Waveband electromagnetic wave absorber and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-9929475-B2
Application number	US-201113697043-A
Country	US
Kind code	B2
Filing date	May 9, 2011
Priority date	May 10, 2010
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

Provided is a wideband electromagnetic wave (EMW) absorber including a magnetic composite having a structure in which magnetic particles are dispersed in a polymer resin, and a plurality of conductive lines arranged in the magnetic composite, and a method of manufacturing the same. The wideband EMW absorber can be used for a device configured to emit EMWs and effectively absorb wideband EMWs.

First claim

The invention claimed is:

1. A system comprising:
a wideband electromagnetic wave (EMW) absorber and a signal line of a device configured to emit EMWs,
the wideband electromagnetic wave (EMW) absorber, which is located on, under, or both on and under the signal line of the device configured to emit EMWs, the EMW absorber comprising a magnetic composite in which magnetic particles are dispersed in a polymer resin; and a plurality of conductive lines arranged in the magnetic composite,
wherein the conductive lines comprise a first plurality of conductive lines periodically arranged at predetermined intervals in a first direction, and a second plurality of conductive lines periodically arranged at at least one predetermined interval in a second direction,
the first plurality of conductive lines arranged in the first direction and the second plurality of conductive lines arranged in the second direction forming a lattice grid, the first plurality of conductive lines arranged in the first direction are arranged parallel to the signal line of the device configured to emit EMWs, the predetermined interval at which the first plurality of conductive lines are arranged in the first direction is equal to the linewidth of the signal line,
the magnetic particles are present at a concentration of about 3 to 80 parts by weight based on 100 parts by weight polymer resin, the magnetic particles comprise particles of at least one kind of carbon-based conductor selected from the group consisting of carbon nanotubes (CNTs), carbon nanofibers (CNFs), carbon black, carbon fiber, and graphene, which are coated with a magnetic body,
a resonant frequency of the magnetic composite is determined by controlling the size and shape of the magnetic particles, the magnetic particles comprise a plurality of magnetic particles having different resonant frequencies, and EMWs are absorbed in a frequency band equal to or higher than the resonant frequency of the magnetic composite.

2. The system of claim 1 , wherein the predetermined interval between the first plurality of conductive lines arranged in the first direction is equal to the interval between the second plurality of conductive lines arranged in the second direction.

3. The system of claim 1 , wherein the first and second pluralities of conductive lines are arranged in a central portion between upper and lower portions of the magnetic composite.

4. The system of claim 1 , wherein the first and second pluralities of conductive lines are formed of a magnetic conductor selected from the group consisting of an iron (Fe)-based metal, a cobalt (Co)-based metal, a nickel (Ni)-based metal, a molybdenum (Mo)-based metal, a manganese (Mn)-based metal, a neodymium (Nd)-based metal and an alloy thereof.

5. The system of claim 1 , wherein the first and second pluralities of conductive lines are formed of a non-magnetic conductor selected from the group consisting of a gold (Au)-based metal, a silver (Ag)-based metal, a copper (Cu)-based metal, an aluminum (Al)-based metal, a platinum (Pt)-based metal, a palladium (Pd)-based metal and an alloy thereof.

6. The system of claim 1 , wherein the conductive lines are formed of at least one kind of carbon-based conductor selected from the group consisting of carbon nanotubes (CNTs), carbon nanofibers (CNFs), carbon black, carbon fibers, and graphene.

7. The system of claim 1 , wherein the magnetic particles are provided in a variety of shapes.

8. The system of claim 1 , wherein at least one kind of carbon-based conductor selected from the group consisting of carbon nanotubes (CNTs), carbon nanofibers (CNFs), carbon black, carbon fibers and graphene is dispersed in the polymer resin in a concentration ranging from 0.01 to 70%, based on the total weight of the magnetic composite.

9. The system of claim 1 , wherein the polymer resin comprises a thermoplastic or thermosetting resin.

10. The system of claim 1 , wherein the magnetic particles comprise at least one ferrite-based oxide.

11. The system of claim 10 , wherein the ferrite-based oxide comprises at least one of a spinel ferrite and a hexagonal ferrite.

12. The system of claim 11 , wherein the spinel ferrite comprises at least one of a spinel-structured ferrite containing a nickel-zinc (Ni—Zn) ferrite, a manganese-zinc (Mn—Zn) ferrite and a copper-zinc (Cu—Zn) ferrite, and
the hexagonal ferrite comprises a hexagonal-structured ferrite comprising at least one of a barium (Ba) ferrite and a strontium (Sr) ferrite.

Assignees

• Lee Sang Kwan
• Lee Sang Bok
• Kim Ki Hyeon
• Choa Yong Ho
• Oh Sung Tag
• Korea Inst Mach & Materials

Inventors

• Lee Sang-Kwan
• Lee Sang-Bok
• Kim Ki Hyeon
• Choa Yong-Ho
• Oh Sung-Tag

Classifications

• H01Q17/004 Primary

  using non-directional dissipative particles, e.g. ferrite powders (H01Q17/005 takes precedence; flake-like H01Q17/002) · CPC title

• Y10T29/49117

  Conductor or circuit manufacturing · CPC title

• H01Q17/002

  using short elongated elements as dissipative material, e.g. metallic threads or flake-like particles · CPC title

• H05K9/0083

  comprising electro-conductive non-fibrous particles embedded in an electrically insulating supporting structure, e.g. powder, flakes, whiskers (H05K9/0086 takes precedence) · CPC title

• H05K9/0086

  comprising a single discontinuous metallic layer on an electrically insulating supporting structure, e.g. metal grid, perforated metal foil, film, aggregated flakes, sintering · CPC title