JPH0622286B2 - Array antenna device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to an array antenna device for transmitting and receiving radar waves, for example.

(Prior Art) An array antenna apparatus as shown in FIG. 5 is an apparatus that performs beam combining of radar waves during transmission and beam combining by digital beam forming (DBF) during reception.

In FIG. 5, A is an antenna unit, which has N antenna elements 11 _{1 to} 11 _N. Each antenna element 11 _{1 to} 11 _N
Are connected to the transceiver modules 12 _{1 to} 12 _N , respectively.
Each of the transmission / reception modules 12 _{1 to} 12 _N is driven by a power supply device B and a drive control device C that are externally connected, and the transmission signal S ₁ from the transmission signal generation source D is sent to each of the modules 12 _{1 to} 12 _N. The frequency signal S ₂ from the local oscillator E is distributed and supplied via the first power distributor 13, the frequency signal S ₂ from the local oscillator E is supplied via the second power distributor 14 for frequency conversion, and the frequency signal S ₂ is supplied from the reference oscillator F for phase detection. The reference signal S _{3 of 3} is distributed and supplied via the third power distributor 15.

Here, the transmission / reception module 12 ₁ is taken out and shown in FIG. 6, and its configuration will be described. The antenna element 11 ₁ is connected to the circulator 12a. This circulator 12
a is for switching between transmission and reception.

First, at the time of transmission, the transmission signal S ₁ is transmitted to the phase shifter 12b.
In after being phase-controlled, amplified by the power amplifier 12c, radiated from the antenna element 11 ₁ via the circulator 12a. At this time, the beam can be formed in any direction by adjusting the phase amount of the phase shifter 12a.

Then, during the reception, the radar waves arriving at the antenna element 11 ₁ (RF signal) is a circulator 12a, RF amplifier
It is input to the mixer 12e via 12d and the local oscillation signal S ₂
Is converted into an IF signal by. This IF signal is input to the mixers 12g and 12h after the unnecessary frequency components are removed by the IF reception processing circuit 12f, and the 90 ° hybrid
The first and second reference frequency signals having different 90 ° phases generated by 12i separate the quadrature component signals I and Q. Each quadrature signal I, Q is an A / D converter
It is adapted to be converted into a digital signal by 12j and 12k and supplied to a beam forming circuit G which is externally connected.

The beam forming circuit G is provided for each transmission / reception module 12 _{1 to} 12 _N.
It inputs the digital I and Q signals from the above and performs beam combining at the digital stage, and forms M multi-beams B _{1 to} B _M , for example.

As described above, the array antenna device that forms beams by different means for transmission and reception is composed of a large number of transmission / reception modules and the like, and is considerably complicated. Also,
In order to function as an array antenna, it is necessary to arrange each antenna element at intervals of at least about a half wavelength. Particularly, in the case of a two-dimensional array array antenna, the transmitting / receiving module must be housed within a cross-sectional area of about half wavelength × half wavelength. Here, when the operating frequency band is high, this cross-sectional area is inevitably small, and for example, in the X band, it is a very small cross-sectional area of about 15 mm × 15 mm. Therefore, the higher the frequency band used, the more difficult the arrangement of the transmitting and receiving modules becomes, and the more difficult it is to cool the heat generated by each module because the space is small. Also, the power distributor that distributes the transmission signal, the local oscillation signal, and the reference signal to each module becomes complicated by the large number of distributions. Especially when arranging the antenna elements two-dimensionally, the space required for this must be ignored. I can't. As described above, in the array antenna device having the above configuration, it is extremely difficult to configure the transmission system and the reception system in the same array arrangement state so that the transmission and the reception can be performed using the same antenna element.

In order to eliminate such a problem, for example, as shown in FIG. 7, a method of arranging the receiving antenna system X and the transmitting antenna system Y separately and separating the modules for transmission and reception to facilitate the arrangement is also available. Conceivable. However, this method results in substantially having two array antennas, which is 2 compared with the aperture of the array antenna apparatus shown in FIG.
There is a drawback in that a double opening is required.

(Problems to be Solved by the Invention) As described above, in the above array antenna device, the arrangement of the transmitting and receiving modules becomes more difficult as the frequency band used becomes higher. And the array antenna aperture must be doubled.

The present invention has been made to solve the above problems, and it is possible to easily arrange transmitting and receiving modules while the antenna element is shared between transmitting and receiving even when the frequency band used becomes high. It is an object of the present invention to provide an array antenna device that can be used.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, an array antenna device according to the present invention includes a plurality of first antenna elements that emit electromagnetic waves and capture incoming electromagnetic waves. And a plurality of second antenna elements arranged in pairs with the first antenna element, and phase control of a signal received by one antenna element interposed between the first and second antenna elements. And a plurality of phase shift circuits for transmitting to the other antenna element, a transmission signal generator for generating a transmission signal, and a plurality of transmission signal generators provided facing the openings of the plurality of second antenna elements. A primary radiator that is supplied with an output signal and supplies a transmission electromagnetic wave to the plurality of second antenna elements through a space, and the first antenna element that is arranged so as to face the openings of the plurality of second antenna elements. And a plurality of third antenna elements that receive the signal transmitted from the second antenna element via the phase shift circuit via the space, and the third antenna elements provided on the plurality of third antenna elements, respectively. And a plurality of reception-only modules that receive the output signal of the antenna element.

(Operation) The array antenna device having the above-mentioned configuration uses the space power feeding method. In the transmitting state, the transmission signal transmitted from the primary radiator is received by the second antenna element, and the phase is controlled by the phase shift circuit. After that, it is transmitted from the first antenna element.
In the receiving state, the signal received by the first antenna element is sent out from the second antenna element, and the signal is received by the third antenna element.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 shows its configuration, where H is an antenna section, I is a transmission signal generator, J is a phase controller, K is a local oscillator, and L is
Is a power distributor and M is a beam forming circuit.

In the antenna section H, N first antenna elements 16 _{1 to} 16 _N are arranged on the beam forming surface, and each antenna element 16 _{1 to} 16 _N is connected to the _first antenna element 16 _{1 to} 16 _N via a phase shift circuit 17 _{1 to} 17 _N. Two antenna elements 18 ₁ to 18 _N are connected. A primary radiator (for example, a horn) 19 is provided at a similar focal position of the openings of the respective second antenna elements 18 ₁ to 18 _N , and the primary radiator 19 is provided.
Is supplied with the transmission signal S ₄ from the transmission signal generator I. The phase amounts of the phase shift circuits 17 _{1 to} 17 _N are controlled by the control signal S ₅ from the phase controller J.

On the other hand, third antenna elements 20 _{1 to} 20 _N for power reception are arranged at positions facing the second antenna elements 18 ₁ to 18 _N, respectively. The third antenna elements 20 _{1 to} 20 _N are connected to the receiving modules 21 _{1 to} 21 _N , respectively. Each of the receiving modules 21 _{1 to} 21 _N inputs the local oscillation signal S ₆ distributed by the power distributor L, and receives the third antenna element 20 ₁ to
After converting the RF signal from 20 _N into an IF signal, phase detection is performed to extract the received signal, which is supplied to the beam forming circuit M. This beam forming circuit M
Is a module for inputting received signals from the respective receiving modules 21 _{1 to} 21 _N and performing beam combining. For example, _M of B _{1 to} B M
It is designed to form individual multi-beams.

The operation of the above configuration will be described below.

First, the transmission state will be described. Primary radiator 19, first
The second antenna elements 16 _{1 to} 16 _N , 18 ₁ to 18 _N and the phase shift circuits 17 _{1 to} 17 _N constitute a space-feeding transmission array antenna. That is, the transmission signal S ₄ is transmitted from the primary radiator 19, is received by the second antenna elements 18 ₁ to 18 _N , and is further transmitted via the phase shift circuits 17 _{1 to} 17 _N to the first antenna elements 16 _{1 to} 16 _{N. Sent} from _N. Here, by controlling the phase amount of each of the phase shift circuits 17 _{1 to} 17 _N through the phase controller J, the collimation phase correction by the spatial power feeding and the phase control necessary for the beam scanning are performed, and as a result, an arbitrary spatial space The beam can be directed in any direction.

Next, the reception state will be described. First and second antenna elements 16 _{1 to} 16 _N , 18 ₁ to 18 _N , phase shift circuit 17 ₁ to 1
7 _N and the third antenna devices 20 _{1 to} 20 _{N form} a spatially feeding type reception array antenna. That is, the first
The RF signals (for example, the reflected waves from the target) obtained by the antenna elements 16 _{1 to} 16 _N of the second antenna are transmitted through the phase shift circuits 17 _{1 to} 17 _N to the second
From the antenna elements 18 ₁ to 18 _{N of} the
The antenna elements 20 _{1 to} 20 _N receive power. Then, after being converted into an IF signal by the receiving modules 21 _{1 to} 21 _N ,
Unnecessary frequency components are removed, the phase is further detected, and the result is input to the beam forming circuit M, whereby M multi-beams are formed.

The primary radiator 19 usually has an opening of about one wavelength, and does not impair the power receiving characteristics of the third antenna elements 20 _{1 to} 20 _N.

Here, the specific configuration of the phase shift circuits 17 _{1 to} 17 _N is
It will be described with reference to the drawings.

FIG. 2A shows a system in which only the phase shifter a is used and the phase is controlled in the transmitting state and the receiving state. The figure (b) is
Although the phase shifter a is used as in the case of (a), the transmission beam is controlled by the phase shifter a at the time of transmission through the transmission / reception switching devices b and c such as a circulator, and the low noise amplifier e is set at the time of reception. This is a method of deriving the received wave to the second antenna element via the above. FIG. 11C is the same as the case of FIG. 11B, but is a method of amplifying the transmission wave by using the transmission amplifier f at the time of transmission.

Next, a specific configuration of the receiving modules 21 _{1 to} 21 _N will be described with reference to FIG.

FIG. 3 (a) is suitable for a so-called IF beam. After the input RF signal is amplified by the low noise amplifier g,
The mixer h mixes the signal with the local oscillation signal S ₆ to convert it into an IF signal, removes unnecessary frequency components in the IF reception processing circuit i, and then outputs it to the beam forming circuit M. FIG. 7B shows the case of the DBF system, in which the received signal extracted by the IF reception processing circuit i of FIG.
The reference signal from the local oscillator l is mixed with frequency signals of 90 ° phase difference controlled by the 90 ° hybrid m and converted into in-phase and 90 ° phase baseband signals. To A / D converters n and g
Is converted into a digital signal by means of the digital processing, and is led to the beam forming circuit M by digital processing. in this case,
Beam synthesis can be performed at the digital stage.

When the array antenna device having the above configuration is used for a radar device, transmission beams corresponding to M reception beams (reception multi-beams) formed by the beam forming circuit M are
If the M beams of θ ₁ , θ ₂ , ..., θ _M are sequentially transmitted in a time division as shown in FIG. 4 by the phase control of the phase shift circuits 17 _{1 to} 17 _N , this transmission is performed. T corresponding to the beam
It is possible to form and receive M receive beams within a time period of −γ.

Needless to say, the beam control at the time of transmission is performed by the phase shift circuits 17 _{1 to} 17 _N corresponding to a predetermined beam direction, but at the time of reception, the setting of the phase shifter a in FIG. Of the second antenna elements 18 ₁ to 18 _N and the third antenna without changing the phase of the RF signals obtained by the antenna elements 16 _{1 to} 16 _N of the _first antenna element, that is, by setting all the phase shift states to the same value. Received signals can be efficiently transmitted between the elements 20 _{1 to} 20 _N.

Here, regarding reception, the antenna elements facing each other (example 1
It is a desirable condition that only 8 ₁ and 20 ₁ ) are coupled and are not affected by other antenna elements.

However, even a slight influence from other elements does not seriously hinder the beam formation. That is,
The amplitude and phase distribution of the aperture surface may be disturbed to some extent, and the performance of the side ropes, etc. may deteriorate, but it can be sufficiently used in a system that can relax the performance conditions of the side ropes.

Specifically, in order to reduce the influence from other elements, for example,
The array surface of the second antenna elements 18 ₁ to 18 _{N and} the array surface of the third antenna elements 20 _{1 to} 20 _N are brought close to each other, or
As the third antenna elements 20 _{1 to} 20 _N , those having a sharp directivity may be used, and the intended function can be sufficiently achieved. The accuracy may be individually designed based on the requirements of the side ropes.

Since the primary radiator 19 has an opening of about one wavelength, for example, the third antenna elements 20 _{1 to} 20 ₁
Even if the third antenna elements 20 _{1 to} 20 _N are arranged on the front surface of the _N array surface, the power receiving characteristics of the third antenna elements 20 _{1 to} 20 _N are not significantly deteriorated.

Therefore, as shown in FIG. 1, the primary radiator 19 does not necessarily have to be arranged between the third antenna elements at the center of the array surface of the third antenna elements 20 _{1 to} 20 _N , and may be, for example, the third antenna element. Part of the antenna element array surface (for example, the central part)
It is also possible to provide an arrangement space in the above and arrange it on the substantially same plane as the third antenna element array surface. Again,
It may be designed individually based on the requirements of the side ropes.

In addition, when the array surfaces of the second antenna elements 18 ₁ to 18 _N and the third antenna elements 20 _{1 to} 20 _N are brought close to each other, the primary radiator 19 also comes close, and the second antenna by the primary radiator 19 is also brought close. The irradiation of radio waves near the edge of the element array surface is reduced, which may lead to a decrease in gain and a decrease in transmission side rope. However, also in this case, the spacing between the second antenna elements 18 ₁ to 18 _N and the array surface of the third antenna elements 20 _{1 to} 20 _N may be determined in accordance with various system requirements.

Therefore, in the array antenna device having the above configuration,
The transmission system circuit portion is separated from the plurality of transmission / reception modules arranged for each antenna element and incorporated in the transmission signal generator I, and the third antenna elements 20 _{1 to} 20 _{N are provided} as reception-only modules 21 _{1 to} 21 _{N. Since} each of them is connected to _N , compared to the case where a transmission / reception module is provided, it is possible to easily cope with the miniaturization of the device even when the operating frequency is high, and the heat generation of the module is reduced. , Cooling becomes easy.

In the above embodiment, the case where the antenna elements are linearly arranged has been described, but the same arrangement can be achieved even if the antenna elements are arranged in all or part of a planar shape, a circumferential shape, or a cylindrical shape. Needless to say. In addition, the second antenna element and the third antenna element are not always 1: 1
However, it is possible to make modifications such as 2: 1 depending on the arrangement space and system requirements.

[Effects of the Invention] As described above, according to the present invention, even if the frequency band used increases, the array antennas can easily arrange the modules for transmission and reception while sharing the antenna element for transmission and reception. A device can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the array antenna apparatus according to the present invention, FIG. 2 is a diagram showing a concrete configuration of a phase shift circuit of the embodiment, and FIG. 3 is a receiving module of the embodiment. FIG. 4 is a diagram for explaining a transmitting and receiving method when the array antenna of the embodiment is used in a radar device, and FIG. 5 is an array antenna device for forming a multi-beam. FIG. 6 is a block diagram showing the configuration of the transmitting / receiving module of the circuit of FIG. 5, and FIG. 7 is a configuration diagram showing means for separating the transmitting system and the receiving system. H ... Antenna part, I ... Transmission signal generator, J ... Phase controller, K ... Local oscillator, L ... Power divider, M ...
Beam forming circuit, 16 _{1 to} 16 _N ... First antenna element,
17 _{1 to} 17 _N ... phase shift circuit, 18 ₁ to 18 _N ... second antenna element, 19 ... primary radiator, 20 _{1 to} 20 _N ... third antenna element, 21 _{1 to} 21 _N ... ... receiving module, _{S 4} ...... transmission signal, _{S 5} ...... phase control signal, _{S 6} ...... local oscillation signal, a ...... phase shifter, b, c ...... duplexer, e ...... low-noise amplifier, f ... Transmitting amplifier, g ... Low noise amplifier,
h ... Mixer, i ... IF reception processing circuit, j, k ... Mixer, m ... 90 ° hybrid, n, o ... A / D converter.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshitaka Sasaki No. 1 Komukai Toshiba Town, Kouki-ku, Kawasaki City, Kanagawa Prefecture Komu Factory, Toshiba Corporation (72) Shinichi Takeya, Komukai Toshiba, Kouki-ku, Kawasaki City, Kanagawa Prefecture Town No. 1 Incorporation company Toshiba Komukai factory (56) References JP-A-54-146562 (JP, A) JP-A-61-172408 (JP, A)

Claims (1)

[Claims] 1. A plurality of first antenna elements that emit electromagnetic waves and capture incoming electromagnetic waves, a plurality of second antenna elements arranged in pairs with the first antenna elements, and A plurality of phase shift circuits interposed between the first and second antenna elements to control the phase of a signal received by one antenna element and transmit the signal to the other antenna element; and a transmission signal generator that generates a transmission signal, A primary radiator provided facing the openings of the plurality of second antenna elements and supplied with an output signal of the transmission signal generator to supply a transmission electromagnetic wave to the plurality of second antenna elements via a space; A plurality of signals arranged to face the openings of the plurality of second antenna elements, the signals being transmitted from the second antenna element via the first antenna element and the phase shift circuit, and receiving the signals via the space. The third And the antenna element, the array antenna apparatus comprising a plurality of receive-only module that receives the output signal of the third antenna element provided in each third antenna element of the plurality.