Electromagnetic wave absorption sheet
US-2020267877-A1 · Aug 20, 2020 · US
Electromagnetic wave absorber
US12176131B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-12176131-B2 |
| Application number | US-201915734714-A |
| Country | US |
| Kind code | B2 |
| Filing date | May 31, 2019 |
| Priority date | Jun 4, 2018 |
| Publication date | Dec 24, 2024 |
| Grant date | Dec 24, 2024 |
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- Title
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Abstract
Official abstract text for this publication.
To provide a transmission-type electromagnetic-wave absorber that can satisfactorily absorb electromagnetic waves of high frequencies in or above the millimeter wave band while reducing the reflection of electromagnetic waves on the surface of the absorber. The transmission-type electromagnetic-wave absorber includes an electromagnetic-wave absorbing layer 1 containing a magnetic iron oxide 1 a that magnetically resonates at a frequency in or above the millimeter-wave band and a binder 1 b containing an organic material. The real part of the complex relative permittivity of the electromagnetic-wave absorber is 5.5 or less at 1 GHz.
First claim
Opening claim text (preview).
The invention claimed is: 1. A transmission-type electromagnetic-wave absorber, comprising: an electromagnetic-wave absorbing layer comprising a magnetic iron oxide that magnetically resonates at a frequency in or above a millimeter-wave band and a binder comprising an organic material, wherein a value of a real part of a complex relative permittivity of the electromagnetic-wave absorber is more than a numerical value of a real part of a complex relative permittivity of the electromagnetic-wave absorber at a volume content of the magnetic iron oxide of 0% and is 5.5 or less at 1 GHz. 2. The electromagnetic-wave absorber according to claim 1 , wherein the real part of the complex relative permittivity of the electromagnetic-wave absorber is 4.2 or less at 1 GHz. 3. The electromagnetic-wave absorber according to claim 1 , wherein the magnetic iron oxide comprises hexagonal ferrite or epsilon magnetic iron oxide. 4. The electromagnetic-wave absorber according to claim 3 , wherein the hexagonal ferrite is strontium ferrite or barium ferrite, and part of a Fe site of the hexagonal ferrite is substituted with a trivalent metal atom. 5. The electromagnetic-wave absorber according to claim 3 , wherein part of a Fe site of the epsilon magnetic iron oxide is substituted with a trivalent metal atom. 6. The electromagnetic-wave absorber according to claim 1 , wherein the binder comprises any of thermosetting rubber, thermoplastic elastomer, or thermoplastic resin. 7. The electromagnetic-wave absorber according to claim 1 , wherein the electromagnetic-wave absorbing layer is in the form of a sheet. 8. The electromagnetic-wave absorber according to claim 1 , wherein the volume content of the magnetic iron oxide contained in the electromagnetic-wave absorbing layer is 3.5% or more.
Assignees
Inventors
Classifications
using short elongated elements as dissipative material, e.g. metallic threads or flake-like particles · CPC title
Electromagnetic shielding materials, e.g. EMI, RFI shielding (H05K9/0003 takes precedence) · CPC title
in a bonding agent · CPC title
- H01F1/348Primary
Hexaferrites with decreased hardness or anisotropy, i.e. with increased permeability in the microwave (GHz) range, e.g. having a hexagonal crystallographic structure · CPC title
comprising electro-conductive non-fibrous particles embedded in an electrically insulating supporting structure, e.g. powder, flakes, whiskers (H05K9/0086 takes precedence) · CPC title
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Frequently asked questions
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- What does patent US12176131B2 cover?
- To provide a transmission-type electromagnetic-wave absorber that can satisfactorily absorb electromagnetic waves of high frequencies in or above the millimeter wave band while reducing the reflection of electromagnetic waves on the surface of the absorber. The transmission-type electromagnetic-wave absorber includes an electromagnetic-wave absorbing layer 1 containing a magnetic iron oxide …
- Who is the assignee on this patent?
- Maxell Ltd
- What technology area does this patent fall under?
- Primary CPC classification H01F1/348. Mapped technology areas include Electricity.
- When was this patent published?
- Publication date Tue Dec 24 2024 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 4 related publications on this page (citations in our corpus or others sharing the same primary CPC).