Frequency selective surface

Abstract

A frequency-selective electromagnetic wave transmission / blocking module includes: a substrate; and a plurality of conductive grid target patterns on the substrate, including: a first inner linear region; a second inner linear region intersecting the first linear region; a first outer linear region and a second outer linear region centered at the midpoint of opposite sides of the center of the first inner linear region; and a third outer linear region and a fourth outer linear region centered at the midpoint of opposite sides of the center of the second inner linear region. Furthermore, at least one of the inner and outer linear regions includes a conductive non-uniform grid pattern with conductive lines of non-uniform length.

Description

Cross-references to related applications

[0001] This application claims priority to Korean Patent Application No. 10-2025-0003676, filed in Korea on January 9, 2025, the entire contents of which are expressly incorporated herein by reference. Technical Field

[0002] Embodiments of this disclosure relate to a surface having a patterned structure configured to selectively transmit and block electromagnetic waves based on frequency. Background Technology

[0003] When a metal mesh, silver nanocoating, or low-emissivity (Low-E) coating with a grid or non-grid structure is applied to the surface of glass or an antenna in a specific pattern, a frequency-selective surface (FSS) can be formed that selectively transmits electromagnetic waves of certain frequencies while blocking other specific frequencies. More specifically, FSSs can be used in glass for buildings or automobiles where security is required (e.g., electric vehicles with large areas of glass or smart homes that prioritize security).

[0004] Furthermore, the outermost line of the entire pattern of the FSS, or the outermost line of a unit of the pattern, is formed in the shape of a long, straight metallic line. This type of linear pattern enhances the frequency-selective transmission / blocking performance of the FSS and maintains a constant blocking frequency. However, if the FSS includes a metallic linear pattern, light refraction may occur, which degrades the visibility of the glass and the accuracy of the transmitted and received signals in the antenna. Summary of the Invention

[0005] Therefore, one object of this disclosure is to overcome the aforementioned disadvantages of the prior art and to provide an FSS that has high-frequency selective transmission / blocking properties for incident electromagnetic waves, without including (e.g., in straight lines) the outermost lines of the metallic pattern included in a transparent FSS applied to glass or the like.

[0006] To address the objectives of this disclosure, according to one embodiment, a frequency-selective electromagnetic wave transmission / blocking surface includes: a surface formed of a conductive material in a grid pattern; and a plurality of target patterns formed by partially removing the conductive material, wherein the target patterns may include linear regions having at least a region formed as an uneven shape with a plurality of protrusions.

[0007] According to another embodiment, a frequency-selective electromagnetic wave transmission / blocking glass may include: glass; a grid pattern formed on the glass by a conductive material; and a plurality of target patterns formed by partially removing the conductive material, wherein the target patterns may include linear regions having at least a region formed as an uneven shape with a plurality of protrusions.

[0008] Furthermore, frequency-selective electromagnetic wave transmission / blocking glass may also include a PET (polyethylene terephthalate) film formed between the glass and the grid pattern. Additionally, multiple target patterns can be formed in the same shape.

[0009] Furthermore, the shape of the target pattern may include: two rectangular inner linear regions, which are orthogonal in a cross shape and share a common center; and a rectangular outer linear region centered at the midpoint of two opposite sides away from the center of each inner linear region. Each of the inner and outer linear regions may include multiple protrusions.

[0010] In addition, the shape of the target pattern may include: two rectangular inner linear regions that are orthogonal in a cross shape and share a common center; and a fan-shaped outer region centered at the midpoint of two opposite sides away from the center of each inner linear region, and the inner linear regions may include multiple protrusions.

[0011] The shape of the target pattern may also include four rectangular linear regions forming four sides, and each of the four rectangular linear regions may include multiple protrusions. Furthermore, the grid pattern can be formed by connecting multiple wires in rows and columns, and the outermost line of the target pattern can be formed by cutting the wires.

[0012] Furthermore, the grid pattern set on the outside of the target pattern can be modified so that a cross-shaped pattern can be repeatedly arranged by cutting all the surrounding edges at the intersection of rows and columns. In addition, the protrusion length R1 of the protrusions formed in the area of ​​the target pattern, and the length R2 in the longitudinal direction perpendicular to the protrusion direction of the protrusions, can be determined based on the average spacing p between the wires, the average width lw of the wires, and the width W of the non-protruding area of ​​the linear area of ​​the target pattern.

[0013] Furthermore, R1 and R2 can be determined to obtain natural numbers that satisfy the following equation: (n-1)*p+(n)*lw≤W≤(n)*p+(n-1)*lw, To satisfy the following equation: And p + 2 * lw ≤ R2.

[0014] According to embodiments of this disclosure, an FSS comprising a metallic pattern whose outermost line is not a straight line can be provided, which can suppress light refraction and thereby improve visibility. Furthermore, regardless of the formation position of the pattern across the entire surface, the FSS according to the embodiments can maintain constant frequency-selective electromagnetic wave transmission / blocking performance.

[0015] The further scope of the invention will become apparent from the detailed description given below. However, it should be understood that while the detailed description and specific examples illustrate preferred embodiments of the invention, they are for illustrative purposes only, as various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art based on this detailed description. Attached Figure Description

[0016] The invention will be more fully understood from the detailed description and accompanying drawings given below. These descriptions and drawings are for illustrative purposes only and are not intended to limit the invention.

[0017] Figure 1 This is a diagram illustrating an uneven grid pattern according to one embodiment and a metal grid pattern in contrast to the uneven grid pattern;

[0018] Figure 2a and Figure 2b This diagram illustrates the problems that arise when designing a frequency-selective electromagnetic wave transmission / blocking pattern for an FSS using a second metal mesh pattern.

[0019] Figure 3 This is a diagram illustrating the non-uniform grid pattern structure and pattern design process of an FSS according to one embodiment;

[0020] Figure 4 This is a diagram illustrating the factors to consider when applying FSS to a non-uniform grid pattern;

[0021] Figure 5a This is a diagram showing the cells of the FSS with the second metal mesh pattern applied;

[0022] Figure 5b This is a diagram showing cells of an FSS with an applied non-uniform grid pattern according to one embodiment;

[0023] Figure 6 and Figure 7 This is a diagram illustrating the application of an FSS with an uneven grid pattern formed on glass according to one embodiment;

[0024] Figures 8a to 8c This is a graph showing the frequency-selective electromagnetic wave transmission / blocking performance of the FSS based on the width variation of the non-uniform grid pattern and the incident angle of the electromagnetic wave according to one embodiment.

[0025] Figure 9 The figure shows simulation results and comparative simulation results according to one embodiment, illustrating the current distribution and the FSS including a non-uniform grid pattern;

[0026] Figure 10 and Figure 11This is a diagram showing cells of an FSS with an applied non-uniform grid pattern according to other embodiments;

[0027] Figures 12 to 16 This is a diagram illustrating the problem of FSS not being applied according to one embodiment;

[0028] Figures 17 to 21 These are graphs and plots illustrating the frequency-selective electromagnetic wave transmission / blocking performance of an FSS with an inhomogeneous grid pattern applied according to one embodiment.

[0029] Figure 22 The graph shows the improvement in visibility achieved by applying an FSS with a non-uniform grid pattern according to one embodiment, compared to the case where the FSS is not applied; and

[0030] Figure 23 This is a diagram illustrating cells of various types of FSS applied according to one embodiment. Detailed Implementation

[0031] A detailed description will now be given with reference to the accompanying drawings, based on the exemplary embodiments disclosed herein. For the sake of brevity with reference to the drawings, identical or equivalent components may be provided with the same reference numerals and their descriptions will not be repeated.

[0032] A detailed description will now be given with reference to the accompanying drawings, based on the exemplary embodiments disclosed herein. Throughout the disclosure, when an element (e.g., a region, layer, section, etc.) is referred to as being "connected" to, "on," or "coupled" to another element, that element may be directly connected to the other element, or there may be intermediate elements present. Conversely, when an element is referred to as being "directly connected" to another element, there are no intermediate elements present.

[0033] This document uses terms such as “comprising”, and it should be understood that these terms are intended to indicate the presence of certain components, functions, or steps disclosed in the specification, and it should also be understood that more or fewer components, functions, or steps may be used as well. Although this document may use terms such as “first”, “second”, etc., to describe various elements, these elements should not be limited by these terms.

[0034] These terms are generally used only to distinguish elements from one another. It will be understood that the terms "first" and "second" are used herein to describe various components, but these components should not be limited by these terms. The terms above are used only to distinguish components from one another. For example, a first component may be referred to as a second component without departing from the scope of the invention, and vice versa. Unless the context clearly specifies otherwise, singular expressions also include plural expressions.

[0035] The terms 'component' or 'module' used in the embodiments may refer to software or hardware elements, such as FPGAs or ASICs, and 'components' or 'modules' may perform a predetermined function. However, 'components' or 'modules' are not limited to software or hardware. A 'component' or 'module' may be located in addressable storage media and configured to be executed by one or more processors. Thus, as an example, a 'component' or 'module' may include elements such as software elements, object-oriented software elements, class elements, and task elements, as well as processes, functions, attributes, programs, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within elements and 'components' or 'modules' may be combined to form 'subcomponents' or 'modules,' or further broken down into additional elements and 'components' or 'modules.'

[0036] The steps of the methods or algorithms described in conjunction with some embodiments of this disclosure can be implemented directly in hardware, as a software module executed by a processor, or a combination of both. The software module can be located in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium can be coupled to a processor, enabling the processor to read information from and write information to the storage medium. Alternatively, the recording medium can be integrated with the processor. The processor and the recording medium can be located in an application-specific integrated circuit (ASIC). The ASIC can be located in a user terminal.

[0037] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings to enable those skilled in the art to understand them. However, this disclosure can be embodied in various modifications and is therefore not limited to the embodiments described herein.

[0038] Figure 1 This is a diagram illustrating a comparison between a metallic mesh pattern and an uneven mesh pattern according to one embodiment. In particular, if a regular pattern is formed using a metallic material on the surface of an object (e.g., glass or an antenna) where electromagnetic waves need to be selectively transmitted / blocked, the effect of transmitting electromagnetic waves of a specific frequency band while blocking another specific frequency band can be achieved.

[0039] When forming metallic patterns on materials where transparency must be ensured, such as glass, a conductor such as metal can be thinly applied and deposited. This thinly applied and deposited conductor, such as metal, can serve as a transparent electrode material to ensure transparency, and the formed metallic regions can generate induced currents when electromagnetic waves are incident upon them, thereby blocking electromagnetic waves of a specific frequency band. Furthermore, patterns formed by thinly applying and depositing metal in the form of multiple intersecting lines can be called metallic mesh patterns. Moreover, metallic meshes can take various forms, such as orthogonal meshes (or rectangular meshes), where multiple thin metallic material lines are arranged in rows and columns at right angles to each other; and irregular meshes, where multiple linear shapes are not arranged according to a specific rule.

[0040] Besides metal mesh patterns, frequency-selective electromagnetic wave transmission / blocking patterns can also be formed by applying and depositing silver nanoparticles or low-emissivity films in specific patterns on the surfaces of glass, antennas, etc. Specifically, the surface in glass or antenna to which frequency-selective electromagnetic wave transmission / blocking patterns (e.g., metal mesh patterns, silver nanoparticle patterns, or low-emissivity film patterns) are applied can be called a frequency-selective surface (FSS). When electromagnetic waves are incident, induced currents appear in the conductive regions of the metal mesh pattern, silver nanoparticle pattern, or low-emissivity film pattern on the FSS. Therefore, electromagnetic wave blocking effects can be achieved by canceling out the electromagnetic waves. Furthermore, the intensity of the induced current can resonate and be formed differently for each frequency range based on the pattern shape, thereby allowing the transmission of electromagnetic waves in a specific frequency band while blocking electromagnetic waves in another specific frequency band.

[0041] Generally, to improve process efficiency, the FSS formation process can use a method of uniformly forming the above-mentioned metal mesh pattern, silver nanopattern, or low-emissivity film pattern over the entire surface, and then removing part of the formed pattern to form a pattern of a specific shape that matches the frequency band to be blocked.

[0042] refer to Figure 1 The metal mesh pattern can be formed as a first metal mesh pattern 15 including the outermost line with a linear structure. In this case, light refraction occurs due to the outermost line area. If the first metal mesh pattern 15 is applied, the user's visibility may be degraded. Alternatively, the metal mesh pattern can be formed as a second metal mesh pattern 16 that does not include the outermost line with a linear structure. In this case, the visibility degradation problem that may occur in the structure of the first metal mesh pattern 15 can be significantly improved; however, when the frequency-selective electromagnetic wave transmission / blocking pattern is formed on a portion of the entire surface, the electromagnetic wave transmission / blocking performance may vary depending on the pattern formation location.

[0043] To solve this problem, a non-uniform grid pattern 17 can be formed according to one embodiment. For example... Figure 1 As shown, the non-uniform grid pattern 17 does not have Figure 1 The outermost line of the linear structure shown is instead, in the region corresponding to the outermost line of the first metal mesh pattern 15, short metal line regions and long metal line regions are formed in a repeating, non-uniform shape, in which the outermost contour alternately protrudes and recedes. Furthermore, as... Figure 1 As shown, the non-uniform grid pattern 17 can have two alternating short metal line regions and two long metal line regions. However, the form of the non-uniform grid pattern 17 is not limited to this; it can have n1 alternating short metal line regions and n2 alternating long metal line regions (n1 and n2 are natural numbers greater than or equal to 1). Furthermore, the non-uniform grid pattern 17 can be formed only in one orientation region or in all orientation regions. By applying the non-uniform grid pattern 17 to the FSS, constant electromagnetic wave transmission / blocking performance can be ensured regardless of the pattern's formation location, and visibility is also improved.

[0044] Next, Figure 2a and Figure 2b This diagram illustrates the problems that arise when designing a frequency-selective electromagnetic wave transmission / blocking pattern for an FSS using a second metallic mesh pattern. Specifically, Figure 2a The process of forming first to third target patterns 60, 61, and 62 in the same cross shape on a metal mesh pattern 50 formed on the entire surface of a glass or antenna is illustrated. Here, forming the target pattern includes cutting the metal mesh pattern 50 along the outermost line of the target pattern. As an additional embodiment, when cutting the metal mesh pattern 50 along the outermost line of the target pattern, the outermost line of the mesh pattern 50 may also be left uncut (see [link to example]). Figure 1 (The outermost line of the grid pattern 15).

[0045] like Figure 2a As shown, the paths of induced current flow along the first actual pattern to the third actual patterns 70, 71, and 72 can be formed differently depending on the formation positions of the first target pattern to the third target pattern 60, 61, and 62. Therefore, when designing the first target pattern to the third target pattern 60, 61, and 62, the transmission / blocking performance of the target band electromagnetic wave may vary depending on the pattern formation position.

[0046] Next, Figure 2b The process of forming a constant frequency-selective electromagnetic wave transmission / blocking pattern on a second grid pattern 16 formed by an orthogonal grid structure is illustrated. As an example, Figure 2bA target pattern 10 with a rectangular shape having a vertical length of 20, a horizontal length of 30, and a center point of 40 is shown. In the aforementioned FSS forming process, a metal mesh pattern can be formed across the entire surface. Therefore, a second metal mesh pattern 16 (forming across the entire area) Figure 1 When the target pattern 10 is formed on the metal line, the center point 41 can be located on the metal line, as in the first case (i.e., case 1), or the center point 42 can be not located on the metal line, as in the second case (i.e., case 2). Figure 2b As shown.

[0047] Furthermore, the first actual pattern 11 in the first case (i.e., case 1) and the second actual pattern 12 in the second case (i.e., case 2) include pattern structures that generate actual electromagnetic wave transmission / blocking effects based on the outermost path of the induced current caused by the incident electromagnetic wave. The shape and size of the outermost metal region forming the induced current in the formed pattern directly affect the frequency-selective electromagnetic wave transmission / blocking performance. As shown in the figure, the vertical lengths 21 and 22 of the pattern are not significantly different, but the horizontal lengths 31 and 32 of the pattern are different. Therefore, when designing the target pattern 10, there may be a problem where the electromagnetic wave transmission / blocking performance in the target band varies depending on the pattern formation location. Furthermore, Figure 2a and Figure 2b The process of forming regular or cross-shaped patterns on a metal mesh pattern is shown, but the same problem may occur when forming other shapes of patterns on metal mesh patterns, silver nanopatterns, or low-emissivity film patterns.

[0048] Next, Figure 3 This is a diagram illustrating the non-uniform grid pattern structure and pattern design process of an FSS according to one embodiment. (Reference) Figure 3 A portion of the opening area of ​​the grid pattern can have a protruding structure, while another portion of the opening area can have a less protruding structure. That is, the target pattern 100 can be set to have a shape corresponding to the non-uniform grid pattern 17, and the vertical length 110, horizontal length 120, and center point 130 of the target pattern can be set. During the FSS formation process, the metal grid pattern can be formed on a constant surface. Therefore, when the target pattern 100 is formed on a metal grid pattern formed on the entire surface, the center point 131 can be located on a metal line, as in the third case (i.e., case 3), or the center point 132 can not be located on a metal line, as in the fourth case (i.e., case 4).

[0049] Furthermore, the third actual pattern 101 in the third case (i.e., case 3) and the fourth actual pattern 102 in the fourth case (i.e., case 4) include pattern structures that generate actual electromagnetic wave transmission / blocking effects based on the outermost path of the induced current caused by the incident electromagnetic wave. For example... Figure 3 As shown, the vertical lengths 111 and 112 of the pattern are not significantly different. Furthermore, the horizontal length 124 of the fourth actual pattern 102 can be the average of the short horizontal length 123 and the long horizontal length 122 of the non-uniform grid pattern on which the fourth actual pattern 102 is formed. Therefore, although the third actual pattern 101 and the fourth actual pattern 102 have different shapes, the area through which the induced current caused by electromagnetic waves flows in the outermost metal region is the same, thus maintaining consistent electromagnetic wave transmission / blocking performance at a specific frequency regardless of the pattern formation location.

[0050] Next, Figure 4 This is a diagram illustrating the factors to consider when applying FSS to non-uniform grid patterns. (Reference) Figure 4 In the orthogonal grid pattern 1000, the spacing between the conductive areas formed by the metal forming each row and each column can be defined as a pitch of 140. Furthermore, in the orthogonal grid pattern 1000, the width of the conductive area forming a line of the grid pattern 1000 can be defined as a line width of 150. Correspondingly, the average spacing between the conductive areas in the irregular grid pattern 2000 can be defined as a pitch of 140, and the width of the conductive area forming a line of the irregular grid pattern 2000 can be defined as a line width of 150.

[0051] also, Figure 4 It shows a pattern 17 capable of forming a non-uniform grid pattern. Figure 1 The target pattern 3000 is a raised target pattern. When the orthogonal grid pattern 1000 is cut along the outermost line including the raised target pattern 3000, the target pattern 3000 can be formed on the surface. In addition, the non-uniform grid pattern 17 can be formed inside the target pattern 3000 and surrounded by the outermost line of the target pattern 3000.

[0052] Figure 4 A rectangular target pattern 3000 with protrusions is also shown. As shown, a grid pattern is cut along the outermost line of the rectangular target pattern 3000, and this grid pattern can protrude from the protrusions, thereby forming a non-uniform grid pattern 170. Furthermore, in the rectangular target pattern 3000 with protrusions, the width of the non-protruding area can be defined as width W160. Similarly, in the rectangular target pattern 3000 with protrusions, the protruding length of the protrusions can be defined as R1170.

[0053] In addition, such as Figure 4 As shown, the length of the protrusion in the longitudinal direction perpendicular to the protrusion direction in the target pattern 3000 can be defined as R2 180. Therefore, if the target pattern 3000 protrudes equally in both directions, the width of the protruding portion of the target pattern 3000 can be W+2R1. For non-uniform grid patterns with irregular grid structures, the aforementioned widths 160, R1 170, and R2 180 can be calculated by measuring the corresponding values ​​in several regions and then taking the average value.

[0054] More specifically, the shape of the target pattern 3000 can be determined by the following mathematical equations 1, 2, and 3. Furthermore, a spacing of 140 is represented as p, a line width of 150 as lw, and a width of 160 as W.

[0055] (Mathematical Formula 1) (n-1)*p+(n)*lw≤W≤(n)*p+(n-1)*lw

[0056] By substituting the spacing p 140, line width lw 150, and width W 160 into the above mathematical formula, we can obtain a natural number 'n' that is greater than or equal to 1.

[0057] (Mathematical Formula 2)

[0058] (Mathematical Formula 3) p+2*lw≤R2

[0059] Furthermore, by substituting 'n' obtained from mathematical formula 1 into mathematical formulas 2 and 3, the ranges of R1 and R2 can be obtained. When the protrusions of the target pattern 3000 are formed within the calculated ranges of R1 and R2, frequency-selective electromagnetic wave transmission / blocking performance can be ensured regardless of the formation position of the target pattern. For example, the minimum R1 (170) of a non-uniform grid pattern 3000 with a spacing of 200 micrometers at 140, a line width (150) of 20 micrometers, and a width (160) of 0.5 millimeters can be ensured to be 0.08 millimeters and 0.3 millimeters respectively.

[0060] Next, Figure 5a This is a diagram showing the cells of the FSS with the second metal mesh pattern 16 applied. (Reference) Figure 5a A frequency-selective electromagnetic wave transmission / blocking pattern 300 can be formed in cell 200, which is a unit of a pattern repeatedly arranged on the surface of the FSS. The frequency-selective electromagnetic wave transmission / blocking pattern 300 includes the path of the induced current of the electromagnetic wave incident on the second metal mesh pattern 16.

[0061] Furthermore, the frequency-selective electromagnetic wave transmission / blocking pattern 300, which employs the second metal mesh pattern 16, can improve visibility by eliminating light refraction effects. However, the frequency-selective electromagnetic wave transmission / blocking performance can vary depending on certain parts of the pattern (such as...). Figure 2a and Figure 2b As shown, the differences (due to the area forming the pattern) are different, thus presenting a problem.

[0062] Next, Figure 5b This is a diagram illustrating cells of an FSS with an applied non-uniform grid pattern according to one embodiment. Reference Figure 5b The first target pattern 400 can be formed in a cell, which is a unit of a pattern repeatedly arranged on the surface of the FSS. According to one embodiment, when electromagnetic waves are incident on the non-uniform grid pattern 17, the first target pattern 400 can be shown as the path of the induced current.

[0063] Furthermore, the first target pattern 400 may include an inner linear region 410 and an outer linear region 420. As shown, in the first target pattern 400, a cross-shaped region may be formed at the center. Furthermore, the cross-shaped region can be formed by intersecting two inner linear regions 410. Additionally, the outer linear region 420, orthogonal to the center of the inner linear region 410, may be formed at the two portions furthest from the center of the inner linear region 410. According to one embodiment, a non-uniform grid pattern 17 may be formed in the inner linear region 410 and the outer linear region 420, such that, in addition to improved visibility, the first target pattern 400 can maintain a constant level of frequency-selective electromagnetic wave transmission / blocking performance in each portion of the pattern, regardless of the region where the pattern is formed. Figure 3 As shown.

[0064] Next, Figure 6 and Figure 7 This is a diagram illustrating the application of an FSS with a non-uniform grid pattern formed on glass according to one embodiment. Reference Figure 6 The first target pattern 400 can be formed on a polyethylene terephthalate (PET) film 510 deposited on the glass 500 (e.g., an FSS module). According to one embodiment, the first target pattern 400 can be formed by depositing a metallic material directly onto the glass 500 in a constant shape without the need for the PET film 510. Figure 6 Only the area of ​​glass 500 with cell 200 set on it is shown, but as Figure 7 As shown, by repeatedly setting multiple cells 200 in a wide area of ​​glass 500, the FSS can include a surface structure including multiple first target patterns 400.

[0065] refer to Figure 7 The first target pattern 400 can be repeatedly formed on the PET film 510 deposited on the glass 500. Figure 7 In this process, multiple first target patterns 400 can be arranged regularly in rows and columns. However, the first target patterns 400 can be arranged irregularly on the PET film 510, or regularly in other ways. Furthermore, regularly arranged first target patterns 400 can provide a certain frequency-selective transmission / blocking performance for electromagnetic waves incident from various directions and at various angles.

[0066] Next, Figures 8a to 8c This is a graph showing the frequency-selective electromagnetic wave transmission / blocking performance of the FSS according to one embodiment, based on the width variation of a non-uniform grid pattern and the incident angle of the electromagnetic wave. Specifically, Figures 8a to 8c This is a graph showing the transmission / blocking performance based on the electromagnetic wave incident angle when the width 160 of the non-uniform grid pattern 17 of the first target pattern 400 is set to 0.5 mm (hereinafter referred to as the first width pattern), when the width 160 of the non-uniform grid pattern 17 of the first target pattern 400 is set to 0.36 mm (hereinafter referred to as the second width pattern), and when the width 160 of the non-uniform grid pattern 17 of the first target pattern 400 is set to 0.64 mm (hereinafter referred to as the third width pattern).

[0067] Furthermore, the spacing 140 is set to 200 micrometers, the line width 150 is set to 20 micrometers, and based on mathematical formulas 1 to 3, it is assumed that R1 170 and R2 180 are minimum values. Additionally, the center frequency of the frequency band to be transmitted is set to 3.5 GHz, and the center frequency of the frequency band to be blocked is set to 4.77 GHz. Furthermore, 3.5 GHz can be defined as the transmission frequency 700, and 4.77 GHz can be defined as the blocking frequency 600.

[0068] refer to Figure 8a The curves show the transmission / blocking performance when electromagnetic waves are directly incident on the FSS (incident angle of 0 degrees). Figure 1 In diagram 4000, electromagnetic wave transmission / blocking results 4001 for a first-width pattern, 4002 for a second-width pattern, and 4003 for a third-width pattern are shown. (Curves) Figure 1 The x-axis represents the electromagnetic wave frequency (unit: GHz), and the y-axis represents the electromagnetic wave blocking level (unit: dB). Reference curve. Figure 14000, although the degree of blocking varies depending on the width 160 of the non-uniform grid pattern 17, all of the first to third width patterns can achieve a high electromagnetic wave blocking effect of 10dB or higher near the blocking frequency 600, and a low electromagnetic wave blocking effect of 5dB or lower near the transmission frequency 700.

[0069] Figure 8b and Figure 8c These are graphs showing the transmission / blocking results of electromagnetic waves when the TM (transverse magnetic mode) and TE (transverse electric mode) components are incident. When an electromagnetic wave passes through the boundary between two media, an incident plane perpendicular to the boundary and containing the electromagnetic wave can be defined.

[0070] Furthermore, electromagnetic waves can possess all polarizations relative to the propagation direction within 360 degrees. Additionally, the vibrational component included in the incident plane and perpendicular to the electromagnetic wave propagation direction can be defined as the TM mode, while the vibrational component perpendicular to both the incident plane and the electromagnetic wave propagation direction can be defined as the TE mode. Both the TE and TM mode components of an electromagnetic wave exhibit similar transmission trends when incident on an FSS, but generally, the TE mode component is blocked to a greater extent. However, when the electromagnetic wave is incident on the FSS from the front at an incident angle of 0 degrees, the TE and TM mode components are blocked to the same degree.

[0071] refer to Figure 8b In graph 2 4100, which shows the transmission / blocking performance of the TM mode component when an electromagnetic wave is incident on the FSS at an incident angle of 60 degrees, the transmission / blocking results 4101, 4102, and 4103 of the electromagnetic wave transmission / blocking are shown for the first width pattern, the second width pattern, and the third width pattern, respectively. As shown, the x-axis of graph 2 4100 represents the electromagnetic wave frequency (in GHz), and the y-axis represents the electromagnetic wave blocking degree (in dB). Referring to graph 2 4100, and comparing it with curve... Figure 1 Similarly, the degree of blocking varies depending on the width 160 of the non-uniform grid pattern 17, but all of the first to third width patterns can achieve a high electromagnetic wave blocking effect of 10dB or higher near the blocking frequency of 600, and a low electromagnetic wave blocking effect of 5dB or lower near the transmission frequency of 700.

[0072] refer to Figure 8cIn graph 34200, which shows the transmission / blocking performance of the TE mode component when an electromagnetic wave is incident on the FSS at a 60-degree angle, the electromagnetic wave transmission / blocking results 4201, 4202, and 4203 of the first width pattern, are shown. As shown, the x-axis of graph 34200 represents the electromagnetic wave frequency (in GHz), and the y-axis represents the electromagnetic wave blocking degree (in dB). Referring to graph 34200, although the blocking degree varies depending on the width 160 of the non-uniform grid pattern 17, all of the first to third width patterns can achieve a high electromagnetic wave blocking effect of 10 dB or higher near the blocking frequency of 600, and a low electromagnetic wave blocking effect of 10 dB or lower near the transmission frequency of 700.

[0073] As described above, even if the width 160 of the first target pattern 400 changes, when forming the non-uniform grid pattern 17 while maintaining the range of R1 170 and R2 180 according to mathematical formulas 1 to 3, a constant frequency-selective transmission / blocking performance can be maintained for electromagnetic waves incident at various angles.

[0074] Next, Figure 9 This is a graph showing the current distribution according to one embodiment and the simulation results of an FSS including a non-uniform mesh pattern, along with a comparison of the simulation results. Specifically, Figure 9 Results 1 (4300) and 2 (4400) are shown. Result 1 (4300) is a frequency-selective electromagnetic wave transmission / blocking pattern 300. Figure 5a Simulation results of the induced current distribution of the incident electromagnetic wave, 24400 is the first target pattern 400 ( Figure 5b Simulation results of the induced current distribution of the incident electromagnetic wave are shown in the figure. As shown in the figure, in both Result 1 (4300) and Result 2 (4400), a relatively strong induced current is formed in the inner linear region of the pattern, which blocks the electromagnetic wave near the blocking frequency of 600 Hz. In contrast, a relatively weak induced current is formed in the outer linear region of the pattern.

[0075] Therefore, the inner linear region provides relatively greater blocking of electromagnetic waves before frequency selection. Furthermore, the first target pattern 400 in result 2 4400 can be formed by distributing a strong current over a wider area through the non-uniform grid pattern 17 of the inner linear region 410, which reduces the inductance formed within the pattern and increases the blocking frequency 600. In contrast, the outer linear region 420 of the first target pattern 400 has a smaller current, but due to the non-uniform grid pattern 17, the current flows through a longer path, thus reducing the blocking frequency 600.

[0076] Next, Figure 10and Figure 11 This is a diagram illustrating cells of an FSS with an applied non-uniform grid pattern according to other embodiments. Reference Figure 10 The second target pattern 401 is formed in a cross shape, similar to the first target pattern 400, with an inner linear region 411 perpendicular to the center and an outer region 421 formed in a region away from the center of the inner linear region 411. As shown, the outer region 421 can be designed to have a larger area and a longer outer line length than the outer linear region 412 of the first target pattern 400.

[0077] Furthermore, the non-uniform mesh pattern 17 can be applied to the inner linear region 411, while the second metallic mesh pattern 16 can be applied to the outer region 421. In addition, the second target pattern 401, like the first target pattern 400, can maintain the non-uniform mesh pattern 17 in the inner linear region 411, which has a greater effect on electromagnetic wave blocking, and even if the outer region 421 does not have the non-uniform mesh pattern 17, it can ensure a longer current flow path, thereby achieving a constant frequency-selective electromagnetic wave transmission / blocking effect similar to the first target pattern 400.

[0078] refer to Figure 11 The third target pattern 402 can be formed by applying a non-uniform grid pattern 17 to the areas excluding the corners of a square or rectangular pattern that shares two centers, has different sizes but has a similar relationship. Furthermore, a second metallic grid pattern 16 can be applied to the areas near the corners of the third target pattern. Additionally, the area corresponding to each side of the third target pattern 402 can function similarly to the internal linear region 410 of the first target pattern 400, and generate a strong induced current for the incident electromagnetic wave.

[0079] Therefore, the non-uniform grid pattern 17 can be maintained within the relevant area and function corresponding to the outer area 421 of the second target pattern 401. Furthermore, the protrusions 430 formed by the non-uniform grid pattern 17 of the third target pattern 402 can be formed in a circular shape, as shown, or they can be formed in a partially square shape, similar to the first target pattern 400 and the second target pattern 401. This can also be applied to the first target pattern 400 and the second target pattern 401.

[0080] Next, Figures 12 to 16 This is a diagram illustrating the problem of FSS without applying the non-uniform grid pattern according to one embodiment. Specifically, Figure 12 The structure of a frequency-selective electromagnetic wave transmission / blocking pattern 300 with a second metal mesh pattern 16 is shown. Figure 12The frequency-selective electromagnetic wave transmission / blocking pattern 300 shown can have its center point 4504 located in the metal region, and the width 4502 of the outermost metal region through which the current substantially flows in the inner linear region 410 can be greater than the width 4503 of the outermost metal region through which the current substantially flows in the outer linear region 420. Figure 12 The structure shown can be called the first structure 4500.

[0081] Figure 13 The application of formation location and Figure 12 The structure of the second metal mesh pattern 16 and the frequency selective electromagnetic wave transmission / blocking pattern 300 are different. Figure 13 The frequency-selective electromagnetic wave transmission / blocking pattern 300 shown may have a width 4602 generally located in the outermost region of the metal through which the current flows in the inner linear region 410, and a width 4603 generally located in the outermost region of the metal through which the current flows in the outer linear region 420. Since the center point 4604 of the pattern is not located within the metal region, the width 4602 may be smaller than the width 4603.

[0082] Figure 14 This illustrates the first structure 4500 when an electromagnetic wave is incident from the front at a 0-degree angle. Figure 12 ) and second structure 4600 ( Figure 13 The transmission / blocking performance curves of the FSS and TM of the first structure are shown in Figure 44700. As shown in the figure, Figure 44700 illustrates the transmission / blocking performance curves of the first structure ( Figure 12 Electromagnetic wave transmission / blocking results 4510 and second structure 4600 ( Figure 13 The electromagnetic wave transmission / blocking results are 4610. Furthermore, curve... Figure 4 The x-axis of 4700 represents the electromagnetic wave frequency (unit: GHz), and the y-axis represents the degree of electromagnetic wave blocking (unit: dB).

[0083] As a curve Figure 4 As shown in 4700, a frequency jump occurred at 4710, where even for the same electromagnetic wave, the blocking frequency 600 band changed based on the pattern formation position. This is because, as Figure 1 As described, when a pattern is designed in any region of a general metal mesh pattern without an outermost line, the area of ​​the region forming the induced current will vary. That is, when a pattern is designed in the form of a first target pattern 400 on a general metal mesh pattern without an outermost line, each cell 200 will exhibit different transmission / blocking performance in different frequency bands, which may lead to a problem of overall blocking or transmission performance degradation.

[0084] refer to Figure 15Corresponding to having a first structure 4500 ( Figure 12 The transmission / blocking performance curves 54800 of the FSS show the electromagnetic wave transmission / blocking results 4520 for the TE and TM mode components of the electromagnetic wave incident at an incident angle of 0 degrees, 4530 for the TE mode component of the electromagnetic wave incident at an incident angle of 60 degrees on the FSS having the first structure 4500, and 4540 for the TM mode component of the electromagnetic wave incident at an incident angle of 60 degrees on the FSS having the first structure 4500. Referring to curve 54800, a blocking performance of 10 dB or higher is shown relatively consistently near the blocking frequency of 600, while a blocking performance of 10 dB or lower is shown near the transmission frequency of 700.

[0085] refer to Figure 16 Corresponding to having a second structure 4600 ( Figure 13 The transmission / blocking performance and component curves of the FSS. Figure 6 Figure 4900 shows the electromagnetic wave transmission / blocking results 4620 for the TE and TM mode components of an electromagnetic wave incident at an incident angle of 0 degrees, the electromagnetic wave transmission / blocking results 4630 for the TE mode component of an electromagnetic wave incident at an incident angle of 60 degrees on an FSS having the second structure 4600, and the electromagnetic wave transmission / blocking results 4640 for the TM mode component of an electromagnetic wave incident at an incident angle of 60 degrees on an FSS having the second structure 4600. Reference curve. Figure 6 Unlike the electromagnetic wave transmission / blocking performance of the first structure 4500 shown in curve 5 4800, at 4900, most of the electromagnetic waves are blocked in a frequency band that deviates significantly from the blocking frequency of around 600, and the degree of blocking of frequencies around the transmission frequency of 700 is also increased.

[0086] refer to Figures 14 to 16 The electromagnetic wave transmission / blocking performance of an FSS that combines the first structure 4500 and the second structure 4600 with the second metal mesh pattern 16 may vary for each cell 200 or for each part within a cell 200. This can lead to problems with FSS performance degradation.

[0087] Next, Figures 17 to 21 These are graphs and curves illustrating the frequency-selective electromagnetic wave transmission / blocking performance of an FSS with a non-uniform grid pattern applied according to one embodiment. Specifically, Figure 17 A first target pattern 400 with an applied non-uniform grid pattern 17 is shown. As shown, the center point 5004 of the first target pattern 400 can be located in the metal region, and the width 5002 of the outermost metal region through which the current actually flows in the inner linear region 410 can be greater than the width 5003 of the outermost metal region through which the current actually flows in the outer linear region 420. Figure 1 The structure shown can be called the third structure 5000.

[0088] Figure 18 It shows the application to the formation location and Figure 17 The structure of the first target pattern 400 is shown, with different positions of the non-uniform grid pattern 17. Figure 18 In the first target pattern 400 shown, the center point 5104 of the pattern is not in the metal region, and the width 5102 of the outermost region of the metal along which the current actually flows in the inner linear region 410 can be greater than the width 5103 of the outermost region of the metal along which the current actually flows in the outer linear region 420.

[0089] refer to Figure 17 and Figure 18 The structure of the width 5002 of the outermost metal region through which the current actually flows within the inner linear region 410 of the third structure 5000 can differ from the structure of the width 5102 of the outermost metal region through which the current actually flows, and the number of linearly formed metal regions can also differ. However, the fourth structure 5100, by including a non-uniform grid pattern 17, can achieve the effect of having the same average width in terms of the current flow path. This can also be applied to the width 5003 of the outermost metal region through which the current flows in the outer linear region 420 of the third structure 5000 and the width 5103 of the outermost metal region through which the current flows in the outer linear region 420 of the fourth structure 5100.

[0090] refer to Figure 19 ,curve Figure 7 Figure 5200 shows the transmission / blocking results of the TE and TM mode components of the third structure 5000 and the fourth structure 5100 when electromagnetic waves are incident on the front of the FSS at an incident angle of 0 degrees. Specifically, the electromagnetic wave transmission / blocking results 5010 of the third structure 5000 and 5110 of the fourth structure 5100 are shown. Similarly, curves... Figure 7 The x-axis of 5200 represents the electromagnetic wave frequency (unit: GHz), and the y-axis represents the degree of electromagnetic wave blocking (unit: dB).

[0091] Reference curve Figure 7 5200, and the curve Figure 4Unlike 4700, there is almost no frequency jump, where for the same electromagnetic wave, the blocking frequency 600 band changes depending on the formation position of the pattern. This is because, as described above, the non-uniform grid pattern 17 is applied in the third structure 5000 and the fourth structure 5100, thereby making the actual current flow areas of the inner linear region 410 and the outer linear region 420 similar. Furthermore, even if the inner linear region 410 is formed with a relatively large area, if the non-uniform grid pattern 17 is applied to the outer linear region 420 to relatively increase the length and area of ​​the path through which the current moves, the effect of compensating for the larger area of ​​the inner linear region 410 can be obtained. Therefore, as the curve... Figure 7 As shown in 5200, regardless of the location of the pattern formation, a constant frequency transmission / blocking performance can be maintained.

[0092] refer to Figure 20 Figure 85300 illustrates the electromagnetic wave transmission / blocking performance of the third structure 5000 based on the incident angle and components of the electromagnetic wave. Specifically, it shows the transmission / blocking results 5020 for the TE and TM mode components of the electromagnetic wave incident at an incident angle of 0 degrees on the FSS with the third structure 5000, 5030 for the TE mode component, and 5040 for the TM mode component. Referring to Figure 85300, a relatively consistent blocking performance of 10 dB or higher is shown near the blocking frequency of 600, while a blocking performance of 10 dB or lower is shown near the transmission frequency of 700.

[0093] refer to Figure 21 ,curve Figure 9 5400 illustrates the transmission / blocking performance of the fourth structure 5100 based on the incident angle and components of electromagnetic waves, and in particular illustrates the transmission / blocking results 5120 for the TE mode and TM mode components of electromagnetic waves incident on the FSS having the fourth structure 5100 at an incident angle of 0 degrees, the transmission / blocking results 5130 for the TE mode component of electromagnetic waves incident on the FSS having the fourth structure 5100 at an incident angle of 60 degrees, and the transmission / blocking results 5140 for the TM mode component of electromagnetic waves incident on the FSS having the fourth structure 5100 at an incident angle of 60 degrees.

[0094] refer to Figures 19 to 21 The electromagnetic wave transmission / blocking performance of the FSS, which is a mixture of the third structure 5000 and the fourth structure 5100 with the non-uniform grid pattern 17, can remain constant over the entire region of the FSS.

[0095] Next, Figure 22The graph illustrates the improved visibility achieved by applying an FSS with a non-uniform grid pattern according to one embodiment, compared to the case where the FSS is not applied. Specifically, Figure 22 Including results 3,5500 and 4,5600, result 3,5500 shows the results of a visibility experiment on a fourth target pattern 405, which has a structure in which the outermost lines are formed on the non-uniform grid pattern 17 of the first target pattern 400, and result 4,5600 shows the first target pattern 400 with the non-uniform grid pattern 17 applied ( Figure 6 The results of visibility tests when applied to glass.

[0096] Referring to results 3,5500 and 4,5600, a virtual pattern 406 of a specific shape can be formed in the area where the first target pattern 400 and the fourth target pattern 405 are not formed. The virtual pattern 406 can have the following form: smaller cross-shaped patterns than the first target pattern 400 and the fourth target pattern 405 are repeated in rows and columns, which can improve visibility.

[0097] Next, Figure 23 This is a diagram illustrating cells to which various types of FSS are applied according to one embodiment. Specifically, Figure 23 A fourth target pattern 5700 in the shape of a cross, a fifth target pattern 5800 in the shape of a circle, and a sixth target pattern 5900 having a shape having straight lines extending from a central point in three directions are shown. These patterns are applied to the non-uniform grid pattern 17 according to embodiments herein. Figure 23 As shown, the non-uniform grid pattern 17 according to the embodiments of this article can be applied to the pattern structure of FSS designed in various ways according to the frequency band to be transmitted / blocked.

[0098] Therefore, by using the FSS including the non-uniform grid pattern 17 and the pattern structure utilizing the non-uniform grid pattern 17 according to one embodiment of the present invention, visibility problems such as light leakage can be improved, while ensuring constant electromagnetic wave transmission / blocking performance, regardless of the formation location of the pattern.

[0099] Although the invention has been described with reference to the illustrated drawings, it should be understood that the invention is not limited to the embodiments and drawings disclosed in this specification, and those skilled in the art will understand that various modifications can be made without departing from the scope and spirit of the invention. Furthermore, although the operational effects of the construction according to the invention are not explicitly described in the description of embodiments, it should be understood that the construction should also have foreseeable effects.

Claims

1. A frequency-selective electromagnetic wave transmission / blocking module, comprising: substrate; as well as The plurality of conductive grid target patterns on the substrate include: First internal linear region; A second internal linear region that intersects with the first internal linear region; A first outer linear region and a second outer linear region, the first outer linear region and the second outer linear region being centered at the midpoint of opposite sides of the center of the first inner linear region; and A third outer linear region and a fourth outer linear region, the third outer linear region and the fourth outer linear region being centered at the midpoint of opposite sides of the center of the second inner linear region. Wherein, at least one of the inner linear region and the outer linear region includes a conductive non-uniform grid pattern with conductive lines of non-uniform length.

2. The frequency-selective electromagnetic wave transmission / blocking module according to claim 1, wherein, The multiple conductive mesh target patterns have the same shape.

3. The frequency-selective electromagnetic wave transmission / blocking module according to claim 2, wherein, The first internal linear region and the second internal linear region intersect each other in a cross shape and have a common center. Each of the inner linear region and the outer linear region includes the conductive non-uniform grid pattern having conductive lines of the non-uniform length.

4. The frequency-selective electromagnetic wave transmission / blocking module according to claim 2, wherein, The first internal linear region and the second internal linear region intersect each other in a cross shape and have a common center. Wherein, the first outer linear region and the second outer linear region are centered at the midpoint of opposite sides relative to the center of the first inner linear region, and the first outer linear region and the second outer linear region comprise fan shapes, and The third outer linear region and the fourth outer linear region are centered at the midpoint of opposite sides of the center of the second inner linear region, and the third outer linear region and the fourth outer linear region include the same sector as the first outer linear region and the second outer linear region.

5. The frequency-selective electromagnetic wave transmission / blocking module according to claim 1, wherein, The non-uniform grid pattern includes a first set of conductive lines that extend longer than the adjacent second set of conductive lines.

6. The frequency-selective electromagnetic wave transmission / blocking module according to claim 5, wherein, The first set of conductive wires includes protruding conductive wires that extend from the second set of conductive wires.

7. The frequency-selective electromagnetic wave transmission / blocking module according to claim 6, wherein, The protruding length R1 and width R2 of the first group of conductive wires, including the protruding conductive wires, are determined based on the average spacing p between adjacent conductive wires, the average width lw of the conductive wires, and the length W of the second group of conductive wires.

8. The frequency-selective electromagnetic wave transmission / blocking module according to claim 7, wherein, Determine R1 and R2 to obtain a natural number n that satisfies the following equation: (n-1)*p+(n)*lw≤W≤(n)*p+(n-1)*lw, To satisfy the following equation: And p + 2 * lw ≤ R2.

9. The frequency-selective electromagnetic wave transmission / blocking module according to claim 5, wherein, The first set of conductive wires includes two conductive wires of the same length.

10. The frequency-selective electromagnetic wave transmission / blocking module according to claim 9, wherein, The second set of conductive wires includes two conductive wires of the same length that are shorter than the first set of conductive wires.

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