Configurable metamaterial absorber with pseudo wideband spectrum

Abstract

Metamaterials attain their behavior due to resonant interactions among their subwavelength components and thus show specific designer features only in a very narrow frequency band. There is no simple way to dynamically increase the operating bandwidth of a narrowband metamaterial, but it may be possible to change its central frequency, shifting the spectral response to a new frequency range. In this paper, we propose and experimentally demonstrate a metamaterial absorber that can shift its central operating frequency by using mechanical means. The shift is achieved by varying the gap between the metamaterial and an auxiliary dielectric slab parallel to its surface. We also show that it is possible to create multiple absorption peaks by adjusting the size and/or shape of the dielectric slab, and to shift them by moving the slab relative to the metamaterial. Specifically, using numerical simulations we design a microwave metamaterial absorber and experimentally demonstrate that its central frequency can be set anywhere in a 1.6 GHz frequency range. The proposed configuration is simple and easy to make, and may be readily extended to THz frequencies.

Analysis of metamaterial absorber in normal and oblique incidence by using interference theory

“…Here the metamaterial resonator is a typical electric-LC (ELC) resonator and has been widy used to design the MMAs. 24,25 Comparing with Fig. 1, layer 1 in Fig.…”

Ultra-Compact Metamaterial Absorber With Low-Permittivity Dielectric Substrate

“…Our previous researches [20,21] show that the added cover layer would contribute to decreasing the operating frequency. As shown in Fig.…”

“…These metamaterial absorbers can operate at almost arbitrary frequency spectra ranged from radio frequencies, microwave and terahertz frequencies, to even optical frequencies [8][9][10][11][12][13]. Moreover, strategies for expanding the operating bandwidths of MAs, such as dual-band [14,15], triple-band [16,17], multiband [18,19], band-tunable [20,21], broad-band [22,23], and ultra-broad-band [24,25] designs, have also been reported in recent years. Simultaneously, the theoretical analysis methods including classic electromagnetic theory [7], interference theory [26], and equivalent circuit/transmission line theory [27] are developed to analyze and guide the design procedures and explain the appeared exciting absorbing properties.…”

A Polarization-Dependent Frequency-Selective Metamaterial Absorber with Multiple Absorption Peaks

“…In recent years, various structures, such as split rings [11], closed rings [12], and fishnet structures [13], have been proposed for MAs. A certain progress has been made in broadband MAs developing [14,15].…”