Multi-band antenna using a selective shielding surface with a multilayer structure

Abstract

The present invention relates to a multi-band antenna using a selective shielding surface of a multi-layer structure. A multi-band antenna using a selective shielding surface of a multi-layer structure according to one embodiment of the present invention comprises: a selective shielding surface of a multi-layer structure that blocks low-band signals and passes high-band signals; a plurality of low-band radiators located on one side of the selective shielding surface of the multi-layer structure and radiating the low-band signals; and a plurality of high-band radiators located on the other side of the selective shielding surface of the multi-layer structure and radiating the high-band signals.

Description

Technology Field

[0001] The present invention relates to a multi-band antenna using a selective shielding surface of a multi-layer structure, and more specifically, to a multi-band antenna using a selective shielding surface of a multi-layer structure that is used in a miniaturized multi-band base station antenna to minimize interference between antennas. Background Technology

[0002] Currently, the installation and demand for 5G communication systems are rapidly increasing, and methods to efficiently use them in conjunction with existing LTE communication networks are being considered. The reason these technologies are being discussed is that installing new base stations to operate 5G communication systems incurs significant costs, and there is a concern that installing additional 5G communication systems on existing base stations could degrade the quality of communication services due to interference between equipment.

[0003] For efficient communication network operation, technologies that enable existing antennas to operate in multiple bands and miniaturize antenna sizes are essential. However, to implement multi-band characteristics, antennas covering 698–960 MHz, 1427–2690 MHz, and 5G communication system bands (sub-6G, 3 GHz frequency bands) must be properly arranged; this inevitably leads to interference between antennas and results in performance degradation.

[0004] Prior art, Registered Patent Publication No. 10-2021-0180595, describes a multi-band base station antenna that effectively suppresses interference between radiators of different bands by introducing a selective shielding surface between a high-band radiator and a low-band radiator. However, the prior art using a single-layer shielding surface has a limitation in that its band-pass performance is narrow. Prior art literature

[0005] Korean Published Patent Application No. 10-2021-0180595 The problem to be solved

[0006] The present invention was devised to solve the problems described above, and the objective of the present invention is to provide a multi-band antenna using a selective shielding surface of a multi-layer structure having wide bandpass performance.

[0007] Another objective of the present invention is to provide a multi-band antenna using a selective shielding surface of a multi-layer structure that maintains pass-through and blocking characteristics even when the angle of the incident wave is changed.

[0008] Another objective of the present invention is to provide a multi-band antenna using a selective shielding surface of a multi-layer structure that is easy to manufacture and install by periodically arranging unit structures (unit cells).

[0009] The objectives of the present invention are not limited to the problems mentioned above, and other objectives and advantages of the present invention not mentioned may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be understood that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. means of solving the problem

[0010] For the above purpose, a multi-band antenna using a selective shielding surface of a multilayer structure according to one embodiment of the present invention comprises: a selective shielding surface of a multilayer structure that blocks low-band signals and passes high-band signals; a plurality of low-band radiators located on one side of the selective shielding surface of the multilayer structure and radiating the low-band signals; and a plurality of high-band radiators located on the other side of the selective shielding surface of the multilayer structure and radiating the high-band signals.

[0011] Preferably, the selective shielding surface of the multilayer structure is a structure in which a plurality of unit cells are repeatedly arranged, and the unit cells include a first metal patch layer including a first metal patch; a second metal patch layer including a second metal patch; and a metal line layer including a metal line, positioned with a spaced-apart space between the first metal patch layer and the second metal patch layer.

[0012] Preferably, it further includes a first intermediate layer provided in the spaced-apart space between the first metal patch layer and the metal line layer; and a second intermediate layer provided in the spaced-apart space between the second metal patch layer and the metal line layer.

[0013] Preferably, the first intermediate layer and the second intermediate layer are made of dielectric material.

[0014] Meanwhile, a selective shielding surface of a multilayer structure in which a passband is set to block a predetermined frequency band is a structure in which a plurality of unit cells are repeatedly arranged, and said unit cells include a first metal patch layer including a first metal patch; a second metal patch layer including a second metal patch; and a metal line layer including a metal line positioned with a spaced-apart space between the first metal patch layer and the second metal patch layer.

[0015] Preferably, it further includes a first intermediate layer provided in the spaced-apart space between the first metal patch layer and the metal line layer; and a second intermediate layer provided in the spaced-apart space between the second metal patch layer and the metal line layer.

[0016] Preferably, the first intermediate layer and the second intermediate layer are made of dielectric material. Effects of the invention

[0017] According to the present invention, through a selective shielding surface of a multilayer structure having wide bandpass performance and blocking low-band incident waves, incident waves in the 3.3GHz to 3.8GHz band are transmitted, and low-band incident waves of 1GHz or less are blocked.

[0018] In addition, according to the present invention, even if the angle of the incident wave changes from 0 to 50 degrees, the blocking and passing characteristics are maintained, and the effect of maintaining stable performance without distortion of the beam pattern is achieved.

[0019] In addition, according to the present invention, a multilayer selective shielding surface can be easily manufactured using a periodically arranged unit structure, thereby providing the effects of cost reduction and ease of installation. Brief explanation of the drawing

[0020] FIG. 1 is a drawing illustrating a multi-band antenna using a selective shielding surface of a multilayer structure according to one embodiment of the present invention. FIG. 2 is a diagram illustrating a unit cell array structure of a selective shielding surface of a multilayer structure according to one embodiment of the present invention. FIG. 3 is a drawing illustrating the detailed structure of a unit cell constituting a selective shielding surface of a multilayer structure according to one embodiment of the present invention. FIG. 4 is a drawing illustrating the thickness of a selective shielding surface of a multilayer structure according to one embodiment of the present invention. FIG. 5 is a diagram illustrating the layer configuration of a selective shielding surface of a multilayer structure according to one embodiment of the present invention. FIG. 6 is a drawing illustrating a first metal patch layer of a shielding surface according to one embodiment of the present invention. FIG. 7 is a drawing illustrating a second metal patch layer of a selective shielding surface of a multilayer structure according to one embodiment of the present invention. FIG. 8 is a drawing illustrating a metal line layer of a selective shielding surface of a multilayer structure according to one embodiment of the present invention. FIG. 9 is a diagram illustrating the horizontal and vertical polarization of electromagnetic waves incident on a unit cell of a selective shielding surface of a multilayer structure according to one embodiment of the present invention. FIG. 10 is a diagram illustrating the electric field distribution of low-band and high-band electromagnetic waves incident on a selective shielding surface of a multilayer structure according to one embodiment of the present invention. FIG. 11 is a diagram comparing the electric field distribution of electromagnetic waves incident on a single-layer shielding surface of the prior art and a multi-layer selective shielding surface according to an embodiment of the present invention. Specific details for implementing the invention

[0021] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols are assigned the same reference number, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably solely for the ease of drafting the specification and do not inherently possess distinct meanings or roles. Furthermore, in describing the embodiments disclosed in this specification, if it is determined that a detailed description of related prior art could obscure the essence of the embodiments disclosed in this specification, such detailed description will be omitted. Additionally, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification; the technical concept disclosed in this specification is not limited by the attached drawings, and it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the invention.

[0022] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0023] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0025] Hereinafter, a multi-band antenna using a selective shielding surface of a multilayer structure according to the present invention will be described in detail with reference to FIGS. 1 to 11.

[0026] Referring to FIG. 1, a multi-band antenna (100) using a multi-layer selective shielding surface has a structure in which a multi-layer selective shielding surface (130) is placed between a low-band radiator (110) and a high-band radiator (120). The low-band radiator (110) operates in a low-frequency band of 1 GHz or less, and the high-band radiator (120) operates in a band of 3.3 GHz to 3.8 GHz. By placing a multi-layer selective shielding surface (130) between the low-band radiator (110) and the high-band radiator (120), interference between the two radiators is effectively blocked, thereby allowing independent radiation characteristics to be maintained in each band.

[0027] In particular, the selective shielding surface (120) of the multilayer structure shields low-frequency signals generated by the low-band radiator (110) and allows high-frequency signals of the high-band radiator (120) to pass through. By doing so, mutual interference between the low-band radiator (110) and the high-band radiator (120) is prevented, thereby enabling a stable radiation pattern to be realized in both radiators.

[0028] The shielding surface is positioned at an appropriate distance between the low-band radiator (110) and the high-band radiator (120), preferably in the range of 0.2λ to 0.4λ of the wavelength of the operating frequency, and through this structure, the overall performance of the antenna system can be improved and beam pattern degradation can be minimized. To reduce interference between antennas occurring within the miniaturized multi-band antenna, the structure can be modified and applied in any form, such as a choke, a metal bar for improving isolation, a reflector, or a lens for improving directivity.

[0029] Referring to FIG. 2, the selective shielding surface (130) of a multilayer structure according to one embodiment of the present invention is a structure in which a plurality of unit cells (131), preferably square unit cells (131), are repeatedly arranged.

[0030] Referring to FIG. 3, the length (W) of one side of a unit cell (131) forming a selective shielding surface (130) of a multilayer structure according to one embodiment of the present invention is set to a range of 0.24λ to 0.28λ of the wavelength of the center frequency of the operating band (see FIG. 3).

[0031] Referring to FIG. 4, the thickness (s1) of the selective shielding surface (130) of the multilayer structure is set to a range of 0.02λ to 0.04λ of the operating band center frequency wavelength.

[0032] Referring to FIG. 5, each unit cell (131) forming a selective shielding surface (130) of a multilayer structure may include a first metal patch layer (200) including a first metal patch, a second metal patch layer (300) including a second metal patch, and a metal line layer (400) including a metal line located with a spaced-apart space between the first metal patch layer (200) and the second metal patch layer (300), and may further include a first intermediate layer (500) provided in the spaced-apart space between the first metal patch layer (200) and the metal line layer (400), and a second intermediate layer (600) provided in the spaced-apart space between the second metal patch layer (300) and the metal line layer (400).

[0033] Referring to FIG. 6, the first metal patch layer (200) comprises four first metal patches (210, 220, 230, 240) in an L-shape formed by overlapping two identical first rectangles (210-1, 210-2). Each first metal patch is located at each vertex of the unit cell (131). In FIG. 6, 2*L2 (L2 is the length of the first rectangle) is set to a range of 0.15λ to 0.19λ based on the wavelength of the center frequency of the operating band, and 2*W2 (W2 is the width of the first rectangle) is set to a range of 0.08λ to 0.11λ.

[0034] Referring to FIG. 7, the second metal patch layer (300) comprises four 'L'-shaped second metal patches (310, 320, 330, 340) formed by overlapping two identical second rectangles (310-1, 310-2). Each second metal patch is located at each vertex of the unit cell (131). Each second metal patch is located at each vertex of the unit cell (131). In FIG. 7, 2*L3 (L3 is the length of the second rectangle) is set to a range of 0.14λ to 0.18 based on the wavelength of the center frequency of the operating band, and 2*W3 (W3 is the width of the second rectangle) is set to a range of 0.08λ to 0.11λ.

[0035] Referring to FIG. 8, the metal line layer (400) includes a first metal line (410) arranged along the side of the unit cell (131) and four second metal lines (420, 430, 440, 450) in the shape of small squares. The length (L5) of one side of the second metal line is set to a range of 0.05λ to 0.07λ based on the wavelength of the center frequency of the operating band. The four second metal lines are arranged in a 2x2 array at a constant interval from each other in the center of the first metal line (410), i.e., the unit cell (131), and the spacing (s5) between the second metal lines is set to a range of 0.01λ to 0.03λ based on the wavelength of the center frequency of the operating band. At this time, the plurality of unit cells (131) include a first unit cell and a second unit cell, and the first metal line (410) of the first unit cell is connected to the first metal line (410) of the adjacent second unit cell.

[0036] The first intermediate layer (500) and the second intermediate layer (600) may use a dielectric material, preferably a material such as SRPP (Self-Reinforced Polypropylene). Specifically, the SRPP material has low-loss characteristics when propagating high-frequency signals and can ensure shielding performance even in a high-speed communication environment while maintaining structural stability. The SRPP can efficiently maintain the spacing between each layer of the shielding surface and prevent performance degradation in high-speed communication.

[0037] According to one embodiment of the present invention, the characteristics according to horizontal and vertical polarization when incident waves are incident on a shielding surface at 0 degrees, 30 degrees, and 50 degrees and are reflected or transmitted according to the horizontal and vertical polarization of the electromagnetic waves incident on the unit cell (131) (see FIG. 9) are described below with reference to FIG. 10.

[0038] Referring to FIG. 10, the blue lines in FIG. 10a, 10b, and 10c represent the energy when an incident wave is transmitted, and the red lines represent the energy when an incident wave is reflected back. Among the blue lines, the solid line represents the characteristics when an incident wave with vertical polarization characteristics passes through, and the dotted line represents the characteristics when an incident wave with horizontal polarization characteristics passes through. Among the red lines, the solid line represents the characteristics when an incident wave with vertical polarization characteristics is reflected, and the dotted line represents the characteristics when an incident wave with horizontal polarization characteristics is reflected. Preferably, the 3.3 GHz to 3.8 GHz band is set as the passband, and the band below 1 GHz is set as the stopband.

[0039] Also, referring to FIG. 10, it can be seen that as the angle of incidence on the selective shielding surface (130) of the multilayer structure increases, the passband characteristics of vertical polarization become wider, and the passband characteristics of horizontal polarization become narrower compared to vertical polarization. Additionally, it can be seen that the selective shielding surface (130) of the multilayer structure exhibits stopping characteristics in the band of 1 GHz or lower. Due to these characteristics, there is almost no change in characteristics even when the multi-band antenna (100) changes the beam direction.

[0040] Specifically, the electric field distribution measurement of the selective shielding surface (130) of the multilayer structure of FIG. 10 is F estimated by electromagnetic simulation min (Minimum frequency) and F max The -10dB reflection loss at (maximum frequency) was used as the standard. F max - F min = BW(band-width of band-pass), and Fc = (F max - F minWhen ) / 2, BW(%) = (BW / Fc)*100. At an incident angle of 0 degrees, BW(%) is measured to be 38%, 31.2% at 30 degrees, and 25.9% at 50 degrees. Additionally, in the 1 GHz band, the cutoff performance is measured to be in the range of -9.8 dB to -7.7 dB as the incident angle changes from 0 degrees to 50 degrees (see Figs. 10a, 10b, and 10c).

[0041] In addition, since the basic electrical characteristics operate in a broadband manner and have current distributions in the vertical, horizontal, ±45°, and circular forms, the selective shielding surface (130) of the multilayer structure according to one embodiment of the present invention has basic characteristics that operate in various polarizations.

[0042] Referring to FIG. 11, the difference in the electric field distribution of electromagnetic waves incident on a single-layer shielding surface of the prior art and a multi-layer selective shielding surface (130) according to an embodiment of the present invention can be observed. The comparison is made by setting the 3.3 GHz to 3.8 GHz band as the passband and the band below 1 GHz as the stopband, and F estimated by electromagnetic simulation min (Minimum frequency) and F max It was based on a -10dB reflection loss at (maximum frequency). When the angle of incidence is 0 degrees, the shielding surface of the single-layer structure has a BW (%) of 22.2%, and the selective shielding surface of the multi-layer structure (130) has a BW (%) of 38.0%; when the angle of incidence is 30 degrees, the shielding surface of the single-layer structure has a BW (%) of 19.7%, and the selective shielding surface of the multi-layer structure (130) has a BW (%) of 31.2%; when the angle of incidence is 50 degrees, the shielding surface of the single-layer structure has a BW (%) of 14.3%, and the selective shielding surface of the multi-layer structure (130) has a BW (%) of 25.9%, confirming that the selective shielding surface of the multi-layer structure (130) has a wider BW (%) at all angles of incidence (see FIG. 11a, FIG. 11b, FIG. 11c).

[0043] Conventional single-layer shielding surfaces had a limitation in that their performance deteriorated rapidly depending on the angle of the incident wave. The present invention overcomes this problem through a multi-layer structure design and can maintain stable pass-through and blocking characteristics without performance degradation at various angles of incidence ranging from 0 to 50 degrees. In particular, the beam pattern distortion phenomenon, which was a problem in single-layer structures, can also be effectively suppressed by applying the selective shielding surface (130) of the multi-layer structure of the present invention.

[0044] In addition, performance degradation of the antenna (100) in multiple bands can be minimized, and consistent performance can be maintained even at various angles of incidence. When applied to a miniaturized antenna system, cost reduction and ease of installation can be expected, and stable communication quality can be guaranteed without beam pattern distortion, especially in a high-speed 5G communication environment.

[0045] The shielding surface of the present invention can be applied not only to small base stations, multi-band base station antennas, and 5G beamforming antennas, but also to various communication environments such as Wi-Fi 6, IoT base stations, and autonomous driving communication systems. In particular, when the selective shielding surface (130) of the multi-layer structure of the present invention is applied to a MIMO (Multiple Input Multiple Output) system using multiple frequency bands, an improvement in antenna performance and a mutual interference suppression effect can be expected simultaneously.

[0046] In the specification of this disclosure (particularly in the claims), the use of the term "above" and similar descriptive terms may be in both singular and plural. Furthermore, where a range is described in this disclosure, it is to include an invention to which individual values ​​belonging to said range are applied (unless otherwise stated), as is equivalent to describing each individual value constituting said range in the detailed description of the invention.

[0047] Unless explicitly stated otherwise, the steps constituting the method according to the present disclosure may be performed in a suitable order. The present disclosure is not necessarily limited by the order in which the steps are described. The use of all examples or exemplary terms (e.g., etc.) in the present disclosure is merely for the purpose of describing the present disclosure in detail, and the scope of the present disclosure is not limited by such examples or exemplary terms unless limited by the claims. Furthermore, a person skilled in the art will understand that various modifications, combinations, and changes may be made according to design conditions and factors within the scope of the claims or equivalents to which they are added.

[0048] Accordingly, the scope of the present disclosure should not be limited to the embodiments described above, and all scopes equivalent to or equivalently modified from the claims set forth below, as well as the claims set forth below, shall be considered to fall within the scope of the scope of the present disclosure. Explanation of the symbols

[0049] 100: Multi-band antenna device using a multi-layered selective shielding surface 110: Low-band radiator 120: High-band radiator 130: Multilayer selective shielding surface 131: Unit cell of multilayer selective shielding surface 200: 1st metal patch layer 300: 2nd metal patch layer 400: Metal line layer 500: First intermediate layer 600: Second intermediate layer

Claims

Claim 1 A multi-band antenna utilizing a selective shielding surface of a multi-layer structure, comprising: a selective shielding surface of a multi-layer structure that blocks low-band signals and passes high-band signals; a plurality of low-band radiators located on one side of the selective shielding surface of the multi-layer structure and radiating the low-band signals; and a plurality of high-band radiators located on the other side of the selective shielding surface of the multi-layer structure and radiating the high-band signals, wherein the selective shielding surface of the multi-layer structure has a structure in which a plurality of unit cells are repeatedly arranged, and the unit cells include: a first metal patch layer including a first metal patch; a second metal patch layer including a second metal patch; a metal line layer including a metal line located with a spaced-apart space between the first metal patch layer and the second metal patch layer; and a first intermediate layer provided in the spaced-apart space between the first metal patch layer and the metal line layer. and includes a second intermediate layer provided in the spaced-apart space between the second metal patch layer and the metal line layer, wherein the unit cell has a square shape and the length of one side of the unit cell is proportional to the wavelength of the center frequency of the operating band, the first metal patch is located at each vertex of the unit cell in an L-shape formed by overlapping two identical first rectangles, and the width and length of the first rectangle are proportional to the wavelength of the center frequency of the operating band, the second metal patch is located at each vertex of the unit cell in an L-shape formed by overlapping two identical second rectangles having a different proportional ratio from the first rectangle, and the width and length of the second rectangle are proportional to the wavelength of the center frequency of the operating band, the first intermediate layer and the second intermediate layer are made of a dielectric material, and the metal line layer comprises a first metal line arranged along the side of the unit cell;A multi-band antenna using a selective shielding surface of a multilayer structure, comprising: four second metal lines arranged in a 2×2 array at regular intervals in the center of the unit cell, wherein each of the four second metal lines is square-shaped, and the length of one side of the second metal line is proportional to the wavelength of the center frequency of the operating band, wherein the plurality of unit cells includes a first unit cell and a second unit cell, and the first metal line of the first unit cell is connected to the first metal line of the second unit cell. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 delete Claim 10 delete Claim 11 delete Claim 12 A multi-band antenna using a multilayer selective shielding surface, wherein the dielectric material is SRPP (Self-Reinforced Polypropylene), in accordance with claim 1. Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete Claim 21 delete Claim 22 delete Claim 23 delete

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