Array antenna

Abstract

The present invention relates to an array antenna using a metasurface cover. The array antenna comprises: an antenna layer in which a plurality of radiation members are disposed on a substrate; and a metasurface cover disposed above the antenna layer so as to surround the plurality of radiation members and guide electromagnetic wave beams emitted from the plurality of radiation elements upward, thereby guiding electromagnetic waves which leak sideways upward and enabling control of beams of respective antennas.

Description

array antenna

[0001] The present invention relates to an array antenna, and more particularly, to an array antenna capable of guiding electromagnetic waves leaking left and right upward and controlling the beams of each antenna using a metasurface cover.

[0002] Conventional microwave frequency band antennas, due to their frequency characteristics, have short wavelengths and strong linearity, resulting in specific directional characteristics. Therefore, array antenna designs are being developed to improve antenna directional performance.

[0003] Array antennas are a common design for enhancing directivity, and can achieve approximately 3 dB of gain when the antenna multiplier is increased. However, as operating frequencies continue to increase and radio environments become increasingly challenging, antenna performance is becoming increasingly important.

[0004] However, designing an antenna in an array configuration to increase gain enhances directivity, but creates shadow areas, which can negatively impact the radio environment. Furthermore, in systems requiring high output, antenna gain is crucial, which necessitates increasing the number of arrays. This, in turn, increases cost, space, and weight, leading to additional problems.

[0005] Accordingly, a technology is required that can improve antenna performance while minimizing the number of array antennas.

[0006] The present invention aims to provide an array antenna capable of obtaining gain by using a metasurface cover.

[0007] Another object of the present invention is to provide an array antenna capable of improving antenna performance without increasing the number of antennas.

[0008] To achieve this purpose, an array antenna according to the present invention comprises an antenna layer having a plurality of radiating elements arranged on a substrate; and a metasurface cover arranged on the upper portion of the antenna layer to surround the plurality of radiating elements and guide an electromagnetic wave beam emitted from the plurality of radiating elements upward.

[0009] In the array antenna according to the present invention, the metasurface cover is formed by a surface layer connected to the upper side of the metasurface and an electrical wall disposed on each edge of the upper surface of the substrate so as to surround the side surfaces of the plurality of radiating elements and overlapping the substrate.

[0010] In the array antenna according to the present invention, the metasurface formed on the surface layer is composed of a plurality of unit cells arranged in two dimensions.

[0011] In the array antenna according to the present invention, some of the plurality of unit cells are arranged in a nonlinear structure to compensate for gain loss occurring at a specific angle due to beam steering of the array antenna.

[0012] In the array antenna according to the present invention, a plurality of gratings formed on the surface layer may have a length of 1 / 4 wavelength and 1 / 2 wavelength of the frequency of use.

[0013] In the array antenna according to the present invention, the surface layer may include a first region forming a space in which the plurality of radiating elements are exposed, and a plurality of second regions arranged symmetrically on one side and the other side of the first region.

[0014] In the array antenna according to the present invention, the plurality of second regions may include a 2-1 region arranged on one side of the first region and a 2-2 region arranged symmetrically with the 2-1 region and having the same shape as the 2-1 region with the 1st region as the center.

[0015] In the array antenna according to the present invention, the 2-1 region may include a first blocking region that is arranged to have a certain width and blocks electromagnetic waves emitted from the plurality of radiation elements from leaking upward, and the 2-2 region may include a second blocking region that is formed in a symmetrical position with respect to the first region and has the same shape as the first blocking region.

[0016] In the array antenna according to the present invention, the 2-1 region may include a first quadrant region and a second quadrant region that are symmetrical with respect to the first blocking region, and the 2-2 region may include a third quadrant region and a fourth quadrant region that are symmetrical with respect to the second end region.

[0017] An array antenna according to the present invention, wherein the size of the grid formed in the first to fourth quadrant regions increases as the distance from the plurality of radiating elements increases.

[0018] In the array antenna according to the present invention, the plurality of radiating elements may be arranged in a straight line to form a row.

[0019] In the array antenna according to the present invention, the plurality of radiating elements can be arranged at equal intervals.

[0020] In the array antenna according to the present invention, the plurality of radiating elements may be formed with the same size.

[0021] In the array antenna according to the present invention, each of the plurality of radiating elements may be formed in a square shape.

[0022] The array antenna according to the present invention can improve antenna performance by guiding electromagnetic waves leaking left and right upward.

[0023] Figure 1 is an exploded perspective view of an array antenna according to the present invention.

[0024] Figure 2 is a plan view of an array antenna according to the present invention.

[0025] Figure 3 is a front view of an array antenna according to the present invention.

[0026] Figure 4 is a cross-sectional view taken along line A-A' of Figure 2.

[0027] Figure 5 is a cross-sectional view taken along line B-B' of Figure 2.

[0028] Figure 6 is an exemplary diagram showing antenna gain when using an array antenna according to the prior art and the present invention.

[0029] With respect to the embodiments of the present invention disclosed in the text, specific structural and functional descriptions are merely illustrative for the purpose of explaining the embodiments of the present invention, and the embodiments of the present invention may be implemented in various forms and should not be construed as being limited to the embodiments described in the text.

[0030] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated in the drawings and described in detail herein. However, this is not intended to limit the present invention to specific disclosed forms, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0031] While terms like "first" and "second" may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component."

[0032] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but there may also be other components in between. Conversely, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Other expressions that describe the relationship between components, such as "between" and "directly between" or "adjacent to" and "directly adjacent to", should be interpreted similarly. Similarly, "disposed on" can mean disposed directly on the surface of another component or disposed above the surface by a distance.

[0033] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprises" or "has" indicate the presence of a disclosed feature, number, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0034] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant technology, and shall not be construed in an idealized or overly formal sense unless explicitly defined herein.

[0035] Meanwhile, if a particular embodiment can be implemented differently, the functions or operations specified within a particular block may occur in a different order than specified in the flowchart. For example, two consecutive blocks may actually be performed substantially simultaneously, or, depending on the related functions or operations, the blocks may be performed in reverse order.

[0036] Hereinafter, the configuration and operation of an array antenna according to the present invention will be described with reference to the attached drawings. For convenience, the array antenna will be described using the Cartesian coordinate system (x-axis, y-axis, z-axis), but it is obvious that the array antenna can also be described using other coordinate systems. In addition, according to the Cartesian coordinate system, the x-axis, y-axis, and z-axis are orthogonal to each other, but the embodiment is not limited thereto. That is, the x-axis, y-axis, and z-axis may intersect each other.

[0037] Fig. 1 is an exploded perspective view schematically showing the configuration of an array antenna according to the present invention, and Fig. 2 is a plan view of the array antenna according to the present invention.

[0038] An array antenna (100) according to the present invention comprises an antenna layer (110) and a metasurface cover (120) disposed on the upper portion of the antenna layer (110) to guide an electromagnetic wave beam upward.

[0039] The antenna layer (110) includes a plurality of radiating elements (112) arranged in a straight line in a column on a substrate (111). In the present embodiment, the substrate (111) is shown in a form in which a plurality of substrates are laminated, but may also be formed as a single layer. A plurality of radiating elements (112) that implement an antenna function by radiating an antenna beam are arranged on the uppermost substrate (111). The substrate (111) may be referred to as an antenna substrate.

[0040] In this embodiment, the plurality of radiation members (112) are all shown to have the same size, for example, all have a square shape, but they may have different shapes and sizes. In this embodiment, the plurality of radiation members (112) are shown to be arranged at equal intervals, but the arrangement intervals and sizes may have various forms depending on the purpose and environment.

[0041] The metasurface cover (120) may be formed by including an electrical wall (121) disposed on the upper surface of the substrate (111) to surround each side of the plurality of radiating elements (112) and a surface layer (122) having a metasurface and bonded to the electrical wall (121) so as to overlap with the substrate (111).

[0042] The electrical wall (121) is intended to block electromagnetic waves emitted from the plurality of radiating elements (112) from leaking to the left and right of the antenna layer and to guide the electromagnetic waves upward. When the electromagnetic waves emitted from the radiating elements (112) encounter the electrical wall (121) made of a conductor, they are reflected. The electrical wall (121) serves to collect the electromagnetic waves emitted from each different radiating element (121). Therefore, the gain of the electromagnetic waves can be increased.

[0043] The surface layer (122) is configured to be placed on each upper surface of the blocking wall (121) by including a first region (122a) that forms an empty space to expose the plurality of radiation members (112) and a second region (122b) that is formed symmetrically on one side and the other side of the first region (122a). Each side of the surface layer (122) has a catch (122e) that has a width that can span the upper surface of the blocking wall (121).

[0044] The second region (122b) includes a second-first region (122b-1) and a second-second region (122b-2) that are arranged symmetrically with respect to the first region (122a).

[0045] The 2-1 region (122b-1) includes a first blocking region (122c-1) in which no pattern unit cell (130) is formed, and a first quadrant region (123-1) and a second quadrant region (123-2) symmetrically arranged on both sides based on the first blocking region (122c-1).

[0046] The 2-2 region (122b-2) includes a second blocking region (122c-2) in which no pattern unit cell (130) is formed, and a third quadrant region (123-3) and a fourth quadrant region (123-4) symmetrically arranged on both sides based on the second blocking region (122c-2).

[0047] The first blocking region (122c-1) and the second blocking region (122c-2) serve to block electromagnetic waves emitted from the plurality of radiation members (112) from leaking to the lateral upper portion of the antenna layer (110).

[0048] The first to fourth quadrants (123-1 to 123-4) forming the metasurface form a pattern and are formed by a plurality of unit cells (130) arranged two-dimensionally into an aggregate structure.

[0049] A metasurface generally refers to a planar structure that performs an optical function by utilizing a two-dimensional thin film pattern. By utilizing the phase shift caused by a plurality of unit cells arranged in two dimensions, a spherical wave passing through the metasurface can be converted into a plane wave, thereby improving the gain of the antenna.

[0050] Each unit cell (130) may include a close area (131) or an opening (open area: 132). The opening (132) may have various sizes and shapes. For example, the opening (132) may have various sizes and shapes from the smallest opening (O1) to the largest opening (O4). When the length of the opening means the size extended in the x-axis direction and the width of the opening means the size extended in the y-axis, the second opening (O2) has twice the length and the same width as the first opening (O1), and has an area twice as large as the first opening (O1). The third opening (O3) has the same length and the same width as the first opening (O1), and has an area twice as large as the first opening (O1). The fourth opening (O4) has a length twice as long and a width twice as wide as the first opening (O1), and an area four times larger than the first opening (O1). The second opening (O2) and the third opening (O3) may have the same area. In addition, the blocking portion (131) may include a plurality of blocking portions having the same size and shape as at least one of the first opening (O1) to the fourth opening (O4).

[0051] Meanwhile, although the present disclosure illustrates and describes the opening (132) as having first to fourth openings (O1 to O4), this is not limited thereto. Specifically, the opening (132) may have less than four or more than six types of openings, and the blocking portion (131) may likewise have less than four or more than six types of blocking portions.

[0052] At least one blocking portion (131) may be arranged between each opening portion (132). Each of the first to fourth quadrants (123-1 to 123-4) forming the metasurface may include a plurality of rows or columns including a plurality of unit cells. Specifically, each of the first to fourth quadrants (123-1 to 123-4) may include a plurality of first rows including only a plurality of blocking portions (131) and a plurality of second rows including a plurality of blocking portions (131) and a plurality of openings (132). For example, each of the first to fourth quadrants (123-1 to 123-4) may have a structure in which a plurality of first rows and a plurality of second rows are alternately arranged.

[0053] Additionally, each of the first to fourth quadrants (123-1 to 123-4) may include a plurality of first rows including only a plurality of blocking portions (131) and a plurality of second rows including a plurality of blocking portions (131) and a plurality of openings (132). For example, each of the first to fourth quadrants (123-1 to 123-4) may have a structure in which a plurality of first rows and a plurality of second rows are alternately arranged.

[0054] In one embodiment, each of the second rows may have a structure in which blocking portions (131) and openings (132) are alternately arranged. At this time, in the second row, the size of the opening (132) adjacent to the edge of the quadrant may be smaller than the size of the opening (132) adjacent to the center of the quadrant. For example, in any second row of the first quadrant (123-1), the size of the first opening (O1) adjacent to the edge is smaller than the size of the second opening (O2) adjacent to the center of the first quadrant (123-1). In addition, in any second row of the first quadrant (123-1), the size of the third opening (O3) adjacent to the edge is smaller than the size of the fourth opening (O4) adjacent to the center of the first quadrant (123-1).

[0055] In one embodiment, each of the second rows may have a structure in which blocking portions (131) and openings (132) are alternately arranged. At this time, in the second row, the size of the opening (132) adjacent to the edge of the quadrant may be smaller than the size of the opening (132) adjacent to the center of the quadrant. For example, in any second row of the first quadrant (123-1), the size of the first opening (O1) adjacent to the edge is smaller than the size of the third opening (O3) adjacent to the center of the first quadrant (123-1). In addition, in any second row of the first quadrant (123-1), the size of the second opening (O2) adjacent to the edge is smaller than the size of the fourth opening (O4) adjacent to the center of the first quadrant (123-1).

[0056] Fig. 3 is a front view of an array antenna according to the present invention. As shown, when viewed in the y-axis direction, a metasurface cover (120) is placed on the uppermost part of an antenna layer (110) forming a plurality of layers, and a blocking wall (121) of the metasurface cover (120) is placed on the upper edge of the antenna layer (110).

[0057] FIG. 4 is a cross-sectional view taken along line A-A' of FIG. 2. It is a cross-sectional view taken along line A-A' of the first region (122a) in the y-axis direction. As shown in the drawing, it can be seen that a plurality of radiation members (112) are arranged on the uppermost substrate of the antenna layer (110). It can be seen that the blocking walls (121) forming the metasurface cover (120) are arranged to face each other in the x-axis direction at the edge portion of the uppermost substrate of the antenna layer (110) and extend in the z-axis direction to form a wall. The inner surface of the upper region of the blocking walls (121) exposes the side wall (122d) of the 2-1 region (122b-1) forming the metasurface cover (120).

[0058] The height (H1) of the blocking wall (121) of the metasurface cover (120) disposed on the uppermost substrate of the antenna layer (110) may have a value between 15 mm and 30 mm. The distance (D1) from the upper surface of the plurality of radiating members (112) to the lower surface of the metasurface cover (120) may have a value between 10 mm and 20 mm. The thickness (T1) of the surface layer (122) of the metasurface cover (120) may have a value between 30 μm and 60 μm, and thus may have a relatively small value compared to the height (H1) of the blocking wall (121). The surface layer (122) of the metasurface cover (120) may have a structure that can be spanned over the upper surface of the blocking wall (121) by a catch (122e) as in the present embodiment, or may have a form that is embedded in the blocking wall (121).

[0059] FIG. 5 is a cross-sectional view taken along line B-B' of FIG. 2. As illustrated, the plurality of radiating elements (112) of the antenna layer (110) do not appear, and a portion of the second-first region (122b-1) forming the metasurface cover (120) can be seen. Unit cells of the first quadrant (123-1) are arranged on the right side in the x-axis direction with respect to the first blocking region (122c-1). Unit cells of the second quadrant (123-2) are arranged on the left side in the x-axis direction with respect to the first blocking region (122c-1). It can be seen that at least one opening (O1 or O2) is formed between the blocking portions (131) of the unit cells forming the first quadrant (123-1) and the second quadrant (123-2). At this time, a second opening (O2) having an area twice as large as that of the first opening (O1) may be formed at a greater distance from the first blocking area (122c-1) than a portion of the first opening (O1).

[0060] Referring to FIG. 6, when the gain measured on both sides of the position where multiple radiating elements are arranged in a conventional antenna without applying a metasurface cover is 11.63 dB, it can be seen that the gain measured on both sides of the position where the radiating elements are arranged is improved by about 1 dB to 12.6 dB by the blocking wall (121) of the metasurface cover (120) of the present invention surrounding the side surfaces of the multiple radiating elements and guiding the electromagnetic waves upward, thereby guiding the electromagnetic waves leaking left and right upward and alleviating the steering loss.

[0061] According to the embodiments described above, by arranging unit cells at the edge of the metasurface where a relatively large loss occurs due to beam steering in order to improve the gain of the array antenna, the electromagnetic waves are concentrated toward the center due to the lattice structure formed on the metasurface, thereby compensating for the beam steering loss at a specific angle, thereby improving the overall gain of the antenna.

[0062] The nonlinear metasurface structure proposed in the invention can be widely used in the fields of base stations, repeater antennas, and radars where beam steering is important, and can also be easily miniaturized and applied to the field of vehicle radars.

[0063] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

[0064] The mode for carrying out the invention has been sufficiently described in the above-mentioned “Best mode for carrying out the invention.”

[0065] The array antenna of the embodiment can be used in a wireless communication system, etc.

Claims

1. An antenna layer having a plurality of radiating elements arranged on a substrate; and An array antenna including a metasurface cover arranged to surround the plurality of radiating elements on the upper portion of the antenna layer and guide an electromagnetic wave beam emitted from the plurality of radiating elements upward.

2. In the first paragraph, the metasurface cover, An electrical wall disposed on the upper surface of the substrate in a manner that surrounds the side surfaces of the plurality of radiation members; and An array antenna comprising a surface layer having a metasurface and bonded to the barrier wall so as to overlap the substrate.

3. In the second paragraph, the meta surface is an array antenna including a plurality of unit cells arranged in a two-dimensional manner.

4. An array antenna in the third paragraph, wherein some of the plurality of unit cells are arranged in a nonlinear structure.

5. In the second paragraph, the metasurface is an array antenna having a length of 1 / 4 wavelength and 1 / 2 wavelength of the frequency of use.

6. In the second paragraph, the surface layer is A first region forming a space in which the plurality of radiation members are exposed; and An array antenna comprising a plurality of second regions arranged symmetrically on one side and the other side of the first region.

7. In the 6th paragraph, the plurality of second regions are A second-first region arranged in a direction intersecting the longitudinal direction of the first region; and An array antenna including a 2-2 region arranged symmetrically with the 2-1 region based on the 1st region.

8. In paragraph 7, The above 2-1 region includes a first blocking region arranged to form a certain width and block electromagnetic waves emitted from the plurality of radiation elements from leaking upwards laterally. An array antenna in which the above 2-2 region includes a second blocking region formed at a symmetrical position with respect to the first region and having the same shape as the first blocking region.

9. In paragraph 8, The above 2-1 region includes a first quadrant region and a second quadrant region that are symmetrical to each other based on the first blocking region, The above 2-2 region is an array antenna including a third quadrant region and a fourth quadrant region that are symmetrical with respect to the second blocking region.

10. An array antenna in accordance with claim 9, wherein the size of the unit cells formed in the first to fourth quadrant regions increases as the distance from the plurality of radiating elements increases.

Images