A flexible multi-layer wave absorbing material with adjustable frequency band and preparation method thereof

Abstract

The invention discloses a flexible multi-layer wave absorbing material with adjustable frequency band and a preparation method thereof. The flexible multi-layer wave absorbing material is the following 1) or 2): 1) a double-layer wave absorbing material composed of a wave absorbing fabric layer and a frequency selective fabric layer or an electromagnetic wave reflecting fabric layer stacked in any order; 2) A multi-layer wave absorbing material composed of a frequency selective fabric layer, a wave absorbing fabric layer and an electromagnetic wave reflecting fabric layer stacked in any order. Fabric; the wave-absorbing fabric layer is made of a wave-absorbing fabric, and the wave-absorbing fabric is a fabric containing a wave-absorbing agent. The invention efficiently designs the periodic arrangement and size of the FSF units required for different frequency bands through simulation, and stacks the FSF with filtering effect, the wave absorbing fabric and the electromagnetic wave reflecting fabric in different stacking sequences and layer combinations, which can be adjusted and controlled. The layered composite material achieves broadband and high-strength absorption in different working frequency bands, improving work efficiency.

Description

technical field [0001] The invention relates to a flexible multilayer wave absorbing material with adjustable frequency band and a preparation method thereof, belonging to the technical field of microwave absorbing materials. Background technique [0002] The absorbing material needs to meet two conditions, one is that the impedance of the material and the free space are as equal as possible, and the other is that it has high electromagnetic wave loss ability, so as to convert electromagnetic wave energy into heat energy or other forms of energy to the greatest extent, without being like electromagnetic shielding. The material produces secondary pollution. Commonly used absorbers are carbonyl iron, ferrite, etc. For example, carbonyl iron is a high permeability absorbing material that relies on hysteresis loss and eddy current loss to attenuate electromagnetic waves. [0003] Different devices have different working frequency bands. In order to ensure the normal operation ...

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Problems solved by technology

[0004] A single absorbing material often has the disadvantages of poor impedance matching, limited absorption performance, and narrow absorbing frequency band.

Multi-layer composite absorbing material is an important means to achieve high-strength and broadband absorption. Patent application (CN 106469858A) discloses a absorber structure, which is multi-layered with metal plates, honeycomb layers, and resistor sheets to obtain broadband, Strong absorbing wave-absorbing material, but the weight of the metal plate is heavy, and the total thickness of the composite material exceeds 20cm. Patent application (CN10983029A) discloses a wave-absorbing composite material and its preparation method, specifically impedance matching layer / three-dimensional graphene layer / The preparation method of the low-frequency electromagnetic loss layer has a wide absorbing frequency band at low frequencies; the patent application (CN 108092006 A) discloses a layered broadband radar absorbing sheet and its preparation method, and the patent application (CN 105744816 B) discloses an electromagnetic wave Shielding composite film, the above two patent applications disclose the preparation method of multi-layer wave-absorbing film, the layer composite materials in the above patents can improve the absorption of electromagnetic waves, but cannot realize the selective transmission of electromagnetic waves in a specific frequency band However, it does not have the unique softness and breathability of fabrics

[0005] At present, there is a lack of multi-layer composite materials that can efficiently control the absorbing frequency band of absorbing materials and meet the needs of absorbing materials with soft and breathable properties.

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