An ultra-wideband, polarization insensitive, and wide incident angle absorber based on an irregular metamaterial structure with layers of water

Abstract

We present the design of a new type of irregular metamaterial structure that can achieve ultra-wideband absorption. The structure is created using 3D-printing to create a shell and contains multiple layers of water. The structure can achieve absorption levels greater than 0.9 in the 6.8–21.0 GHz range, with a relative bandwidth of 101.93%. The absorber also works in a wide range of incidence angles with different modes and is polarization insensitive. Measurement results obtained from a microwave experiment coincide well with the simulation results. The proposed metamaterial could be broadly applied in various civilian and military products in the future.

Electromagnetically induced transparency metamaterial with strong toroidal dipole response

“…Generally, a toroidal dipole's surface current can be viewed as a circular head-to-tail arrangement of magnetic dipoles [5], and its applicability in metamaterials research has proved pretty diverting. A metamaterial [6,7] is an artificial material with many unique characteristics not found in natural materials, such as a negative refractive index [8,9], perfect absorption [10,11], and the superlens phenomenon [12]. The strong toroidal dipole response in metamaterials regularly exhibits unattainable electromagnetic phenomena, such as resonant transparency [13,14], unconventional optical activity [15], and optical switch [16].…”

A direct laser-synthesized magnetic metamaterial for low-frequency wideband passive microwave absorption

“…The absorber, designed and fabricated using LDW, has the widest bandwidth reported thus far, with the lowest thickness in the low-frequency band. Figure 13 presents a comparison of the fractional bandwidth and relative thickness (relative thickness = thickness/λ L , where λ L is the wavelength corresponding to the minimum operating frequency) of conventional, metamaterial [13,[47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65], and proposed absorbers, thus demonstrating the improvement in the microwave absorption achieved by the metamaterial designed and achieved through LDW.…”

Structural design and optimization of double-cross shape broadband absorption metamaterial based on CB-ABS

“…Compared with magnetic materials, carbon-based materials have the ability to absorb electromagnetic waves with lower density, making it easier to meet lightweight and broadband design requirements. Under the premise of meeting the specified size and surface quality, 3D printing components prepared with engineering plastics and resins such as (Polylactic Acid, PLA) and (Acrylonitrile-Butadiene-Styrene composites, ABS) can have good machining performance and light weight (Dong et al, 2020;Duan et al, 2021;Kotsilkova et al, 2017;Shen et al, 2018). And since graphene has good dielectric loss properties, Yin et al (2019) used reduced graphene oxide (RGO) as the absorbent, while PLA as the matrix to prepare composite metamaterials with a gradient index of impedance (GRIN).…”