Size-efficient metamaterial absorber at low frequencies: Design, fabrication, and characterization

Abstract

Articles you may be interested inA novel ultrathin and broadband microwave metamaterial absorber J. Appl. Phys. 116, 094504 (2014); 10.1063/1.4894824Bandwidth-enhanced polarization-insensitive microwave metamaterial absorber and its equivalent circuit model Integrating non-planar metamaterials with magnetic absorbing materials to yield ultra-broadband microwave hybrid absorbers Appl. Phys. Lett.We numerically and experimentally demonstrated a metamaterial perfect absorber (MPA) in MHz region based on a planar sandwiched metal-dielectric-metal structure. First, the single-peak perfect absorption was obtained at 400 MHz. The ratios of the periodicity of unit cells and the thickness to the absorption wavelength are 1/12 and 1/94, respectively. The advantage of structural design and the mechanism for the low-frequency MPA are described in detail by the comparison between calculation, simulation, and experiment. Influence of the incident angle of electromagnetic (EM) wave for both transverse-electric (TE) and transverse-magnetic (TM) polarization on absorption was also investigated, and the absorption was maintained to be above 95% at incident angles up to 30 . Finally, we propose a self-asymmetric structure, which induces the dual-band perfect absorption in the same range of frequency. The EM behavior of the excitation modes and the mechanism of the dual-band MPA are clearly explained. Especially, when two resonance modes are finely controlled to be close enough, the bandwidth (full width at half maximum) of MPA is enhanced to be nearly wider twice than that in case of single-peak perfect absorption. The enhanced bandwidth is still well preserved by varying the incident angle up to 30 for both TE and TM polarization. The results were also confirmed by both simulation and experiment. Our work is promising for potential practical applications in the radio range, such as radio-frequency shielding devices, single/dualfrequency filters, and switching devices. V C 2015 AIP Publishing LLC.

Miniaturization for ultrathin metamaterial perfect absorber in the VHF band

“…Interestingly, the ratios between thicknesses t and lattice constant a of MPA to the operation wavelength λ at 102 MHz are optimized to be only: t / λ  = 1/816 and a / λ  = 1/84. These values are the smallest among the currently-published structures212223242526272829. The nature of perfect absorption can be explained by the impedance matching theory30.…”

“…3(a) 233233. L 1 and L 2 are the effective inductances of the top quarter of meta-surface and the via interconnect located at each quadrant of the unit cell, respectively.…”

Low‐cost and miniaturized metamaterial absorber using 3D printed swastika symbol

“…For a low‐frequency MM absorber, the unit cell size is an important factor because of a periodic configuration of a MM. Therefore, various unit cell geometry for miniaturization has been proposed in a low frequency . For instance, a snake‐shape unit cell is proposed to design MM absorbers at 2 GHz and 400 MHz .…”

“…A needlepoint‐shape MM unit cell is designed using a magnetic material at 400 MHz . A planar sandwiched metal‐dielectric‐metal unit cell is proposed to minimize the MM unit cell size at 400 MHz . The unit cell size of the MM absorber is reduced by loading lumped capacitors and vertical interconnects at 102 MHz .…”

Comment on "A Wideband Wide-Angle Ultra-Thin Metamaterial Microwave Absorber"

“…With further developments, research in this area includes achieving near unity absorption characteristics for multiband, broadband frequencies maintaining polarization insensitive and ultra-thin profile. There are articles which report broadband absorption phenomenon [2][3][4][5][6]. However, on further investigations, it was found that the broadband absorption resulted from ignorance of cross-polarized reflections from the structures.…”