A kind of flexible low frequency wave absorbing sheet and preparation method thereof

Abstract

A flexible low-frequency wave absorbing sheet and a preparation method thereof. The wave absorbing sheet is formed by superimposing and hot pressing four layers of flexible rubber films, and each layer of the rubber film is filled with the same various functional additives, powders and different electromagnetic wave absorption. agent. From the outside to the inside of the absorber, the first and third layers of rubber film are filled with micro-nano spherical magnetic metal particles, which have both good impedance matching characteristics and electromagnetic wave attenuation characteristics; the second and fourth layers are filled with micron-sized two-dimensional sheets. Magnetic metal powder with strong electromagnetic wave attenuation characteristics. The present invention also includes a preparation method of the flexible low-frequency wave absorbing sheet. The low-frequency wave absorbing sheet of the present invention not only has broadband and strong absorption performance in the low frequency of microwave, but also has the advantages of thin thickness, low areal density, high and low temperature resistance, high flame retardant grade, green environmental protection, and can be attached to any shape target surface. , has a good application prospect in the field of military radar stealth technology and electromagnetic compatibility of civil electronic products.

Description

technical field [0001] The invention relates to a wave-absorbing material, in particular to a flexible low-frequency wave-absorbing sheet and a preparation method thereof. Background technique [0002] With the development of wireless microwave communication technology represented by 5G communication, the number of industrial electronic equipment and household electronic products is increasing, and the functions are diversified, the size is miniaturized, and the operating frequency is concentrated in the GHz frequency band. In addition, the radar detection technology is improving day by day. In order to increase the detection distance, the working frequency of the detection radar is developed to the microwave low frequency band (L, S, and C bands), and the radar is invisible. The comprehensive performance of absorbing materials puts forward higher requirements. In order to solve the problem of electromagnetic interference and improve the stealth performance of radar, absorb...

AI Technical Summary

Problems solved by technology

The microwave absorbing agent powder filled with microwave low-frequency absorbing film includes spherical magnetic metal powder and flake magnetic metal powder. Low-frequency wave absorbing film filled with spherical carbonyl ferromagnetic metal powder has a wide effective absorption bandwidth, but it needs to be filled with more than 90 wt.% Magnetic powder, resulting in thickness (>2.0mm) and surface density (>5.0kg / m 2 ) are large, costly, and have reduced flexibility and mechanical properties, which are not suitable for popularization and application; low-frequency wave-absorbing plates filled with flake-like sendust magnetic metal powder have small thickness and surface density, but they are easy to reflect electromagnetic waves and cause effective Narrow absorption bandwidth and poor electromagnetic properties make it difficult to meet the needs of practical applications

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