CN111081417A - Flexible electromagnetic wave-absorbing material - Google Patents
Flexible electromagnetic wave-absorbing material Download PDFInfo
- Publication number
- CN111081417A CN111081417A CN201911264291.4A CN201911264291A CN111081417A CN 111081417 A CN111081417 A CN 111081417A CN 201911264291 A CN201911264291 A CN 201911264291A CN 111081417 A CN111081417 A CN 111081417A
- Authority
- CN
- China
- Prior art keywords
- component
- electromagnetic wave
- shielding
- flexible
- wave
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0073—Shielding materials
- H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J7/00—Adhesives in the form of films or foils
- C09J7/20—Adhesives in the form of films or foils characterised by their carriers
- C09J7/22—Plastics; Metallised plastics
- C09J7/25—Plastics; Metallised plastics based on macromolecular compounds obtained otherwise than by reactions involving only carbon-to-carbon unsaturated bonds
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B11/00—Communication cables or conductors
- H01B11/02—Cables with twisted pairs or quads
- H01B11/06—Cables with twisted pairs or quads with means for reducing effects of electromagnetic or electrostatic disturbances, e.g. screens
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/04—Flexible cables, conductors, or cords, e.g. trailing cables
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
- H01B7/18—Protection against damage caused by wear, mechanical force or pressure; Sheaths; Armouring
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/01—Magnetic additives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/34—Silicon-containing compounds
- C08K3/36—Silica
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2301/00—Additional features of adhesives in the form of films or foils
- C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
- C09J2301/12—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers
- C09J2301/122—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present only on one side of the carrier, e.g. single-sided adhesive tape
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2301/00—Additional features of adhesives in the form of films or foils
- C09J2301/40—Additional features of adhesives in the form of films or foils characterized by the presence of essential components
- C09J2301/41—Additional features of adhesives in the form of films or foils characterized by the presence of essential components additives as essential feature of the carrier layer
Abstract
The invention relates to a flexible electromagnetic wave-absorbing material, which is a composite material mainly used in the field of electromagnetic shielding and shielding, and comprises a component A and a component B, wherein the component A is used as a base material of the composite material, and the component B is uniformly mixed and distributed in the component A, wherein: the component A takes a base material of POLYURETHANE ELASTOMER (POLYURETHANE ELASTOMER) as a continuous phase; and the component B is mixed with a High Permeability magnetic material (High Permeability Powder) as a disperse phase; and the mass ratio of the component A to the component B can be adjusted according to different electromagnetic frequency band values, so as to realize electromagnetic shielding of different bands. Compared with the existing shielding material, the wave-absorbing material has the technical advantages of low cost, simple manufacturing process, suitability for coating shielding of materials with different shapes and the like, and particularly has the technical advantage of adapting to the requirements of different shielding wave bands by adjusting the mass ratio.
Description
Technical Field
The invention relates to the field of electronic materials, in particular to a novel flexible electromagnetic wave-absorbing material which is low in cost, simple in manufacturing process, suitable for coating shielding flexible sheet materials of different products and capable of meeting requirements of different shielding wave bands by adjusting the mass ratio of components.
Background
A wave-absorbing material refers to a material that absorbs or substantially attenuates electromagnetic wave energy incident on its surface, thereby reducing electromagnetic wave interference. The electromagnetic radiation causes direct and indirect damage to human bodies through thermal effect, non-thermal effect and cumulative effect, and interferes with the operation of electronic equipment and the transmission of communication to influence the normal work of the electronic equipment. Therefore, how to treat electromagnetic pollution, solve electromagnetic interference, and find a wave-absorbing material capable of resisting and weakening electromagnetic wave radiation has become a major subject of material science.
As for the absorption mechanism of the traditional wave-absorbing material, the traditional wave-absorbing material can be divided into an impedance matching type and a resonant type. Firstly, the typical structure of the impedance matching type wave-absorbing material adopts a cone-shaped wave-absorbing material, the cone structure of the material enables the impedance to have a gradual change process from the bottom end of the wave-absorbing material, but the material has the defects of large thickness and easy cracking. The matching layer wave-absorbing material is based on a conical wave-absorbing material, and the thickness of the material is reduced under the condition of not influencing the wave-absorbing effect. The wave-absorbing material is provided with an impedance matching layer between incidence and absorption. The impedance matching layer has an impedance value between that of air and the absorbing layer. The matching effect is significant when the thickness of the matching layer is λ/4, and thus, its use is limited by the shape of the product. The resonance type wave-absorbing material is also called as a lambda/4 wave-absorbing material by utilizing the interference principle to reduce the reflection of electromagnetic waves and comprises a Dallenbach layer, a Salisbury screen and an Iaumann layer. The impedance of such materials is not matched to air and the material has certain thickness requirements and therefore does not completely absorb all of the electromagnetic energy. In order to research an electromagnetic wave-absorbing material which has shielding function and is suitable for electronic products or scenes, technical personnel design a wave-absorbing material with a composite layered structure according to different wave-absorbing material mechanisms, and the main principle is to stack material layers with different wave-absorbing principles in a layered manner. For example, the chinese patent with the publication number CN 107858115a discloses a patch type wave-absorbing material, that is, the above structure is adopted. Although the composite layer structure is suitable for the traditional shielding material and greatly improves the use limit of the product, the manufacturing process is more complex, the cost of the used material is higher, and the use limit of all products cannot be completely broken through. Thus, the prior art is deficient and is subject to further improvement.
Disclosure of Invention
The invention of the technical scheme aims to: the novel flexible electromagnetic wave-absorbing material is simple in manufacturing process, good in electromagnetic shielding effect, suitable for electromagnetic shielding coating of different products and capable of meeting requirements of different shielding wave bands by adjusting mass ratio.
The invention relates to a flexible electromagnetic wave-absorbing material, which is characterized by comprising a composite material consisting of a component A and a component B, wherein the composite material takes the component A as a base material, and the component B is uniformly mixed and distributed in the component A, wherein the base material of the component A and a POLYURETHANE ELASTOMER (POLYURETHANE ELASTOMER) is a continuous phase; and the component B, a High Permeability magnetic material (High Permeability Powder) is mixed into a disperse phase; and the mass ratio of the component A to the component B can be adjusted according to different electromagnetic frequency band values, so as to realize electromagnetic shielding of different bands.
Preferably, the polyurethane elastomer is an Epoxy resin (Epoxy resin). The epoxy resin is the best base material of the current soft plastic compound, has electric insulation performance, and has good electric insulation performance even if the voltage is high at 1000 volts, so the epoxy resin is suitable for any electronic products.
Preferably, the high permeability magnetic material is a mixture of Ferrite (Ferrite) and Silica (Silica) for consumption of electromagnetic interference sources.
Preferably, the composite material composed of the component A and the component B is prepared by a lamination drying process.
Preferably, the composite material composed of the component A and the component B can be arranged into flexible films in the shapes of sheets, strips, blocks and any combination of the shapes according to customization needs.
Preferably, the thickness of the flexible film is 3.5mm +/-0.25 mm.
Preferably, the surface of the flexible film is uniformly provided with an adhesive layer.
Preferably, the adhesive layer is 3M glue.
The core point of the invention is that a designer can meet the requirements of different shielding wave bands (the wave-absorbing frequency range is from 200Mhz to 12 Ghz) by adjusting the mass component distribution ratio of the shielding material according to the actual requirements of materials such as electronic equipment or communication cables. Meanwhile, the physical characteristics that the base material such as epoxy resin material is soft in texture, strong in plasticity and excellent in insulativity and can bear high voltage below 1000 volts are utilized, and the adaptability of the shielding material is greatly enhanced. Specifically, designers can manufacture films with a certain thickness and coat the films on any electronic equipment and communication cables, so that the film meets the requirements of any shape or space and is suitable for any electronic products.
Advantageous effects
The invention provides a flexible electromagnetic shielding material and provides a brand new design idea of the shielding material, specifically, the shielding material takes a component A as a base material, and the component B is uniformly mixed and distributed in the component A, wherein the component A and the base material of a POLYURETHANE ELASTOMER (POLYURETHANE ELASTOMER) are continuous phases; and the component B is mixed with a High Permeability magnetic material (High Permeability Powder) as a disperse phase; the mass ratio of the component A to the component B can be adjusted according to different electromagnetic frequency band values, so that electromagnetic shielding designers in different bands can meet the requirements of different shielding bands by adjusting the mass component ratio of the shielding material according to the actual requirements of materials such as electronic equipment or communication cables. As can be seen from the above description, the flexible electromagnetic shielding material has the following beneficial effects:
firstly, designers can meet the requirements of different shielding wave bands by adjusting the mass component ratio of the shielding material according to the actual requirements of materials such as electronic equipment or communication cables. Meanwhile, the physical characteristics of soft texture and strong plasticity of base materials such as epoxy resin and the like are utilized, and designers can manufacture the base materials into films with certain thickness to cover any equipment and communication cables, so that the requirements of any shape or space are met.
Secondly, the shielding device has the advantages of low cost, simple manufacturing process, good shielding effect and the like.
Detailed Description
Embodiment 1 provides a flexible electromagnetic wave absorbing material, which includes a composite material composed of a component a and a component B, the composite material uses the component a as a base material, and the component B is uniformly mixed and distributed in the component a, wherein the component a uses an Epoxy resin (Epoxy resin) base material as a continuous phase; the component B is a dispersed phase formed by mixing ferrous salt (Ferrite) and silicon dioxide (Silica); and the mass ratio of the component A to the component B is as follows: 45% of Epoxy resin (Epoxy resin), 44% of Ferrite (Ferrite) and 11% of silicon dioxide (Silica).
Preferably, the polyurethane elastomer is an Epoxy resin (Epoxy resin). The epoxy resin is the best base material of the current soft plastic compound, has electric insulation performance, and has good electric insulation performance even if the voltage is high at 1000 volts, so the epoxy resin is suitable for any electronic products.
Preferably, the high permeability magnetic material is a mixture of Ferrite (Ferrite) and Silica (Silica) for consumption of electromagnetic interference sources.
Preferably, the composite material composed of the component A and the component B is prepared by a lamination drying process.
Preferably, the composite material composed of the component A and the component B can be arranged into flexible films in the shapes of sheets, strips, blocks and any combination of the shapes according to customization needs.
Preferably, the thickness of the flexible film is 3.5mm +/-0.25 mm.
Preferably, the surface of the flexible film is uniformly provided with an adhesive layer.
Preferably, the adhesive layer is 3M glue.
Shielding mechanism of the material: the invention is formed by taking Epoxy resin elastomer (Epoxy elastomer) as a carrier and combining high-grade magnetism and dielectric electromagnetic wave absorbing materials for mixing, refining and mixing, is different from the traditional ferrite magnetic coupling principle and the traditional rigid shielding material, and can be randomly changed in shape, such as: the invention relates to a sheet, strip and block three-dimensional space which can be combined into a required three-dimensional space at will, wherein the film wave-absorbing effect is multiplied as the reflection and scattering results are increased. The invention uses the characteristic principle of electromagnetic wave to continuously consume and shield, so as to achieve the shielding requirement result of continuity and guarantee.
The shielding effect principle of the invention is that the interference source is internally absorbed and converted by the high-grade magnetic and dielectric electromagnetic wave absorbing material of the component B (ferrite + silicon dioxide), and the interference is consumed and lost for a plurality of times and countless times by utilizing the multiple reflection and scattering effect to achieve the shielding effect. The invention uses the characteristic principle of the electromagnetic wave to consume and shield continuously, and further achieves the shielding requirement result of continuity and guarantee, the biggest difference and advantage of the invention and the traditional material are realized, and the mixing process of the invention can perfectly combine the corresponding shielding space adaptability to achieve the working result of simpler construction and higher efficiency.
Test experimental data:
through tests, as shown in table 1, the flexible electromagnetic wave-absorbing film is adjusted according to the component proportion, has the effect in the wave-absorbing frequency range from 200Mhz to 12Ghz, and can be adapted to the requirements of any frequency range in the market.
Table 1:
as various changes could be made in the above without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense, and that all changes which come within the meaning and range of equivalency of the specification are therefore intended to be embraced therein.
Claims (8)
1. The flexible electromagnetic wave-absorbing material is characterized by comprising a composite material consisting of a component A and a component B, wherein the component A is used as a base material, and the component B is uniformly mixed and distributed in the component A, wherein:
the component A, a base material of POLYURETHANE ELASTOMER (POLYURETHANE ELASTOMER) is a continuous phase; and
the component B, a High Permeability magnetic material (High Permeability Powder) is mixed into a disperse phase; and
the mass ratio of the component A to the component B can be adjusted according to different electromagnetic frequency band values, and the component A and the component B are used for realizing electromagnetic shielding of different bands.
2. A flexible electromagnetic wave material as claimed in claim 1, wherein said polyurethane elastomer is Epoxy resin (Epoxy resin).
3. A flexible electromagnetic wave material as claimed in claim 1, wherein the high permeability magnetic material is a mixture of Ferrite (Ferrite) and Silica (Silica) for dissipating electromagnetic interference sources.
4. A flexible electromagnetic wave material as claimed in claim 1, wherein said composite material of component a and component B is formed by a lamination drying process.
5. The flexible electromagnetic wave material of claim 1, wherein the composite material composed of component a and component B can be provided as flexible films in the form of sheets, strips, blocks or any combination thereof according to the customization needs.
6. A flexible electromagnetic wave material as claimed in claim 5, wherein said flexible film has a thickness of 3.5mm ± 0.25 mm.
7. A flexible electromagnetic wave absorbing material according to claim 5 or 6, wherein an adhesive layer is uniformly distributed on the surface of the flexible film.
8. A flexible electromagnetic wave absorbing material according to claim 7, wherein said adhesive layer is 3M glue.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911264291.4A CN111081417A (en) | 2019-12-11 | 2019-12-11 | Flexible electromagnetic wave-absorbing material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911264291.4A CN111081417A (en) | 2019-12-11 | 2019-12-11 | Flexible electromagnetic wave-absorbing material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111081417A true CN111081417A (en) | 2020-04-28 |
Family
ID=70313702
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911264291.4A Pending CN111081417A (en) | 2019-12-11 | 2019-12-11 | Flexible electromagnetic wave-absorbing material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111081417A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1887038A (en) * | 2003-11-25 | 2006-12-27 | 爱克工业株式会社 | Electromagnetic wave shielding resin composition, ferrite-coated metal magnetic microparticle suitable for use therein and process for producing the same |
| CN101445716A (en) * | 2008-12-29 | 2009-06-03 | 安徽大学 | Novel wave-absorbing material and preparation method thereof |
| CN104285262A (en) * | 2012-05-10 | 2015-01-14 | 同和电子科技有限公司 | Magnetic part, metal powder used therein and manufacturing method therefor |
| CN106977986A (en) * | 2017-04-28 | 2017-07-25 | 山东欧铂新材料有限公司 | A kind of resin antiradar coatings and preparation method thereof |
| CN108218240A (en) * | 2018-01-29 | 2018-06-29 | 湖南航天磁电有限责任公司 | A kind of unorganic glass base complex ferrite absorbing material and preparation method thereof |
| CN108394938A (en) * | 2018-04-17 | 2018-08-14 | 哈尔滨工业大学 | A kind of pros' bodily form strontium ferrite wave absorbing agent and preparation method thereof |
| CN110540735A (en) * | 2019-08-20 | 2019-12-06 | 南方科技大学 | Epoxy resin-based composite wave-absorbing material and preparation method and application thereof |
-
2019
- 2019-12-11 CN CN201911264291.4A patent/CN111081417A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1887038A (en) * | 2003-11-25 | 2006-12-27 | 爱克工业株式会社 | Electromagnetic wave shielding resin composition, ferrite-coated metal magnetic microparticle suitable for use therein and process for producing the same |
| CN101445716A (en) * | 2008-12-29 | 2009-06-03 | 安徽大学 | Novel wave-absorbing material and preparation method thereof |
| CN104285262A (en) * | 2012-05-10 | 2015-01-14 | 同和电子科技有限公司 | Magnetic part, metal powder used therein and manufacturing method therefor |
| CN106977986A (en) * | 2017-04-28 | 2017-07-25 | 山东欧铂新材料有限公司 | A kind of resin antiradar coatings and preparation method thereof |
| CN108218240A (en) * | 2018-01-29 | 2018-06-29 | 湖南航天磁电有限责任公司 | A kind of unorganic glass base complex ferrite absorbing material and preparation method thereof |
| CN108394938A (en) * | 2018-04-17 | 2018-08-14 | 哈尔滨工业大学 | A kind of pros' bodily form strontium ferrite wave absorbing agent and preparation method thereof |
| CN110540735A (en) * | 2019-08-20 | 2019-12-06 | 南方科技大学 | Epoxy resin-based composite wave-absorbing material and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103700951B (en) | Complex media double-deck FSS structure SRR metal level ultra-thin absorbing material | |
| Yuan et al. | Broadband microwave absorption properties of ultrathin composites containing edge-split square-loop FSS embedded in magnetic sheets | |
| CN102634177B (en) | A kind of composite electromagnetic shield materials for cable | |
| KR102522857B1 (en) | High-performance shielding sheet and preparation method thereof and coil module comprising the same | |
| Bae et al. | Miniaturized broadband ferrite T-DMB antenna for mobile-phone applications | |
| Lee et al. | Role of small permeability in gigahertz ferrite antenna performance | |
| CN105655721A (en) | Double-waveband composite broadband wave absorbing material based on frequency selective surface | |
| CN106332533A (en) | Wave-absorbing metamaterial | |
| TWI482585B (en) | Shielding composite diaphragm | |
| Huang et al. | Broadband and ultrathin screen with magnetic substrate for microwave reflectivity reduction | |
| KR20200015374A (en) | Electromagnetic-wave-absorbing composite sheet | |
| KR100849496B1 (en) | Composition for complex sheet with thermal dissipation, emi shielding and absorption in target frequency range, and products manufactured therefrom | |
| CN113692212B (en) | Multilayer wave absorber structure and application thereof | |
| Tran et al. | Enhanced microwave absorption properties of Y‐Co2Z/PANI hexaferrites composites in the frequency range of 0.1–18 GHz | |
| Mu et al. | Microwave absorption properties of composite powders with low density | |
| CN109546352A (en) | A kind of super matching absorbing material of the two waveband being made of secondary wavelength resonance structure | |
| Ji et al. | Miniaturized T-DMB antenna with a low–loss Ni–Mn–Co ferrite for mobile handset applications | |
| CN111081417A (en) | Flexible electromagnetic wave-absorbing material | |
| Choi et al. | Enhanced microwave absorption properties of Zn-substituted SrW-type hexaferrite composites in the Ku-band | |
| Fakharian et al. | Numerical analysis of mushroom-like and uniplanar EBG structures utilizing spin sprayed Ni (–Zn)–Co ferrite films for planar antenna | |
| Yang et al. | (0 0 1) Co2Z filled random Co2Z powder: A lightweight and broadband with enhanced electromagnetic wave absorption properties | |
| CN203105046U (en) | Structure for inhibition of electromagnetic wave interference, and flexible printed circuit comprising the same | |
| Gong et al. | Design of ultra wideband microwave absorber effectual for objects of arbitrary shape | |
| CN203895608U (en) | Multi-band-frequency wave-transmitting meta material, antenna housing and antenna system | |
| Yang et al. | Design of a P-band absorber based on metamaterial and magnetic material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200428 |
|
| RJ01 | Rejection of invention patent application after publication |