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JP-7856319-B2 - Electromagnetic wave shielding structure

JP7856319B2JP 7856319 B2JP7856319 B2JP 7856319B2JP-7856319-B2

Inventors

  • 苫米地 英人

Assignees

  • コグニティブリサーチラボ株式会社

Dates

Publication Date
20260511
Application Date
20231018

Claims (20)

  1. A first component made of a first material which is a conductor, A second member comprising a second material having a conductivity lower than that of the first material and higher corrosion resistance than that of the first material, An electromagnetic wave shielding structure comprising, The second member covers at least a portion of the surface of the first member. An electromagnetic wave shielding structure wherein at least one of the surface of the first member on the side in contact with the second member and the outer surface of the second member has irregularities formed on it for diffusely reflecting external electromagnetic waves that are to be shielded by the electromagnetic wave shielding structure, and the height or depth of the irregularities is 1/10 to 1/50 of the wavelength of the external electromagnetic waves.
  2. The first member has a first surface exposed to electromagnetic waves and a second surface located on the opposite side of the first surface. The electromagnetic wave shielding structure according to claim 1, characterized in that the second member covers at least the first surface among the first and second surfaces.
  3. The electromagnetic wave shielding structure according to claim 2, characterized in that at least the second member of the first member and the second member has a mesh structure.
  4. The electromagnetic wave shielding structure according to claim 2, characterized in that the second member consists of at least two auxiliary mesh members having mutually different mesh patterns, and the auxiliary mesh members are stacked to cover the first member.
  5. The second member has a first surface that covers the surface of the first member, and a second surface located on the opposite side of the first surface. The electromagnetic wave shielding structure according to claim 2, characterized in that the surface of the second surface has irregularities formed on it, or the second surface is formed in a corrugated shape.
  6. The electromagnetic wave shielding structure according to claim 1, characterized in that the first member is rod-shaped or linear, and the second member covers the outer circumferential surface of the first member.
  7. The electromagnetic wave shielding structure according to claim 1, characterized in that the first material is gold, silver, or copper.
  8. The electromagnetic wave shielding structure according to claim 1, characterized in that the second material is stainless steel or titanium.
  9. The electromagnetic wave shielding structure according to claim 1, characterized in that the second material has the property of transmitting electromagnetic waves rather than reflecting them.
  10. The electromagnetic wave shielding structure according to claim 9, characterized in that the second material is glass or resin.
  11. The electromagnetic wave shielding structure according to claim 1, characterized in that the first member has irregularities formed on the surface in contact with the second member, forming a mesh structure, or the surface in contact with the second member is curved.
  12. The electromagnetic wave shielding structure according to claim 11, characterized in that the second material is a resin.
  13. The electromagnetic wave shielding structure according to claim 1, further comprising a grounding wire for grounding the first component.
  14. The electromagnetic wave shielding structure is configured as a flat panel, and each side of the panel has protrusions and recesses formed within the same plane as the panel to enable connection with adjacent panels, as described in claim 1.
  15. An electromagnetic wave shielding system installed in a driving lane where an ETC (Electronic Toll Collection) system is installed, The electromagnetic wave shielding system includes an electromagnetic wave shielding body formed between the driving lane and a second driving lane adjacent to the driving lane. The electromagnetic wave shielding body prevents radio waves emitted from the roadside antenna installed in the second driving lane, which are reflected off vehicles traveling in the second driving lane, from reaching the roadside antenna in the driving lane. An electromagnetic wave shielding system wherein the electromagnetic wave shielding body consists of an electromagnetic wave shielding structure according to any one of claims 1 to 14 .
  16. The electromagnetic wave shielding system according to claim 15 , characterized in that the electromagnetic wave shield has a length of at least the length of one large vehicle.
  17. The electromagnetic wave shielding system according to claim 15 , characterized in that the electromagnetic wave shielding body consists of a wall-like structure.
  18. The electromagnetic wave shielding system according to claim 17 , characterized in that the height of the wall-like structure is set higher than the height of the roadside antenna that transmits radio waves to vehicles traveling in the travel lane.
  19. The electromagnetic wave shielding system according to claim 17 , characterized in that the wall-like structure has a length along the driving lane that includes at least the roadside antenna of the driving lane between them.
  20. The electromagnetic wave shielding system according to claim 15 , characterized in that the electromagnetic wave shielding body is a tunnel-shaped structure covering the driving lane.

Description

This invention relates to an electromagnetic wave shielding structure that blocks the passage of electromagnetic waves, and further to an electromagnetic wave shielding system that utilizes this electromagnetic wave shielding structure. This electromagnetic wave shielding structure serves as the material for a Faraday cage. In recent years, many problems have arisen that are caused by electromagnetic waves (external electromagnetic waves). For example, electromagnetic noise generated from various devices can cause malfunctions in electronic equipment. Given the current international situation, the risk of an EMP (Electromagnetic Pulse) attack cannot be ignored. In most cases, electronic devices become unusable when subjected to an EMP attack. Recently, malfunctions of ETC (Electronic Toll Collection System) systems at toll booths on toll roads have become a concern. Specifically, the problem is that when large vehicles pass through ETC lanes in succession, the system may not be able to accurately determine the passage of those vehicles. This is presumed to be caused by unintended reflection of radio waves. Furthermore, it is necessary to block electromagnetic waves leaking from electronic devices. This is because if leaked electromagnetic waves are detected and analyzed, it could lead to information leaks. For this reason, many countermeasures against electromagnetic waves have been proposed. One method of protection against electromagnetic waves is the Faraday cage, which has been well-known for some time. A Faraday cage refers to a container or cage made of conductive material, or the space enclosed by such a container or cage. Since electric field lines cannot penetrate the internal space surrounded by conductors, the electric field from the outside is shielded. Specifically, within the space, charges are rearranged to cancel out the electric field from the outside, so the electric field becomes zero. For example, Japanese Patent Publication No. 9-257948 and Japanese Patent Publication No. 62-36565 describe examples of the use of a Faraday cage. Japanese Patent Application Publication No. 9-257948Japanese Patent Application Publication No. 62-36565 This is a perspective view of an electromagnetic wave shielding structure according to a first embodiment of the present invention.This is a plan view of the first modified example of the second component constituting the electromagnetic wave shielding structure.This is a plan view of a second modified example of the second component constituting the electromagnetic wave shielding structure.Figure 4(A) is a plan view of a third modified example of the second member constituting the electromagnetic wave shielding structure, and Figure 4(B) is a side view thereof.This is a perspective view of an electromagnetic wave shielding structure according to a second embodiment of the present invention.This is a perspective view of an electromagnetic wave shielding structure according to a third embodiment of the present invention.This is a plan view of an electromagnetic wave shielding structure according to a fourth embodiment of the present invention.This is a cross-sectional view of the first member according to the first example of the fifth embodiment of the present invention.This is a cross-sectional view of the first member according to the second example of the fifth embodiment of the present invention.This is a perspective view showing an overview of a toll booth on a toll road equipped with ETC (Electronic Toll Collection).This is a front view of a first example of an electromagnetic wave shielding system according to a sixth embodiment of the present invention.This is a front view of a second example of an electromagnetic wave shielding system according to the sixth embodiment of the present invention.This is a schematic diagram, viewed from the side, showing the positional relationship between a roadside antenna, a moving vehicle, and a following vehicle in an electromagnetic wave shielding system according to the seventh embodiment of the present invention.This is a schematic diagram viewed from above, similar to Figure 13. (First embodiment) Figure 1 is a perspective view of an electromagnetic wave shielding structure 100 according to a first embodiment of the present invention. The electromagnetic wave shielding structure 100 is composed of a first member 110 made of a first material, a second member 120 made of a second material, and a grounding wire 130 for grounding the first member 110. The first component 110 has a cubic shape. The first material constituting the first component 110 is a conductor. For example, the first material is a metal, more specifically, a highly conductive metal such as gold, silver, or copper. The second member 120 is a flat plate with a constant thickness. The second material constituting the second component 120 is made of a material having a conductivity lower than that of the first material and higher corrosion resistance