JP2009033083A - Radio wave absorber and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily control radio wave absorption performance without causing any problems of weight burdens on an object structure or workability. <P>SOLUTION: The radio wave absorber includes a radio wave absorbing layer 20 in which radio wave absorbing materials 21 are arranged in stripes on the surface of a metal frame 1 at an interval from each other by arranging a plurality of foamed urethane resins 22 in stripes at positions securing a prescribed interval on the surface of the metal frame 1, then applying a liquid radio wave absorbing materials 21 with hardenability mutually between the foamed urethane resins 22, and applying a polyurethane resin material which is a top coating material with weathering ability respectively on the surface of the foamed urethane resins 22 and the surface of the radio wave absorbing materials 21 further. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio wave absorber and a method for manufacturing the same.

  Conventionally, in order to prevent various obstacles caused by irregular reflection of radio waves, a radio wave absorber is provided in a building or a high-rise building. In recent years, the spread of wireless LANs and mobile phones has increased remarkably, and therefore, many wave absorbers have been applied for the purpose of preventing the influence of the irregular reflection of radio waves indoors and outdoors on the communication quality. Yes.

  As this type of radio wave absorber, for example, a radio wave absorber using a ferrite magnetic material is used. According to this radio wave absorber, when radio waves are incident on the ferrite magnetic body, the radio waves are attenuated and lost while passing through the ferrite magnetic body. As a result, it is possible to suppress radio interference caused by irregular reflection of radio waves, and to ensure communication quality of a wireless LAN or a mobile phone (for example, see Patent Document 1).

  As the electromagnetic wave absorber other than the above, there are a three-dimensional shape such as a triangular pyramid, a sheet shape, or a liquid type material premised on painting as the electromagnetic wave absorbing material.

JP 2002-115346 A

  By the way, in the electromagnetic wave absorber using a ferrite magnetic body, since the weight of a ferrite magnetic body increases, it cannot be said that it is preferable at the point of the weight burden to an application object, and the workability. In addition, since the three-dimensional shape has a great influence on the appearance quality such as the design, it is generally used in a room such as an anechoic chamber, and application to the outside of the building may be significantly limited.

  On the other hand, radio wave absorbers using sheet-like radio wave absorbers and liquid type radio wave absorbers are relatively lightweight, which is advantageous in terms of weight burden and workability compared to those using ferrite magnetic bodies. Become. However, radio wave absorbers using these sheet-like radio wave absorbing materials and liquid type radio wave absorbing materials have the radio wave absorption performance such as the center frequency, the amount of absorption, the frequency band to be absorbed, etc. The current situation is that the thickness is controlled. That is, only the component and thickness are parameters for determining the radio wave absorption performance, and it is difficult to set the center frequency, the amount of absorption, and the frequency band to be absorbed that match the radio wave to be absorbed.

  In view of the above circumstances, an object of the present invention is to provide a radio wave absorber capable of easily controlling radio wave absorption performance without incurring problems of weight burden and workability on a target building, and a method for manufacturing the same. There is.

  In order to achieve the above object, a radio wave absorber according to claim 1 of the present invention is a radio wave absorber material having a sheet shape on the surface of a base material, or a liquid radio wave absorber material having curability with a certain width. In addition, the radio wave absorption layer is configured by being arranged at equal intervals.

  Further, in the method for manufacturing a radio wave absorber according to claim 2 of the present invention, the spacing members having a relative dielectric constant equivalent to that of air are arranged in stripes at positions where a predetermined spacing is ensured on the surface of the substrate. And a step of applying a curable liquid wave absorbing material between the spacing members.

  Further, the method for manufacturing a radio wave absorber according to claim 3 of the present invention includes the step of applying a weather-resistant top coat material on the surface of the spacing member and the surface of the radio wave absorber material in claim 2 described above. Is further included.

  According to a fourth aspect of the present invention, there is provided a method of manufacturing a radio wave absorber, comprising: placing a radio wave absorbing material having a sheet shape or a curable liquid radio wave absorbing material over the entire surface of a substrate; And a step of removing the radio wave absorbing material from a position where a predetermined interval is secured on the surface of the material.

  The radio wave absorber according to claim 5 of the present invention is a plate-like wave absorber having a certain width and length made of a radio wave absorber material having a sheet shape on the surface of a base material or a liquid radio wave absorber material having curability. Further, the radio wave absorption layer is configured by arranging them at equal intervals in the width direction and the length direction.

  In the method for manufacturing a radio wave absorber according to claim 6 of the present invention, the height according to the frequency band of the radio wave to be absorbed from the surface of the base material at a position where a predetermined interval is secured on the surface of the base material. And a step of arranging the spacing members in a grid pattern so as to protrude only, and a step of applying a curable liquid wave absorbing material to the surface of the substrate.

  According to a seventh aspect of the present invention, there is provided a method of manufacturing a radio wave absorber according to the sixth aspect, wherein a coating material having weather resistance is applied to the surface of the spacing member and the surface of the radio wave absorber. Is further included.

  According to claim 8 of the present invention, the method for manufacturing a radio wave absorber according to claim 6 is characterized in that the step of removing the spacing member from the surface of the substrate and the weather resistance between the surface of the radio wave absorber material and each other. And a step of applying an overcoating material having a property.

  According to the present invention, since the radio wave absorbing material is arranged in a striped pattern in the radio wave absorption layer, the width direction dimension of the radio wave absorbing material determines the frequency of the radio wave to be absorbed as well as the thickness direction of the plate. Parameter. This greatly improves the degree of freedom in designing the radio wave absorption layer, and makes it possible to easily control the radio wave absorption performance such as the center frequency, the amount of absorption, the frequency band to be absorbed, etc. . In addition, since a sheet-shaped radio wave absorbing material or a curable liquid radio wave absorbing material is applied, there is no possibility of incurring a weight burden on the target building or a problem in workability.

  Exemplary embodiments of a radio wave absorber and a method for manufacturing the same according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment 1)
FIG. 1 shows a radio wave absorber 10 according to Embodiment 1 of the present invention. The radio wave absorber 10 illustrated here is for suppressing radio interference caused by a terrestrial television broadcasting steel tower as a reflection source. The radio wave absorbing layer 20 and the overcoat layer 30 are formed on the surface of the metal frame 1 constituting the steel tower. It has.

  The radio wave absorption layer 20 is configured by using a metal frame 1 of a steel tower as a base material and arranging a radio wave absorption material 21 on the surface of the metal frame 1 so as to have a predetermined thickness. The radio wave absorbing material 21 is a material in which the relative permittivity and the relative magnetic permeability are appropriately adjusted according to the frequency of the radio wave to be absorbed. For example, a nano-crystalline alloy (soft magnetic material) is added to a liquid epoxy resin material having curability. It is possible to apply a mixture of. An undercoat layer 40 is provided between the radio wave absorbing material 21 and the surface of the metal frame 1 in order to improve adhesion between them. As the undercoat layer 40, for example, an adhesive such as a curable epoxy resin material can be applied.

  As is clear from FIG. 1, the radio wave absorbing material 21 constituting the radio wave absorbing layer 20 is arranged in a striped pattern at a position that secures a space between each other on the surface of the metal frame 1. The radio wave absorbing material 21 constituting each stripe has a uniform width over the entire length, and is provided on the surface of the metal frame 1 in such a manner that the width of the interval secured between each other is uniform.

  In the radio wave absorption layer 20, the interval holding members 22 are disposed at the portions between the radio wave absorption materials 21. The spacing member 22 is made of a material having a relative dielectric constant substantially equal to that of air, for example, a foaming urethane resin.

  The overcoat layer 30 ensures desired weather resistance for the radio wave absorption layer 20, and is provided so as to cover the entire surface of the radio wave absorption layer 20. As the overcoating material constituting the overcoating layer 30, for example, a polyurethane resin material can be applied.

  FIG. 2 is a cross-sectional view showing a process of manufacturing the radio wave absorber 10 on the metal frame 1 of the steel tower, and FIG. 3 is a perspective view thereof. That is, when configuring the radio wave absorber 10, first, an epoxy resin material to be the undercoat layer 40 is applied to the surface of the metal frame 1.

  Next, the spacing members 22 made of a foamable urethane resin are arranged in a striped pattern at regular intervals on the surface of the metal frame 1 through the undercoat layer 40 made of an epoxy resin material.

  Thereafter, the radio wave absorbing material 21 is applied so as to cover the interval holding member 22, and the surface thereof is matched with the surface of the interval holding member 22.

  Finally, if the overcoat layer 30 is formed by applying a polyurethane resin material to the surface of the spacing member 22 and the surface of the radio wave absorbing material 21, the radio wave absorber 10 is configured on the surface of the metal frame 1. .

  In the manufacturing process described above, the thickness of the interval holding member 22 and the size of the interval secured between the interval holding members 22 are appropriately set according to the frequency band of the radio wave to be absorbed. Specifically, by adjusting these dimensions as appropriate, the equivalent permittivity and equivalent permeability are controlled, and by reducing the Q value, radio wave absorption performance of a certain level or more can be obtained in a wide frequency band. The thickness of the spacing member 22 and the dimension of the spacing secured between the spacing members 22 are set.

  FIG. 4 is a graph showing the relationship between the frequency of radio waves and the radio wave absorption performance by performing a simulation on the radio wave absorber manufactured according to the manufacturing process of FIG. In FIG. 4, the thick line indicates the porosity of the radio wave absorbing material constituting the radio wave absorbing layer, that is, the ratio of the surface area of the spacing member to the surface area of the radio wave absorbing layer is 1%. In FIG. 2%. On the other hand, the thin line in FIG. 4 is for a conventional radio wave absorber that is a comparative example in which a radio wave absorption layer is formed of a continuous radio wave absorption material (porosity = 0). In any of the radio wave absorbers, the thickness of the radio wave absorption layer from the base material is the same, for example, 3 mm.

  As is apparent from FIG. 4, in the comparative example indicated by the thin line, the peak value of the radio wave absorption performance is 12 dB, and the frequency of the radio wave that can obtain the radio wave absorption performance of 10 dB or more is 400 to 650 MHz.

  On the other hand, according to the radio wave absorber of the present invention in which the porosity is 1% and 2%, the peak value of the radio wave absorption performance is improved together with 13 dB and 14 dB, and the radio wave absorption performance of 10 dB or more is obtained. The frequency of radio waves that can be used is also greatly expanding. Furthermore, the frequency at which the radio wave absorption performance reaches a peak also changes according to the porosity of the radio wave absorption material, that is, according to the interval between the radio wave absorption materials.

  Therefore, if the above-described radio wave absorber 10 is applied to a steel tower, the radio wave absorption layer 20 can absorb radio waves over a wide band and various frequencies. As a result, it is possible to suppress radio wave interference caused by radio waves over a wide band and various frequencies without incurring a situation in which construction costs increase or a problem of load resistance to the building where the radio wave absorber 10 is provided. It becomes.

  In Embodiment 1 described above, the radio wave absorber 10 in which the thickness of the radio wave absorption layer 20 is 3 mm and the porosity is 1% or 2% is illustrated, but the present invention is not necessarily limited to these values. For example, the thickness of the radio wave absorption layer 20 may be in the range of about 0.01 to 30 mm, and the porosity may be set to any value of 50% or less. However, one cycle of the stripe formed by the radio wave absorbing material 21 and the spacing member 22 needs to be set to 1/5 or more with respect to the wavelength of the radio wave to be absorbed in consideration of the radio wave absorption performance.

  Further, the material constituting the undercoat layer 40, the overcoat layer 30, the spacing holding member 22, and the radio wave absorbing material 21 are not limited to those of the first embodiment, and may be appropriately changed according to the required radio wave absorption performance. It doesn't matter. Even in this case, if the radio wave absorbing material 21 is arranged in such a manner as to ensure a space between each other, the dimension in the width direction of the radio wave absorbing material 21 becomes a parameter for determining the radio wave absorption performance. As in the first embodiment, the degree of freedom in designing the radio wave absorption layer 20 is greatly improved, and it is possible to control the frequency of the radio waves that can be absorbed and to increase the bandwidth thereof.

  Moreover, in Embodiment 1 mentioned above, although the space | interval holding member 22 is arrange | positioned between the electromagnetic wave absorption materials 21, it is not necessary to arrange | position the space | interval holding member 22 necessarily. For example, in the radio wave absorber 100 of the modification shown in FIG. 5, a member constituting the overcoat layer 130 is disposed between the radio wave absorbing materials 121. The topcoat layer 130 applied in the modified example ensures the desired weather resistance for the radio wave absorption layer 120 as in the case of the first embodiment, and for example, a polyurethane resin material can be applied.

  6 is a cross-sectional view showing a process of manufacturing the radio wave absorber 100 shown in FIG. 5 on the metal frame 1 of the steel tower, and FIG. 7 is a perspective view thereof. That is, when configuring the radio wave absorber 100, first, an epoxy resin material to be the undercoat layer 140 is applied to the surface of the metal frame 1.

  Next, the spacing members 122 made of foamable urethane resin are arranged in a striped pattern at regular intervals on the surface of the metal frame 1 through the undercoat layer 140 made of an epoxy resin material.

  Thereafter, a curable liquid wave absorbing material 121 is applied so as to cover the interval holding member 122, and the surface thereof is matched with the surface of the interval holding member 122.

  When the applied radio wave absorbing material 121 is cured, all the interval holding members 122 are removed, and a space is secured between the radio wave absorbing materials 121.

  Finally, if the overcoat layer 130 is formed by applying a polyurethane resin material between the surface of the radio wave absorbing material 121 and between them, the radio wave absorber 100 of the modification shown in FIG. It will be.

  Also in the radio wave absorber 100 of the modified example configured as described above, since the radio wave absorbing material 121 is arranged in a manner to ensure a gap between each other, the width direction dimension of the radio wave absorbing material 121 has the radio wave absorbing performance. Since it is a parameter for determination, like in the first embodiment, the degree of freedom in designing the radio wave absorption layer 120 is greatly improved, and it is possible to control the frequency of the radio wave that can be absorbed and to increase the bandwidth thereof. become.

  In FIG. 6, the spacing member 122 is made of a foamable urethane resin. However, it is not always necessary to apply the foamable urethane resin, and when the radio wave absorbing material 121 is applied, the radio wave absorbing material 121 is applied. As long as it can be divided into stripes, any device may be applied. However, it is preferable that the radio wave absorbing material 121 is rich in peelability.

(Embodiment 2)
8 and 9 show the above-described second embodiment of the radio wave absorber. Similarly to the first embodiment, the radio wave absorber 200 exemplified here is for suppressing radio interference caused by a terrestrial television broadcasting steel tower as a reflection source, and is provided on the surface of the metal frame 1 constituting the steel tower. A radio wave absorption layer 220 and an overcoat layer 230 are provided. In FIG. 8, the topcoat layer 230 is omitted, but the topcoat layer 230 is provided so as to cover the entire surface of the radio wave absorption layer 220.

  The radio wave absorption layer 220 has a metal frame 1 of a steel tower as a base material, and has a thickness t (see FIG. 9) according to the frequency band of the radio wave to be absorbed by the radio wave absorption layer 220 on the surface of the metal frame 1. In this configuration, the radio wave absorbing material 221 is disposed. The thickness of the radio wave absorption layer 220 is, for example, 1 to 5 mm. The radio wave absorbing material 221 is a material in which the relative dielectric constant and the relative magnetic permeability are appropriately adjusted according to the frequency of the radio wave to be absorbed. For example, a nanocrystalline alloy (soft magnetic material) is added to a liquid epoxy resin material having curability. It is possible to apply a mixture of. An undercoat layer 240 is provided between the radio wave absorbing material 221 and the surface of the metal frame 1 in order to improve adhesion between them. As the undercoat layer 240, for example, an adhesive such as a curable epoxy resin material can be applied.

  As is apparent from FIGS. 8 and 9, the radio wave absorbing material 221 constituting the radio wave absorbing layer 220 is located at a position that secures a space between each other on the surface of the metal frame 1 in the vertical direction and the left and right directions in FIG. It is arranged in the direction. The radio wave absorbing material 221 has a rectangular parallelepiped shape having the same width (left and right direction in FIG. 8) and length (up and down direction in FIG. 8). The width and length of the radio wave absorbing material 221 are appropriately set according to the frequency band of the radio wave to be absorbed. The electromagnetic wave absorbing material 221 is provided on the surface of the metal frame 1 in such a manner that the width of the interval secured between them is uniform in the vertical direction and the horizontal direction in FIG.

  A spacing member 222 is disposed at a portion of the radio wave absorbing layer 220 that is between the radio wave absorbing materials 221. The spacing member 222 is made of a material having a relative dielectric constant substantially equal to that of air, for example, a foaming urethane resin. The spacing member 222 has the same thickness as the radio wave absorption layer 220 and is formed in a lattice shape.

  The overcoat layer 230 is intended to ensure desired weather resistance for the radio wave absorption layer 220 and is provided in a manner covering the entire surface of the radio wave absorption layer 220. As the overcoating material constituting the overcoating layer 230, for example, a polyurethane resin material can be applied.

  FIG. 10 shows a process of manufacturing the radio wave absorber 200 on the metal frame 1 of the steel tower. That is, when configuring the radio wave absorber 200, first, an epoxy resin material to be the undercoat layer 240 is applied to the surface of the metal frame 1.

  Next, a grid-like spacing member 222 made of a foamable urethane resin is disposed on the surface of the metal frame 1 through an undercoat layer 240 made of an epoxy resin material.

  Thereafter, a curable liquid wave absorbing material 221 is applied to the surface of the metal frame 1, and the surface thereof is matched with the surface of the spacing member 222. As this method, a liquid wave absorbing material 221 having a curable property is spread on the surface of the metal frame 1 until it exceeds the surface of the gap holding member 222, and at the stage where the spread wave absorbing material 221 is cured, the gap holding member. The part beyond the surface of 222 may be removed. Alternatively, a curable liquid wave absorbing material 221 may be applied to the surface of the metal frame 1 so that the surface thereof matches the surface of the spacing member 222. In addition, as an application | coating means used for this method, it is good to use sprayers, such as a spray gun, a brush.

  Finally, if a polyurethane resin material is applied to the surface of the spacing member 222 and the surface of the radio wave absorbing material 221 to form the overcoat layer 230, the radio wave absorber 200 is configured on the surface of the metal frame 1.

  Also in the radio wave absorber 200 of the second embodiment configured as described above, the radio wave absorber material 221 is arranged in a manner that ensures a space between each other, so that the radio wave absorber material is the same as in the first embodiment. The dimension of the width direction 221 (left and right direction in FIG. 8) is a parameter for determining the radio wave absorption performance. Furthermore, in the radio wave absorber 200 of the second embodiment configured as described above, not only the width direction of the radio wave absorbing material 221 but also the length direction (vertical direction in FIG. 8) determines the radio wave absorption performance. It becomes a parameter. For this reason, the degree of freedom in designing the radio wave absorption layer 220 is significantly improved as compared with the first embodiment, and it is possible to control the frequency of the radio waves that can be absorbed and to increase the bandwidth thereof.

  Therefore, if the above-described radio wave absorber 200 is applied to a steel tower, the radio wave absorption layer 220 can absorb radio waves over a wide band and various frequencies. As a result, it is possible to suppress radio interference caused by radio waves over a wide band and various frequencies without incurring a situation in which construction costs increase and a problem of load resistance to the building where the radio wave absorber 200 is provided. It becomes.

  In addition, in the radio wave absorber 200 according to Embodiment 2 configured as described above, the thickness t (see FIG. 10) that the radio wave absorption layer 220 should have the height of the spacing member 222 protruding from the surface of the metal frame 1. ) And the radio wave absorbing material 221 is applied after the spacing member 222 is disposed. For this reason, when the radio wave absorbing material 221 is applied, the thickness of the radio wave absorbing material 221 can be managed accurately and the construction is facilitated.

  Further, the material constituting the undercoat layer 240, the overcoat layer 230, the spacing member 222, and the radio wave absorbing material 221 are not limited to those of the second embodiment, and may be appropriately changed according to the required radio wave absorption performance. It doesn't matter. Even in this case, if the radio wave absorbing material 221 is arranged in a manner to ensure a space between each other, the width direction (left and right direction in FIG. 8) size and length direction (up and down in FIG. 8) of the radio wave absorbing material 221 are arranged. (Direction) dimension is a parameter for determining the radio wave absorption performance, so that the degree of freedom in designing the radio wave absorption layer 220 is greatly improved as in the first embodiment, and the frequency control of the radio wave that can be absorbed and its Broadband can be achieved.

  In the second embodiment described above, the rectangular wave absorber 221 having the same width (left and right direction in FIG. 8) and length (up and down direction in FIG. 8) is illustrated. It is not necessary. For example, the radio wave absorber 221 may be configured in a plate shape in which the surface fixed to the metal frame 1 forms a parallelogram.

  In the second embodiment described above, the spacing member 222 is disposed between the radio wave absorbing materials 221, but the spacing member 222 is not necessarily disposed. For example, in the radio wave absorber 300 of the modification shown in FIG. 11, a member constituting the overcoat layer 330 is disposed between the radio wave absorbing materials 321. The topcoat layer 330 applied in the modified example ensures desired weather resistance for the radio wave absorption layer 320 as in the second embodiment, and for example, a polyurethane resin material can be applied.

  FIG. 12 shows a process of manufacturing the radio wave absorber 300 shown in FIG. 11 on the metal frame 1 of the steel tower. That is, when configuring the radio wave absorber 300, first, an epoxy resin material to be the undercoat layer 340 is applied to the surface of the metal frame 1.

  Next, a grid-like spacing member 322 made of a foamable urethane resin is disposed on the surface of the metal frame 1 through an undercoat layer 340 made of an epoxy resin material.

  Thereafter, a curable liquid wave absorbing material 321 is applied to the surface of the metal frame 1, and the surface thereof is matched with the surface of the spacing member 322. As this method, a liquid wave absorbing material 321 having a curable property is spread on the surface of the metal frame 1 until it exceeds the surface of the gap holding member 322, and the spread wave absorbing material 321 is cured at the stage where the spread wave absorbing material 321 is cured. The portion beyond the surface of 322 may be removed. Alternatively, a curable liquid wave absorbing material 321 may be applied to the surface of the metal frame 1 so that the surface thereof matches the surface of the spacing member 322. In addition, as an application | coating means used for this method, it is good to use sprayers, such as a spray gun, a brush.

  Thereafter, the interval holding member 322 is removed, and an interval is secured between the radio wave absorbing materials 321.

  Finally, when a top coat layer 330 is formed by applying a polyurethane resin material between the surface of the radio wave absorbing material 321 and between them, the radio wave absorber 300 of the modification shown in FIG. It will be.

  Also in the radio wave absorber 300 of the modified example configured as described above, since the radio wave absorbing material 321 is arranged in a manner to ensure a gap between each other, the radio wave absorbing material 321 of the radio wave absorbing material 321 is the same as in the first embodiment. The dimension in the width direction (left-right direction in FIG. 8) is a parameter for determining the radio wave absorption performance. Furthermore, in the radio wave absorber 300 of the modified example configured as described above, not only the width direction of the radio wave absorbing material 321 but also the length direction (vertical direction in FIG. 8) are parameters for determining the radio wave absorption performance. Become. For this reason, the degree of freedom in designing the radio wave absorption layer 320 is significantly improved as compared with the first embodiment, and it is possible to control the frequency of the radio wave that can be absorbed and to increase the bandwidth thereof.

  Moreover, in the radio wave absorber 300 of the modified example configured as described above, the thickness t (see FIG. 12) that the radio wave absorption layer 320 should have the height of the spacing member 222 protruding from the surface of the metal frame 1. The wave absorbing material 321 is applied after the interval holding member 322 is arranged and set to be the same. For this reason, when applying the radio wave absorbing material 321, the thickness of the radio wave absorbing material 321 is accurately managed and the construction is facilitated.

  In FIG. 12, the spacing member 322 is made of a foamable urethane resin. However, the foamable urethane resin is not necessarily applied, and when the radio wave absorbing material 321 is applied, the radio wave absorbing material 321 is applied. Any material can be applied as long as it can be divided into a lattice shape. However, it is preferable that the radio wave absorbing material 321 has excellent peelability.

  Furthermore, in the first and second embodiments and the modifications described above, the radio wave absorbers 10, 100, 200, and 300 are configured using the metal frame 1 of the steel tower to be applied as a base material. Of course, the substrate may be provided separately for the application target.

  Furthermore, in Embodiments 1 and 2 described above and modifications thereof, radio waves applied to television broadcasting are described as application targets, but it goes without saying that the application targets are not limited to TV radio waves. Of course, the present invention can also be applied as a radio wave absorber for improving the communication quality of a wireless LAN or a mobile phone.

  Moreover, although Embodiment 1 and 2 mentioned above and those modifications have illustrated what applied the liquid wave-absorbing material which has sclerosis | hardenability, the wave-absorbing material comprised previously in the sheet form is illustrated. You may apply.

  Further, in the above-described first and second embodiments and the modifications thereof, the radio wave absorbing material is arranged in advance at a position where a predetermined interval is secured on the surface of the base material. After the radio wave absorbing material is disposed, the radio wave absorbing material may be removed from a position where a predetermined interval is secured on the surface of the base material.

It is a conceptual diagram which shows the structure of the electromagnetic wave absorber which is Embodiment 1 of this invention. It is sectional drawing which shows the manufacturing process of the electromagnetic wave absorber shown in FIG. FIG. 3 is a perspective view of FIG. 2. It is the graph which implemented the simulation in the electromagnetic wave absorber shown in FIG. 1, and showed the relationship between the frequency of an electromagnetic wave, and electromagnetic wave absorption performance. It is a conceptual diagram which shows the modification of the electromagnetic wave absorber shown in FIG. It is sectional drawing which shows the manufacturing process of the electromagnetic wave absorber shown in FIG. FIG. 7 is a perspective view of FIG. 6. It is a front conceptual diagram which shows the structure of the electromagnetic wave absorber which is Embodiment 2 of this invention. It is the sectional view on the AA line in FIG. It is a cross-sectional perspective view which shows the manufacturing process of the electromagnetic wave absorber shown in FIG. It is a conceptual diagram which shows the modification of the electromagnetic wave absorber shown in FIG. It is a cross-sectional perspective view which shows the manufacturing process of the electromagnetic wave absorber shown in FIG.

Explanation of symbols

1 Metal frame (base material)
DESCRIPTION OF SYMBOLS 10 Radio wave absorber 20 Radio wave absorption layer 21 Radio wave absorption material 22 Space | interval holding member 30 Topcoat layer 40 Undercoat layer 100 Radio wave absorber 120 Radio wave absorption layer 121 Radio wave absorption material 122 Spacing member 130 Topcoat layer 140 Undercoat layer 200 Radio wave absorber 220 Radio wave Absorbing layer 221 Radio wave absorbing material 222 Interval holding member 230 Overcoat layer 240 Undercoat layer 300 Radio wave absorber 320 Radio wave absorbing layer 321 Radio wave absorbing material 322 Interval holding member 330 Overcoat layer 340 Undercoat layer

Claims (8)

  The radio wave absorption layer is configured by arranging a radio wave absorption material that is in the form of a sheet on the surface of a base material or a liquid radio wave absorption material having a curable property at a constant width and at equal intervals. An electromagnetic wave absorber. A step of arranging a spacing member having a relative dielectric constant equivalent to air in a striped manner at a position where a predetermined spacing is secured on the surface of the substrate;
And a step of applying a curable liquid wave absorbing material between the spacing members. A method of manufacturing a wave absorber, comprising:   The method of manufacturing a radio wave absorber according to claim 2, further comprising a step of applying a weather-resistant top coat material to the surface of the spacing member and the surface of the radio wave absorber material. Placing a radio wave absorbing material in the form of a sheet on the entire surface of the substrate, or a liquid radio wave absorbing material having curability; and
And a step of removing the radio wave absorbing material from a position where a predetermined interval is ensured on the surface of the base material.   A radio wave absorbing material having a sheet shape on the surface of the base material or a liquid radio wave absorbing material having curability is configured in a plate shape having a certain width and length, and the width direction and the length direction of each other. A radio wave absorber characterized in that a radio wave absorption layer is configured by being arranged at equal intervals. A step of arranging the spacing members in a grid shape in a manner that protrudes from the surface of the base material at a height corresponding to the frequency band of the radio wave at a position where a predetermined spacing is secured on the surface of the base material;
Applying a curable liquid wave absorbing material to the surface of the base material. A method for producing a wave absorber, comprising:   The method of manufacturing a radio wave absorber according to claim 6, further comprising a step of applying a weather-resistant top coat material to the surface of the spacing member and the surface of the radio wave absorber material. Removing the spacing member from the surface of the substrate;
The method of manufacturing a radio wave absorber according to claim 6, further comprising a step of applying a topcoat material having weather resistance between the surface of the radio wave absorber material and each other.

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