# US 2023/0056535 A1 · Multi-layer wave absorber structure and use thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0056535 A1 - Document ID: US20230056535A1 - Status: Published application - Kind: A1 - Application number: 17/893,230 - Filed: 2022-08-23 - Published: 2023-02-23 - Earliest claimed: 2021-08-23 - Assignees: Peking University - Applicants: Peking University - Inventors: Jinbo YANG; Zhou LIU; Wenyun YANG; Jingzhi HAN; Changsheng WANG; Shunquan LIU - Web page: https://patentgrep.com/patent/US20230056535A1 ## CPC - H01Q 17/008: {with a particular shape (H01Q17/007 takes precedence)} - H05K 9/0081: {Electromagnetic shielding materials, e.g. EMI, RFI shielding (H05K9/0003 takes precedence)} - H01Q 17/00: Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems - H05K 9/0056: {specially adapted for microwave applications} - H05K 9/0088: {comprising a plurality of shielding layers; combining different shielding material structure} - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract The present disclosure relates to the technical field of microwave absorption, and in particular, to a multi-layer wave absorber structure and use thereof. The multi-layer wave absorber structure has a sandwich structure, and an intermediate layer of the sandwich structure is an electromagnetic loss-free dielectric layer. The electromagnetic loss-free dielectric layer includes a vacuum layer, an air layer, a paraffin layer, or a polytetrafluoroethylene layer. The added electromagnetic loss-free dielectric layer enhances impedance matching by modulating phases of electromagnetic waves, such that loss of the electromagnetic waves in a composite wave absorbing layer of the multi-layer wave absorber structure is enhanced, and an effective absorption bandwidth is further improved. The multi-layer wave absorber structure provided by the present disclosure has higher universality and operability, and has an effect of improving an effective absorption bandwidth for wave absorbing devices made of various composite wave absorbing materials. ## Claims ### Claim 1 A multi-layer wave absorber structure, having a sandwich structure, wherein an intermediate layer of the sandwich structure is an electromagnetic loss-free dielectric layer. ### Claim 2 (depends on 1) The multi-layer wave absorber structure according to claim 1, comprising a metal backing and a first composite wave absorbing material layer, the electromagnetic loss-free dielectric layer, and a second composite wave absorbing material layer that are sequentially stacked on a surface of the metal backing. ### Claim 3 (depends on 1) The multi-layer wave absorber structure according to claim 1, wherein the electromagnetic loss-free dielectric layer comprises a vacuum layer, an air layer, or an electromagnetic loss-free material layer, and the electromagnetic loss-free material layer is made of one or more materials selected from the group consisting of paraffin, epoxy resin, and polytetrafluoroethylene. ### Claim 4 (depends on 2) The multi-layer wave absorber structure according to claim 2, wherein the electromagnetic loss-free dielectric layer comprises a vacuum layer, an air layer, or an electromagnetic loss-free material layer, and the electromagnetic loss-free material layer is made of one or more materials selected from the group consisting of paraffin, epoxy resin, and polytetrafluoroethylene. ### Claim 5 (depends on 2) The multi-layer wave absorber structure according to claim 2, wherein compositions of the first composite wave absorbing material layer and the second composite wave absorbing material layer each comprise an electromagnetic wave absorbing agent and a binder. ### Claim 6 (depends on 5) The multi-layer wave absorber structure according to claim 5, wherein the electromagnetic wave absorbing agent comprises one or more materials selected from the group consisting of graphene, carbonyl iron, ferrite, and rare earth-transition intermetallic compounds. ### Claim 7 (depends on 6) The multi-layer wave absorber structure according to claim 6, wherein the rare earth-transition intermetallic compounds comprise La2Fe4Co10B and/or Ce1.75Sm0.25Fe17N3-δ. ### Claim 8 (depends on 1) Use of the multi-layer wave absorber structure according to claim 1 to provide microwave absorption. ### Claim 9 (depends on 8) The use according to claim 8, wherein the multi-layer wave absorber structure comprises a metal backing and a first composite wave absorbing material layer, the electromagnetic loss-free dielectric layer, and a second composite wave absorbing material layer that are sequentially stacked on a surface of the metal backing. ### Claim 10 (depends on 8) The use according to claim 8, wherein the electromagnetic loss-free dielectric layer comprises a vacuum layer, an air layer, or an electromagnetic loss-free material layer, and the electromagnetic loss-free material layer is made of one or more selected from the group consisting of paraffin, epoxy resin, and polytetrafluoroethylene. ### Claim 11 (depends on 9) The use according to claim 9, wherein the electromagnetic loss-free dielectric layer comprises a vacuum layer, an air layer, or an electromagnetic loss-free material layer, and the electromagnetic loss-free material layer is made of one or more selected from the group consisting of paraffin, epoxy resin, and polytetrafluoroethylene. ### Claim 12 (depends on 9) The use according to claim 9, wherein compositions of the first composite wave absorbing material layer and the second composite wave absorbing material layer each comprise an electromagnetic wave absorbing agent and a binder. ### Claim 13 (depends on 12) The use according to claim 12, wherein the electromagnetic wave absorbing agent comprises one or more materials selected from the group consisting of graphene, carbonyl iron, ferrite, and rare earth-transition intermetallic compounds. ### Claim 14 (depends on 13) The use according to claim 13, wherein the rare earth-transition intermetallic compounds comprise La2Fe4Co10B and/or Ce1.75Sm0.25Fe17N3-δ.