WO2018142501A1 - Antenna device - Google Patents

Abstract

When electromagnetic waves have arrived from a space, a controller (20) controls a first regulator (12) or a second regulator (18) in accordance with an other reception signal Er2 distributed by a signal distributor (13), so that an antenna (1) is irradiated with the electromagnetic waves, whereby a transmission signal E r3 having the same amplitude and the opposite phase as scattered waves Es scattered by the antenna (1) is emitted by the antenna (1).

Description

Antenna device

The present invention relates to an antenna device that radiates a transmission signal having the same amplitude and opposite phase as an electromagnetic wave scattered by an antenna.

When an electromagnetic wave arrives from space, the electromagnetic wave may be scattered by the antenna by being irradiated on the antenna.
At this time, the ratio of the intensity of the electromagnetic wave arriving from the space to the intensity of the scattered wave, which is an electromagnetic wave scattered by the antenna, is called a radar cross section (RCS: Radar Cross Section).

When the RCS in the arrival direction is large, there is a high possibility that the presence of a moving body or the like equipped with an antenna is detected, and thus the necessity for reducing the RCS in the arrival direction is high.
As a typical method for reducing the RCS in the direction of arrival, a method using a radio wave absorber is known.
The radio wave absorber can absorb the electromagnetic wave coming from the space and lose the power of the electromagnetic wave, thus preventing the scattering of the electromagnetic wave coming from the space and reducing the scattered wave returning to the arrival direction. Can do. Thereby, the RCS in the arrival direction is reduced.

However, in the case of a method using a radio wave absorber, the performance of the antenna device may be degraded.
For example, in the case where the antenna device includes an antenna having strong directivity, if the radio wave absorber is disposed in order to reduce RCS in the direction having strong directivity, RCS in the direction having strong directivity can be reduced. However, there is a problem that the function of transmitting and receiving signals, which is the original function of the antenna, is lost.
In the case of the method using the radio wave absorber, only the RCS of the scattered wave determined by the shape of the antenna among the scattered waves scattered by the antenna (hereinafter referred to as “structural mode RCS”). For this reason, the electromagnetic wave arriving from the space excites the feeding point of the antenna, so that the RCS of the scattered wave re-radiated from the antenna (hereinafter referred to as “antenna mode RCS”) cannot be reduced. There is.

The following Patent Document 1 discloses an antenna device that can solve the above-described problems.
The RCS reduction method used by this antenna apparatus is a method for preventing scattered waves from returning strongly in a specific direction in space by setting the plurality of antenna elements constituting the array antenna by shifting the phases.

JP 2016-167769 A

Since the conventional antenna device is configured as described above, the structural mode RCS and the antenna mode RCS can be reduced. However, the original functions of the antenna such as transmission / reception of communication signals are lost during the period in which the structural mode RCS and the antenna mode RCS are reduced. Or the subject that the original function of an antenna was restricted occurred.

The present invention has been made to solve the above-described problems, and an antenna device capable of transmitting or receiving a communication signal even during a period in which the structural mode RCS and the antenna mode RCS are reduced is provided. Objective.

An antenna device according to the present invention radiates a transmission signal as an electromagnetic wave to space while receiving an electromagnetic wave arriving from space and outputting a reception signal of the electromagnetic wave, and an amplitude of the reception signal output from the antenna and A first adjuster that adjusts the phase; a signal distributor that distributes the received signal whose amplitude and phase are adjusted by the first adjuster; and the amplitude and phase of one received signal that is distributed by the signal distributor A second adjuster that adjusts and outputs the received signal, the amplitude and phase of which have been adjusted, to the antenna as a transmission signal. When the electromagnetic wave arrives from the space, the controller irradiates the antenna with the electromagnetic wave. Thus, the other receiving signal distributed by the signal distributor so that a transmission signal having the same amplitude and opposite phase as the scattered wave, which is an electromagnetic wave scattered by the antenna, is radiated from the antenna. It is obtained so as to control the first regulator or a second regulator according to Patent.

According to this invention, when the electromagnetic wave arrives from the space, the controller irradiates the antenna with the electromagnetic wave. Is configured to control the first adjuster or the second adjuster according to the other received signal distributed by the signal distributor such that the structural mode RCS and the antenna mode RCS are reduced. There is an effect that transmission or reception of a communication signal can be performed even during a period during which the communication signal is transmitted.

It is a block diagram which shows the antenna apparatus by Embodiment 1 of this invention. It is a block diagram which shows the antenna apparatus by Embodiment 2 of this invention. It is a block diagram which shows the antenna apparatus by Embodiment 3 of this invention. It is a block diagram which shows the controller 20 of the antenna apparatus by Embodiment 4 of this invention. It is a hardware block diagram which shows the controller 20 of an antenna apparatus. It is a hardware block diagram of a computer in case the controller 20 is implement | achieved by software or firmware. It is a flowchart which shows the process sequence in case the controller 20 is implement | achieved by software or firmware. 6 is an explanatory diagram illustrating an example of a table stored in a table storage unit 52. FIG. It is a block diagram which shows the antenna apparatus by Embodiment 5 of this invention.

Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.

Embodiment 1 FIG.
1 is a block diagram showing an antenna apparatus according to Embodiment 1 of the present invention.
In FIG. 1, an antenna 1 radiates a transmission signal output from a signal transmission / reception unit 2 or a communication signal to be transmitted as an electromagnetic wave to the space, while receiving an electromagnetic wave arriving from the space, and signals the received signal of the electromagnetic wave as a signal. Output to the transmission / reception unit 2.
The antenna 1 may be any antenna as long as it satisfies the angle characteristics and input / output characteristics in a desired frequency band.

Here, the electromagnetic wave that has arrived from the space may be an external unnecessary wave or an electromagnetic wave related to a communication signal to be received.
The transmission signal is a signal having the same amplitude and opposite phase as the scattered wave that is an electromagnetic wave scattered by the antenna 1.
The scattered wave scattered by the antenna 1 is a scattered wave determined by the shape of the antenna 1. The scattered wave in which the electromagnetic wave arriving from the space is reflected by the antenna 1 and the electromagnetic wave arriving from the space are the antenna. By exciting one feeding point, scattered waves re-radiated from the antenna 1 are included.
Note that the RCS of the scattered wave determined by the shape of the antenna 1 is the structural mode RCS, and the scattered wave re-radiated from the antenna 1 when the electromagnetic wave arriving from the space excites the feeding point of the antenna 1. RCS is an antenna mode RCS.

The signal transmission / reception unit 2 includes a transmission / reception switch 11, a first adjuster 12, a signal distributor 13, a receiver 14, an A / D converter 15 as an analog / digital converter, and a D / A conversion as a digital / analog converter. 16, a transmitter 17, and a second adjuster 18.
In FIG. 1, the receiver 14 is represented as “Rx” and the transmitter 17 is represented as “Tx”.
The transmission / reception switch 11 is realized by, for example, a circulator, and outputs a transmission signal output from the second adjuster 18 or a communication signal to be transmitted to the antenna 1, and receives a reception signal output from the antenna 1. Output to the first regulator 12.

The first adjuster 12 is a receiver-side adjuster, and includes a low noise amplifier (LNA: Low Noise Amplifier) 12a and a phase shifter 12b.
The first adjuster 12 adjusts the amplitude and phase of the reception signal output from the transmission / reception switch 11 and outputs the reception signal adjusted in amplitude and phase to the signal distributor 13.
In the low noise amplifier 12a, the amount of adjustment of the amplitude, which is a gain, is controlled by the controller 20, and the amplitude of the reception signal output from the transmission / reception switch 11 is adjusted.
The phase adjustment amount of the phase shifter 12b is controlled by the controller 20, and the phase of the reception signal whose amplitude is adjusted by the low noise amplifier 12a is adjusted.

The signal distributor 13 is realized by a directional coupler, for example. The signal distributor 13 distributes the received signal whose amplitude and phase are adjusted by the first adjuster 12, and the second received signal is divided into two. The other received signal divided into two is output to the receiver 14.
The receiver 14 performs a reception process on the reception signal output from the signal distributor 13 and outputs the reception signal after the reception process to the A / D converter 15 as an electric signal. Since the reception process itself is a known technique, a detailed description thereof will be omitted, but the reception process includes, for example, a received signal detection process, a demodulation process, a frequency conversion process, and the like.
The A / D converter 15 converts the electrical signal output from the receiver 14 from an analog signal to a digital signal, and outputs the converted digital signal to the controller 20.

The D / A converter 16 converts the communication signal to be transmitted output from the controller 20 from a digital signal to an analog signal, and outputs the communication signal that is the converted analog signal to the transmitter 17.
The transmitter 17 performs a transmission process on the communication signal output from the D / A converter 16 and outputs the communication signal after the transmission process to the second adjuster 18. Since the transmission process itself is a known technique and will not be described in detail, the transmission process includes, for example, a frequency conversion process and a modulation process of a communication signal.

The second adjuster 18 is a transmitter-side adjuster, and includes a phase shifter 18a and a variable amplifier (VGA: Variable Gain Amplifier) 18b.
The second adjuster 18 adjusts the amplitude and phase of the reception signal output from the signal distributor 13 or the communication signal output from the transmitter 17.
The second adjuster 18 outputs the reception signal adjusted in amplitude and phase to the transmission / reception switch 11 as a transmission signal, and outputs the communication signal adjusted in amplitude and phase to the transmission / reception switch 11.
The phase adjustment amount of the phase shifter 18 a is controlled by the controller 20 and adjusts the phase of the reception signal output from the signal distributor 13 or the communication signal output from the transmitter 17.
In the variable amplifier 18b, the amount of adjustment of the amplitude, which is a gain, is controlled by the controller 20, and the amplitude of the reception signal or communication signal whose phase is adjusted by the phase shifter 18a is adjusted.
The variable amplifier 18b is not limited to the VGA, and may be realized by a combination of an amplifier and an attenuator.

The controller 20 is realized by, for example, a computer having a memory, a semiconductor integrated circuit on which a CPU (Central Processing Unit) is mounted, or a one-chip microcomputer.
Controller 20 stores the scattered wave E ^s being scattered by the previously antenna 1, so that the transmission signal of the scattered wave E ^s and the same amplitude and opposite phases to be scattered by the antenna 1 is radiated from the antenna 1, The first regulator 12 or the second regulator 18 is controlled in accordance with the digital signal output from the A / D converter 15.

That is, when receiving the communication signal to be received, the controller 20 adjusts the phase by the phase adjuster 18 a included in the second adjuster 18 according to the digital signal output from the A / D converter 15. The amount of amplitude and the amount of amplitude adjustment by the variable amplifier 18b are controlled.
Further, when transmitting the communication signal to be transmitted, the controller 20 determines the amplitude of the low noise amplifier 12a included in the first adjuster 12 according to the digital signal output from the A / D converter 15. The adjustment amount and the adjustment amount of the phase by the phase shifter 12b are controlled.
Scattered wave E ^s scattered by the antenna 1 is a scattered wave which is determined by the shape of the antenna 1, knowing the shape of the antenna 1 can be grasped in advance by simulation calculation or the like.

In the formula (1), the amplitude of _{A s} is scattered wave ^{E s,} phi _s is the phase of the scattered wave ^{E s.}

Next, the operation will be described.
First, an operation when receiving a communication signal to be received will be described.
During the communication signal receiving operation, the amplitude adjustment amount Γ _r2 by the low noise amplifier 12a included in the first adjuster 12 is set to a fixed adjustment amount by the controller 20.
The phase adjustment amount φ _r2 by the phase shifter 12b included in the first adjuster 12 is set to a fixed adjustment amount by the controller 20.

The antenna 1 receives an electromagnetic wave arriving from a space and outputs a reception signal ^{Er 1 of the} electromagnetic wave to the signal transmission / reception unit 2.

In Expression (2), A _r1 is the amplitude of the reception signal E ^r1 , and φ _r1 is the phase of the reception signal E ^r1 .

When the transmission / reception switch 11 of the signal transmission / reception unit 2 receives the reception signal E ^r1 output from the antenna 1, the transmission / reception switch 11 outputs the reception signal E ^r1 to the first adjuster 12.
Low-noise amplifier 12a of the first regulator 12 receives the received signal E ^r1 output from the duplexer 11, by the adjustment amount gamma _r2 amplitude being set by the controller 20, the received signal E ^r1 Adjust the amplitude.
The phase adjuster 12 b of the first adjuster 12 adjusts the phase of the received signal whose amplitude is adjusted by the low noise amplifier 12 a by the phase adjustment amount φ _r2 set by the controller 20.
The reception signal ^{Er 2} after the amplitude and phase are adjusted by the first adjuster 12 is output to the signal distributor 13.

When the signal distributor 13 receives the reception signal E ^r2 output from the first adjuster 12, the signal distributor 13 distributes the reception signal E ^r2 into two and distributes the two received signals E ^r2 into the second adjuster. The other received signal ^Er2 divided into two is output to the receiver 14.
Receiver 14, the signal when the distributor 13 receives the received signal E ^r2 output from, carried out reception processing for the received signal E ^r2, A / D converter receiving signal E ^r2 as an electric signal after reception processing 15 is output.
The A / D converter 15 converts the electrical signal output from the receiver 14 from an analog signal to a digital signal, and outputs the converted digital signal to the controller 20.

Phaser 18a of the second regulator 18, upon receiving the received signals E ^r2 output from the signal divider 13, only the phase adjustment amount phi _r3, which is set by the controller 20, the phase of the received signal E ^r2 Adjust.
Variable amplifier 18b of the second regulator 18, by the adjustment amount gamma _r3 amplitude set by the controller 20 to adjust the amplitude of the received signal E ^r2 whose phase is adjusted by the phase shifter 18a.
The reception signal whose amplitude and phase are adjusted by the second adjuster 18 is output to the transmission / reception switch 11 as a transmission signal ^Er3 .

When the transmission / reception switch 11 receives the transmission signal ^Er3 output from the second adjuster 18, the transmission / reception switch 11 outputs the transmission signal ^Er3 to the antenna 1. Accordingly, the transmission signal ^Er3 is radiated from the antenna 1 to the space as an electromagnetic wave.
Here, the amplitude of the transmission signal ^{E r3} radiated from the antenna _{1 (Γ r3 Γ r2 A r1} ) is the same as the amplitude _{A s} of the scattered wave ^{E s} scattered by the antenna 1 and transmit signal ^{E r3} If the phase (φ _r1 + φ _r2 + φ _r3 ) is opposite to the phase φ _s of the scattered wave E ^s scattered by the antenna 1, the sum of the transmission signal E ^r3 and the scattered wave E ^s becomes zero. As a result, the scattered wave E ^s is canceled in the transmission signal E ^r3, reception of the scattered waves E ^s of the external becomes difficult.

When the controller 20 receives the digital signal output from the A / D converter 15 of the signal transmission / reception unit 2, the controller 20 analyzes the digital signal, and the electromagnetic wave received by the antenna 1 is related to the communication signal to be received. Or an electromagnetic wave related to an unnecessary wave coming from the outside. Since this electromagnetic wave determination method is a known technique, detailed description thereof is omitted.
Controller 20, when the electromagnetic waves received by the antenna 1 is an electromagnetic wave according to the unwanted wave, since it is highly necessary to reduce the radar cross section, the scattered wave E ^s and the same amplitude and opposite phase being scattered by the antenna 1 The phase adjustment amount φ _r3 by the phase shifter 18a and the amplitude adjustment amount Γ _r3 by the variable amplifier 18b are controlled so that the transmission signal E ^r3 is radiated from the antenna 1.

When the electromagnetic wave received by the antenna 1 is an electromagnetic wave related to a communication signal to be received, the controller 20 is included in, for example, the second adjuster 18 because the necessity for reducing the radar cross-sectional area is low. The variable amplifier 18b is controlled so that the gain of the variable amplifier 18b becomes zero. In this case, there is no possibility that the transmission signal E ^r3 scattered wave E ^s and the same amplitude and opposite phases to be scattered by the antenna 1 is radiated from the antenna 1.
However, this is only an example, as in the case the electromagnetic waves received by the antenna 1 is an electromagnetic wave according to the unnecessary wave, the transmission of the scattered wave E ^s and the same amplitude and opposite phases to be scattered by the antenna 1 signal E ^r3 May be radiated from the antenna 1.

Hereinafter, the control of the phase adjustment amount φ _r3 and the amplitude adjustment amount Γ _{r3 by} the controller 20 will be specifically described.
Controller 20 analyzes the digital signal output from the A / D converter 15 of the signal transmitting and receiving unit 2, the received signal ^{E r2} amplitude (Γ _r2 A _r1) and of the received signal ^{E r2} phase (φ _r1 + φ _r2 ) is specified.
Next, the controller 20, the amplitude _{A s} of the scattered wave ^{E s} which is stored in advance, since the amplitude (Γ _r2 A _r1) of the received signal ^{E r2,} the same amplitude and the amplitude _{A s} of the scattered wave ^{E s} to calculate the adjustment amount gamma _r3 amplitude for obtaining the amplitude (Γ _r3 Γ _r2 a _r1) of the transmission signal ^{E r3} made.

Further, the controller 20 is the phase phi _s of the scattered wave ^{E s} stored in advance, because the phase (φ _r1 + φ _r2) of the received signal ^{E r2,} the scattered wave ^{E s} phase phi _s antiphase A phase adjustment amount φ _r3 for obtaining the phase (φ _r1 + φ _r2 + φ _r3 ) of the transmission signal E ^r3 is calculated.

Controller 20, calculating the adjustment amount gamma _r3 amplitude, as the adjustment amount of the amplitude by the variable amplifiers 18b of the second regulator 18, sets the adjustment amount gamma _r3.
Controller 20, calculating the adjustment amount phi _r3 of phase, as the adjustment amount of the phase by phase shifter 18a of the second regulator 18, sets the adjustment amount phi _r3.

Next, an operation when transmitting a communication signal to be transmitted will be described.
During the communication signal transmission operation, the amplitude adjustment amount Γ _r3 by the variable amplifier 18b included in the second adjuster 18 is set to a fixed adjustment amount by the controller 20.
The phase adjustment amount φ _r3 by the phase shifter 18a included in the second adjuster 18 is set to a fixed adjustment amount by the controller 20.

The controller 20 outputs a communication signal to be transmitted to the D / A converter 16 of the signal transmission / reception unit 2.
Upon receiving the communication signal to be transmitted output from the controller 20, the D / A converter 16 converts the communication signal from a digital signal to an analog signal, and outputs the converted analog signal to the transmitter 17.
The transmitter 17 performs a transmission process on the communication signal that is an analog signal output from the D / A converter 16, and outputs the communication signal after the transmission process to the second adjuster 18.

When the phase adjuster 18a of the second adjuster 18 receives the communication signal after transmission processing output from the transmitter 17, the communication after the transmission processing is performed by the phase adjustment amount φ _r3 set by the controller 20. Adjust the signal phase.
The variable amplifier 18b of the second adjuster 18 adjusts the amplitude of the communication signal whose phase is adjusted by the phase adjuster 18a by the amplitude adjustment amount Γ _r3 set by the controller 20.
The communication signal whose amplitude and phase are adjusted by the second adjuster 18 is output to the transmission / reception switch 11.
When receiving / transmitting the communication signal output from the second adjuster 18, the transmission / reception switch 11 outputs the communication signal to the antenna 1. Thereby, a communication signal is radiated | emitted to space from the antenna 1 as electromagnetic waves.

Even during transmission of communication signals, unwanted waves may come from the outside.
The antenna 1 receives an electromagnetic wave that has arrived from space, and outputs the received signal ^{Er1 of the} electromagnetic wave represented by the above formula (2) to the signal transmission / reception unit 2.
When the transmission / reception switch 11 of the signal transmission / reception unit 2 receives the reception signal E ^r1 output from the antenna 1, the transmission / reception switch 11 outputs the reception signal E ^r1 to the first adjuster 12.

Low-noise amplifier 12a of the first regulator 12 receives the received signal E ^r1 output from the duplexer 11, the amplitude set by the controller 20 by the adjustment amount gamma _r2, of the received signal E ^r1 Adjust the amplitude.
The phase adjuster 12 b of the first adjuster 12 adjusts the phase of the received signal whose amplitude is adjusted by the low noise amplifier 12 a by the phase adjustment amount φ _r2 set by the controller 20.
The reception signal ^{Er 2} represented by the expression (3) after the amplitude and phase are adjusted by the first adjuster 12 is output to the signal distributor 13.

When the signal distributor 13 receives the reception signal E ^r2 output from the first adjuster 12, the signal distributor 13 distributes the reception signal E ^r2 into two and distributes the two received signals E ^r2 into the second adjuster. The other received signal ^Er2 divided into two is output to the receiver 14.
Receiver 14, the signal when the distributor 13 receives the received signal E ^r2 output from, carried out reception processing for the received signal E ^r2, A / D converter receiving signal E ^r2 as an electric signal after reception processing 15 is output.
The A / D converter 15 converts the electrical signal output from the receiver 14 from an analog signal to a digital signal, and outputs the converted digital signal to the controller 20.

Phaser 18a of the second regulator 18, upon receiving the received signals E ^r2 output from the signal divider 13, a phase which is set by the controller 20 by the adjustment amount phi _r3, of the received signal E ^r2 Adjust the phase.
Variable amplifier 18b of the second regulator 18, by the adjustment amount gamma _r3 amplitude being set by the controller 20 to adjust the amplitude of the received signal E ^r2 whose phase is adjusted by the phase shifter 18a.
The reception signal whose amplitude and phase are adjusted by the second adjuster 18 is output to the transmission / reception switch 11 as the transmission signal ^Er3 represented by the above equation (4).

When the transmission / reception switch 11 receives the transmission signal ^Er3 output from the second adjuster 18, the transmission / reception switch 11 outputs the transmission signal ^Er3 to the antenna 1. Accordingly, the transmission signal ^Er3 is radiated from the antenna 1 to the space as an electromagnetic wave.
Here, the amplitude of the transmission signal ^{E r3} radiated from the antenna _{1 (Γ r3 Γ r2 A r1} ) is the same as the amplitude _{A s} of the scattered wave ^{E s} scattered by the antenna 1 and transmit signal ^{E r3} If the phase (φ _r1 + φ _r2 + φ _r3 ) is opposite to the phase φ _s of the scattered wave E ^s scattered by the antenna 1, the sum of the transmission signal E ^r3 and the scattered wave E ^s becomes zero. As a result, the scattered wave E ^s is canceled in the transmission signal E ^r3, reception of the scattered waves E ^s of the external becomes difficult.

When the controller 20 receives the digital signal output from the A / D converter 15 of the signal transmission / reception unit 2, the controller 20 analyzes the digital signal and converts the electromagnetic wave received by the antenna 1 into an unnecessary wave that has arrived from the outside. It is determined whether the electromagnetic wave is such. Since this electromagnetic wave determination method is a known technique, detailed description thereof is omitted.
Controller 20, when the electromagnetic waves received by the antenna 1 is an electromagnetic wave according to the unwanted wave, since it is highly necessary to reduce the radar cross section, the scattered wave E ^s and the same amplitude and opposite phase being scattered by the antenna 1 The amount of amplitude adjustment Γ _r2 by the low-noise amplifier 12a and the amount of phase adjustment φ _r2 by the phase shifter 12b are controlled so that the transmission signal E ^r3 is radiated from the antenna 1.

Hereinafter, the control of the amplitude adjustment amount Γ _r2 and the phase adjustment amount φ _{r2 by} the controller 20 will be specifically described.
Controller 20 analyzes the digital signal output from the A / D converter 15 of the signal transmitting and receiving unit 2, the received signal ^{E r2} amplitude (Γ _r2 A _r1) and of the received signal ^{E r2} phase (φ _r1 + φ _r2 ) is specified.
Next, the controller 20 calculates the amplitude A _r1 of the reception signal E ^r1 by dividing the amplitude (Γ _r2 A _r1 ) of the reception signal E ^r2 by the adjustment amount Γ _r2 of the current amplitude.
Next, the controller 20, the amplitude _{A s} of the scattered wave ^{E s} stored in advance, and the amplitude _{A r1} of a received signal ^{E r1,} a fixed amount of adjustment gamma _r3 Prefecture by the variable amplifier 18b, the scattered wave ^{E s} An amplitude adjustment amount Γ _r2 for obtaining the amplitude (Γ _r3 Γ _r2 A _r1 ) of the transmission signal E ^r3 having the same amplitude as the amplitude A _s is calculated.

Further, the controller 20 calculates the phase φ _r1 of the reception signal E ^r1 by subtracting the current phase adjustment amount φ _r2 from the phase (φ _r1 + φ _r2 ) of the reception signal E ^r2 .
Controller 20, the phase phi _s of the scattered wave ^{E s} stored in advance, the phase phi _r1 of the reception signal ^{E r1,} a fixed adjustment amount phi _r3 Metropolitan by phase shifter 18a, the phase phi of the scattered wave ^{E s} A phase adjustment amount φ _r2 for obtaining the phase (φ _r1 + φ _r2 + φ _r3 ) of the transmission signal E ^{r3 having} a phase opposite to that of _s is calculated.

Controller 20, calculating the adjustment amount gamma _r2 amplitude, as the adjustment amount of the amplitude due to the low-noise amplifier 12a of the first regulator 12, sets the adjustment amount gamma _r2.
Controller 20, calculating the adjustment amount phi _r2 of the phase, as an adjustment amount of the phase by the phase shifter 12b of the first regulator 12, sets the adjustment amount phi _r2.

As apparent from the above, according to the first embodiment, when the controller 20 receives an electromagnetic wave from the space, the electromagnetic wave is applied to the antenna 1 and thereby scattered by the antenna 1. The first regulator 12 or the second adjustment according to the other received signal E ^r2 distributed by the signal distributor 13 so that the transmission signal E ^r3 having the same amplitude and opposite phase as the wave E ^s is radiated from the antenna 1 Since the device 18 is configured to be controlled, the communication signal can be transmitted or received even while the structural mode RCS and the antenna mode RCS are reduced.

Embodiment 2. FIG.
In the first embodiment, an example is shown in which the second adjuster 18 adjusts not only the transmission signal ^Er3 but also the amplitude and phase of the communication signal to be transmitted.
In the second embodiment, the second adjuster 18 adjusts only the amplitude and phase of the transmission signal ^Er3 and separately provides a third adjuster 30 that adjusts the amplitude and phase of the communication signal to be transmitted. Will be explained.

2 is a block diagram showing an antenna device according to Embodiment 2 of the present invention. In FIG. 2, the same reference numerals as those in FIG.
The third adjuster 30 includes a phase shifter 30a and a high power amplifier (HPA) 30b.
The third adjuster 30 adjusts the amplitude and phase of the transmission target communication signal output from the transmitter 17.
The phase adjustment amount of the phase shifter 30 a is controlled by the controller 31 and adjusts the phase of the communication signal output from the transmitter 17.
The high output amplifier 30b is an amplifier capable of setting a gain larger than that of the variable amplifier 18b.
In the high-power amplifier 30b, the amplitude adjustment amount, which is a gain, is controlled by the controller 31, and the amplitude of the communication signal whose phase is adjusted by the phase shifter 30a is adjusted.

As in the controller 20 of FIG. 1, the controller 31 is realized by, for example, a computer having a memory, a semiconductor integrated circuit on which a CPU is mounted, or a one-chip microcomputer.
The controller 31, like the controller 20 of FIG. 1, stores the scattered wave E ^s being scattered by the previously antenna 1, the scattered wave E ^s and the same amplitude and opposite phase transmission signals scattered by the antenna 1 The first regulator 12 or the second regulator 18 is controlled in accordance with the digital signal output from the A / D converter 15 so that ^Er3 is radiated from the antenna 1.
The controller 31 also controls the amplitude adjustment amount by the high-power amplifier 30b and the phase adjustment amount by the phase adjuster 30a included in the third adjuster 30 when the communication signal to be transmitted is radiated to the space. To do.
The amplitude adjustment amount by the high-power amplifier 30b and the phase adjustment amount by the phase shifter 30a are controlled by the controller 31 regardless of the reduction of the radar cross-sectional area, and are controlled according to the communication environment, for example. .

Next, the operation will be described.
The operation when receiving the communication signal to be received is the same as in the first embodiment.
An operation when transmitting a communication signal to be transmitted will be described.

The controller 31 outputs a communication signal to be transmitted to the D / A converter 16 of the signal transmission / reception unit 2.
Upon receiving the communication signal to be transmitted output from the controller 31, the D / A converter 16 converts the communication signal from a digital signal to an analog signal, and outputs the converted analog signal to the transmitter 17.
The transmitter 17 performs transmission processing on the communication signal that is an analog signal output from the D / A converter 16, and outputs the communication signal after the transmission processing to the third adjuster 30.

When the phase adjuster 30a of the third adjuster 30 receives the communication signal after the transmission processing output from the transmitter 17, the communication after the transmission processing is performed by the phase adjustment amount φ _r4 set by the controller 31. Adjust the signal phase.
The high-power amplifier 30b of the third adjuster 30 adjusts the amplitude of the communication signal whose phase is adjusted by the phase adjuster 30a by the amplitude adjustment amount Γ _r4 set by the controller 31.
The communication signal whose amplitude and phase are adjusted by the third adjuster 30 is output to the transmission / reception switch 11.
When receiving / transmitting the communication signal output from the third adjuster 30, the transmission / reception switch 11 outputs the communication signal to the antenna 1. Thereby, a communication signal is radiated | emitted to space from the antenna 1 as electromagnetic waves.

The antenna 1 receives an electromagnetic wave that has arrived from space, and outputs the received signal ^{Er1 of the} electromagnetic wave represented by the above formula (2) to the signal transmission / reception unit 2.
When the transmission / reception switch 11 of the signal transmission / reception unit 2 receives the reception signal E ^r1 output from the antenna 1, the transmission / reception switch 11 outputs the reception signal E ^r1 to the first adjuster 12.

Low-noise amplifier 12a of the first regulator 12 receives the received signal E ^r1 output from the duplexer 11, the amplitude set by the controller 31 by the adjustment amount gamma _r2, of the received signal E ^r1 Adjust the amplitude.
The phase adjuster 12 b of the first adjuster 12 adjusts the phase of the received signal whose amplitude is adjusted by the low noise amplifier 12 a by the phase adjustment amount φ _r2 set by the controller 31.
The reception signal ^{Er 2} represented by the expression (3) after the amplitude and phase are adjusted by the first adjuster 12 is output to the signal distributor 13.

When receiving the reception signal ^Er2 output from the first adjuster 12, the signal distributor 13 distributes the reception signal ^Er2 into two and ^{divides the} reception signal ^Er2 into two as in the first embodiment. The signal ^Er2 is output to the second adjuster 18, and the other received signal ^Er2 divided into two is output to the receiver 14.
When receiving the reception signal E ^r2 output from the signal distributor 13, the receiver 14 performs a reception process on the reception signal E ^r2 as in the first embodiment, and receives the reception signal E ^r2 after the reception process. Is output to the A / D converter 15 as an electrical signal.
The A / D converter 15 converts the electrical signal output from the receiver 14 from an analog signal to a digital signal, and outputs the converted digital signal to the controller 31.

Phaser 18a of the second regulator 18, upon receiving the received signals E ^r2 output from the signal divider 13, a phase which is set by the controller 31 by the adjustment amount phi _r3, of the received signal E ^r2 Adjust the phase.
The variable amplifier 18b of the second adjuster 18 adjusts the amplitude of the reception signal E ^r2 whose phase is adjusted by the phase adjuster 18a by the amplitude adjustment amount Γ _r3 set by the controller 31.
The reception signal whose amplitude and phase are adjusted by the second adjuster 18 is output to the transmission / reception switch 11 as the transmission signal ^Er3 represented by the above equation (4).
When the transmission / reception switch 11 receives the transmission signal ^Er3 output from the second adjuster 18, the transmission / reception switch 11 outputs the transmission signal ^Er3 to the antenna 1. Accordingly, the transmission signal ^Er3 is radiated from the antenna 1 to the space as an electromagnetic wave.

When the controller 31 receives the digital signal output from the A / D converter 15 of the signal transmission / reception unit 2, the controller 31 analyzes the digital signal and receives it by the antenna 1 as in the controller 20 of FIG. It is determined whether the electromagnetic wave is an electromagnetic wave related to an unnecessary wave that has come from the outside.
When the electromagnetic wave received by the antenna 1 is an electromagnetic wave related to an unnecessary wave, the controller 31 has a high necessity for reducing the radar cross-sectional area, and therefore, like the controller 20 of FIG. To control.
That is, the control unit 31, in the same manner as the control unit 20 of FIG. 1, such that the transmission signal E ^r3 scattered wave E ^s and the same amplitude and opposite phases to be scattered by the antenna 1 is radiated from the antenna 1, a low noise The amplitude adjustment amount Γ _r2 by the amplifier 12a and the phase adjustment amount φ _r2 by the phase shifter 12b are controlled.

According to the second embodiment, as in the first embodiment, there is an effect that transmission or reception of a communication signal can be performed even during a period in which the structural mode RCS and the antenna mode RCS are reduced.
Further, according to the second embodiment, the third adjuster 30 that adjusts the amplitude and phase of the communication signal to be transmitted is provided, and the second adjuster 18 determines only the amplitude and phase of the transmission signal ^Er3. Since the adjustment is made, it is possible to increase the power in the communication signal to be transmitted while reducing the radar cross-sectional area.

Embodiment 3 FIG.
In the second embodiment, an example in which the second adjuster 18 including the phase shifter 18a and the third adjuster 30 including the phase shifter 30a is provided.
In the third embodiment, an example in which the phase shifter 18a included in the second adjuster 18 and the phase shifter 30a included in the third adjuster 30 are shared will be described.

FIG. 3 is a block diagram showing an antenna apparatus according to Embodiment 3 of the present invention. In FIG. 3, the same reference numerals as those in FIGS.
The phase shifter 41 adjusts the phase of one received signal E ^r2 distributed by the signal distributor 13 by the phase adjustment amount φ _r3 set by the controller 44.
The phase shifter 41 adjusts the phase of the communication signal output from the transmitter 17 by the phase adjustment amount φ _r4 set by the controller 44.
In the third embodiment, the variable amplifier 18b corresponds to the first amplitude adjuster, and the high output amplifier 30b corresponds to the second amplitude adjuster.
In the third embodiment, the variable amplifier 18b, the high-power amplifier 30b, and the phase shifter 41 correspond to the second adjuster.

In the first changeover switch 42, the port A is connected to the variable amplifier 18b, the port B is connected to the phase shifter 41, and one received signal ^Er2 distributed by the signal distributor 13 is transferred to the variable amplifier 18b or phase shifter. 41 is a switch for switching the path to be output to 41.
The second changeover switch 43 has a port A connected to the high-power amplifier 30b and a port B connected to the variable amplifier 18b. The phase of the received signal ^Er2 or communication signal adjusted by the phase shifter 41 is changed to the variable amplifier 18b. Alternatively, it is a path switching switch that outputs to the high-power amplifier 30b.

The controller 44 is realized by, for example, a computer having a memory, a semiconductor integrated circuit on which a CPU is mounted, a one-chip microcomputer, or the like, similarly to the controller 20 in FIG. 1 and the controller 31 in FIG.
When receiving the communication signal to be received, the controller 44 controls the first changeover switch 42 so that one received signal ^Er2 distributed by the signal distributor 13 is output to the phase shifter 41. At the same time, the second changeover switch 43 is controlled so that the reception signal ^Er2 whose phase is adjusted by the phase shifter 41 is output to the variable amplifier 18b.
When transmitting the communication signal to be transmitted, the controller 44 controls the first changeover switch 42 so that one received signal ^Er2 distributed by the signal distributor 13 is output to the variable amplifier 18b. At the same time, the second changeover switch 43 is controlled so that the communication signal whose phase is adjusted by the phase shifter 41 is output to the high output amplifier 30b.

The controller 44, in the same manner as the control unit 31 of the controller 20 and 2 of Figure 1, stores the scattered wave E ^s scattered in advance by the antenna 1.
When receiving the communication signal to be received, the controller 44 outputs from the A / D converter 15 so that the transmission signal E ^r3 having the same amplitude and opposite phase as the scattered wave E ^s is radiated from the antenna 1. The amplitude adjustment amount Γ _r3 by the variable amplifier 18b and the phase adjustment amount φ _r3 by the phase shifter 41 are controlled in accordance with the digital signal.
When transmitting the communication signal to be transmitted, the controller 44 controls the amplitude adjustment amount Γ _r4 by the high-power amplifier 30b and the phase adjustment amount φ _r4 by the phase shifter 41.
Further, the controller 44 adjusts the first adjuster according to the digital signal output from the A / D converter 15 so that the transmission signal E ^r3 having the same amplitude and opposite phase as the scattered wave E ^s is radiated from the antenna 1. 12 controls the amplitude adjustment amount Γ _r2 by the low noise amplifier 12a and the phase adjustment amount φ _r2 by the phase shifter 12b.

Next, the operation will be described.
First, an operation when receiving a communication signal to be received will be described.
During the communication signal receiving operation, the amplitude adjustment amount Γ _r2 by the low noise amplifier 12a included in the first adjuster 12 is set to a fixed adjustment amount by the controller 44.
The phase adjustment amount φ _r2 by the phase shifter 12b included in the first adjuster 12 is set to a fixed adjustment amount by the controller 44.
The output port of the first changeover switch 42 is set to port B by the controller 44, and the output port of the second changeover switch 43 is set to port B by the controller 44.

The antenna 1 receives an electromagnetic wave that has arrived from space, and outputs the received signal ^{Er1 of the} electromagnetic wave represented by the above formula (2) to the signal transmission / reception unit 2.
When the transmission / reception switch 11 of the signal transmission / reception unit 2 receives the reception signal E ^r1 output from the antenna 1, the transmission / reception switch 11 outputs the reception signal E ^r1 to the first adjuster 12.
Low-noise amplifier 12a of the first regulator 12 receives the received signal E ^r1 output from the duplexer 11, by the adjustment amount gamma _r2 amplitude being set by the controller 44, the received signal E ^r1 Adjust the amplitude.
The phase adjuster 12 b of the first adjuster 12 adjusts the phase of the received signal whose amplitude is adjusted by the low noise amplifier 12 a by the phase adjustment amount φ _r2 set by the controller 44.
The reception signal ^{Er 2} represented by the expression (3) after the amplitude and phase are adjusted by the first adjuster 12 is output to the signal distributor 13.

When the signal distributor 13 receives the reception signal ^Er2 output from the first adjuster 12, the signal distributor 13 distributes the reception signal ^Er2 into two and distributes the one reception signal ^Er2 divided into two to the first changeover switch. The other received signal ^Er2 divided into two is output to the receiver 14.
Receiver 14, the signal when the distributor 13 receives the received signal E ^r2 output from, carried out reception processing for the received signal E ^r2, A / D converter receiving signal E ^r2 as an electric signal after reception processing 15 is output.
The A / D converter 15 converts the electrical signal output from the receiver 14 from an analog signal to a digital signal, and outputs the converted digital signal to the controller 20.

When the first changeover switch 42 receives the reception signal E ^r2 output from the signal distributor 13, the output port is set to the port B by the controller 44, so that the reception signal ^{Er 2 is transferred} to the phase shifter 41. Output.
Phaser 41, upon receiving the received signals E ^r2, which is output from the first selector switch 42, by adjusting the amount phi _r3 of set phase by controller 44, adjusts the phase of the received signal E ^r2, phase The adjusted reception signal ^Er2 is output to the second changeover switch 43.

When the second changeover switch 43 receives the phase-adjusted reception signal ^Er2 output from the phase shifter 41, the output port is set to the port B by the controller 44, so that the reception signal ^Er2 is variable. Output to amplifier 18b.
Variable amplifier 18b, upon receiving the received signals E ^r2 output from the second selector switch 43, by the adjustment amount gamma _r3 amplitude set by the controller 44, adjusts the amplitude of the received signal E ^r2.
The reception signal represented by Expression (4) after the amplitude is adjusted by the variable amplifier 18b is output to the transmission / reception switch 11 as the transmission signal ^Er3 .

Upon receiving the transmission signal ^Er3 output from the variable amplifier 18b, the transmission / reception switch 11 outputs the transmission signal ^Er3 to the antenna 1. Accordingly, the transmission signal ^Er3 is radiated from the antenna 1 to the space as an electromagnetic wave.
Here, the amplitude of the transmission signal ^{E r3} radiated from the antenna _{1 (Γ r3 Γ r2 A r1} ) is the same as the amplitude _{A s} of the scattered wave ^{E s} scattered by the antenna 1 and transmit signal ^{E r3} If the phase (φ _r1 + φ _r2 + φ _r3 ) is opposite to the phase φ _s of the scattered wave E ^s scattered by the antenna 1, the sum of the transmission signal E ^r3 and the scattered wave E ^s becomes zero. As a result, the scattered wave E ^s is canceled in the transmission signal E ^r3, reception of the scattered waves E ^s of the external becomes difficult.

Upon receiving the digital signal output from the A / D converter 15 of the signal transmission / reception unit 2, the controller 44 analyzes the digital signal in the same manner as the controller 20 in FIG. 1 and the controller 31 in FIG. Then, it is determined whether the electromagnetic wave received by the antenna 1 is an electromagnetic wave related to a communication signal to be received or an electromagnetic wave related to an unnecessary wave coming from the outside.
The controller 44, when the electromagnetic waves received by the antenna 1 is an electromagnetic wave according to the unwanted wave, since it is highly necessary to reduce the radar cross section, the scattered wave E ^s and the same amplitude and opposite phase being scattered by the antenna 1 The phase adjustment amount φ _r3 by the phase shifter 41 and the amplitude adjustment amount Γ _r3 by the variable amplifier 18b are controlled so that the transmission signal E ^r3 is radiated from the antenna 1.

When the electromagnetic wave received by the antenna 1 is an electromagnetic wave related to a communication signal to be received, the controller 44 is included in, for example, the second adjuster 18 because it is less necessary to reduce the radar cross-sectional area. The variable amplifier 18b is controlled so that the gain of the variable amplifier 18b becomes zero. In this case, there is no possibility that the transmission signal E ^r3 scattered wave E ^s the same amplitude and opposite phases to be scattered by the antenna 1 is radiated from the antenna 1.
However, this is only an example, as in the case the electromagnetic waves received by the antenna 1 is an electromagnetic wave according to the unnecessary wave, the transmission of the scattered wave E ^s and the same amplitude and opposite phases to be scattered by the antenna 1 signal E ^r3 May be radiated from the antenna 1.

Hereinafter, the control of the phase adjustment amount φ _r3 and the amplitude adjustment amount Γ _r3 by the controller 44 will be described in detail.
The controller 44 analyzes the digital signal output from the A / D converter 15 of the signal transmitting and receiving unit 2, the received signal ^{E r2} amplitude (Γ _r2 A _r1) and of the received signal ^{E r2} phase (φ _r1 + φ _r2 ) is specified.
Next, the controller 44, the amplitude _{A s} of the scattered wave ^{E s} stored in advance, since the amplitude (Γ _r2 A _r1) of the received signal ^{E r2,} the same amplitude and the amplitude _{A s} of the scattered wave ^{E s} to calculate the adjustment amount gamma _r3 amplitude of formula (5) for obtaining a composed amplitude of the transmission signal ^{_{E r3 (Γ r3 Γ r2 a}} r1).
The control unit 44 is composed and phase phi _s of the scattered wave ^{E s} stored in advance, because the phase (φ _r1 + φ _r2) of the received signal ^{E r2,} the scattered wave ^{E s} phase phi _s antiphase A phase adjustment amount φ _{r3 represented} by Expression (6) for obtaining the phase (φ _r1 + φ _r2 + φ _r3 ) of the transmission signal E ^r3 is calculated.

The controller 44, calculating the adjustment amount gamma _r3 amplitude, as the adjustment amount of the amplitude by the variable amplifiers 18b, sets an adjustment amount gamma _r3.
The controller 44, calculating the adjustment amount phi _r3 of phase, as the adjustment amount of the phase by the phase detector 41, sets the adjustment amount phi _r3.

Next, an operation when transmitting a communication signal to be transmitted will be described.
During the communication signal transmission operation, the output port of the first changeover switch 42 is set to port A by the controller 44, and the output port of the second changeover switch 43 is set to port A by the controller 44. The

The controller 44 outputs the communication signal to be transmitted to the D / A converter 16 of the signal transmission / reception unit 2.
Upon receiving the communication signal to be transmitted output from the controller 44, the D / A converter 16 converts the communication signal from a digital signal to an analog signal, and outputs the converted analog signal to the transmitter 17.
The transmitter 17 performs transmission processing on the communication signal that is an analog signal output from the D / A converter 16, and outputs the communication signal after the transmission processing to the phase shifter 41.

When receiving the communication signal after transmission processing output from the transmitter 17, the phase shifter 41 adjusts the phase of the communication signal after transmission processing by the phase adjustment amount φ _r4 set by the controller 44. The communication signal after the phase adjustment is output to the second changeover switch 43.
When the second changeover switch 43 receives the communication signal after the phase adjustment output from the phase shifter 41, the output port is set to the port A by the controller 44, so that the communication signal is sent to the high output amplifier 30b. Output.

The high-power amplifier 30b adjusts the amplitude of the communication signal output from the second switch 43 by the amplitude adjustment amount Γ _r4 set by the controller 44.
The communication signal whose amplitude is adjusted by the high output amplifier 30 b is output to the transmission / reception switch 11.
When the transmission / reception switch 11 receives the communication signal output from the high-power amplifier 30b, the transmission / reception switch 11 outputs the communication signal to the antenna 1. Thereby, a communication signal is radiated | emitted to space from the antenna 1 as electromagnetic waves.

The antenna 1 receives an electromagnetic wave that has arrived from space, and outputs the received signal ^{Er1 of the} electromagnetic wave represented by the above formula (2) to the signal transmission / reception unit 2.
When the transmission / reception switch 11 of the signal transmission / reception unit 2 receives the reception signal E ^r1 output from the antenna 1, the transmission / reception switch 11 outputs the reception signal E ^r1 to the first adjuster 12.

Low-noise amplifier 12a of the first regulator 12 receives the received signal E ^r1 output from the duplexer 11, the amplitude set by the controller 44 by the adjustment amount gamma _r2, of the received signal E ^r1 Adjust the amplitude.
The phase adjuster 12 b of the first adjuster 12 adjusts the phase of the received signal whose amplitude is adjusted by the low noise amplifier 12 a by the phase adjustment amount φ _r2 set by the controller 44.
The reception signal ^{Er 2} represented by the expression (3) after the amplitude and phase are adjusted by the first adjuster 12 is output to the signal distributor 13.

When the signal distributor 13 receives the reception signal ^Er2 output from the first adjuster 12, the signal distributor 13 distributes the reception signal ^Er2 into two and distributes the one reception signal ^Er2 divided into two to the first changeover switch. The other received signal ^Er2 divided into two is output to the receiver 14.
When receiving the reception signal E ^r2 output from the signal distributor 13, the receiver 14 performs a reception process on the reception signal E ^r2 as in the first embodiment, and receives the reception signal E ^r2 after the reception process. Is output to the A / D converter 15 as an electrical signal.
The A / D converter 15 converts the electrical signal output from the receiver 14 from an analog signal to a digital signal, and outputs the converted digital signal to the controller 44.

When the first changeover switch 42 receives the reception signal ^Er2 output from the signal distributor 13, since the output port is set to the port A by the controller 44, the reception signal ^Er2 is sent to the variable amplifier 18b. Output.
The variable amplifier 18b adjusts the amplitude of the received signal E ^{r2 by} the amplitude adjustment amount Γ _r3 set by the controller 44.
The reception signal whose amplitude has been adjusted by the variable amplifier 18b is output to the transmission / reception switch 11 as the transmission signal ^Er3 represented by the above equation (4).
Upon receiving the transmission signal ^Er3 output from the variable amplifier 18b, the transmission / reception switch 11 outputs the transmission signal ^Er3 to the antenna 1. Accordingly, the transmission signal ^Er3 is radiated from the antenna 1 to the space as an electromagnetic wave.

Upon receiving the digital signal output from the A / D converter 15 of the signal transmission / reception unit 2, the controller 44 analyzes the digital signal in the same manner as the controller 20 in FIG. 1 and the controller 31 in FIG. Then, it is determined whether the electromagnetic wave received by the antenna 1 is an electromagnetic wave related to an unnecessary wave that has come from the outside.
The controller 44, when the electromagnetic waves received by the antenna 1 is an electromagnetic wave according to the unwanted wave, since it is highly necessary to reduce the radar cross section, the scattered wave E ^s and the same amplitude and opposite phase being scattered by the antenna 1 The amount of amplitude adjustment Γ _r2 by the low-noise amplifier 12a and the amount of phase adjustment φ _r2 by the phase shifter 12b are controlled so that the transmission signal E ^r3 is radiated from the antenna 1.

Hereinafter, the control of the amplitude adjustment amount Γ _r2 and the phase adjustment amount φ _r2 by the controller 44 will be specifically described.
The controller 44 analyzes the digital signal output from the A / D converter 15 of the signal transmitting and receiving unit 2, the received signal ^{E r2} amplitude (Γ _r2 A _r1) and of the received signal ^{E r2} phase (φ _r1 + φ _r2 ) is specified.
Next, the controller 44 calculates the amplitude A _r1 of the reception signal E ^r1 by dividing the amplitude (Γ _r2 A _r1 ) of the reception signal E ^r2 by the adjustment amount Γ _r2 of the current amplitude.
Next, the controller 44, the amplitude _{A s} of the scattered wave ^{E s} stored in advance and the amplitude _{A r1} received signal ^{E r1,} fixed adjustment amount gamma _r3 Prefecture by the variable amplifier 18b, the scattered wave ^{E s} calculating the amplitude _{a s} and an amplitude (Γ _r3 Γ _r2 a _r1) adjustment amount gamma _r2 amplitude of formula (7) for obtaining a transmission signal ^{E r3} having the same amplitude.

Further, the controller 44 calculates the phase φ _r1 of the received signal E ^r1 by subtracting the current phase adjustment amount φ _r2 from the phase (φ _r1 + φ _r2 ) of the received signal E ^r2 .
The controller 44 includes a phase phi _s of the scattered wave ^{E s} stored in advance, the phase phi _r1 of the reception signal ^{E r1,} a fixed adjustment amount phi _r3 Metropolitan by phase shifter 18a, the phase phi of the scattered wave ^{E s} _The phase adjustment amount φ _{r2 represented} by the equation (8) for obtaining the phase (φ _r1 + φ _r2 + φ _r3 ) of the transmission signal E ^{r3 having} a phase opposite to _s is calculated.

The controller 44, calculating the adjustment amount gamma _r2 amplitude, as the adjustment amount of the amplitude due to the low-noise amplifier 12a of the first regulator 12, sets the adjustment amount gamma _r2.
The controller 44, calculating the adjustment amount phi _r2 of the phase, as an adjustment amount of the phase by the phase shifter 12b of the first regulator 12, sets the adjustment amount phi _r2.

According to the third embodiment, as in the first and second embodiments, the communication signal can be transmitted or received even during the period in which the structural mode RCS and the antenna mode RCS are reduced.
Further, according to the third embodiment, the phase shifter 41 functions as the phase shifter 18 a included in the second adjuster 18 and the phase shifter 30 a included in the third adjuster 30. Therefore, the number of phase shifters can be reduced and the configuration can be simplified as compared with the second embodiment.

Embodiment 4 FIG.
In the fourth embodiment, the components that determine the adjustment amounts of the amplitude and phase in the controllers 20, 31, 44 of FIGS. 1 to 3 will be specifically described.

4 is a block diagram showing a controller 20 of an antenna apparatus according to Embodiment 4 of the present invention.
FIG. 4 shows a configuration diagram of the controller 20, but the controller 31 shown in FIG. 2 and the controller 44 shown in FIG. It becomes the same configuration diagram.
FIG. 5 is a hardware configuration diagram showing the controller 20 of the antenna apparatus.
The arrival direction estimation unit 51 is realized by, for example, the arrival direction estimation circuit 61 shown in FIG. 5, and performs processing for estimating the arrival direction θ of the electromagnetic wave that has arrived from the digital signal output from the A / D converter 15. carry out.

Table storage unit 52 is intended to be implemented in the memory circuit 62 shown in FIG. 5, for example, the arrival direction θ of the electromagnetic wave, the correspondence relationship between the amplitude A _s and phase phi _s of the scattered wave E ^s being scattered by the antenna 1 Is stored.
The scattered wave specifying unit 53 is realized by, for example, the scattered wave specifying circuit 63 shown in FIG. 5, and the arrival direction estimated by the arrival direction estimating unit 51 with reference to the table stored in the table storage unit 52. It carries out a process of specifying the amplitude a _s and phase phi _s of the scattered wave E ^s corresponding to theta.

The adjustment amount determination unit 54 is realized by, for example, the adjustment amount determination circuit 64 shown in FIG.
Adjustment amount determination unit 54, when receiving the communication signal to be received is, the amplitude A _s and phase phi _s of the identified scattered wave E ^s by scattered wave identification unit 53, an amplitude adjustment by the low-noise amplifier 12a A process of determining the amplitude adjustment amount Γ _r3 by the variable amplifier 18b and the phase adjustment amount φ _r3 by the phase shifter 18a from the amount Γ _r2 and the phase adjustment amount φ _r2 by the phase shifter 12b is performed.
When transmitting the communication signal to be transmitted, the adjustment amount determination unit 54 adjusts the amplitude A _s and phase φ _{s of} the scattered wave E ^s specified by the scattered wave specification unit 53 and the amplitude adjustment amount by the variable amplifier 18b. A process of determining an amplitude adjustment amount Γ _r2 by the low noise amplifier 12a and a phase adjustment amount φ _r2 by the phase shifter 12b from Γ _r3 and the phase adjustment amount φ _r3 by the phase shifter 18a is performed.

In FIG. 4, each of the arrival direction estimation unit 51, the table storage unit 52, the scattered wave identification unit 53, and the adjustment amount determination unit 54, which are components of the controller 20, includes dedicated hardware as shown in FIG. It is assumed that the arrival direction estimation circuit 61, the storage circuit 62, the scattered wave identification circuit 63, and the adjustment amount determination circuit 64 are realized.
Here, the memory circuit 62 may be, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory Memory, or an EEPROM (Electrically Erasable Memory). A volatile semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD (Digital Versatile Disc), and the like are applicable.
The arrival direction estimation circuit 61, the scattered wave identification circuit 63, and the adjustment amount determination circuit 64 include, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), and an FPGA. (Field-Programmable Gate Array) or a combination thereof is applicable.

The components of the controller 20 are not limited to those realized by dedicated hardware, and the controller 20 may be realized by software, firmware, or a combination of software and firmware.
Software and firmware are stored as programs in the memory of the computer. The computer means hardware that executes a program, and includes, for example, a CPU, a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a processor, a DSP (Digital Signal Processor), and the like.
FIG. 6 is a hardware configuration diagram of a computer when the controller 20 is realized by software or firmware.
When the controller 20 is realized by software or firmware, the table storage unit 52 is configured on the memory 71 of the computer, and the processing procedures of the arrival direction estimation unit 51, the scattered wave identification unit 53, and the adjustment amount determination unit 54 are processed. A program to be executed by the computer may be stored in the memory 71, and the processor 72 of the computer may execute the program stored in the memory 71.
FIG. 7 is a flowchart showing a processing procedure when the controller 20 is realized by software or firmware.

Next, the operation will be described.
When the arrival direction estimation unit 51 of the controller 20 receives the digital signal output from the A / D converter 15, the arrival direction estimation unit 51 estimates the arrival direction θ of the electromagnetic wave arriving from the digital signal (step ST1 in FIG. 7).
Since the process of estimating the arrival direction θ of the electromagnetic wave from the digital signal is a known technique, detailed description thereof is omitted.

Scattered wave identification unit 53, the arrival direction estimation unit 51 estimates the arrival direction θ of the electromagnetic wave from the arrival direction θ of the electromagnetic wave, the scattered waves E ^s scattered in the arrival direction θ by the antenna 1 the amplitude A _s and phase φ _s is specified (step ST2 in FIG. 7).
That is, the scattered wave identification unit 53, from the table stored in the table storage unit 52, acquires the amplitude A _s and phase phi _s of the scattered wave E ^s corresponding to been arrival direction θ estimated by the arrival direction estimation unit 51 To do.
FIG. 8 is an explanatory diagram illustrating an example of a table stored in the table storage unit 52.
In the example of FIG. 8, if the arrival direction of the electromagnetic wave theta is theta _1, as the amplitude A _s and phase phi _s of the scattered wave E ^s, of the scattered wave E ^s corresponding to the direction of arrival theta ₁ amplitude A _s1 and the phase phi _{Get s1} .
Moreover, the arrival direction theta of electromagnetic waves if theta _2, the amplitude _{A s} and phase phi _s of the scattered wave ^{E s,} to obtain the amplitude _{A s2} and phase phi _s2 scattered wave ^{E s} corresponding to the direction of arrival theta ₂ .

If the communication signal is being received (step ST3: YES in FIG. 7), the adjustment amount determination unit 54 uses the amplitude adjustment amount Γ _r2 by the low noise amplifier 12a set to be fixed and the phase shifter 12b. The phase adjustment amount φ _r2 is acquired.
Then, the adjustment amount determining unit 54, the amplitude A _s and phase phi _s of the identified scattered wave E ^s by scattered wave identification unit 53, a low noise amplifier 12a by the phase by the amplitude adjustment amount gamma _r2 and phaser 12b From the adjustment amount φ _r2 , the amplitude adjustment amount Γ _r3 by the variable amplifier 18b and the phase adjustment amount φ _r3 by the phase shifter 18a are determined (step ST4 in FIG. 7).
Specifically, the adjustment amount determining unit 54, the amplitude of the amplitude _{A s} and receive signals ^{E r2} of the scattered wave ^{E s} a (gamma _r2 A _r1) By substituting the above equation (5), according to the variable amplifier 18b The amplitude adjustment amount Γ _r3 can be calculated.
Moreover, the adjustment amount determining unit 54, the scattered wave ^{E s} of the phase phi _s and the received signal ^{E r2} phases (phi _r1 + phi _r2) By substituting the above equation (6), the phase adjustment of the by phase shifter 18a The quantity φ _r3 can be calculated.

When the communication signal is being transmitted (step ST3 in FIG. 7: NO), the adjustment amount determination unit 54 adjusts the amplitude adjustment amount Γ _r3 by the variable amplifier 18b set to be fixed and the phase by the phase shifter 18a. The adjustment amount φ _r3 is acquired.
Then, the adjustment amount determining unit 54, the amplitude A _s and phase phi _s of the identified scattered wave E ^s by scattered wave identification unit 53, an amplitude by the variable amplifiers 18b adjustment amount gamma _r3 and by phase shifter 18a phases of From the adjustment amount φ _r3 , the amplitude adjustment amount Γ _r2 by the low noise amplifier 12a and the phase adjustment amount φ _r2 by the phase shifter 12b are determined (step ST5 in FIG. 7).
Specifically, the adjustment amount determining unit 54 calculates the amplitude A _r1 of the reception signal E ^r1 by dividing the amplitude (Γ _r2 A _r1 ) of the reception signal E ^r2 by the adjustment amount Γ _r2 of the current amplitude. . Then, the adjustment amount determining unit 54, and the amplitude _{A s} of the scattered wave ^{E s,} is substituted with the amplitude _{A r1} of a received signal ^{E r1,} the adjustment amount gamma _r3 and the above equation fixed by the variable amplifier 18b (7) Thus, the amplitude adjustment amount Γ _r2 by the low noise amplifier 12a can be calculated.
Further, the adjustment amount determination unit 54 calculates the phase φ _r1 of the reception signal E ^r1 by subtracting the adjustment amount φ _r2 of the current phase from the phase (φ _r1 + φ _r2 ) of the reception signal E ^r2 . Then, the adjustment amount determining unit 54, and the phase phi _s of the scattered wave ^{E s,} substitutes the phase phi _r1 of the reception signal ^{E r1,} the adjustment amount phi _r3 and the above equation fixed by phase shifter 18a (8) Thus, the phase adjustment amount φ _r2 by the phase shifter 12b can be calculated.

As can be seen from the above, according to the fourth embodiment, the controller 20 estimates the arrival direction θ of the incoming electromagnetic wave from the digital signal output from the A / D converter 15. 51, the arrival direction θ estimated by the arrival direction estimation unit 51, a scattered wave identification unit 53 for identifying the amplitude a _s and phase phi _s of the scattered wave E ^s scattered in the arrival direction θ by the antenna 1, the receiving when receiving a communication signal of interest, the amplitude a _s and phase phi _s of the identified scattered wave E ^s by scattered wave identification unit 53, according to the amplitude adjustment amount gamma _r2 and phaser 12b by the low-noise amplifier 12a When the amplitude adjustment amount Γ _r3 by the variable amplifier 18b and the phase adjustment amount φ _r3 by the phase shifter 18a are determined from the phase adjustment amount φ _r2 and the communication signal to be transmitted is transmitted, the scattered wave is specified. According to part 53 Ri and amplitude _{A s} and phase phi _s of the identified scattered waves ^{E s,} the phase adjustment amount phi _r3 Prefecture by the amplitude adjustment amount gamma _r3 and phase shifter 18a by the variable amplifier 18b, the amplitude adjustment by the low-noise amplifier 12a Since the adjustment amount determining unit 54 for determining the amount Γ _r2 and the phase adjustment amount φ _r2 by the phase shifter 12b is provided, the amplitude adjustment amount is determined from the digital signal output from the A / D converter 15. In addition, there is an effect that the adjustment amount of the phase can be determined.

Embodiment 5 FIG.
In the first to fourth embodiments, an antenna apparatus including the antenna 1 and the signal transmission / reception unit 2 is illustrated.
In the fifth embodiment, an antenna device in which a plurality of sets of antennas 1 and signal transmission / reception units 2 are mounted will be described.

FIG. 9 is a block diagram showing an antenna apparatus according to Embodiment 5 of the present invention.
In the example of FIG. 9, N (N is an integer of 2 or more) sets of antennas 1 and signal transmission / reception units 2 are mounted.
In FIG. 9, antennas 1-1 to 1-N correspond to the antenna 1 of FIGS.
The signal transmission / reception units 2-1 to 2-N correspond to the signal transmission / reception unit 2 shown in FIGS.
In FIG. 9, it is assumed that the antenna device includes the controller 20, and the controller 20 controls the first adjuster 12 and the second adjuster 18 in the signal transmission / reception units 2-1 to 2-N. However, instead of the controller 20, the controller 31 of FIG. 2 or the controller 44 of FIG. 3 may be mounted.

By providing N antennas 1-1 to 1-N, an active phased array antenna (APAA) can be constructed.
The APAA can set an amplitude and a phase capable of reducing the radar cross section without losing the function as an antenna in transmission / reception of communication signals.
That is, the APAA includes a radiation array pattern that is an array pattern for the antennas 1-1 to 1-N to transmit and receive communication signals, and an RCS array pattern that is an array pattern for unnecessary waves to avoid transmission and reception of unnecessary waves. Can be formed simultaneously.
Therefore, nulls can be formed in the arrival direction of unnecessary waves to avoid transmission / reception of unnecessary waves, and the period during which structural mode RCS and antenna mode RCS are reduced as in the first to fourth embodiments. Especially, there exists an effect which can perform transmission or reception of a communication signal.

In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

The present invention is suitable for an antenna device that radiates a transmission signal having the same amplitude and opposite phase as an electromagnetic wave scattered by an antenna.

1,1-1 to 1-N antenna, 2,2-1 to 2-N signal transmission / reception unit, 11 transmission / reception switcher, 12 first adjuster, 12a low noise amplifier, 12b phase shifter, 13 signal distributor, 14 receiver, 15 A / D converter, 16 D / A converter, 17 transmitter, 18 second adjuster, 18a phase adjuster, 18b variable amplifier (first amplitude adjuster), 20 controller, 30 Third adjuster, 30a phase shifter, 30b high output amplifier (second amplitude adjuster), 31 controller, 41 phase shifter, 42 first changeover switch, 43 second changeover switch, 44 controller, 51 Arrival direction estimation unit, 52 Table storage unit, 53 Scattered wave identification unit, 54 Adjustment amount determination unit, 61 Arrival direction estimation circuit, 62 Storage circuit, 63 Scattered wave identification circuit, 64 Adjustment amount determination circuit, 7 Memory, 72 processor.

Claims (8)

1. An antenna that radiates a transmission signal as an electromagnetic wave to space, receives an electromagnetic wave arriving from space, and outputs a reception signal of the electromagnetic wave;
   A first adjuster for adjusting the amplitude and phase of the received signal output from the antenna;
   A signal distributor for distributing the received signal whose amplitude and phase are adjusted by the first adjuster;
   A second adjuster that adjusts the amplitude and phase of one of the received signals distributed by the signal distributor and outputs the received signal adjusted in amplitude and phase to the antenna as a transmission signal;
   When an electromagnetic wave arrives from space, the electromagnetic wave is applied to the antenna, so that a transmission signal having the same amplitude and opposite phase as the scattered wave that is an electromagnetic wave scattered by the antenna is emitted from the antenna. And a controller for controlling the first adjustor or the second adjuster according to the other received signal distributed by the signal distributor.
2. The controller is
   When receiving a communication signal to be received, the second received signal is distributed according to the other received signal distributed by the signal distributor so that a transmission signal having the same amplitude and opposite phase as the scattered wave is radiated from the antenna. Control the amount of amplitude and phase adjustment by the adjuster of
   When transmitting a communication signal to be transmitted, the first signal is transmitted according to the other received signal distributed by the signal distributor so that a transmission signal having the same amplitude and opposite phase as the scattered wave is radiated from the antenna. 2. The antenna device according to claim 1, wherein an adjustment amount of amplitude and phase by the adjuster is controlled.
3. The antenna apparatus according to claim 1, further comprising a third adjuster that adjusts an amplitude and a phase of a communication signal to be transmitted and outputs the communication signal adjusted in amplitude and phase to the antenna.
4. The second regulator is
   A first amplitude adjuster for adjusting the amplitude of one received signal distributed by the signal distributor;
   A second amplitude adjuster for adjusting the amplitude of the communication signal to be transmitted;
   A phase shifter for adjusting the phase of one of the received signals distributed by the signal distributor or the phase of the communication signal to be transmitted;
   A first changeover switch for outputting one received signal distributed by the signal distributor to the first amplitude adjuster or the phase shifter;
   A second changeover switch for outputting a reception signal whose phase is adjusted by the phase shifter or a communication signal whose phase is adjusted by the phase shifter to the first amplitude adjuster or the second amplitude adjuster; The antenna device according to claim 1, wherein:
5. The controller is
   When receiving a communication signal to be received, the first selector switch is controlled so that one received signal distributed by the signal distributor is output to the phase shifter, and the phase shifter Controlling the second changeover switch so that the phase-adjusted received signal is output to the first amplitude adjuster;
   When transmitting a communication signal to be transmitted, the first changeover switch is controlled so that one received signal distributed by the signal distributor is output to the first amplitude adjuster; 5. The antenna apparatus according to claim 4, wherein the second changeover switch is controlled so that a communication signal whose phase is adjusted by the phase shifter is output to the second amplitude adjuster.
6. The controller is
   When receiving a communication signal to be received, the first received signal is distributed according to the other received signal distributed by the signal distributor so that a transmission signal having the same amplitude and opposite phase as the scattered wave is radiated from the antenna. Controlling the amplitude adjustment amount by the amplitude adjuster and the phase adjustment amount by the phase shifter,
   When transmitting a communication signal to be transmitted, the amplitude adjustment amount by the second amplitude adjuster and the phase adjustment amount by the phase shifter are controlled, and a transmission signal having the same amplitude and opposite phase as the scattered wave 6. The antenna according to claim 5, wherein an amount of adjustment of amplitude and phase by the first adjuster is controlled in accordance with the other received signal distributed by the signal distributor so that the signal is radiated from the antenna. apparatus.
7. The controller is
   A direction-of-arrival estimation unit that estimates the direction of arrival of the electromagnetic wave that has arrived from the other received signal distributed by the signal distributor;
   From the arrival direction estimated by the arrival direction estimation unit, a scattered wave identification unit that identifies the amplitude and phase of the scattered wave scattered by the antenna in the arrival direction;
   When receiving the communication signal to be received, the second adjustment is performed based on the amplitude and phase of the scattered wave specified by the scattered wave specifying unit and the adjustment amount of the amplitude and phase in the first adjuster. When determining the amount of adjustment of the amplitude and phase by the detector and transmitting the communication signal to be transmitted, the amplitude and phase of the scattered wave specified by the scattered wave specifying unit, the amplitude and phase of the second adjuster The antenna apparatus according to claim 1, further comprising: an adjustment amount determination unit that determines an adjustment amount of an amplitude and a phase by the first adjuster from a phase adjustment amount.
8. A plurality of sets of the antenna, the first adjuster, the signal distributor, and the second adjuster are prepared,
   The antenna device according to claim 1, wherein the controller controls the first adjustor or the second adjuster included in a plurality of sets.

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