ELECTROMAGNETIC WAVE ABSORBER

• Main Authors: FUJITA MASAO, HIROI TOSHIO
• Format: Patent
• Language: English; Japanese
• Published: 22.09.2023
• Subjects: CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; PERFORMING OPERATIONS; PRINTED CIRCUITS; TRANSPORTING

To realize an electromagnetic wave absorber that can satisfactorily absorb multiple types of electromagnetic waves with different frequencies in a high frequency band above the millimeter wave band.SOLUTION: In an electromagnetic wave absorber in which an electromagnetic wave absorbing layer is formed by laminating multiple magnetic layers containing magnetic iron oxide that has magnetic resonance at high frequencies above the millimeter wave band. The magnetic layer includes a magnetic iron oxide in particle form and a resin binder, and among the plurality of laminated magnetic layers, the difference in absolute value of impedance between two adjacent layers is 350 Ω or less, and the input impedance of the magnetic layer aligned with respect to the input impedance of the other adjacent magnetic layer.SELECTED DRAWING: Figure 1 【課題】ミリ波帯域以上の高い周波数帯域において周波数の異なる複数種類の電磁波を良好に吸収することができる電磁波吸収体を実現する。【解決手段】ミリ波帯以上の高周波数で磁気共鳴する磁性酸化鉄が含まれた磁性体層が複数層積層されて電磁波吸収層を構成する電磁波吸収体であって、前記磁性体層は、粒子状の前記磁性酸化鉄と樹脂製バインダーとを含み、複数積層された前記磁性体層のうち、隣り合う２つの層のインピーダンスの絶対値の差が３５０Ω以下であり、前記磁性体層の入力インピーダンスが、隣接する他の前記磁性体層の入力インピーダンスに対して整合されている。【選択図】図１