公开(公告)号：US20230129032A1

公开(公告)日：2023-04-27

申请号：US17915273

申请日：2021-03-02

Applicant: NITTO DENKO CORPORATION

Inventor： Koji SAKAMOTO ,  Takahiko ITO ,  Naoto OE

IPC: C08J5/18 ,  G01S7/02

Abstract: A resin sheet includes the porous structure. The porous structure is configured to adjust transmission of a millimeter wave. The porous structure has a relative permittivity varying in a thickness direction of the resin sheet such that a difference between average relative permittivities in two adjacent layer portions is a predetermined value or less, the layer portions each having a particular thickness smaller than a wavelength of the millimeter wave. The porous structure includes a boundary portion being one of the layer portions, the boundary portion having a maximum average relative permittivity. The relative permittivity increases in stages from end portions of the porous structure toward the boundary portion, the end portions being defined in the thickness direction of the resin sheet.

公开(公告)号：US20230140996A1

公开(公告)日：2023-05-11

申请号：US17915317

申请日：2021-02-25

Applicant: NITTO DENKO CORPORATION

Inventor： Koji SAKAMOTO ,  Takahiko ITO ,  Naoki NAGAOKA ,  Shu SASAKI ,  Daiki KATO

IPC: B32B5/18 ,  B32B27/08 ,  B32B27/32 ,  B32B25/08 ,  B32B27/34

CPC classification number: B32B5/18 ,  B32B27/08 ,  B32B27/32 ,  B32B25/08 ,  B32B27/34 ,  B32B2266/025 ,  B32B2266/0257 ,  B32B2250/04 ,  B32B2250/24 ,  B32B2250/22 ,  B32B2307/206 ,  B32B2305/026 ,  B32B2266/104 ,  B32B2457/00

Abstract: A resin sheet includes a porous structure. The porous structure is configured to adjust transmission of a millimeter wave. The porous structure has a relative permittivity varying in stages in a thickness direction of the resin sheet from a plane on which the millimeter wave is incident, the relative permittivity varying such that a difference between average relative permittivities in two adjacent layer portions is a predetermined value or less, the layer portions each having a particular thickness smaller than a wavelength of the millimeter wave. The porous structure has, as pores, only pores each having a pore diameter equal to or less than 10% of the wavelength of the millimeter wave.