna is made to coincide with this direction, the reception signal of this antenna is calculated, and subtracted from the reception signal of the main antenna, that is, the first antenna to obtain the interference included in the reception signal of the first antenna. Remove the wave signal component.

The third antenna is an antenna having a plurality of lobes whose directional directions can be controlled so as to cancel the influence of a plurality of interfering waves.

Further, one antenna is provided with the functions of the second antenna and the third antenna, the main beam direction is scanned, the arrival direction of the interfering wave is specified, and then the main beam direction of this antenna is changed to this direction. The interference signal component contained in the reception signal of the main antenna is removed by matching and subtracting the calculated reception signal from the reception signal of the main antenna.

[0012]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 11 is a main antenna which is a first antenna, 12 and 13 are sub-antennas whose main beam direction can be changed by an electrical or mechanical means, and a sub-antenna 12 is a third antenna and a sub-antenna 1
3 corresponds to the second antenna. 14 and 15 are control circuits for changing the main beam directions of the sub-antennas 12 and 13, 1
Reference numeral 6 is an arithmetic circuit, and 17 is a control device.

The operation of this embodiment will be described with reference to FIG. FIG. 2 is a flowchart of a program stored in the memory of the computer in the control device 17. In the memory, the directivity pattern of the main antenna 11 is sampled at an arbitrary angle and its gain (power value) is stored.
As for the sub-antenna 12, the directivity pattern of only the main lobe is sampled at an arbitrary angle and its gain (power value) is stored. The sub-antenna 13 constantly scans the main lobe by the control circuit 15 over the range of ± 180 ° in the horizontal direction and ± 180 ° in the vertical direction with reference to the front direction of the main antenna 11 to obtain the input level and angle information of the received radio wave. Output to the control device 17. The control device 17 is composed of an A / D converter 18, a computer 19, and a signal processing circuit 20, as shown in FIG.

In the control unit 17, the input level of the sub-antenna 13 and the gain of the side lobe of the main antenna 11 are taken along the steps 21 to 27 of the flowchart of FIG. 2 except for the front direction of the main lobe of the main antenna 11. The angle θ ₁ that maximizes the product of is specified. Vice antenna 1 in this angle θ ₁
A control signal is output to the control circuit 14 of the sub-antenna 12 so that the main beam directions of 2 coincide with each other. As shown in FIG. 4, the gain directivity pattern of the main antenna is F (θ), the gain in the main lobe direction is F (θ ₀ ), and the gain in the θ ₁ direction described above is F (θ ₁ ). Now, let us say that the gain in the front direction of the main lobe of the sub-antenna 12 is h. From the controller 17 to the arithmetic circuit 1
If a control signal is output to 6 so that the input v from the sub antenna is multiplied by F (θ ₁ ) / h, the output y of the arithmetic circuit 16 is the side lobe in the θ ₁ direction included in the received signal u of the main antenna 11. Becomes equal to the interference signal received by
By subtracting this from u in the arithmetic unit 6, the interference wave can be removed and the desired wave / interference wave ratio can be increased.

Example 2. It should be noted that in the above embodiment, only the interference wave in one direction can be removed, but the present invention is not limited to this, and an antenna having a plurality of main lobes capable of controlling the pointing direction is used as the sub antenna 12 of the third antenna. This makes it possible to remove the interfering waves received by the side lobes of the main antenna 11.

Embodiment 3. In this embodiment, the sub antenna 12
By making it possible to perform beam scanning and to fix it in a specific direction, it is possible to provide one antenna with the functions of two sub-antennas as in the first embodiment. That is, the antenna 12 is capable of beam scanning and fixing the main beam in a specific direction. After the beam scanning is performed to specify the arrival direction of the interfering wave, the main beam is matched with the arrival direction of the interfering wave. The calculation output of the reception signal of 12 is added to the reception signal of the main antenna 11 to remove the interfering wave component.
3 can be eliminated.

[0017]

As described above, according to the present invention, the main antenna and the two sub-antennas are provided, the arrival direction of the interfering wave is specified by the received signal of the one sub-antenna, and the direction of the main beam is determined. Since the arithmetic processing of the reception signal of the other one sub-antenna matched to the direction of arrival is subtracted from the reception signal of the main antenna, an antenna device capable of canceling the interference wave component of the main antenna is obtained. To be If one antenna has the functions of the above two sub-antennas, the system becomes more inexpensive and the same effect can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an antenna device according to the present invention.

FIG. 2 is a flowchart of a program stored in a memory of a computer in the control device.

FIG. 3 is a configuration diagram of a control device.

FIG. 4 is a directivity pattern of a main antenna and a sub antenna.

FIG. 5 is a configuration diagram showing a conventional antenna device of this type.

[Explanation of symbols]

 1 Main Antenna 2 Auxiliary Antenna 3 Mixer 4 Local Oscillator 5 Sidelobe Canceller 6 Arithmetic Device 11 Main Antenna 12 Sub-Antenna 1 13 Sub-Antenna 2 14 Sub-Antenna 1 Control Circuit 15 Sub-Antenna 2 Control Circuit 16 Arithmetic Circuit 17 Control Circuit 18 A / D converter 19 Computer 20 Signal processing circuit

Claims (3)

[Claims] 1. A first antenna for receiving a desired wave and an interfering wave, a second antenna capable of scanning a direction of a main beam within a predetermined angle range, a reception input level of the second antenna, and the above-mentioned first antenna. It is possible to sequentially match the direction of the main beam with the direction of the main beam and the arithmetic unit that specifies the arrival direction of the interference wave that affects the first antenna based on the calculation with the gain directivity of the first antenna. The third antenna and this third
An arithmetic unit for calculating a received signal of the antenna of claim 1 and adding it to the received signal of the first antenna. 2. The third antenna is an antenna having a plurality of lobes under the control of the pointing direction, and interference waves received by a plurality of side lobes of the first antenna are removed. The antenna device according to the item. 3. A single antenna having the functions of the second and third antennas, scanning the main beam direction to identify the arrival direction of the interfering wave, and then the main beam direction of the one antenna. 2. The antenna device according to claim 1, wherein the received signal is calculated so as to coincide with the direction of arrival and the calculated received signal is subtracted from the received signal of the main antenna.