Subwavelength Layered Three-dimensional Broadband Absorbing Structure Based on Lossy Frequency Selective Surface

Abstract

The invention discloses a sub-wavelength layered three-dimensional broadband absorbing structure based on a loss type frequency selective surface. The sub-wavelength layered three-dimensional broadband absorbing structure is a periodic array structure formed by a plurality of structural units. Each structural unit consists of four annular frequency selective surfaces a dielectric layer serving asa supporting layer, a ferrite layer arranged at the lower surface of the dielectric layer, and a metal backing plate arranged at the lower surface of the ferrite layer; and the four annular frequencyselective surfaces are uniformly distributed in the dielectric layer in the vertical direction. The ferrite layer uses ferrite with a working frequency lower than 2 GHz; and the annular frequency selective surfaces are made of conductive materials with the electric conductivity of 100-200 S / m. According to the invention, with the sub-wavelength layered three-dimensional broadband absorbing structure, the wide-band absorption of spatial electromagnetic waves is realized. The sub-wavelength layered three-dimensional broadband absorbing structure has advantages of being insensitive to electromagnetic wave polarization, having the light weight, having a simple structure, being easy to process, having the low cost, having the wide working frequency band and having the relative thin thickness.

Description

technical field [0001] The invention belongs to the field of electromagnetic field and microwave technology, and in particular relates to a sub-wavelength layered three-dimensional broadband wave-absorbing structure based on a lossy frequency selective surface. Background technique [0002] The absorbing material can realize the absorption of the incident electromagnetic wave and achieve the effect of reducing the reflection. Traditional absorbing materials, such as Jaumann absorbers and Salisbury screens, paste lossy films on the medium with a thickness of 1 / 4 wavelength from the back metal backplane, forming standing waves so that energy is confined in the medium, and the lossy film passes through the surface. The loss of the film and the medium achieves wave absorption, but its disadvantage is that it is thicker. Today's wave-absorbing materials mainly realize the characteristics that natural materials do not have by designing artificial electromagnetic metamaterials. Fo...

AI Technical Summary

Problems solved by technology

Traditional absorbing materials, such as Jaumann absorbers and Salisbury screens, paste lossy films on the medium with a thickness of 1 / 4 wavelength from the back metal backplane, forming standing waves so that energy is confined in the medium, and the lossy film passes through the surface. The loss of the film and the medium achieves wave absorption, but its disadvantage is that it is thicker

Today's wave-absorbing materials mainly realize the characteristics that natural materials do not have by designing artificial electromagnetic metamaterials. For example, using metasurfaces to design wave-absorbing structures with a very thin thickness can achieve perfect absorption of electromagnetic waves at a certain frequency point. But the disadvantage is that the absorbing frequency band is relatively narrow

[0003] Traditional absorbing materials and new supersurface absorbing structures are generally two-dimensional structures. Due to their structural limitations, it is difficult to design a thin thickness, wide absorbing frequency band, and good low-frequency absorbing performance; for some three-dimensional Absorbing materials, such as patent CN107302139A, proposes a dielectric structure-type layered absorbing material based on low dielectric constant, which has multi-band absorption effects, but each frequency band has a narrow-band response; patent CN106380626A proposes a broadband absorbing material The material adopts FeSi layer and carbonyl iron layer to be responsible for the absorption of low frequency and high frequency respectively, but the absorption effect of low frequency is not good, only -8dB, high frequency can only reach -10dB absorption of 9-14GHz, and the preparation process is complicated

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