Title:
ELECTROMAGNETIC WAVE ABSORBER
Document Type and Number:
Japanese Patent JP2021125495
Kind Code:
A
Abstract:
To provide an electromagnetic wave absorber capable of satisfactorily absorbing electric waves of a millimeter wave region without reflection so as to suitably cope with millimeter wave communications for a 5-th generation wireless communication system (5G), a collision-preventing radar of a motor vehicle, or the like.SOLUTION: An electromagnetic wave absorber according to the present invention comprises: an electric wave absorber layer; a spacer; and a reflection layer. The electric wave absorber layer includes: a first electric wave-absorbing sheet and a second electric wave-absorbing sheet. The first and second electric wave-absorbing sheets are adjacent to each other. Each electric wave-absorbing sheet contains a first component and a second component. The first component consists of a fiber of 2.0 Ωcm or less in specific resistance. The content of the first component in each electric wave-absorbing sheet is 0.05-0.3 mass%. The second component is 1.0×108 Ωcm or more in specific resistance. The content of the second component in each electric wave-absorbing sheet is 50-99.9 mass%. The first and second electric wave-absorbing sheets are laminated so that the ratio (εRa/εRb) of a dielectric constant (εRa) in a direction where the electric wave absorber layer takes the maximum dielectric constant, and a dielectric constant (εRb) in a direction perpendicular to the direction where the electric wave absorber layer shows the maximum dielectric constant falls in a range of 1.0-1.3.SELECTED DRAWING: None
Inventors:
KARASAKI HIDEAKI
TAKANO TOMOKO
OMORI TAIRA
TAKANO TOMOKO
OMORI TAIRA
Application Number:
JP2020015992A
Publication Date:
August 30, 2021
Filing Date:
February 03, 2020
Export Citation:
Assignee:
TORAY INDUSTRIES
International Classes:
H05K9/00; H01Q17/00