An ultrathin and broadband metamaterial absorber using multi-layer structures

Abstract

An ultrathin and broadband absorber is investigated in this paper. The metamaterial absorber is composed of a periodic array of loop-dielectric multilayered structure. By tuning the scale factor of the loop and the height of every layer, a desirable refractive index dispersion spectrum is realized, which is the reason to realize a successive anti-reflection in a wide frequency range. The interference mechanism and resonance absorption are identified through analytical derivation and numerical simulations. Numerical results show that the absorption at normal incidence is above 90% in the frequency range of 8.37–21 GHz. Moreover, the structure has a thickness of 3.65 mm (only 0.10λ to 0.26λ at the lowest and highest frequencies, respectively). The explanation to the physical mechanism of the metamaterial absorber is presented and verified.

A Novel Six-Band Polarization-Insensitive Metamaterial Absorber With Four Multiple-Mode Resonators

“…However, in the early stage, most of the metamaterial absorbers (MMAs) are single-band [6,7] or polarization-sensitive [8,9]. To achieve different features, such as multiband and polarization-insensitive [10][11][12][13][14][15][16][17][18], many efforts are put to develop the MMAs, and a variety of design methods have been reported in the past few years. For a multi-band absorber, the reported design methods can be mainly classified into three types.…”

Varied absorption peaks of dual-band metamaterial absorber analysis by using reflection theory

“…Moreover, the manufacturing cost of MMA is relatively lower. Benefiting from advanced nanofabrication technologies, currently, the designed MMAs operate at various frequency spectra scaled from microwave [1][2][3][4], terahertz [5] and near infrared [6,7] to the optical bands [8], by using different metamaterial resonators. Among these studies, the dual-band and multi-band MMA with high absorption is a hot area of research, because they have many promising applications, such as explosive detection, thermal detectors and bolometers [9][10][11][12].…”

Experimental verification of total absorption by a low-loss thin dielectric layer

“…Also, in combination with metallic backed planes, thin layers have been studied including slits in dielectric layers, 8,9 holes or cavities in the metallic plane, 10,11 and even metal-dielectric multilayered structures. 12 Wide incidence angles can be explored with any of these possible element configurations. 13 Also, if the sub-wavelength thickness requirement is relaxed, performance improvements in broadband operation can be achieved.…”