JP2011244260A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device which has the phase centers of the two taper slot antennas (TSA) orthogonal to each other match each other, and which has no unwanted emission from a feeder line.SOLUTION: An antenna device is composed of first and second TSAs 100 and 200. On both the sides of multilayer dielectric substrates 101 and 201 of the first and second TSAs 100 and 200, taper slot lines (105a, b) and (205a, b) are formed by first pair of ground conductors 102 and 202 and second pair of ground conductors 103 and 203. Linear conductors 107 and 207 one end of which is short-circuited to the first pair of ground conductors 102 and 202 and the other end of which is a feeding point form triplate lines 110 and 210 with the second pair of ground conductors 103 and 203. The first and second TSAs 100 and 200 are orthogonal to each other and combined so that the center lines O1 and O2 of their taper slot lines match each other, and the lengths of their linear conductors 107 and 207 are equal to each other.

Description

  The present invention relates to an antenna device used for applications such as radar, and in particular, an antenna that can be applied to an element antenna for an array antenna that transmits and receives two orthogonal linearly polarized waves or circularly polarized waves over a wide frequency band. It relates to the device.

  One type of ultra-wideband antenna is a tapered slot antenna (hereinafter abbreviated as “TSA”). Furthermore, as an example of a TSA array that can transmit and receive two orthogonal linearly polarized waves, there is a TSA array shown in FIG. Another example is the TSA shown in FIG. In both cases, two linearly polarized waves orthogonal to each other can be transmitted and received by combining TSA orthogonally.

Tan-Huat Chio, Daniel H. Schaubert, “Parameter Study and Design of Wide-Band Wides Dual-Polarized Tapered Slot Antenna Arrays,” IEEE Transactions on Antona Prot. 48, no. 6, pp. 879-886, June, 2000 Tanabe, Haneishi, “Polarized antenna using linear taper slot antenna with coplanar line excitation”

  In Non-Patent Document 1, a plurality of triplate line feed type TSA elements having the same shape are prepared, and each of them is connected in a lattice shape via a conductor post, thereby enabling transmission and reception of two orthogonal linearly polarized waves. A TSA array is configured. Although such a configuration has an advantage of facilitating the manufacture of an array antenna, two orthogonal TSAs are used as one pair element, and a feed module is provided for each pair element to construct a phased array antenna. Assuming that the phase centers of the two TSAs constituting the pair element are deviated, especially when transmitting and receiving circularly polarized waves, it is necessary to have a configuration capable of correcting the phase of the deviation over a wide band. There are challenges. In order to avoid this, a power supply module may be provided for each TSA element. In this case, the number of power supply modules is doubled, so that the entire phased array antenna apparatus is large-scale and the configuration is complicated. There is a problem that the cost increases.

  In Non-Patent Document 2, since two orthogonal TSAs are combined so that the center lines of the respective taper slot lines are the same, their phase centers coincide with each other and circular polarization is assumed. However, it can be expected that a good circular polarization characteristic is obtained over a wide band and a wide angle. However, since the coplanar lines for feeding the TSA are arranged on the surface of the single-layer dielectric substrate at right angles to the extending direction of the TSA, the symmetry of the antenna structure is poor and there is no need to generate from the coplanar lines. There are problems that the radiation pattern of the antenna is disturbed due to the influence of the radiated wave and that the isolation characteristics between two orthogonal TSA elements are poor. The deterioration of isolation causes a decrease in the gain of the antenna, and when two TSA elements are combined with circularly polarized waves, the axial ratio is deteriorated, which is not preferable.

  The present invention has been made in order to solve the above-described problems. It is an object of the present invention to obtain an antenna device in which the phase centers of two orthogonal TSAs coincide with each other and there is no unnecessary radiation from the TSA feed line. Objective.

  The antenna device according to the present invention is an antenna device including first and second tapered slot antennas having substantially the same outer shape, and each of the first and second tapered slot antennas includes a dielectric substrate, a dielectric substrate, and a dielectric substrate. Formed between the first and second ground conductor pairs respectively constituted by ground conductors provided on both surfaces of the body substrate and the first and second ground conductor pairs on both surfaces of the dielectric substrate; First and second slots extending in a tapered shape from the proximal end portion to the distal end portion of the dielectric substrate, and provided in a plane substantially parallel to the ground conductor inside the dielectric substrate, one end of the first dielectric substrate The first and second ground conductor pairs are provided with first and second tapered slot lines on both surfaces of the dielectric substrate. Each of the linear conductors is formed with first and second taper slots. The first and second tapered slot antennas are orthogonal to each other and each of the first and second tapered slot lines is provided so as to be orthogonal to the first line and form a triplate line together with the second ground conductor pair. Are combined so that their center lines coincide with each other, and the lengths of the respective linear conductors are equal.

  According to the present invention, it is possible to obtain an antenna device in which the phase centers of two orthogonal TSAs coincide with each other and there is no unnecessary radiation from the TSA feed line.

It is a figure which shows the antenna apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the antenna apparatus which concerns on Embodiment 1 of this invention, and its electric power feeding method. It is a figure which shows the structure of the antenna device which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the antenna device which concerns on Embodiment 3 of this invention. It is a figure which shows the antenna apparatus which concerns on Embodiment 4 of this invention. It is a figure which shows the antenna apparatus which concerns on Embodiment 5 of this invention. It is a figure which shows the antenna apparatus which concerns on Embodiment 6 of this invention. It is a figure which shows the structure of the conductor plate with a metal plate grid used with the antenna apparatus which concerns on Embodiment 6 of this invention.

Embodiment 1 FIG.
Fig.1 (a) is a schematic diagram which shows the external appearance of the antenna apparatus which concerns on Embodiment 1 of this invention. This antenna device is configured by combining a first triplate line feed type TSA100 and a second triplate line feed type TSA200 having the same external shape.

FIG. 1B is a schematic diagram showing the antenna device disassembled into a first triplate line feed type TSA100 and a second triplate line feed type TSA200.
In the first triplate line feed type TSA 100, 101 is a multilayer dielectric substrate formed by superposing two dielectric substrates, and 102a and 102b are ground conductors on both surfaces of the multilayer dielectric substrate 101. The first ground conductor pair 102 is configured, and 103 a and 103 b are ground conductors on both surfaces of the multilayer dielectric substrate 101, and the second ground conductor pair 103 is configured. On both surfaces of the multilayer dielectric substrate 101, there is a front end portion from the base end portion 101 a (−Z direction side) of the multilayer dielectric substrate 101 between the first ground conductor pair 102 and the second ground conductor pair 103. A first slot 104a and a second slot 104b that are tapered toward 101b (+ Z direction side) are formed. Then, the first taper slot line 105a and the second taper slot line 105b are formed on both surfaces of the multilayer dielectric substrate 101 by the first ground conductor pair 102 and the second ground conductor pair 103, respectively. . Reference numeral 106 denotes a notch provided in the base end portion 101a of the multilayer dielectric substrate 101 constituting the first triplate line feed type TSA 100, and a part of the multilayer dielectric substrate 101 extends from the base end portion 101a to the tip end portion 101b. It is formed by being cut out in a rectangular shape toward.

  Similarly, in the second triplate line feed type TSA 200, 201 is a multilayer dielectric substrate, the ground conductors 202a and 202b constitute a first ground conductor pair 202, and the ground conductors 203a and 203b are second ground planes. A conductor pair 203 is formed. A first slot 204a and a second slot 204b are formed between the first ground conductor pair 202 and the second ground conductor pair 203, respectively. A first tapered slot line 205a and a second tapered slot line 205b are formed by the conductor pair 203, respectively. Reference numeral 206 denotes a notch provided in the front end portion 201b of the multilayer dielectric substrate 201 constituting the second triplate line feed type TSA200.

  As shown in FIGS. 1A and 1B, the first and second triplate line feed type TSAs 100 and 200 are combined so as to be orthogonal to each other through the notches 106 and 206.

  In FIGS. 1A and 1B, assuming that the plane including the multilayer dielectric substrate 101 is the XZ plane and the plane including the multilayer dielectric substrate 201 is the YZ plane, the + Z direction is the main radiation direction in this antenna device. .

  FIG. 2 is a schematic diagram showing a power feeding method of the first and second triplate line power feeding type TSAs 100 and 200. Reference numerals 107 and 207 denote linear conductors, and 108 and 208 denote through holes. The L-shaped linear conductors 107 and 207 are arranged in the plane sandwiched between the two dielectric substrates constituting the multilayer dielectric substrates 101 and 201, that is, the ground conductors (inside the multilayer dielectric substrates 101 and 201). 102a, b, 103a, b) and (202a, b, 203a, b), respectively. The linear conductor 107 and the second ground conductor pair 103 form the triplate line 110, and similarly, the linear conductor 207 and the second ground conductor pair 203 form the triplate line 210. One end of each of the linear conductors 107 and 207 is short-circuited to the first ground conductor pair 102 and 202 by the through holes 108 and 208 so as to be orthogonal to the tapered slot lines (105a, b) and (205a, b). After extending, it bends at a right angle in the -Z direction, and the other ends 107a and 207a serve as feed points to which a connector or a structure connectable to an external high-frequency electronic device such as a coaxial line is connected. With this structure, the first ground conductor pair 102 and the second ground conductor pair 103 of the first triplate line feed type TSA 100, and the first ground conductor pair 202 of the second triplate line feed type TSA 200, A potential difference is applied to each of the second ground conductor pair 203, and the radio wave travels along the tapered slot lines (105a, b) and (205a, b), from the + Z direction front ends of the multilayer dielectric substrates 101 and 201. Radiated into space.

  The notch 106 of the first triplate line feed type TSA 100 is within a range where it does not contact the linear conductor 107 along the center line O1 of the tapered slot line (105a, b) from the base end portion 101a of the multilayer dielectric substrate 101. The notch 206 of the second triplate line feed type TSA 200 is in contact with the linear conductor 207 along the center line O2 of the tapered slot line (205a, b) from the tip 201b of the multilayer dielectric substrate 201. It is provided within the range not to be.

  The total length of the linear conductor 107 from the through hole 108 to the feeding point 107a of the first triplate line feed type TSA 100 and the linear conductor 207 from the through hole 208 to the feeding point 207a of the second triplate line feed type TSA 200. Are equal to each other, the phases of the radio waves at the positions P1 and P2 at which the linear conductors 107 and 207 intersect the tapered slot lines (105a and b) and (205a and b) are made to coincide with each other.

  A position P1 where the linear conductor 107 intersects the tapered slot line (105a, b) and a position P2 where the linear conductor 207 intersects the tapered slot line (205a, b) are a tapered slot line (105a, b), They are shifted from each other along the center lines O1 and O2 of (205a, b). However, the length of this shift is sufficiently shorter than the wavelength λ corresponding to the maximum frequency of the radio wave to be used (a wavelength considering that the wavelength is shortened by the dielectric), for example, from 1/10 of the wavelength λ. Because of this, the effect of this shift is small.

  As described above, the first triplate line feed type TSA 100 and the second triplate line feed type TSA 200 are orthogonal to each other and the center of each tapered slot line (105a, b), (205a, b). The lines O1 and O2 are combined so as to coincide with each other, and the lengths of the respective linear conductors 107 and 207 are equal. Therefore, the phases of the radio waves of the first triplate line feed type TSA 100 and the second triplate line feed type TSA 200 coincide with each other at the antenna opening end in the + Z direction. That is, the phase centers of two orthogonal TSAs coincide. Accordingly, the phase of the far field can be matched. Further, the linear conductors 107 and 207 form the triplate lines 110 and 210 together with the second ground conductor pair 103 and 203. Since a triplate line is used for feeding the antenna device, there is no unnecessary radiation from the line.

  Further, as shown in FIGS. 1A and 1B, the first triplate line feed type TSA 100 and the second triplate line feed type TSA 200 are respectively formed by taper slot lines (105a, b), The center lines O1 and O2 of (205a, b) coincide with each other, and when viewed on the XY plane, they appear to be gathered at one point. Therefore, a distribution circuit is connected to the two feeding points 107a and 207a, and the plane of polarization of the antenna device is shifted obliquely with respect to the direction along the X axis and Y axis, or a 90 degree hybrid is connected to form a circle. Polarized light can be emitted.

  Furthermore, the shape of the linear conductors 107 and 207 has an asymmetric structure in the XZ plane and the YZ plane, respectively, but since the linear line is inserted in the dielectric body, the influence is externally It does not appear and the external structure of the antenna device has symmetry. Therefore, a sufficiently low isolation level is obtained between two orthogonal TSAs, and the radiation pattern shape is hardly disturbed.

Embodiment 2. FIG.
FIG. 3 is a schematic diagram showing the structure of an antenna device according to Embodiment 2 of the present invention. The same components as those described above are denoted by the same reference numerals and description thereof is omitted. In FIG. 3, 311a and 311b are slots having a width wider than the widths at the base ends (the −Z direction side) of the first and second slots 104a and 104b of the first triplate line feed type TSA300. Yes, and provided so as to be connected to the respective base ends of the first and second slots 104a and 104b. Similarly, 411a and 411b are slots having a width wider than the width at the base end of each of the first and second slots 204a and 204b of the second triplate line feed type TSA 400. The slots 204a and 204b are provided so as to be connected to the base ends of the slots 204a and 204b. As a result, a slot line having a wider slot width is connected to the respective base end portions of the tapered lot lines (105a, b) and (205a, b) of the first and second triplate line feed type TSA 300, 400. The

  The radio waves fed from the triplate lines 310 and 410 to the tapered slot lines (105a, b) and (205a, b) preferably propagate only to the + Z direction side of the antenna opening end, but a part of the radio wave is −Z. Will propagate to the rear side of the antenna. Then, the power feeding device located behind the antenna device is affected, and it becomes necessary to take measures to increase the interference resistance of the power feeding device. Therefore, by connecting a slot line having a wide slot width to the respective base end portions of the tapered slot lines (105a, b) and (205a, b), components of radio waves propagating backward can be suppressed. This is because the characteristic impedance of the line becomes higher as the slot width is wider as the property of the slot line, so that the rear side of the antenna device appears to be open.

Embodiment 3 FIG.
FIG. 4 is a schematic diagram showing the structure of an antenna device according to Embodiment 3 of the present invention. The same components as those described above are denoted by the same reference numerals and description thereof is omitted. In FIG. 4, reference numerals 512 and 612 denote a number of through holes.

  It is desirable that the linear conductors 107 and 207 are located at an exactly middle position inside the multilayer dielectric substrates 101 and 201, that is, at equal distances from the ground conductors on both surfaces of the multilayer dielectric substrates 101 and 201, respectively. Thereby, the potentials of the ground conductors on both surfaces of the multilayer dielectric substrates 101 and 201 can be kept equal.

  However, when the linear conductors 107 and 207 are biased from one intermediate position inside the multilayer dielectric substrates 101 and 201 to one ground conductor surface due to the influence of a manufacturing error or the like, on both surfaces of the multilayer dielectric substrates 101 and 201 A potential difference is generated between the two ground conductors, and a parallel plate mode in which the ground conductors on both surfaces of the multilayer dielectric substrates 101 and 201 are waveguides propagates. This parallel plate mode becomes a factor that disturbs the radiation pattern of the antenna device, and problems such as an increase in the amount of coupling between elements occur when an array antenna device described later is considered.

  Therefore, by short-circuiting the ground conductors provided on both surfaces of the multilayer dielectric substrates 101 and 201 with a large number of through-holes 512 and 612 where they do not overlap the linear conductors 107 and 207, the parallel plate mode can be realized. Occurrence can be prevented.

  In the antenna device according to the third embodiment, a slot line having a wide slot width is connected to the respective base end portions of the tapered slot lines (105a, b) and (205a, b) as in the second embodiment. By doing so, the component of the radio wave propagating backward can be suppressed.

Embodiment 4 FIG.
FIG. 5 is a schematic diagram showing an antenna apparatus according to Embodiment 4 of the present invention. The same components as those described above are denoted by the same reference numerals and description thereof is omitted. In FIG. 5, reference numeral 713 denotes a first conductor plate, which is provided at the base end (−Z direction side) of the antenna device shown in the first embodiment.

  By disposing the conductor plate 713 at the base end of the antenna device, that is, the rear side, unnecessary radiation to the rear side of the antenna can be completely eliminated. The radio wave radiated to the antenna rear side is reflected by the conductor plate 713 and re-radiated to the antenna front side. Therefore, an effect that the gain of the antenna device is improved can be obtained. At this time, depending on the installation position of the conductor plate 713 or the operating frequency, the reflected wave from the conductor plate 713 and the direct wave of the antenna device may overlap with each other in opposite phases, and the main beam may be null (zero radiation). However, by making the installation position of the conductor plate 713 variable, it is possible to shift the frequency at which nulls are generated in the main beam to the outside of the use frequency band, and to avoid the generation of nulls.

  In the fourth embodiment, the configuration in which the conductor plate 713 is provided at the base end portion of the antenna device shown in the first embodiment is shown. However, the base end portion of the antenna device shown in the second and third embodiments is shown. The same effect can be obtained even if the conductor plate 713 is provided.

Embodiment 5 FIG.
In the first to fourth embodiments described above, a single element antenna has been described. However, an antenna device in which a plurality of elements are arranged on a plane to form an array may be configured. A high-gain array antenna device can be obtained by exciting a plurality of elements in the same phase, and a beam can be scanned in an arbitrary direction by exciting each arrayed element antenna with a phase difference. A phased array antenna device can be obtained.

  FIG. 6 is a schematic diagram showing an antenna apparatus according to Embodiment 5 of the present invention. The same components as those described above are denoted by the same reference numerals and description thereof is omitted. This antenna device is obtained by arranging a plurality of antenna devices shown in Embodiment 1 in a planar shape. In FIG. 6, reference numeral 1000 denotes a first triplate line feed type TSA group in which a plurality of first triplate line feed type TSAs 100 are arranged, and reference numeral 2000 denotes a second type in which a plurality of second triplate line feed type TSAs 200 are arranged. 2 represents a triplate line feed type TSA group.

  At this time, the plurality of first triplate line power supply type TSAs 100 are arranged such that the adjacent first ground conductor pair 102 and second ground conductor pair 103 are short-circuited. Similarly, in the plurality of second triplate line feed type TSA 200, the adjacent first ground conductor pair 202 and second ground conductor pair 203 are arranged in a short circuit. If conduction between adjacent elements can be obtained as in this structure, unnecessary reflection at a connection portion between elements can be suppressed.

  In the fifth embodiment, a configuration in which a plurality of antenna devices shown in the first embodiment are arranged to form an array is shown. However, even if a plurality of antenna devices shown in the second, third, and fourth embodiments are arranged in an array, the arrangement is made. Good.

Embodiment 6 FIG.
FIG. 7 is a schematic diagram showing an antenna device according to Embodiment 6 of the present invention, and FIG. 8 is a schematic diagram showing a structure of a conductor plate with a metal plate grid used in this antenna device. The same components as those described above are denoted by the same reference numerals and description thereof is omitted. In FIG. 8, reference numeral 814 denotes a second conductor plate, and 815 denotes a metal plate grid formed by combining a plurality of metal plates, which are third conductor plates, in a grid pattern. The metal plate grid 815 is short-circuited on the conductor plate 814 and constitutes a conductor plate 817 with a metal plate grid. In addition, rectangular notches 816 that reach the conductor plate 814 are formed between the lattice points of the metal plate grid 815.

  As shown in FIG. 7, the first triplate line feed type TSA group 1000 and the second triplate of the array antenna apparatus shown in the fifth embodiment are formed in each notch 816 of the conductor plate with metal plate grid 817. The base end portions (−Z direction side) of the line feed type TSA group 2000 are respectively inserted.

  In the array antenna apparatus shown in the fifth embodiment, a rectangular cavity region is generated between adjacent elements. Here, particularly on the antenna base end side where the slot width of the tapered slot line is narrow, the rectangular cavity region is surrounded by a conductor surface, and resonance occurs in the rectangular cavity region when the frequency of the radio wave used increases. there is a possibility. This resonance phenomenon is not necessary for the operation of the array antenna device, and energy is lost, which is not preferable.

  Thus, by providing a conductor plate 817 with a metal plate grid instead of the conductor plate 713 as shown in the fourth embodiment, the metal plate grid 815 exists as a conductor wall between the rectangular hollow regions. The rectangular hollow area is subdivided. As a result, the frequency causing the unnecessary resonance can be shifted to a higher frequency side.

  In the sixth embodiment, a configuration in which a plurality of antenna devices shown in the first embodiment are arranged to form an array and the metal plate grid-attached conductor plate 817 is provided is shown in the second and third embodiments. The same effect can be obtained by providing a metal plate grid-attached conductor plate 817 in a plurality of antenna devices arranged in an array.

  100, 300, 500 First triplate line feed type TSA, 200, 400, 600 Second triplate line feed type TSA, 101, 201 Dielectric substrate (multilayer dielectric substrate), 101a, 201a Base end (base end of multilayer dielectric substrate), 102, 202, 302, 402 first ground conductor pair, 103, 203, 303, 403 second ground conductor pair, 104a, 204a first slot, 104b, 204b Second slot, 105a, 205a First tapered slot line, 105b, 205b Second tapered slot line, 106, 206 Notch, 107, 207 Linear conductor, 107a, 207a Feed point, 110, 210 , 310, 410 Triplate line, 512, 612 through-hole, 713 conductor plate (first conductor , 814 Conductor plate (second conductor plate), 815 Metal plate grid (conductor plate grid), 816 Notch, O1, O2 Center lines of the first and second tapered slot lines, P1, P2 linear conductors A position that intersects the first and second tapered slot lines.

Claims (7)

An antenna device including first and second tapered slot antennas having substantially the same outer shape,
Each of the first and second tapered slot antennas is
A dielectric substrate;
First and second ground conductor pairs each constituted by ground conductors provided on both surfaces of the dielectric substrate;
First and second slots formed between the first and second ground conductor pairs on both surfaces of the dielectric substrate and extending in a tapered shape from the base end portion to the tip end portion of the dielectric substrate. When,
A linear conductor provided in a plane substantially parallel to the ground conductor inside the dielectric substrate, with one end short-circuited to the first ground conductor pair and the other end serving as a feeding point;
The first and second ground conductor pairs form first and second tapered slot lines on both surfaces of the dielectric substrate, respectively.
The linear conductor is provided so as to be orthogonal to the first and second tapered slot lines to form a triplate line together with the second ground conductor pair,
The first and second taper slot antennas are combined such that the center lines of the first and second taper slot lines are orthogonal to each other and the center lines of the first and second taper slot lines coincide with each other, and the lengths of the respective linear conductors An antenna device characterized in that they are equal. The antenna device according to claim 1,
The base end portion of the dielectric substrate of the first tapered slot antenna is provided with a cutout within a range that does not contact the linear conductor along the center line of the first and second tapered slot lines. ,
The tip of the dielectric substrate of the second tapered slot antenna is provided with a cutout within a range that does not contact the linear conductor along the center line of the first and second tapered slot lines,
A position where the linear conductor of the first tapered slot antenna intersects with a center line of the first and second tapered slot lines; and the linear conductor of the second tapered slot antenna and the first and second The position where the center line of the two taper slot lines intersects is shifted by a length shorter than about 1/10 of the wavelength of the radio wave used along the center lines of the first and second taper slot lines. Arranged,
The first and second tapered slot antennas are combined through the notches so that they are orthogonal to each other and the center lines of the first and second tapered slot lines coincide with each other. An antenna device. The antenna device according to claim 1 or 2,
The base end portions of the first and second taper slot lines of the first and second taper slot antennas have a width greater than the slot width at the base end portions of the first and second taper slot lines. A slot line having a wide slot width is connected to each other. The antenna device according to any one of claims 1 to 3,
In the first and second tapered slot antennas, the ground conductors provided on both surfaces of the dielectric substrate are short-circuited at a location where the ground conductors do not overlap with one or more through holes. An antenna device characterized by the above. The antenna device according to any one of claims 1 to 4,
An antenna device, wherein a first conductor plate is provided at a base end portion of the antenna device. The antenna device according to any one of claims 1 to 5,
A plurality of antenna devices are arranged on a plane to form an array,
The antenna device, wherein the first and second ground conductor pairs of the adjacent antenna devices are short-circuited. The antenna device according to claim 6 when dependent on any one of claims 1 to 4,
A second conductor plate;
A conductor plate grid provided on the second conductor plate and configured by combining a plurality of third conductor plates in a grid pattern;
The conductor plate grid is short-circuited to the second conductor plate and provided with notches between the lattice points,
An antenna device, wherein each of the base end portions of the first and second tapered slot antennas in the antenna device is inserted into each of the notches provided in the conductor plate grid.

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