Electric wave transmission control device

Abstract

To provide an electric wave transmission control device having a wider frequency span in which transmissivity of electric waves can be improved.SOLUTION: An electric wave transmission control device 10 attached to window glass 100 (a structure) includes: a dielectric plate 11 (a dielectric substance) having a certain planar size; and a holding plate 13 which holds the dielectric plate 11 so that the dielectric plate 11 faces the window glass 100. The holding body 13 includes two advancing / retreating mechanisms 13a, 13b and two movable parts 131a, 131b (a cavity adjustment mechanism 13) for adjustment of a cavity width G between the dielectric plate 11 and the window glass 100.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] The present invention relates to a radio wave transmission control device that is attached to a structure. [Background technology]

[0002] Conventionally, a device (radio wave transmission control device) has been proposed that is attached to a structure, such as a building material or building component, to improve the transmittance of radio waves through the structure (see Patent Document 1). This device is configured as a dielectric structure (which may include voids) using a dielectric. By attaching this dielectric structure (device) to a structure, such as a window glass, the transmittance of radio waves having a frequency corresponding to the dielectric constant of the dielectric structure and its structural characteristics (e.g., dielectric thickness, void thickness) at the portion of the structure (e.g., window glass) where the dielectric structure (device) is attached can be improved. This can improve the transmittance of, for example, 5G (e.g., using the 3.7 GHz band) radio waves transmitted from base stations installed by mobile phone carriers at the portion of the structure (e.g., window glass) where the dielectric structure (device) is attached, resulting in improved indoor mobile phone reception sensitivity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-511466 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned conventional devices have a narrow frequency bandwidth capable of improving the transmittance of radio waves through structures (e.g., window glass). Meanwhile, as shown in FIG. 1, for example, in the frequency band (F1-F2: e.g., the 3.7 GHz band) used for mobile phone communications, different frequency bands are allocated to multiple telecommunications carriers. In the example shown in FIG. 1, five telecommunications carriers (Company A, Company B, Company C, Company D, and Company E) are allocated the following bands: (F1-F1+δ) to Company A, (F1+δ-F1+2δ) to Company B, (F1+2δ-F1+3δ) to Company C, (F1+3δ-F1+4δ) to Company D, and (F1+4δ-F2) to Company E.

[0005] In such a situation, if the conventional dielectric structure (device) described above is attached to the window glass (structure) of a house, the bandwidth of transmission frequencies that can be improved by the dielectric structure (device) is narrow, so while the transmittance of radio waves from Company A is improved, the transmittance of radio waves from other telecommunications carriers may not be improved to the same extent as that of Company A. For this reason, if one were to try to improve the transmittance of radio waves in the entire frequency band used by mobile phones (the entire F1-F2 band in Figure 1) through a structure (for example, window glass), it would be necessary to prepare multiple dielectric structures (devices) that can improve the transmittance of radio waves for multiple telecommunications carriers.

[0006] The present invention has been made in view of the above circumstances, and provides a radio wave transmission control device having a wider frequency bandwidth that allows improvement in the transmittance of radio waves. [Means for solving the problem]

[0007] The radio wave transmission control device of the present invention is a radio wave transmission control device that is attached to a structure, and has a dielectric material having a certain area and a holding part that holds the dielectric material facing the structure, and the holding part includes an adjustment mechanism that adjusts the gap between the dielectric material and the structure.

[0008] With this configuration, the distance (gap width) between the dielectric material and the structure can be adjusted, and the path conditions (path length) of the incident radio waves and the reflected radio waves in a system including the structure and the dielectric material can be adjusted according to the distance (gap width).

[0009] The radio wave transmission control device of the present invention is a radio wave transmission control device that is attached to a structure, and has a dielectric material having a certain area, and a holding part that holds the dielectric material so that it faces the structure, and the holding part has a structure that holds the dielectric material in a state where the distance between the dielectric material and the structure changes in a predetermined direction.

[0010] With this configuration, the distance between the dielectric material and the structure changes in a predetermined direction, and therefore the path conditions (path lengths) of the incident radio waves and the reflected radio waves in the system including the structure and the dielectric material differ at each position in the predetermined direction depending on the distance that changes in the predetermined direction.

[0011] In the radio wave transmission control device according to the present invention, the dielectric material is not particularly limited as long as it is made of a dielectric material, and may be, for example, a dielectric plate or a multi-layer dielectric material having a structure in which a plurality of dielectric layers, each having a certain surface area, are stacked at certain intervals.

[0012] The radio wave transmission control device of the present invention is a radio wave transmission control device to be attached to a structure, and comprises a multi-layered dielectric material in which a plurality of dielectric layers, each having a certain surface area, are stacked at a certain interval, and a holding portion that holds the multi-layered dielectric material so that it faces the structure, and the multi-layered dielectric material has a structure in which the interval between one dielectric layer and another dielectric layer adjacent to the dielectric layer changes in a predetermined direction.

[0013] With this configuration, in the multi-layered dielectric material held opposite the structure, the distance between one dielectric layer and another dielectric layer adjacent to that dielectric layer changes in a predetermined direction, so that the path conditions (path lengths) of the incident radio waves and reflected radio waves in the system including the structure and the multi-layered dielectric material differ at each position in the predetermined direction depending on the distance that changes in the predetermined direction.

[0014] The radio wave transmission control device described above can be attached to a window glass as the structure, and can also be attached to a double-glazed window glass as the structure, which has a structure in which multiple glass sheets are stacked with gaps between them and a metal foil layer is formed on the surface of any one of the multiple glass sheets. [Effects of the Invention]

[0015] According to the radio wave passage control device of the present invention, it is possible to obtain a wider frequency band characteristic that allows improvement in radio wave transmittance. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram showing an example of frequency band allocation to each mobile communication company. [Figure 2] FIG. 2 is a diagram showing a state in which the radio wave transmission control device according to the embodiment of the present invention is attached to a window glass (structural body). [Figure 3A] FIG. 3A is an enlarged cross-sectional view (part 1) showing the structure of the radio wave transmission control device according to the first embodiment of the present invention attached to a window glass. [Figure 3B] FIG. 3B is an enlarged cross-sectional view (part 2) showing the structure of the radio wave transmission control device according to the first embodiment of the present invention attached to a window glass. [Figure 4] FIG. 4 is a graph showing the results of a simulation of radio wave transmission when the radio wave transmission control device having the structure shown in FIGS. 3A and 3B is attached to a window glass. [Figure 5A]FIG. 5A is a diagram schematically showing the states of incident radio waves, reflected radio waves, and transmitted radio waves on window glass. [Figure 5B] FIG. 5B is a diagram schematically showing the states of incident radio waves, reflected radio waves, and transmitted radio waves in a system including a window glass and a dielectric plate in a radio wave transmission control device. [Figure 6A] FIG. 6A is an enlarged cross-sectional view (part 1) showing the structure of the radio wave transmission control device according to the first embodiment of the present invention attached to Low-E double glazing. [Figure 6B] FIG. 6B is an enlarged cross-sectional view (part 2) showing the structure of the radio wave transmission control device according to the first embodiment of the present invention attached to Low-E double glazing. [Figure 7] FIG. 7 is a graph showing the results of a simulation of radio wave transmission through the radio wave transmission control device having the structure shown in FIGS. 6A and 6B. [Figure 8A] FIG. 8A is an enlarged cross-sectional view (part 1) showing a modified example of the radio wave transmission control device according to the first embodiment of the present invention attached to a Low-E double glazing. [Figure 8B] FIG. 8B is an enlarged cross-sectional view (part 2) showing a modified example of the radio wave transmission control device according to the first embodiment of the present invention attached to a Low-E double glazing. [Figure 9] FIG. 9 is a graph showing the results of a simulation of radio wave transmission through the radio wave transmission control device having the structure shown in FIGS. 8A and 8B. [Figure 10] FIG. 10 is an enlarged cross-sectional view showing the structure of a radio wave transmission control device according to the second embodiment of the present invention attached to a window glass. [Figure 11] FIG. 11 is a graph showing the results of a simulation of radio wave transmission through the radio wave transmission control device having the structure shown in FIG. [Figure 12A] FIG. 12A is a diagram schematically showing the states of input radio waves, reflected radio waves, and transmitted radio waves at position y1 on a window glass to which a radio wave transmission control device according to the second embodiment of the present invention is attached. [Figure 12B]FIG. 12B is a diagram schematically showing the states of input radio waves, reflected radio waves, and transmitted radio waves at position y2 on a window glass to which a radio wave transmission control device according to the second embodiment of the present invention is attached. [Figure 13] FIG. 13 is an enlarged cross-sectional view showing a modified example of the structure of the radio wave transmission control device according to the second embodiment of the present invention. [Figure 14] FIG. 14 is an enlarged cross-sectional view showing the structure of a radio wave transmission control device according to a second embodiment of the present invention attached to a Low-E double glazing. [Figure 15] FIG. 15 is a graph showing the results of a simulation of radio wave transmission through the radio wave transmission control device having the structure shown in FIG. [Figure 16] FIG. 16 is an enlarged cross-sectional view showing a modified example of the radio wave transmission control device according to the second embodiment of the present invention attached to a Low-E double glazing. [Figure 17] FIG. 17 is a graph showing the results of a simulation of radio wave transmission through the radio wave transmission control device having the structure shown in FIG. [Figure 18] FIG. 18 is an enlarged cross-sectional view showing the structure of a radio wave transmission control device according to the third embodiment of the present invention attached to a window glass. [Figure 19] FIG. 19 is an enlarged cross-sectional view showing a modified example of the radio wave transmission control device according to the third embodiment of the present invention attached to a window glass. [Figure 20] FIG. 20 is an enlarged cross-sectional view showing another example of the structure of the dielectric material. [Figure 21] FIG. 21 is an enlarged plan view showing still another structural example of the dielectric material. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] A radio wave transmission control device according to an embodiment of the present invention is attached to a structure, for example, as shown in Fig. 2. In Fig. 2, the radio wave transmission control device 10 is fixed to a window glass 100 (structure) of a building, for example, to its radio wave incident surface 110, by a mechanical method using a fixture or the like, or by an adhesive or the like. The radio wave control device 10 according to a first embodiment of the present invention is configured as shown in Figs. 3A and 3B.

[0019] 3A and 3B, the radio wave transmission control device 10 includes a dielectric plate 11 (dielectric material) having a predetermined dielectric constant ε and a holder 13 (holding portion) that holds the dielectric plate 11. The dielectric plate 11 is rectangular and has a predetermined thickness and faces (front and back) with a predetermined area (area width) that can be said to have a surface extent relative to the thickness. The dielectric plate 11 can be made of materials such as inorganic materials such as glass, alumina, and titanium oxide, organic materials such as resin, composite materials of multiple inorganic materials, composite materials of multiple organic materials, and composite materials of inorganic and organic materials. The dielectric plate 11 is arranged parallel to the radio wave incident surface 110 of the window glass 100 (single glass) and is slidably housed in a rectangular cylindrical guide frame 12 that is fixed upright on the radio wave incident surface 110 of the window glass 100. The holder 13 holds the dielectric plate 11 housed in the guide frame 12 so as to face the radio wave incident surface 110 of the window glass 100, and has two advancing and retreating mechanisms 13a and 13b and two movable parts 131a and 131b (adjustment mechanisms). The tip of one movable part 131a is fixed to one edge part of the back surface of the dielectric plate 11, and the tip of the other movable part 131b is fixed to an edge part of the back surface of the dielectric plate 11 that faces the one edge part. The specific structure of each of the advancing / retreating mechanisms 13a, 13b is not particularly limited as long as it is a structure that can move the corresponding movable parts 131a, 131b forward and backward, and may be, for example, a structure that moves the movable parts 131a, 131b forward and backward by manually rotating a rotary operation part, a structure that moves the movable parts 131a, 131b forward and backward using a slider, a structure that allows the movable parts 131a, 131b to be pushed in and advanced in a click-like manner when a certain advancing pressure is applied by a spring, or a structure that moves the movable parts 131a, 131b forward and backward using a drive source such as a micromotor.

[0020] In the radio wave transmission control device 10 described above, when the movable parts 131a and 131b are fully retracted (see FIG. 3A), the distance between the back surface of the dielectric plate 11 (the surface facing the radio wave incident surface 100 of the window glass 100) and the radio wave incident surface 110 of the window glass 100 is smallest, and the gap width therebetween is maintained at the minimum gap width Go. Also, when the movable parts 131a and 131b are fully advanced (see FIG. 3B), the distance between the back surface of the dielectric plate 11 and the radio wave incident surface 110 of the glass window 110 is largest, and the gap width therebetween is maintained at the maximum gap width Gm. Then, by advancing and retracting the movable parts 131a and 131b using the advancing and retracting mechanisms 13a and 13b, the gap width G between the back surface of the dielectric plate 11 and the radio wave incident surface 110 of the window glass 110 can be adjusted between the minimum gap width Go and the maximum gap width Gm.

[0021] FIG. 4 shows the results of a simulation of radio wave transmission when the radio wave transmission control device 10 having the above-described structure (see FIGS. 3A and 3B) is attached to a window glass 100 (single glass).

[0022] Dielectric plate 11: Dielectric constant ε=6.9 Thickness t=6.0mm Window Glass 100: Dielectric constant ε=6.9 Thickness t=8mm Under the condition that, The gap width G (spacing) between the dielectric plate 11 and the radio wave incident surface 110 of the window glass 100 is G=1.5mm G=0.7mm G=0.1mm The simulation was carried out by changing

[0023] In Figure 4, the characteristic line Q0 (dashed line) shows the transmittance characteristics against frequency when radio waves are incident on the radio wave incident surface 110 of the window glass 100 on which the radio wave transmission control device 10 (dielectric plate 11) is not attached.

[0024] When the gap width G between the back surface of the dielectric plate 11 (the surface facing the radio wave incident surface 110 of the window glass 100) and the radio wave incident surface 110 of the window glass 100 was 1.5 mm (G = 1.5), the transmittance versus frequency characteristic shown by characteristic line Q1 (solid) was obtained. When the gap width G between the back surface of the dielectric plate 11 and the radio wave incident surface 110 of the window glass 100 was 0.7 mm (G = 0.7), the transmittance versus frequency characteristic shown by characteristic line Q2 (dashed line) was obtained. When the gap width G between the back surface of the dielectric plate 11 and the radio wave incident surface 110 of the window glass 100 was 0.1 mm (G = 0.1), the transmittance versus frequency characteristic shown by characteristic line Q3 (dashed line) was obtained.

[0025] From the above simulation results (FIG. 4), it was confirmed that attaching the radio wave transmission control device 10 to the window glass 100 can improve the transmittance of radio waves in a certain frequency band. It was also found that adjusting the gap width G (spacing) between the back surface of the dielectric plate 11 and the radio wave incident surface 110 of the window glass 100 can achieve high radio wave transmittance in a wider frequency range (at least 3 GHz to 4.5 GHz), and that the radio wave transmittance can be improved. The following reasons are presumed to be responsible for this.

[0026] 5A, when radio waves of frequency f are directly incident on the radio wave incident surface 110 of the window glass 100, there are incident radio waves IDW (f: frequency (same below)) that are incident on the radio wave incident surface 110, radio waves RFW(f) that are reflected by the window glass 100, and transmitted radio waves TMW(f) that are transmitted through the window glass 100. In this case, of the incident radio waves IDW(f) that are incident on the dielectric plate 11, the components other than the reflected radio waves RFW(f) that are not transmitted through the window glass 100 become transmitted radio waves TMW(f) that are transmitted through the window glass 100.

[0027] On the other hand, when a radio wave transmission control device 10 having the above-described structure is attached to the radio wave incident surface 110 of the window glass 100, as shown in Figure 5B, there are incident radio waves IDW(f) incident on the surface of the dielectric plate 11, reflected radio waves RFW1(f) at the dielectric plate 11, transmitted radio waves TMW1(f) passing through the dielectric plate 11 from the front side, reflected radio waves RFW2(f) at the window glass 100, transmitted radio waves TMW2(f) passing through the dielectric plate 11 from the back side, and transmitted radio waves TMW(f) passing through the window glass 110. In this situation, in a system S including the radio wave transmission control device 10 (dielectric plate 11) and window glass 100 (structure), the components of the incident radio wave IDW(f) incident on the dielectric plate 11 that do not pass through the window glass 100, other than the reflected radio wave RFW1(f) at the dielectric plate 11 and the transmitted radio wave TMW2(f) that passes through the back side of the dielectric plate 11, become the transmitted radio wave TMW(f) that passes through the window glass 100. Here, interference occurs between the reflected radio wave RFW1(f) at the dielectric plate 11 and the transmitted radio wave TMW2(f) that passes through the back side of the dielectric plate 11 due to differences in their path lengths. Depending on the state of interference, the amount of the composite wave of the reflected radio wave RFW1(f) and the transmitted radio wave TMW2(f) varies. Here, the state of interference depends on the path length, i.e., the gap width G (spacing), and the wavelength of the radio wave, i.e., the frequency.

[0028] From this, it can be considered that by adjusting the gap width G (spacing), for radio waves of a certain frequency f, the amount of composite wave of the reflected radio waves RFW1(f) at the dielectric plate 11 and the transmitted radio waves TMW2(f) that transmit from the back side of the dielectric plate 11 can be reduced, in other words, the amount of transmitted radio waves TMW(f) that transmit through the window glass 100 for a constant incident radio wave IDW(f) can be increased. From this consideration, it can be considered that by adjusting the gap width G (spacing) between the back side of the dielectric plate 11 and the radio wave incident surface 110 of the window glass 100, the radio wave transmittance (amount of transmitted radio waves) can be improved over a wider frequency range.

[0029] In this way, radio wave transmittance is improved over a wider frequency range, making it possible to improve the transmittance of radio waves over a relatively wide frequency band allocated to multiple communication line providers without having to prepare multiple dielectric structures (devices).

[0030] The radio wave transmission control device 10 having the above-described structure may be attached to a Low-E double glazing 200 as a structure, as shown in FIGS. 6A and 6B.

[0031] 6A and 6B, the Low-E double glazing 200 has a structure in which a first glass sheet 201 and a second glass sheet 202 are laminated with an air gap AG between them. A metal foil layer 203 (for example, a silver foil layer) is formed on the surface of the second glass sheet 202 by vapor deposition or the like. Then, a radio wave transmission control device 10 (including a dielectric plate 11, a guide frame 12, and a holder 13) having the same structure as that described above (see FIGS. 3A and 3B) is fixed to the radio wave incident surface 210, which is the surface of the first glass sheet 201 of the Low-E double glazing 200, by a mechanical method using a fixture or an adhesive, in the same manner as described above.

[0032] As described above, in the radio wave transmission control device 10 attached to the radio wave incident surface 210 of the Low-E double glazing 200, similar to the previous example (see FIGS. 3A and 3B), the advancing and retracting movements of the movable parts 131a and 131b by the advancing and retracting mechanisms 13a and 13b advance and retract the dielectric plate 11 slidably housed in the rectangular cylindrical guide frame 12. In this way, the distance between the back surface of the dielectric plate 11 and the radio wave incident surface 210 of the Low-E double glazing 200 can be adjusted between a minimum and a maximum, that is, the gap width G between them can be adjusted between a minimum gap width Go (see FIG. 6A) and a maximum gap width Gm (see FIG. 6B).

[0033] FIG. 7 shows the results of a simulation of radio wave transmission when the radio wave transmission control device 10 is attached to the radio wave incident surface 201 (surface of the second glass sheet 201) of the Low-E double glazing 200 having the above-described structure.

[0034] Dielectric plate 11: Dielectric constant ε=4.8 Thickness t=2.8mm Low-E double glazing 200: First glass plate dielectric constant ε=6.9 First glass plate thickness t=3mm Metal foil layer thickness t=25nm Air gap AG=16mm Second sheet glass dielectric constant ε=6.9 Second glass plate thickness t = 3 mm Under the condition that, The gap width G (spacing) between the dielectric plate 11 and the radio wave incident surface 210 of the Low-E double glazing 200 (first glass sheet 201) is G=9.0mm G=7.5mm G=6.0mm The simulation was carried out by changing

[0035] In Figure 7, the characteristic line Q0 (dashed line) shows the transmittance characteristics against frequency when radio waves are incident on the radio wave incident surface 110 of the window glass 100 on which the radio wave transmission control device 10 (dielectric plate 11) is not attached.

[0036] When the gap width between the back surface of the dielectric plate 11 (the surface facing the radio wave incident surface 210 of the Low-E double glazing 200 (first glass sheet 201)) and the radio wave incident surface 210 of the Low-E double glazing 200 (first glass sheet 201) was 9.0 mm (G = 9.0), the transmittance versus frequency characteristic shown by characteristic line Q1 (solid) was obtained. When the gap width G between the back surface of the dielectric plate 11 and the radio wave incident surface 210 of the Low-E double glazing 200 was 7.5 mm (G = 7.5 mm), the transmittance versus frequency characteristic shown by characteristic line Q2 (dashed line) was obtained. When the gap width G between the back surface of the dielectric plate 11 and the radio wave incident surface 210 of the Low-E double glazing 200 was 6.0 mm (G = 6.0), the transmittance versus frequency characteristic shown by characteristic line Q3 (dashed line) was obtained.

[0037] The simulation results (FIG. 7) confirmed that attaching the radio wave transmission control device 10 to the Low-E double glazing 200 can improve the transmittance of radio waves in a certain frequency band. It was also found that adjusting the gap width G (spacing) between the back surface of the dielectric plate 11 and the radio wave incident surface 110 of the Low-E double glazing 200 (first glass sheet 201) can achieve high radio wave transmittance over a wider frequency range (at least 3.6 GHz to 4.2 GHz), and that this radio wave transmittance can be improved. This is presumably because, similar to the reasons described above, the conditions of the incident radio wave, reflected radio wave, and transmitted radio wave (see FIG. 5) in the system S including the radio wave transmission control device 10 (dielectric plate 11) and the Low-E double glazing 200 (structure) change depending on the gap width G (spacing).

[0038] The radio wave transmission control device 10 according to the first embodiment of the present invention can also be configured (modified) as shown in Figures 8A and 8B. This radio wave transmission control device 10 is characterized in that, instead of the dielectric plate 11 described above, a multi-layer dielectric material having a structure in which a plurality of dielectric layers are stacked at intervals (gaps) is used as the dielectric material.

[0039] 8A and 8B, the radio wave transmission control device 10 is attached to the radio wave incident surface 210 of a Low-E double glazing 210. The Low-E double glazing 200 has the same structure as described above (having a first glass sheet 201, a second glass sheet 202, a metal foil layer 203, and an air gap AG: see FIGS. 6A and 6B). The radio wave transmission control device 10 includes a multilayer dielectric material 15 and a holder 13 that holds the multilayer dielectric material 15. The multilayer dielectric material 15 has a structure in which a first dielectric plate 151 and a second dielectric plate 152, each serving as a dielectric layer, are stacked while a predetermined air gap AG (spacing) is maintained by a spacer frame 153. The first dielectric plate 151 and the second dielectric plate 152 each have a rectangular shape and have surfaces (front and back) with a predetermined thickness and a predetermined area (area width) that can be said to have a surface extent relative to the thickness. The first dielectric plate 151 and the second dielectric plate 152 each have a predetermined dielectric constant. These dielectric constants may be the same or different. The first dielectric plate 151 and the second dielectric plate 152 may each be made of the same material as the dielectric plate 11 (see FIGS. 3A and 3B) described above. The first dielectric plate 151 and the second dielectric plate 152 may be made of the same material or different materials.

[0040] The multilayer dielectric material 15 is disposed parallel to the radio wave incident surface 210 of the first glass sheet 201 of the Low-E double glazing 200, and is slidably housed within a rectangular cylindrical guide frame 12 that is fixed upright on the radio wave incident surface 210. The holder 13 has the same structure as described above (including advancing and retreating mechanisms 13a, 13b and movable parts 131a, 131b), and holds the multilayer dielectric material 15 housed within the guide frame 12 so that it can move forward and backward. The advancing and retreating movements of the movable parts 131a, 131b by the advancing and retreating mechanisms 13a, 13b of the holder 13 allow the distance between the multilayer dielectric material 15 (second dielectric plate 152) and the radio wave incident surface 210 of the Low-E double glazing 200 to be adjusted between a minimum and a maximum, i.e., the gap width G between them can be adjusted between a minimum gap width Go (see FIG. 8A) and a maximum gap width Gm (see FIG. 8B).

[0041] Figure 9 shows the results of a simulation of radio wave transmission when a radio wave transmission control device 10 including the above-mentioned multi-layer dielectric material 15 is attached to the radio wave incident surface 210 (surface of the second glass sheet 201) of a low-E double glazing 200.

[0042] Multilayer dielectric material 15: First dielectric plate permittivity ε=6.9 First dielectric plate thickness t=8.2mm Second dielectric plate permittivity ε=6.9 Second dielectric plate thickness t=9.3mm Spacing (gap) AG=17mm Low-E double glazing 200: First glass plate dielectric constant ε=6.9 First glass plate thickness t=3mm Metal foil layer thickness t=25nm Air gap AG=16mm Second sheet glass dielectric constant ε=6.9 Second glass plate thickness t = 3 mm Under the conditions of The gap width (spacing) G between the multi-layer dielectric material 15 and the radio wave incident surface 210 of the Low-E double glazing 200 is G=8.10mm G=5.98mm G=3.85mm The simulation was carried out by changing

[0043] In Figure 9, characteristic Q0 (dashed line) shows the transmittance characteristic against frequency when radio waves are incident on the radio wave incident surface 210 of the Low-E double glazing 200 that does not have the radio wave transmission control device 10 (multilayer dielectric material 15) installed.

[0044] When the gap width between the back surface of the multilayer dielectric material 15 (second dielectric plate 152) (the surface facing the radio wave incident surface 210 of the Low-E double-glazing glass 200) and the radio wave incident surface 210 of the Low-E double-glazing glass 200 was 8.10 mm (G = 8.10), the transmittance versus frequency characteristic shown by characteristic line Q1 (solid) was obtained. When the gap width G between the back surface of the multilayer dielectric material 15 and the radio wave incident surface 210 of the Low-E double-glazing glass 200 was 5.98 mm (G = 5.98), the transmittance versus frequency characteristic shown by characteristic line Q2 (dashed line) was obtained. When the gap width G between the back surface of the multilayer dielectric material 15 and the radio wave incident surface 210 of the Low-E double-glazing glass 200 was 3.85 mm (G = 3.85), the transmittance versus frequency characteristic shown by characteristic line Q3 (dashed line) was obtained.

[0045] The above simulation results (FIG. 9) confirmed that attaching the radio wave transmission control device 10 (multilayer dielectric material 15) to the radio wave incident surface 210 of the Low-E double glazing 200 can improve the transmittance of radio waves in a certain frequency band. It was also found that adjusting the gap width G (spacing) between the rear surface of the multilayer dielectric material 15 (second dielectric plate 152) and the radio wave incident surface 110 of the Low-E double glazing 200 (first glass sheet 201) can achieve high radio wave transmittance over a wide frequency range (at least 3.6 GHz to 4.2 GHz), and that this radio wave transmittance can be improved. The reason for this is similar to that described above, and is presumed to be due to the fact that the conditions (see FIG. 5) of the incident radio wave, reflected radio wave, and transmitted radio wave in the system S including the radio wave transmission control device 10 (multilayer dielectric material 15) and the Low-E double glazing 200 (structure) change depending on the gap width G (spacing).

[0046] Next, a radio wave transmission control device according to a second embodiment of the present invention will be described.

[0047] A radio wave control device 10 according to the second embodiment of the present invention is configured as shown in FIG.

[0048] 10, the radio wave transmission control device 10 includes a dielectric plate 11 (dielectric material) having a predetermined dielectric constant ε and a holding frame 16 (holding portion) that holds the dielectric plate 11 so as to face a radio wave incident surface 110 of a window glass 100 (single glass: structure). As in the above-described example (see FIGS. 3A and 3B), the dielectric plate 11 can be made of materials such as glass, inorganic materials such as alumina or titanium oxide, organic materials such as resin, composite materials of multiple inorganic materials, composite materials of multiple organic materials, or composite materials of inorganic and organic materials. The holding frame 16 holds the dielectric plate 11 so as to be tilted in direction y (from left to right on the paper surface of FIG. 10). As a result, the distance G between the dielectric plate 11 and the window glass 100, more specifically, the distance G (gap) between the back surface of the dielectric plate 11 (the surface facing the radio wave incident surface 110 of the window glass 100) and the radio wave incident surface 110 of the window glass 100, changes uniformly in the direction y from the minimum distance (gap width) G1 to the maximum distance (gap width) G2.

[0049] FIG. 11 shows the results of a simulation of radio wave transmission when the radio wave transmission control device 10 having the above-described structure (see FIG. 10) is attached to a window glass 100 (single glass).

[0050] Dielectric plate 11: Dielectric constant ε=6.9 Thickness t=6.0mm Window Glass 100: Dielectric constant ε=6.9 Thickness t=8mm The gap between the dielectric plate 11 and the window glass 10 (gap width) G = 0.1 mm (G1) to 1.5 mm (G2) The simulation was carried out under these conditions.

[0051] As shown in FIG. 11, a characteristic of high transmittance was obtained over a relatively wide frequency range, as indicated by characteristic line Q1 (solid). Note that characteristic line Q0 (dashed line) shows the transmittance versus frequency characteristic when radio waves are incident on the radio wave incident surface 110 of a window glass 100 to which no radio wave transmission control device 10 (dielectric plate 11) is attached. From these simulation results (FIG. 11), it was confirmed that attaching the radio wave transmission control device 10 (including the tilted dielectric plate 11) to the radio wave incident surface 210 of the window glass 100 can improve the radio wave transmittance in a certain frequency band. Furthermore, by tilting the dielectric plate 11 in a predetermined direction y and changing the gap G between the back surface of the dielectric plate 11 and the radio wave incident surface 110 of the window glass 100 in the predetermined direction y, it was found that high radio wave transmittance can be obtained over a wider frequency range (at least 3.5 GHz to 4.3 GHz), and that the radio wave transmittance can be improved. This is presumably due to the following reasons.

[0052] As described above, when the radio wave transmission control device 10 is attached to the radio wave incident surface 110 of the window glass 100 with the distance G between the back surface of the dielectric plate 11 and the radio wave incident surface 110 of the window glass 100 varying uniformly in the direction y, the radio wave situation at position y1 where the distance G(y1) is relatively narrow is shown in Figure 12A, and the radio wave situation at position y2 where the distance G(y2) is relatively wide is shown in Figure 12B.

[0053] 12A, at position y1, there are incident radio waves IDW(f) incident on the surface of the dielectric plate 11, reflected radio waves RFW1(f, y1) at the dielectric plate 11, transmitted radio waves TMW1(f, y1) passing through the dielectric plate 11 from the front side, reflected radio waves RFW2(f, y1) at the window glass 100, transmitted radio waves TMW2(f, y1) passing through the dielectric plate 11 from the back side, and transmitted radio waves TMW(f, y1) passing through the window glass 110. In this situation, in a system S including the radio wave transmission control device 10 (dielectric plate 11) and the window glass 100, it can be said that at position y1, of the incident radio waves IDW(f) incident on the dielectric plate 11, components other than the reflected radio waves RFW1(f, y1) at the dielectric plate 11 and the transmitted radio waves TMW2(f, y1) that do not pass through the window glass 100 become transmitted radio waves TMW(f, y1) passing through the window glass 100. Here, interference occurs between the radio wave RFW1(f, y1) reflected by the dielectric plate 11 and the transmitted radio wave TMW2(f, y1) that transmits from the back side of the dielectric plate 11, depending on the difference in their path lengths. Depending on the state of interference, the amount of the composite wave of the reflected radio wave RFW1(f, y1) and the transmitted radio wave TMW2(f, y1) varies. Here, the state of interference depends on the path length, i.e., the distance (gap width) G(y1) between the dielectric plate 11 and the window glass 100, and the wavelength of the radio wave, i.e., the frequency.

[0054] From this, it can be considered that when a radio wave IDW(f1) of frequency f1 is incident at a position y1 where the distance G between the back surface of the dielectric plate 11 and the radio wave incident surface 110 of the window glass 100 is relatively narrow, resulting in an interference state in which the amount of the composite wave of the reflected radio wave RFW1(f, y1) and the transmitted radio wave TMW2(f, y1) is further reduced, the transmitted radio wave TMW(f1, y1) that passes through the window glass 100 will increase.

[0055] On the other hand, in Figure 12B, at position y2, as in the case of position y1 described above, there are incident radio waves IDW(f) incident on the surface of the dielectric plate 11, reflected radio waves RFW1(f, y2) at the dielectric plate 11, transmitted radio waves TMW1(f, y2) passing through the dielectric plate 11 from the front side, reflected radio waves RFW2(f, y2) at the window glass 100, transmitted radio waves TMW2(f, y2) passing through the dielectric plate 11 from the back side, and transmitted radio waves TMW(f, y2) passing through the window glass 110. In such a situation, in a system S including a radio wave transmission control device 10 (dielectric plate 11) and a window glass 100, when a radio wave IDW(f2) of frequency f2 is incident at a position y2 where the distance between the back surface of the dielectric plate 11 and the radio wave incident surface 110 of the window glass 100 is relatively wide, which creates an interference state in which the amount of the composite wave of the reflected wave RFW1(f, y2) and the transmitted radio wave TW2(f, y2) is further reduced, it is thought that the transmitted radio wave TMW(f2, y2) that transmits through the window glass 100 will increase.

[0056] From the above considerations, it is estimated that the transmitted radio waves TMW(f, y) at frequencies corresponding to the distance G between the rear surface of the dielectric plate 11 and the radio wave incident surface 110 of the window glass 100 at each position in the direction y of the dielectric plate 11 will increase. This is thought to make it possible to obtain high radio wave transmittance over a relatively wide frequency range.

[0057] In the example described above (see FIG. 10), the dielectric plate 11 is uniformly inclined in a certain direction y, so that the distance (gap width) G between the window glass 100 (structure) and the dielectric plate 11 (dielectric material) changes uniformly in the direction y, but the invention is not limited to this. For example, the radio wave transmission control device 10 may be configured so that the distance G between the window glass 100 (structure) and the dielectric plate 11 (dielectric material) changes discontinuously, for example, in a stepwise manner, in the certain direction y.

[0058] In the example described above (see FIG. 10), there was a gap between the window glass 100 (structure) and the dielectric plate 11 (dielectric material), but as shown in FIG. 13, another dielectric material 18 (preferably having a dielectric constant that does not significantly impair the transmission of radio waves) may be provided between the window glass 100 (structure) and the dielectric plate 11 (dielectric material). Furthermore, this dielectric material 18 may be, for example, densely packed throughout the entire retaining frame 16 sandwiched between the window glass 100 (structure) and the dielectric plate 11 (dielectric material), or the dielectric material 18 may be present in one or more spaces within the retaining frame 16 sandwiched between the window glass 100 (structure) and the dielectric plate 11 (dielectric material).

[0059] By providing another dielectric material 18 between the window glass 100 (structure) and the dielectric plate 11 (dielectric material) in this manner, it is possible to reinforce the dielectric plate 11, whose outer edge portion is held by the holding frame 16, against external pressure (wind pressure, flying objects, etc.).

[0060] The radio wave transmission control device 10 having the above-described structure (see FIG. 10) may be attached to the radio wave incident surface 210 of a Low-E double glazing 200 having the same structure as described above (see FIGS. 6A and 6B), as shown in FIG. 14. Simulation results relating to radio wave transmission in this case are shown in FIG. 15.

[0061] Dielectric plate 11: Dielectric constant ε=4.8 Thickness t=2.8mm Low-E double glazing 200: First glass plate dielectric constant ε=6.9 First glass plate thickness t=3mm Metal foil layer thickness t=25nm Air gap AG=16mm Second sheet glass dielectric constant ε=6.9 Second glass plate thickness t = 3 mm The gap between the dielectric plate 11 and the Low-E double glazing 200 (gap width) G = 6 mm to 9 mm The simulation was carried out under these conditions.

[0062] As shown in FIG. 15, a characteristic of high transmittance was obtained over a relatively wide frequency range, as indicated by characteristic line Q1 (solid). Note that characteristic line Q0 (dashed line) shows the transmittance versus frequency characteristic when radio waves are incident on the radio wave incident surface 210 of the Low-E double glazing 200 without the radio wave transmission control device 10 (dielectric plate 11) attached. From these simulation results (FIG. 15), it was confirmed that attaching the radio wave transmission control device 10 (including the tilted dielectric plate 11) to the radio wave incident surface 210 of the Low-E double glazing 200 can improve the radio wave transmittance in a certain frequency band. Furthermore, by tilting the dielectric plate 11 in the predetermined direction y and changing the gap G between the back surface of the dielectric plate 11 and the radio wave incident surface 210 of the Low-E double glazing 200 in the predetermined direction y, it was found that high radio wave transmittance can be obtained over a wider frequency range (at least 3.6 GHz to 4.2 GHz), and that the radio wave transmittance can be improved. The reason for this is the same as that mentioned above, and is presumably due to the fact that the conditions of the incident radio waves, reflected radio waves, and transmitted radio waves (see Figures 12A and 12B) in the system S including the radio wave transmission control device 10 (electrical body plate 11) and the Low-E double glazing 200 (structure) change in the direction y depending on the distance G in the y direction between the dielectric plate 11 and the Low-E double glazing 200.

[0063] In the example described above (see FIG. 14), another dielectric material may be provided between the dielectric plate 11 and the Low-E double glazing 200, similar to the example shown in FIG.

[0064] The radio wave transmission control device 10 according to the second embodiment of the present invention can also be configured (modified) as shown in Fig. 16. This radio wave transmission control device 10 is characterized in that, instead of the dielectric plate 11 described above, a multi-layer dielectric material having a structure in which a plurality of dielectric layers are stacked at certain intervals is used as the dielectric material.

[0065] 16, the radio wave transmission control device 10 is attached to the radio wave incident surface 210 of a Low-E double glazing 200. The Low-E double glazing 200 has the same structure as described above (having a first glass sheet 201, a second glass sheet 202, a metal foil layer 203, and an air gap AG: see FIGS. 6A, 6B, 8A, 8B, and 14). The radio wave transmission control device 10 includes a multilayer dielectric material 15 as a dielectric material and a holding frame 16 (holding portion) that holds the multilayer dielectric material 15 so as to face the radio wave incident surface 210 of the Low-E double glazing 200. As in the example described above (see FIGS. 8A and 8B), the multilayer dielectric material 15 has a structure in which a first dielectric plate 151 and a second dielectric plate 152 are stacked together while maintaining a predetermined gap (air gap) AG by a spacer frame 153. The multilayer dielectric member 15 is held by a holding frame 16 (holding portion) so as to be inclined in the direction y (from left to right on the paper surface of FIG. 16).

[0066] FIG. 17 shows the results of a simulation of radio wave transmission when the radio wave transmission control device 10 having the above-described structure (see FIG. 16) is attached to the radio wave incident surface 210 of the Low-E double glazing 200.

[0067] Multilayer dielectric material 15: First dielectric plate permittivity ε=6.9 First dielectric plate thickness t=8.2mm Second dielectric plate permittivity ε=6.9 Second dielectric plate thickness t=9.3mm Spacing (gap) AG=17mm Low-E double glazing 200: First glass plate dielectric constant ε=6.9 First glass plate thickness t=3mm Metal foil layer thickness t=25nm Air gap AG=16mm Second sheet glass dielectric constant ε=6.9 Second glass plate thickness t = 3 mm The gap between the multi-layer dielectric material 15 and the Low-E double-glazing glass 200 (gap width) G = 3.85 mm to 8.10 mm The simulation was carried out under these conditions.

[0068] As shown in Figure 17, the transmittance was high over a relatively wide frequency range, as indicated by the characteristic line Q1 (solid). The characteristic line Q0 (dashed line) shows the transmittance versus frequency characteristic when radio waves are incident on the radio wave incident surface 210 of the Low-E double glazing 200 without the radio wave transmission control device 10 (multilayer dielectric material 15). These simulation results (Figure 17) confirmed that attaching the radio wave transmission control device 10 (including the tilted multilayer dielectric material 15) to the radio wave incident surface 210 of the Low-E double glazing 200 can improve the radio wave transmittance in a certain frequency band. Furthermore, tilting the multilayer dielectric material 15 in the predetermined direction y to change the gap (gap width) G between the back surface of the multilayer dielectric material 15 and the radio wave incident surface 210 of the Low-E double glazing 200 in the predetermined direction y can achieve high radio wave transmittance over a wider frequency range (at least 3.7 GHz to 4.1 GHz). The reason for this is the same as that mentioned above, and is presumed to be due to the fact that the conditions of the incident radio waves, reflected radio waves, and transmitted radio waves in the system S including the radio wave transmission control device 10 (multilayer dielectric material 15) and the Low-E double-glazing 200 (structure) change in the y direction in accordance with the change in the distance (gap width) G in the y direction between the multilayer dielectric material 15 and the Low-E double-glazing 200.

[0069] Next, a radio wave transmission control device according to a third embodiment of the present invention will be described.

[0070] The radio wave transmission control device 10 according to the third embodiment of the present invention is configured as shown in FIG.

[0071] 18, the radio wave transmission control device 10 includes a multi-layer dielectric material 17 and a holding frame 16 (holding portion) that holds the multi-layer dielectric material 17 so as to face the radio wave incident surface 110 of the window glass 100. The multi-layer dielectric material 17 has a structure in which a first dielectric plate 171 and a second dielectric plate 172 are stacked while maintaining a certain distance between them by a spacer frame 173. Each of the first dielectric plate 171 and the second dielectric plate 172 has a predetermined dielectric constant ε.

[0072] In the multi-layer dielectric material 17, the spacer frame 173 separates the first dielectric plate 171 and the second dielectric plate 172 so that the second dielectric plate 172 is inclined relative to the first dielectric plate 171 in the direction y. As a result, the distance between the first dielectric plate 171 and the second dielectric plate 172 varies uniformly in the direction y from a maximum distance (maximum gap width) G1 to a minimum distance (minimum gap width) G2. The holding frame 16 holds the multi-layer dielectric material 17 so that the first dielectric plate 171 of the multi-layer dielectric material 17 is parallel to the radio wave incident surface 110 of the window glass 100.

[0073] In the radio wave transmission control device 10 having such a structure, similar to the radio wave transmission control device 10 according to the second embodiment of the present invention shown in Fig. 10, the path lengths of the incident radio waves and the reflected radio waves in a system including the window glass 100 and the multi-layered dielectric material 17 vary at each position in the direction y depending on the interval (gap width) G that varies in the direction y. From this, it is presumed that the transmittance through the window glass 100 of radio waves of a frequency that corresponds to the interval G between the multi-layered dielectric material 17 and the window glass 100 at each position in the direction y of the multi-layered dielectric material 17 increases. It is therefore considered that a high radio wave transmittance can be obtained over a relatively wide frequency range.

[0074] The multi-layer dielectric material 17 having the above-described structure can also be held as shown in Fig. 19 (variant example). In this case, the holding frame 19 that holds the multi-layer dielectric material 17 holds the multi-layer dielectric material 17 so that the second dielectric plate 172, not the first dielectric plate 171, is parallel to the radio wave incident surface 110 of the window glass 100.

[0075] In this case, as in the third embodiment (FIG. 18), in a system including the window glass 100 and the multi-layered dielectric material 17, the path lengths of the incident radio waves and the reflected radio waves differ at each position in the y direction in accordance with the space (gap width) G between the multi-layered dielectric material 17 and the window glass 100, which changes in the y direction. From this, it is presumed that the transmittance through the window glass 100 of radio waves of a frequency corresponding to the gap G between the multi-layered dielectric material 17 and the window glass 100 at each position in the y direction of the multi-layered dielectric material 17 increases. It is therefore considered that high radio wave transmittance can be obtained over a relatively wide frequency range.

[0076] Although the dielectric plate 11 and the multilayer dielectric materials 15 and 17 have been described as the dielectric materials constituting the radio wave transmission control device 10, the present invention is not limited to these and any dielectric material having a certain surface area may be used. For example, a dielectric plate 20 having an air gap AG formed therein as shown in FIG. 20 may be used (a dielectric material may exist in this air gap AG). The dielectric constant ε of a dielectric material may affect the transmittance of radio waves. For example, as shown in FIG. 21, by forming one or more through holes 31 in a dielectric plate 30 (dielectric material), the dielectric constant ε of the dielectric plate 30 can be adjusted to an appropriate value.

[0077] 16, 18, and 19, another dielectric material may be provided between the first dielectric plates 151, 171 and the second dielectric plates 152, 172 of the multi-layer dielectric materials 15, 17. Also, another dielectric material may be provided between the multi-layer dielectric materials 15, 17 and the structure (Low-E double glazing 200, window glass 100).

[0078] In the above-described examples, the radio wave transmission control device 10 is attached to the radio wave incident surface (110, 210) of the dielectric objective (window glass 100, Low-E double glazing 200), but this is not limiting. The radio wave transmission control device 10 may be attached to the surface of the dielectric objective (window glass 100, Low-E double glazing 200) on the radio wave exit side (for example, the surface of the window glass 100 opposite the radio wave incident surface 110), or the radio wave transmission control device 10 may be attached to each of the radio wave incident surface and the radio wave exit surface of the dielectric objective.

[0079] Furthermore, in each of the above-mentioned examples, the outer shape of the dielectric objective (window glass 100, Low-E double glazing 200) was rectangular, but this is not limited to this, and the outer shape may be any shape having a certain surface area.

[0080] The above describes embodiments and modifications of the present invention, but these embodiments and modifications of each part are presented as examples and are not intended to limit the scope of the invention. These novel embodiments described above can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and modifications are included within the scope and spirit of the invention, and are also included in the invention described in the claims. [Industrial Applicability]

[0081] The radio wave transmission control device according to the present invention has the characteristic of having a wider frequency bandwidth in which the transmittance of radio waves can be improved, and is useful as a radio wave transmission control device to be attached to a structure. [Explanation of symbols]

[0082] 10 Radio wave transmission control device 11 Dielectric plate 12 Guide frame 13 Holding body 13a, 13b Advancement / retraction mechanism 131a, 131b Movable parts 15 Multilayer dielectric material 151 First dielectric plate 152 Second dielectric plate 153 Spacer frame 16, 19 Retaining frame 17 Multilayer dielectric material 171 First dielectric plate 172 Second dielectric plate 173 Spacer frame 18 Dielectric materials 100 Window Glass 110 Radio wave incidence surface 200 Low-E double glazing 210 Radio wave incidence surface

Claims

1. A radio wave transmission control device attached to a structure, a dielectric object having a certain surface area; a holding portion that holds the dielectric object so as to face the structure, The holder is A radio wave transmission control device including an adjustment mechanism for adjusting the gap between the dielectric material and the structure.

2. A radio wave transmission control device attached to a structure, a dielectric object having a certain area; a holding portion that holds the dielectric object so as to face the structure, The holding portion is A radio wave transmission control device having a structure that holds the dielectric material in a state where the distance between the dielectric material and the structure changes in a predetermined direction.

3. 3. The radio wave transmission control device according to claim 1, wherein the dielectric material is a dielectric plate.

4. 3. The radio wave transmission control device according to claim 1, wherein the dielectric material is a multi-layer dielectric material having a structure in which a plurality of dielectric layers, each having a certain surface area, are stacked at certain intervals.

5. A radio wave transmission control device attached to a structure, a multi-layer dielectric body in which a plurality of dielectric layers, each having a certain surface area, are stacked at intervals; a holding portion that holds the multi-layer dielectric material so as to face the structure, The multi-layer dielectric material has a structure in which the distance between one dielectric layer and another dielectric layer adjacent to the first dielectric layer changes in a predetermined direction.

6. The radio wave transmission control device according to claim 1, 2 or 5, which is attached to a window glass as the structure.

7. 6. The radio wave transmission control device according to claim 1, 2 or 5, which is attached to a double-glazed window glass as the structure, the double-glazed window glass having a structure in which a plurality of glass sheets are stacked with gaps therebetween and a metal foil layer is formed on the surface of any one of the plurality of glass sheets.

Images