KR101584774B1 - Phase retardation cell and antenna including the same - Google Patents

Abstract

A phase delay cell and an antenna including the same are provided. A phase delay cell according to an embodiment of the present invention includes: a reflection plate; A first unit cell spaced apart from the reflection plate and symmetrically formed with a first pattern spaced apart from the reflection plate by a predetermined distance so as to delay a phase of a signal reflected from the reflection plate; And a second unit cell spaced apart from the first unit cell and symmetrically formed with a second pattern spaced apart from the first unit cell so as to improve cross-polarization isolation in the reflector.

Description

[0001] PHASE DELETED CELL AND ANTENNA INCLUDING THE SAME [0002]

BACKGROUND OF THE INVENTION Field of the Invention [0002] Embodiments of the present invention relate to a phase delay cell and an antenna including the same, and more particularly, to an antenna that can be used for satellite communication and radar.

In recent years, as interest and researches on satellite communication and radar have progressed, demand for a reflector antenna in the GHz band has been increasing. Reflector antennas are known as antennas suitable for satellite communication because of their simple structure, simple installation and high gain characteristics. In the case of a reflector antenna, the difference between the magnitudes of co-polarization and cross-polarization is an important factor in signal analysis and peer identification. Here, the same polarization means a desired polarization component, and the cross polarization means an unwanted polarization component perpendicular to the same polarization component. For example, in the case of linear polarization, the vertical polarization and the horizontal polarization are opposite to each other.

Korean Patent Publication No. 2010-0095799 (2010.09.01)

Embodiments of the present invention provide a phase delay cell capable of correcting a phase difference of a reflected wave generated by implementing a parabolic reflector antenna in a flat plate shape and improving cross polarization performance and an antenna including the same .

According to an exemplary embodiment of the present invention, A first unit cell spaced apart from the reflection plate and symmetrically formed with a first pattern spaced apart from the reflection plate by a predetermined distance so as to delay a phase of a signal reflected from the reflection plate; And a second unit cell spaced apart from the first unit cell and symmetrically formed with a second pattern spaced apart from the first unit cell by a predetermined distance so as to improve cross-polarization isolation in the reflection plate, Cell is provided.

The first unit cell may include a first stub extending from one end of the first pattern to have a predetermined length.

The first unit cell may further include a second stub extending from the other end of the first pattern to have a predetermined length.

The first pattern may be formed in a cubic shape.

The second unit cell may include a third stub extending from one end and the other end of the second pattern to have a predetermined length.

The second pattern may have a linear shape.

According to another exemplary embodiment of the present invention, there is provided an antenna including at least two phase delay cells as described above.

According to another exemplary embodiment of the present invention, A first substrate including at least two first unit cells spaced apart from the reflection plate and symmetrically formed with a first pattern spaced apart from each other by a predetermined distance so as to delay a phase of a signal reflected by the reflection plate; And at least two second unit cells spaced apart from the first substrate and symmetrically formed with a second pattern spaced apart from each other by a predetermined distance so as to improve cross-polarization isolation in the reflector An antenna is provided, comprising a second substrate.

The first unit cell may include a first stub extending from one end of the first pattern to have a predetermined length.

The first unit cell may further include a second stub extending from the other end of the first pattern to have a predetermined length.

The first pattern may be formed in a cubic shape.

The second unit cell may include a third stub extending from one end and the other end of the second pattern to have a predetermined length.

The second pattern may have a linear shape.

According to the embodiments of the present invention, it is possible to sequentially change the phase of the reflected wave over a wide range through the first unit cell, thereby facilitating the synthesis of the reflected waves.

In addition, according to the embodiments of the present invention, cross-polarization isolation in the reflector can be improved through the second unit cell.

1 is a diagram illustrating a phase delay cell according to an embodiment of the present invention;
2 is an exploded perspective view of a phase delay cell according to an embodiment of the present invention.
3 is a view showing a pattern formed in a first unit cell according to an embodiment of the present invention;
4 is a graph showing the phases of reflected waves varying according to the length and frequency of the first and second stubs according to an embodiment of the present invention.
5 is a view showing a pattern formed in a second unit cell according to an embodiment of the present invention;
6 is a view for explaining an effect of improving cross-polarization isolation in a reflector by a second unit cell according to an embodiment of the present invention;
7 is a view illustrating an antenna according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, this is an exemplary embodiment only and the present invention is not limited thereto.

In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intention or custom of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

The technical idea of the present invention is determined by the claims, and the following embodiments are merely a means for efficiently describing the technical idea of the present invention to a person having ordinary skill in the art to which the present invention belongs.

FIG. 1 is a view showing a phase delay cell 100 according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a phase delay cell 100 according to an embodiment of the present invention. 1 and 2, a phase delay cell 100 according to one embodiment of the present invention includes a reflector 102, a first spacing 104-1, a second spacing 104-2, A first unit cell 106-1, a second unit cell 106-2, and a pattern 108,

The reflector 102 is made of a conductor and serves as a reflector and a ground. The reflection plate 102 may be formed in various shapes such as a square shape or a circular shape in a planar shape in which both sides are not bent.

The spacers 104 are structures that separate the spacing between the reflector 102, the first unit cell 106-1, and the second unit cell 106-2. The phase delay cell 100 according to an embodiment of the present invention is formed by stacking a plurality of unit cells 106-1 and 106-2 and the plurality of unit cells 106-1 , 106-2. The first unit cell 106-1 may be spaced apart from the reflector 102 by a predetermined distance through the first separator 104-1. The distance between the reflection plate 102 and the first unit cell 106-1 may vary depending on, for example, the phase size of the reflected wave to be changed. The second unit cell 110 may be spaced apart from the reflector 102 and the first unit cell 106-1 by a predetermined distance through the second spacers 104-2. The spacers 104-1 and 104-2 preferably use a material having a dielectric constant similar to air or air in order to minimize the loss of reflected waves, but the present invention is not limited thereto. The spacers 104-1 and 104-2 may be, for example, a honeycomb, a foam, a jig, or the like.

The unit cells 106-1 and 106-2 are plates on which the pattern 108 or 110 is formed, and may be, for example, a substrate. Like the reflector 102, the unit cells 106-1 and 106-2 may have various plate shapes such as a square or a circle. The unit cells 106-1 and 106-2 may have a shape corresponding to the shape of the reflection plate 102, but are not limited thereto. The first unit cell 106-1 and the second unit cell 106-2 may be spaced apart from each other by a second distance 104-2.

The first unit cells 106-1 are symmetrically formed with the patterns 108 spaced apart from each other by a predetermined distance so as to delay the phase of the signal reflected by the reflection plate 102. [ In the case of a reflector antenna, a parabolic reflector is generally used. However, such a parabolic reflector is disadvantageous in that it is difficult to process and it is difficult to manufacture because of its large weight and bulky size. Recently, a flat antenna in which a parabolic reflector is formed as a flat plate reflector is widely used for home or satellite communications. However, when a parabolic reflector is implemented as a flat plate reflector, the distance between the radiation source and the parabolic reflector And the distance between the radiation source and the flat plate-shaped reflection plate is changed, so that the phase difference of the reflected wave is generated, and the directivity of the antenna is deteriorated. As the distance from the center of the reflector increases, the distance difference between the radiation source, the parabolic reflector, and the flat plate reflector increases, and the phase difference of the reflected wave also increases. Table 1 is a table showing the phase difference of the reflected wave generated when a parabolic reflector is implemented as a flat plate-shaped reflector.

Distance from reflector center (mm) Reflex
Phase difference (°) 0 6.428 18 -40.48 36 -121.732 54 -237.328 72 -387.268 90 -571.552 108 -790.18

As shown in Table 1, when the distance from the center of the reflector is about 18 mm, the phase difference of the reflected wave is only about -40 °. However, when the reflector is about 90 mm away from the center of the reflector, the phase difference of the reflector reaches about -571 ° have. Accordingly, the embodiments of the present invention correct the phase difference of the reflected wave generated when the parabolic reflector is implemented as a plate-like reflector through the first unit cell 106-1.

When the phase delay cell 100 is formed into a square shape, the horizontal and vertical lengths of the pattern 108 formed in the first unit cell 106-1 may be, for example, 0.4? 0.5? have. The detailed structure of the pattern 108 formed in the first unit cell 106-1 will be described later in detail with reference to Fig.

The second unit cells 106-2 are symmetrically formed with the patterns 110 spaced apart from each other by a predetermined distance so as to improve the degree of cross polarization separation in the reflection plate 102. [ In the case of a reflector antenna, the difference between the magnitudes of co-polarization and cross-polarization is an important factor for signal analysis and peer identification, and it is important to distinguish (or distinguish) It is important. For example, the larger the amplitude difference between the vertical polarization and the horizontal polarization is, the wider the detection range of the radar increases the detection distance. Cross-polarization isolation refers to the ratio of the right-polarized wave power at the same receiver to the cross-polarization power at a given receiver, for two waves transmitted with the same power and orthogonal polarization at the same frequency. For example, the higher the degree of cross polarization separation, the more easily the vertical polarization and the horizontal polarization can be separated. In order to improve cross-polarization performance in the reflection plate 102 regardless of the performance of the horn antenna, the second unit cell 106- 2) to easily separate signals having different polarizations.

The horizontal and vertical lengths of the pattern 110 formed in the second unit cell 106-2 may be, for example, 0.4λ to 0.5λ. The detailed configuration of the pattern 110 formed in the second unit cell 106-2 will be described later in detail with reference to FIG.

3 is a view showing a pattern 108 formed in a first unit cell 106-1 according to an embodiment of the present invention. As shown in FIG. 3, the pattern 108 formed in the first unit cell 106-1 has a basic structure in which the first patterns 302 are spaced apart from each other by a predetermined distance, and are formed so as to be symmetrical up and down and left and right. Here, the first pattern 302 may be formed, for example, in a cubic shape. The spacing may be, for example, about 0.1 lambda to 0.2 lambda.

Also, the first stub 304 may extend from one end of the first pattern 302 to have a predetermined length. According to embodiments of the present invention, the length of the first stub 304 may be adjusted to delay the phase of the signal reflected by the reflector 102. [ At this time, not only the entire first stubs 304 included in the pattern 108 may be adjusted to have the same length, but the lengths of the first stubs 304 may be adjusted differently. That is, the basic structure in which the first patterns 302 are formed so as to be symmetrical with respect to the up and down and left and right by a predetermined distance is maintained, and the lengths of the first stubs 304 formed at one end of each first pattern 302 are The phase of the reflected wave can be changed by adjusting it differently. By sequentially adjusting the length of the first stub 304, it is possible to sequentially change the phase of the reflected wave over a wide range, thereby facilitating the synthesis of the reflected waves. In addition, the phase of the reflected wave can be changed by adjusting the width of the first stub 304.

Further, the second stub 306 may extend from the other end of the first pattern 302 to have a predetermined length. According to the embodiments of the present invention, it is possible to make a phase change of a sequentially reflected wave in a narrow range by adjusting the length of the second stub 306. [ At this time, not only can all the second stubs 306 included in the pattern 108 have the same length, but also the lengths of the respective second stubs 306 can be adjusted differently. The second stub 306 is for fine tuning of the reflected wave phase, and the phase of the reflected wave can be more finely adjusted as compared with the first stub 304. [ For example, assuming that the phase of the reflected wave is changed by -20 degrees when the length of the first stub 304 is extended by 0.5 mm at the same frequency, when the length of the second stub 306 is extended by 0.5 mm, The phase can be changed by -2 degrees. The phase of the reflected wave can also be changed by adjusting the width of the second stub 306 like the first stub 304. [ The shape of the second stub 306 is only one example, and may be various shapes that can finely change the phase of the reflected wave. Although the first stub 304 and the second stub 306 are shown extending from one end and the other end of the first pattern 302 in the vertical direction, the present invention is not limited thereto. The first stub 304 And the second stub 306 may extend from the first end and the other end of the first pattern 302 at a predetermined angle.

FIG. 4 is a graph showing the phases of reflected waves varying according to the length and frequency of the first and second stubs 304 and 306 according to an embodiment of the present invention.

4, it is assumed that the lengths of the first stub 304 and the second stub 306 are the same, and the lengths of the first stub 304 and the second stub 306 are 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, and 3.5 mm, the phase change of the reflected wave according to the frequency change is shown. As shown in FIG. 4, the pattern 108 formed in the first unit cell 106-1 exhibits a large phase change of the reflected wave at a specific frequency, for example, in the vicinity of about 8 GHz. That is, the pattern 108 formed on the first unit cell 106-1 has a structure having a surface having characteristics of a magnetic conductor in a specific frequency region, that is, an artificial magnetic conductor (AMC) structure . Also, according to embodiments of the present invention, as the lengths of the first stub 304 and the second stub 306 are changed, the phase of the reflected wave changes according to the frequency change, and the phase change is sequentially I can see the rise. Therefore, the pattern 108 formed in the first unit cell 106-1 has a wide phase change bandwidth compared to the conventional patch antenna, and by adjusting the length of the first stub 304 or the second stub 306 It is possible to sequentially change the phase of the reflected wave in a wide range.

5 is a view showing a pattern 110 formed in a second unit cell 106-2 according to an embodiment of the present invention. As shown in FIG. 5, the pattern 110 formed in the second unit cell 106-2 has a basic structure in which the second patterns 502 are symmetrically formed with a predetermined spacing. Here, the second pattern 502 may be, for example, a straight line. The spacing may be, for example, about 0.1 lambda to 0.2 lambda. Although the second pattern 502 is illustrated as being symmetrically formed on the left and right, the second pattern 502 is not limited thereto, and the second pattern 502 may be formed to be symmetrical up and down. For example, when the signal radiated from the radiation source is vertically polarized, the second pattern 502 may be formed to be symmetrical with respect to the left and right at a predetermined interval. However, if the signal radiated from the radiation source is horizontally polarized, 502 may be formed to be spaced apart from each other by a predetermined distance to be symmetrical with respect to the vertical direction. That is, the symmetry direction of the second pattern 502 may vary depending on the polarization characteristic of the signal radiated from the radiation source.

In addition, the third stub 504 may extend from one end and the other end of the second pattern 502 to have a predetermined length. According to embodiments of the present invention, in order to further improve the cross-polarization isolation in the reflection plate 102, the first stub 304 is formed to extend from one end and the other end of the linear pattern 502 . The lengths of the first stubs 304 may be the same, but the lengths of the first stubs 304 may be slightly different depending on the positions of the first stubs 304. On the other hand, the pattern 110 formed in the second unit cell 106-2 has a surface having the characteristic of magnetic conductor in a specific frequency region, like the pattern 108 formed in the first unit cell 106-1 Structure, i.e., an artificial magnetic conductor (AMC) structure.

6 is a view for explaining an effect of improving cross-polarization isolation in the reflector 102 by the second unit cell 106-2 according to an embodiment of the present invention. 6 (a) is a view showing a traveling direction of the vertical polarized wave in the reflection plate 102 when the second unit cell 106-2 according to the embodiment of the present invention is used, and FIG. 6 (b) Is a view showing a traveling direction of the horizontal polarized wave in the reflection plate 102 when the second unit cell 106-2 according to an embodiment of the present invention is used. Here, it is assumed that the vertical polarization is the desired polarization component and the horizontal polarization is the undesired polarization component.

6A, it can be confirmed that the vertical polarized wave radiated through the radiation source 602 is reflected by the reflection plate 102 and travels in one direction (or a direction perpendicular to the reflection plate 102) .

However, as shown in FIG. 6 (b), it can be seen that the horizontal polarized wave emitted through the radiation source 602 is scattered without being reflected in one direction in the reflection plate 102. That is, according to the embodiments of the present invention, the desired polarization component (e.g., vertical polarization) is collected in one direction through the second unit cell 106-2 and the unwanted polarization component (e.g., Can be scattered to improve cross-polarization isolation.

7 is a view illustrating an antenna 700 according to an embodiment of the present invention. The antenna 700 according to an embodiment of the present invention includes at least two phase delay cells 100 described above. Specifically, the antenna 700 includes a reflection plate 102, a first spacing 104-1, a second spacing 104-2, a first substrate 106-1 ', a second substrate 106-2 ') And patterns 108 and 110, respectively. The first substrate 106-1 'includes at least two or more first unit cells 106-1 and the second substrate 106-2' includes the second unit cells 106-2. At least two or more. At this time, each of the patterns 108 and 110 may be arranged at a predetermined interval on the first substrate 106-1 'or the second substrate 106-2'. The arrangement interval of the patterns 108 and 110 may be, for example, 0.5λ to 0.8λ. Each of the patterns 108 and 110 may be arranged in a circular shape around the center of the reflector 102 on the first substrate 106-1 'and the second substrate 106-2'. At this time, the patterns 108 and 110 having different shapes may be arranged according to the distance from the center of the reflection plate 102. For example, the length of the first stub 304, the second stub 306, or the third stub 504 may vary depending on the distance from the center of the reflector 102.

Here, the antenna 700 is formed as a two-layer laminated structure including the first substrate 106-1 'and the second substrate 106-2'. However, the antenna 700 is not limited thereto, May be formed in a variety of structures such as a three-layer or a four-layer laminate structure such as a first substrate 106-1 ', a second substrate 106-2', a third substrate (not shown), and a fourth substrate It is possible. A pattern of AMC structure may be formed on the first substrate 106-1 ', the second substrate 106-2', the third substrate, and the fourth substrate, The spacing can be spaced. The third substrate and the fourth substrate may be patterned with a pattern similar to the pattern 108 or 110 described above. The structure in which the AMC structure is laminated shows a remarkably improved cross polarization property as compared with the single layer AMC structure. In addition, the cross-polarization characteristics can be further improved as the number of layers of the AMC structure increases.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, I will understand. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by equivalents to the appended claims, as well as the appended claims.

100: phase delay cell
102: reflector
104-1: First separator
104-2: second separator
106-1: first unit cell
106-2: second unit cell
106-1 ': a first substrate
106-2 ': second substrate
108, 110: pattern
302: 1st pattern
304: first stub
306: second stub
502: the second pattern
504: Third stub
602: radiation source
700: antenna

Claims (13)

Reflector;
A first unit cell spaced apart from the reflection plate and symmetrically formed with a first pattern spaced apart from the reflection plate by a predetermined distance so as to delay a phase of a signal reflected from the reflection plate; And
And a second unit cell spaced apart from the first unit cell and symmetrically formed with a second pattern spaced apart from the first unit cell so as to improve cross-polarization isolation in the reflection plate,
Wherein the first unit cell and the second unit cell are spaced apart from each other and stacked on the reflector so that the desired polarization component of the signal radiated through the radiation source is collected in one direction and the unwanted polarization component is scattered.
The method according to claim 1,
Wherein the first unit cell includes a first stub extending from one end of the first pattern to have a predetermined length.
The method of claim 2,
Wherein the first unit cell further comprises a second stub extending to have a predetermined length from the other end of the first pattern.
The method according to claim 1,
Wherein the first pattern is formed in a cubic shape.
The method according to claim 1,
And the second unit cell includes a third stub extending to have a predetermined length from one end and the other end of the second pattern.
The method according to claim 1,
Wherein the second pattern is formed in a linear shape.
An antenna comprising at least two phase delay cells as claimed in any one of claims 1 to 6.
Reflector;
A first substrate including at least two first unit cells spaced apart from the reflection plate and symmetrically formed with a first pattern spaced apart from each other by a predetermined distance so as to delay a phase of a signal reflected by the reflection plate; And
At least two second unit cells spaced apart from the first substrate and symmetrically formed with a second pattern spaced apart from each other by a predetermined distance so as to improve cross-polarization isolation in the reflection plate, 2 substrate,
Wherein the first substrate and the second substrate are spaced apart from each other and stacked on the reflector so that the desired polarization component of the signal radiated through the radiation source is collected in one direction and the unwanted polarization component is scattered.
The method of claim 8,
Wherein the first unit cell includes a first stub extending from one end of the first pattern to have a predetermined length.
The method of claim 9,
Wherein the first unit cell further includes a second stub extending from the other end of the first pattern to have a predetermined length.
The method of claim 8,
Wherein the first pattern is formed in a cuboid shape.
The method of claim 8,
And the second unit cell includes a third stub extending to have a predetermined length from one end and the other end of the second pattern.
The method of claim 8,
And the second pattern has a straight shape.

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