US-12627068-B2 - Radio wave control system

Abstract

A radio wave control system includes a phase adjustment plate that transmits a radio wave from a second main surface to a first main surface and focuses the radio wave on a focal point; and a reflection plate installed at a position irradiated with the radio wave transmitted through the phase adjustment plate.

Inventors

• Akira Kumagai
• Keisuke Arai
• Osamu Kagaya
• Yasuo Morimoto

Assignees

• AGC Inc.

Dates

Publication Date

20260512

Application Date

20240111

Priority Date

20210719

Claims (13)

1. 1 . A radio wave control system comprising: a phase adjustment plate that transmits a radio wave from a second main surface to a first main surface and focuses the radio wave on a focal point; and a reflection plate installed at a position irradiated with the radio wave transmitted through the phase adjustment plate, the reflection plate is installed at a position satisfying ( P×S )/( P 0× S 0)>1, where P is a value obtained by integrating power of the radio wave transmitted through the phase adjustment plate on the reflection plate, S is an area of a half-power plane on the reflection plate, P0 is a value obtained by integrating power of the radio wave transmitted through the phase adjustment plate on the reflection plate in a case where the phase adjustment plate is not provided, and S0 is an area of a half-power plane on the reflection plate in the case where the phase adjustment plate is not provided, and wherein the reflection plate is disposed at a position separated from the focal point of the phase adjustment plate by 7% or more of a focal length of the phase adjustment plate.
2. 2 . The radio wave control system according to claim 1 , wherein the reflection plate is installed at a position where a power integral value of the radio wave on the reflection plate is larger than the power integral value of the radio wave on the reflection plate when the phase adjustment plate is not provided.
3. 3 . The radio wave control system according to claim 1 , wherein in an electric power distribution of the radio wave on the reflection plate, an area of a region in which an electric power is more than or equal to a half-value of a maximum electric power is 50% or more of an area of the reflection plate.
4. 4 . The radio wave control system according to claim 1 , wherein the reflection plate is disposed at a position other than the focal point of the phase adjustment plate, and the position other than the focal point is a position where an electric field intensity is less than 80% of a maximum value of the electric field intensity on an axis passing through a center of the phase adjustment plate and the focal point.
5. 5 . The radio wave control system according to claim 1 , wherein the reflection plate is installed at a position satisfying Ave[|E|]/Ave[|E f |]>1, where Ave[|E|] is a value obtained by averaging absolute values of electric field intensities of radio waves transmitted through the phase adjustment plate on the reflection plate, and Ave[|E f |] is a value obtained by averaging absolute values of electric field intensities of radio waves on the reflection plate when the reflection plate is placed at the focal point.
6. 6 . The radio wave control system according to claim 5 , wherein within a region on the reflection plate irradiated with the radio wave transmitted through the phase adjustment plate, a region, in which an electric power in an electric power distribution of the radio wave is more than or equal to a half-value of a maximum electric power, is a continuous region without a hole.
7. 7 . The radio wave control system according to claim 1 , wherein reflection phase on a reflection surface of the reflection plate is changed for each location on the surface.
8. 8 . The radio wave control system according to claim 1 , wherein the reflection plate is a reflection plate that reflects the radio wave at an angle other than specular reflection.
9. 9 . The radio wave control system according to claim 1 , wherein a reflection angle of the reflection plate is electrically changeable.
10. 10 . The radio wave control system according to claim 1 , wherein the reflection plate is installed on a wall or a ceiling.
11. 11 . The radio wave control system according to claim 1 , wherein the phase adjustment plate and the reflection plate are provided in one case.
12. 12 . The radio wave control system according to claim 1 , wherein the reflection plate has a quadrangle shape in which one side is 10λ or more and 40λ or less, λ being a wavelength of radio waves in air, or the reflection plate has a circular shape in which a diameter is 10λ or more and 50λ or less.
13. 13 . The radio wave control system according to claim 1 , wherein a frequency band of the radio waves is 1 GHz to 300 GHz.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application is a continuation application of International Application No. PCT/JP2022/027614, filed Jul. 13, 2022, which claims priority to Japanese Patent Application No. 2021-119125 filed Jul. 19, 2021. The contents of these applications are incorporated herein by reference in their entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave control system for controlling radio waves for wireless communication. 2. Description of the Related Art Conventionally, there has been known a configuration in which an antenna or a bundled body is provided outdoors or on a window in order to improve reception performance of radio waves indoors. For example, Japanese unexamined patent application publication No. 2002-237717 proposes an antenna device in which a bundled body is provided on an indoor side of a window to concentrate radio waves, thereby improving reception performance of radio waves indoors. SUMMARY OF THE INVENTION Problems to be Solved by the Invention In the bundled body described in Japanese unexamined patent application publication No. 2002-237717, electric power can be concentrated at an indoor focal point, but there is no effect of concentrating radio waves at places other than the indoor focal point. Therefore, when an electronic device such as a smartphone or a laptop computer is used indoors at different positions or plural electronic devices are used at plural positions at the same time, the reception performance of the electronic devices may deteriorate. The present disclosure provides a radio wave control system capable of improving radio wave intensity in a wide range. Means for Solving the Problem According to an aspect of the present disclosure, a radio wave control system including a phase adjustment plate that transmits a radio wave from a second main surface to a first main surface and focuses the radio wave on a focal point; and a reflection plate installed at a position irradiated with the radio wave transmitted through the phase adjustment plate, is provided. Effects of the Invention According to the present disclosure, it is possible to improve radio wave intensity in a wide range in a radio wave control system. BRIEF DESCRIPTION OF THE DRAWINGS Other objects and further features of the present disclosure will be apparent from the following detailed description when read in conjunction with the accompanying drawings, in which: FIG. 1 is a diagram schematically illustrating a radio wave control system according to a first embodiment of the present invention; FIG. 2 is a cross-sectional view of a glass plate with a phase adjustment plate according to the first embodiment; FIG. 3 is a diagram for explaining an operation principle of the radio wave control system according to the first embodiment; FIG. 4 is a diagram showing an example of a conductive pattern provided on the phase adjustment plate according to the first embodiment; FIG. 5 is a diagram schematically illustrating a reflection angle when the reflection plate of the present invention is a reflect array; FIG. 6 is a diagram for explaining a mechanism for adjusting a reflection angle in each cell of the reflect array on which a radio wave transmitted through the phase adjustment plate is incident; FIG. 7 is a schematic block diagram of the radio wave control system according to the first embodiment; FIG. 8 is a diagram of a calculation model for simulating an electric field of a radio wave transmitted through the phase adjustment plate; FIG. 9 is a diagram showing an electric field intensity and a phase of the radio wave transmitted through the phase adjustment plate for each distance from the phase adjustment plate; FIG. 10 is a diagram schematically illustrating how the electric field of the radio wave transmitted through the phase adjustment plate spreads on the reflection plate; FIG. 11 is a diagram showing a power integral value and a half-power diameter for each distance from the phase adjustment plate; FIG. 12 is a diagram showing a ratio (P×S)/(P0×S0) of a product of the power integral value on the reflection plate and an area of the half-power plane on the reflection plate with the phase adjustment plate being present to a product of the power integral value on the reflection plate and an area of the half-power plane on the reflection plate without the phase adjustment plate, for each distance from the phase adjustment plate; FIG. 13 is a table showing the theoretical formula of a power reflected from the reflection plate; FIG. 14 is a diagram of a calculation model for simulating an electric field spreading from the reflection plate of the present invention; FIG. 15 is a radar chart showing an electric field intensity at a peripheral radius of 1 m around the reflection plate when the reflection plate is provided at a focal point of the phase adjustment plate in the calculation model of FIG. 14; FIG. 16 is a radar c