KR20210046545A - Array antenna device for using spatial power spectrum combining and thereof controlling method - Google Patents

Abstract

Provided is an array antenna device using spatial power spectrum combining. The present invention includes a uniform linear array antenna module including antennas which are uniformly and linearly arranged; an array antenna determiner configured to select sub-array antennas arranged at a first distance and second distance from the array antennas in the uniform linear array antenna module in order to derive spatial spectrum components from the uniform linear array antenna module; a spatial spectrum component deriver configured to separately derive spatial power spectrum components from signals received through the selected sub-array antennas selected by the array antenna determiner; and an azimuth calculator configured to calculate an azimuth by performing a calculation with a first spatial spectrum component and a second spatial spectrum component which are separately derived, thereby obtaining the characteristics of a narrow main lobe and a low grating lobe at the same time.

Description

Array antenna device for using spatial power spectrum combining and thereof controlling method

The present invention relates to an array antenna device using spatial power spectrum combining, and more particularly, to an array antenna device capable of improving angular resolution and grating lobe characteristics of a radar using spatial power spectrum combining.

In general, radar transmits a signal generated according to the system requirements through an antenna, detects the echo signal reflected from the target and returns using the antenna and receiver, and processes the distance, speed, and angle of the target through signal processing. It performs the function of detecting the back.

The waveform of a radar signal is largely classified into a pulsed radar or a continuous waveform radar depending on its shape, and among continuous wave radars, frequency modulated continuous waveform (FMCW) radars that use a signal whose frequency is modulated according to time are many. Is used.

In the FMCW radar, the distance of the target is estimated according to the beat frequency component, which is the difference between the transmitted signal and the received signal, and the moving speed of the target is derived according to the Doppler frequency component, and each reception from the receiving antenna array. The angle of the target is derived according to the phase difference between the signals.

However, in order to improve the angular resolution in the conventional array antenna, the width of the -3dB beam of the array antenna response must be reduced, and thus the number or spacing of the receiving antennas must be increased. However, increasing the number of antennas is limited by the configuration of the receiving circuit and the amount of signal processing computation, and increasing the antenna spacing has a limitation because the main lobe and the grating lobe become close.

The present invention is to solve the conventional problem, in order to improve the angular resolution without increasing the number of antennas and to reduce the grating lobe, the beamforming spatial power spectrum for an array with a narrow spacing and a spatial power for an array with a wide spacing An object of the present invention is to provide an array antenna device using spatial power spectrum combining that can derive the angle of the target through the element multiplication of the spectrum.

The object of the present invention is not limited to the above-mentioned object, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

An array antenna device using spatial power spectrum combining according to an embodiment of the present invention for achieving the above object comprises: a uniform linear array antenna module comprising a uniform and linear array antenna; An array antenna determiner for selecting sub-array antennas having a first spacing and a second spacing from the array antennas in the uniform linear array antenna module, respectively, to derive a spatial spectrum element from the uniform linear array antenna module; A spatial spectrum element derivation unit for deriving each spatial power spectrum element by using a signal received through the sub array antenna selected by the array antenna determining unit; And an azimuth angle calculator configured to calculate an azimuth angle by calculating the respective derived first spatial spectral elements and second spatial spectral elements.

It is preferable that the azimuth calculation unit calculates the azimuth angle through a multiplication operation of the elements of the first and second spatial power spectrum.

The uniform linear array antenna module may include a plurality of uniform and linearly arranged first antennas having a first spacing, and an n+1th antenna provided to have a second spacing from a terminal antenna of the first antenna. .

In addition, the array antenna determiner sets the first interval to 0.5 λ, and the second interval to be a multiple of the first interval.

The array antenna determination unit determines a plurality of array antennas having at least one interval so as to derive a plurality of spatial spectral elements, and the azimuth calculation unit calculates an azimuth angle through a product operation of a plurality of spatial power spectrum elements. It can also be calculated.

An array antenna control method using spatial power spectrum combining according to an embodiment of the present invention includes: receiving a signal from a uniform linear array antenna module comprising a uniform and linear array antenna; Selecting a sub-array antenna having a first spacing and a second spacing to derive a spatial spectrum element from the uniform linear array antenna module; Deriving a spatial power spectrum element using each signal received through the selected sub-array antenna; And calculating an azimuth angle by calculating the derived first and second spatial spectral elements, respectively.

In the calculating of the azimuth angle, it is preferable to calculate the azimuth angle through a multiplication operation of the elements of the first and second spatial power spectrum.

In addition, the receiving of a signal from the uniform linear array antenna module includes a plurality of uniform and linearly arranged first antennas having a first spacing, and an n-th provided to have a second spacing with a terminating antenna of the first antenna. It may be an array antenna module consisting of a +1 antenna.

In the selecting of the array antenna, it is preferable to set the first spacing of the array antennas to 0.5 λ, and to set the second spacing of the array antennas to a multiple of the first spacing.

The selecting of the array antenna includes determining a plurality of array antennas having at least one spacing so as to derive a plurality of spatial spectral elements, and calculating the azimuth angle, through the determined plurality of array antennas. The azimuth angle may be calculated by multiplying the calculated spatial power spectral elements.

According to an embodiment of the present invention, a spatial power spectrum obtained through beamforming from an array of first intervals and a spatial power spectrum obtained through beamforming from an array of second intervals are multiplied by elements, resulting in a narrow main lobe and low grating. It has the effect of obtaining the characteristics of the robe at the same time.

1 is a block diagram illustrating an array antenna device using spatial power spectrum combining according to the present invention.
2 is a view for explaining an example of an array antenna provided in the uniform linear array antenna module of FIG.
3 is a reference diagram for explaining an example of signal reception by the uniform linear array antenna module of FIG. 1;
4 is a reference diagram for explaining an array antenna selected for angular resolution in the uniform linear array antenna module of FIG. 1;
5 is a reference diagram for explaining an array antenna selected for suppressing a gating lobe in the uniform linear array antenna module of FIG. 1;
6 is a reference diagram for explaining an example of a spatial power spectrum result when one target is positioned at 0 degrees in an embodiment of the present invention.
7 is a reference diagram for explaining a spatial power spectrum result derived from beamforming when two targets are positioned at an angle of 20 degrees and 40 degrees, respectively, in an embodiment of the present invention.
8 is a reference diagram for explaining an antenna in which six reception array antennas are arranged at 0.5λ intervals.
9 is a reference diagram for explaining an antenna in which six reception array antennas are arranged at intervals of 1λ.
10 is a reference diagram for explaining a spatial power spectrum result derived from beamforming of a general uniform linear array antenna and a uniform linear array antenna according to the present invention when one target is positioned at an angle of 0 degrees.
11 is a reference diagram for explaining spatial power spectrum results derived from beamforming of a general uniform linear array antenna and a uniform linear array antenna according to the present invention when two targets are positioned at 20 degrees and 40 degrees, respectively.
12 is a flowchart illustrating a method of controlling an array antenna using spatial power spectrum combining according to an embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims. Meanwhile, terms used in the present specification are for explaining embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, "comprises" and/or "comprising" refers to the presence of one or more other components, steps, operations and/or elements in which the recited component, step, operation and/or element is Or does not preclude additions.

1 is a block diagram illustrating an array antenna device using spatial power spectrum combining according to the present invention.

As shown in FIG. 1, an array antenna device using spatial power spectrum combining according to an embodiment of the present invention includes a uniform linear array antenna module 100, an array antenna determination unit 200, and a spatial spectrum element derivation unit 300. ) And an azimuth angle calculation unit 400.

The uniform linear array antenna module 100 includes uniform and linear array antennas 100-1 to 100-n as shown in FIG. 2. The uniform linear array antenna module 100 is a plurality of uniform and linearly arranged first antennas 110-1 to 110-n having a first spacing.

3 is a reference diagram for explaining an example of signal reception by the uniform linear array antenna module of FIG. 1.

As shown in FIG. 3, when the number of reception antennas is N and the distance between the antennas is d and the direction of the target is θ, the main lobe of the array antenna beam pattern is [Equation 1], side lobe is [Equation 2], null is [Equation 3], grating lobe is [Equation 4], -3dB beam width ) Is represented by [Equation 5].

In the antenna beam pattern, the narrower the -3dB beamwidth of the main lobe, the better the angular resolution.Therefore, the antenna spacing (d) or number (N) must be increased. In addition, when the antenna spacing is increased, the grating lobe may appear within a desired field-of-view (FoV) by [Equation 4]. In [Equation 4], θ0 is the steering angle of the main lobe, and when d is 0.5λ or less, the grating lobe does not occur at a viewing angle within ±90°.

When the number of receiving antennas is N and the number of echo signals reflected from the target is M, the received signal can be expressed as x(t) as shown in [Equation 6], and has a weight (w) given to each antenna element as a coefficient. Since the signal y(t) steered by the linear combination of antenna outputs is represented by [Equation 7], the spatial power spectrum P(w) derived by beamforming can be represented by [Equation 8]. . K in Equation 8 is the number of samples of the received signal.

In general beamforming (CBF), in order to find the position where the spatial power spectrum represents the maximum value by pointing the array antenna, the weight (wCBF) of [Equation 9] is used as a(θ) of [Equation 6]. Normalized to size 1 and applied, the resulting spatial power spectrum (PCBF) is represented by [Equation 10].

Since the general beamforming performance is determined by the antenna spacing, number, etc. according to the response of the array antenna shown in [Equation 1] to [Equation 5], a method of increasing angular resolution while minimizing unwanted grating lobes is required. .

In order to derive a spatial spectrum element from the uniform linear array antenna module 100, the array antenna determination unit 200 includes sub-array antennas for angular resolution having a first spacing and a grating lobe having a second spacing. Select a sub array antenna. Here, the first interval of the sub-array antenna for angular resolution is 0.5 λ as shown in FIG. 4, and the second interval of the sub-array antenna for suppressing the gating lobe is of the first interval as shown in FIG. It is preferable that it is λ which is twice.

The spatial spectrum element derivation unit 300 derives each spatial power spectrum element by using a signal received through the sub array antenna selected by the array antenna determination unit 200.

The azimuth angle calculation unit 400 calculates an azimuth angle by calculating the derived first and second spatial spectral elements, respectively. It is preferable that the azimuth angle calculation unit 400 calculates the azimuth angle through an element multiplication operation of the first and second spatial power spectra.

According to an embodiment of the present invention, a spatial power spectrum obtained through beamforming from an array of first intervals and a spatial power spectrum obtained through beamforming from an array of second intervals are multiplied by elements, resulting in a narrow main lobe and low grating. It has the effect of obtaining the characteristics of the robe at the same time.

Further, according to an embodiment of the present invention, the angular resolution may be improved by adjusting the spacing within the number of antennas, and the grating lobe may be reduced.

In one embodiment of the present invention, the receiving channel is composed of 6 antennas, and the distance between the receiving antennas is arranged by combining the distance between the receiving antennas with an interval of 0.5λ that does not occur within the grating lobe and an interval of 1λ to improve the angular resolution. do. The number and spacing of antennas selected here are values arbitrarily selected for verification through simulation and can be changed as necessary.

Of the 6 array antennas, the spatial power spectrum is obtained for 4 arrays of receive channels 1, 2, 3, 4, and the spatial power spectrum is calculated for 4 arrays of receive channels 1, 3, 5, 6, and element multiplication is performed. A narrow main lobe characteristic from a 1λ spacing arrangement and a low grating lobe characteristic from a 0.5λ spacing arrangement can be obtained at the same time.

6 is a reference diagram for explaining an example of a spatial power spectrum result when one target is positioned at 0 degrees in an embodiment of the present invention.

In FIG. 6, a dashed line is a spatial power spectrum for four arrays (0.5λ intervals) of reception channels 1, 2, 3, and 4 of FIG. 5, and a dotted line is 4 of reception channels 1, 3, 5, and 6 of FIG. It is the spatial power spectrum for an array of dogs (1λ interval), and the solid line is the component product of the two spatial power spectra.

When the interval is 0.5λ, there is no grating lobe, but the width of the main lobe is wide. When the interval is 1λ, the width of the main lobe is narrow, but the grating lobe occurs within ±90°.

However, looking at the component product of the two spatial power spectra, it can be seen that the width of the main lobe is similar to that when the interval is 0.5λ, and the grating lobe is reduced.

7 is a reference diagram for explaining a spatial power spectrum result derived from beamforming when two targets are positioned at an angle of 20 degrees and 40 degrees, respectively, in an embodiment of the present invention.

In FIG. 7, a dashed-dotted line is a spatial power spectrum for four arrays (0.5λ intervals) of reception channels 1, 2, 3, and 4 of FIG. 4, and a dotted line is 4 of reception channels 1, 3, 5, and 6 of FIG. It is the spatial power spectrum for an array of dogs (1λ interval), and the solid line is the component product of the two spatial power spectra.

If two targets are located at a position other than 0 degrees, there is no grating lobe when the distance is 0.5λ, but the width of the main lobe is wide, so the two targets cannot be distinguished. When the distance is 1λ, the width of the main lobe is narrow. The two targets can be distinguished, but a grating lobe occurs near the main lobe.

However, looking at the component product of the two spatial power spectra, the width of the main lobe is similar to that when the spacing is 0.5λ, so it can be seen that the two targets can be distinguished and the grating lobe is also reduced.

Meanwhile, in order to compare the results of the general uniform linear array antenna with the array result of FIG. 6, FIG. 8 is a diagram for explaining an antenna in which six reception array antennas are arranged at 0.5λ intervals, and FIG. 9 is a six reception array. A diagram for describing antennas in which antennas are arranged at intervals of 1λ.

10 is an example of a spatial power spectrum result derived from beamforming of a general uniform linear array antenna and a uniform linear array antenna according to the present invention when one target is positioned at an angle of 0 degrees.

In FIG. 10, the dashed-dotted line is the spatial power spectrum for 6 arrays (0.5λ intervals) of the reception channels 1 to 6 of FIG. 8, and the dotted line is for the 6 arrays (1λ interval) of the reception channels 1 to 6 of FIG. It is a spatial power spectrum, and the dashed line is a spatial power spectrum for 6 arrays (an interval combination of 0.5λ and 1λ) of the reception channels 1 to 6 of FIGS. 8 and 9.

And the solid line is an element product of two spatial power spectra composed of four arrays of FIGS. 4 and 5. When the interval is 0.5λ, there is no grating lobe, but the width of the main lobe is the widest. When the interval is 1λ, the width of the main lobe is the narrowest, but the grating lobe occurs within ±90°.

In the combination of 0.5λ and 1λ spacing, the width of the main lobe is wider after the uniform array of 0.5λ spacing, and although the size is small, a grating lobe occurs within ±90°.

However, when looking at the component product of the two spatial power spectra for the four arrays, the width of the main lobe is narrower after the uniform array of 1λ intervals, and the grating lobe does not occur.

11 is a reference diagram for explaining spatial power spectrum results derived from beamforming of a general uniform linear array antenna and a uniform linear array antenna according to the present invention when two targets are positioned at 20 degrees and 40 degrees, respectively.

In FIG. 11, the dashed-dotted line is the spatial power spectrum for 6 arrays (0.5λ intervals) of the reception channels 1 to 6 of FIG. 8, and the dotted line is for the 6 arrays (1λ interval) of the reception channels 1 to 6 of FIG. It is a spatial power spectrum, and the dashed line is a spatial power spectrum for 6 arrays (an interval combination of 0.5λ and 1λ) of the reception channels 1 to 6 of FIGS. 8 and 9.

And the solid line is the component product of the two sub-spatial power spectrums composed of the four arrays of FIGS. 4 and 5. When the interval is 0.5λ, there is no grating lobe, but the width of the two main lobes is the widest. When the gap is 1λ, the width of the main lobe is narrowest, but a grating lobe occurs near the main lobe.

In the combination of 0.5λ and 1λ spacing, the width of the two main lobes is wider after the uniform array of 0.5λ spacing, and although the size is small, a grating lobe also occurs near the main lobe.

However, when looking at the component product of the two spatial power spectra for the four arrays, the width of the main lobe is narrower after the uniform array of 1λ intervals, and the grating lobe does not occur.

On the other hand, according to another embodiment of the present invention, the array antenna determination unit determines a plurality of array antennas having at least one or more intervals to derive a plurality of spatial spectral elements, and the azimuth calculation unit includes a plurality of spatial powers. The azimuth angle can also be calculated by multiplying the elements of the spectrum.

12 is a flowchart illustrating a method of controlling an array antenna using spatial power spectrum combining according to an embodiment of the present invention.

As shown in FIG. 12, a signal is received from a uniform linear array antenna module comprising a uniform and linear array antenna (S100).

Thereafter, in order to derive a spatial spectrum element from the uniform linear array antenna module, sub array antennas for angular resolution having a first spacing and sub array antennas for suppressing a gating lobe having a second spacing are selected (S200). ). In the step of selecting the array antenna (S200), it is preferable to set the first spacing of the array antennas to 0.5 λ, and to set the second spacing of the array antennas to a multiple of the first spacing.

Subsequently, spatial power spectrum elements are each derived using each signal received through the selected sub-array antenna (S300).

Thereafter, the azimuth angle is calculated by calculating the respective derived first and second spatial spectral elements (S400). In the calculating of the azimuth angle (S400), it is preferable to calculate the azimuth angle by multiplying the elements of the first and second spatial power spectrums.

In the receiving of a signal from the uniform linear array antenna module (S100), a plurality of first antennas arranged uniformly and linearly having a first distance and a terminal antenna of the first antenna and a second distance are provided. An array antenna module consisting of a +1 antenna may be used.

On the other hand, in the array antenna control method using spatial power spectrum combination according to another embodiment of the present invention, the step of selecting the array antenna (S200) includes a plurality of spaces having at least one or more intervals so as to derive a plurality of spatial spectrum elements. In the step of determining the array antenna of and calculating the azimuth angle (S400), the azimuth angle may be calculated through a multiplication operation of a plurality of spatial power spectrum elements calculated through the determined plurality of array antennas.

In the above, the configuration of the present invention has been described in detail with reference to the accompanying drawings, but this is only an example, and if one of ordinary skill in the art to which the present invention belongs, various modifications and changes within the scope of the technical idea of the present invention Of course this is possible. Therefore, the scope of protection of the present invention should not be limited to the above-described embodiments, but should be determined by the description of the following claims.

Claims (12)

A uniform linear array antenna module consisting of uniform and linear array antennas;
An array antenna determiner for selecting sub-array antennas having a first interval and a second interval from the array antennas in the uniform linear array antenna module to derive a spatial spectrum element from the uniform linear array antenna module;
A spatial spectrum element derivation unit for deriving each spatial power spectrum element by using a signal received through the sub array antenna selected by the array antenna determining unit; And
An array antenna device using spatial power spectrum combining comprising an azimuth angle calculator configured to calculate an azimuth angle by calculating the respective derived first spatial spectrum elements and second spatial spectrum elements.
The method of claim 1,
The azimuth calculation unit,
An array antenna device using spatial power spectrum combining to calculate an azimuth angle by multiplying elements of the first and second spatial power spectrums.
The method of claim 1,
The uniform linear array antenna module,
An array antenna device using spatial power spectrum combining, including a plurality of first antennas uniformly and linearly arranged having a first spacing and an n+1 th antenna provided to have a second spacing with the terminating antenna of the first antenna.
The method of claim 1,
The array antenna determining unit,
The array antenna device using spatial power spectrum combining to set the first interval to 0.5 λ.
The method of claim 4,
The second interval is
An array antenna device using spatial power spectrum combining that is set to be a multiple of the first interval.
The method of claim 1,
The array antenna determining unit,
To derive a plurality of spatial spectral elements, a plurality of array antennas having at least one spacing are determined,
The azimuth calculation unit,
An array antenna device using spatial power spectrum combining to calculate an azimuth angle through multiplication of elements of a plurality of spatial power spectrums.
Receiving a signal from a uniform linear array antenna module consisting of uniform and linear array antennas;
Selecting a sub-array antenna having a first spacing and a second spacing to derive a spatial spectrum element from the uniform linear array antenna module;
Deriving a spatial power spectrum element using each signal received through the selected sub-array antenna; And
And calculating an azimuth angle by calculating the respective derived first and second spatial spectral elements.
The method of claim 7,
The step of calculating the azimuth angle,
An array antenna control method using spatial power spectrum combining to calculate an azimuth angle through a multiplication operation of elements of the first and second spatial power spectrums.
The method of claim 7,
Receiving a signal from the uniform linear array antenna module,
Array using spatial power spectrum combination, which is an array antenna module comprising a plurality of first antennas uniformly and linearly arranged with a first interval and an n+1th antenna provided to have a second interval with a terminal antenna of the first antenna Antenna control method.
The method of claim 7,
Selecting the array antenna,
The array antenna control method using spatial power spectrum combining to set the first interval of the array antenna to 0.5 λ.
The method of claim 10,
Selecting the array antenna,
The array antenna control method using spatial power spectrum combining in which the second interval of the array antenna is set to be a multiple of the first interval.
The method of claim 7,
Selecting the array antenna,
To derive a plurality of spatial spectral elements, a plurality of array antennas having at least one spacing are determined,
The step of calculating the azimuth angle,
An array antenna control method using spatial power spectrum combining to calculate an azimuth angle through a multiplication operation of a plurality of spatial power spectrum elements calculated through the determined plurality of array antennas.

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