Multiband polarisation insensitive metamaterial absorber based on circular fractal structure

Abstract

In this study, the authors present a geometrically symmetrical fractal structure called circular fractal structure. The iterative process of the geometric construction is illustrated and the dimension of the proposed circular fractal structure is 1.5729 based on the similarity dimension. Then, a polarisation insensitive multiband perfect metamaterial absorber (MMA) is proposed based on the circular fractal structure. The proposed MMA has three near‐perfect absorption bands for both transverse electric (TE) and transverse magnetic (TM) polarisations based on the theory of the fractal geometry. The current distribution on the top and bottom surfaces of the MMA are presented to preferably understand the physical mechanism behind the multiband absorption. The simulated results match the experimental results well. For both TE and TM polarisations, the three absorption frequencies are f1 = 2.29 GHz, f2 = 4.28 GHz, and f3 = 11.71 GHz, with the absorptivity of 98.7, 99.4, and 99.5%. Both experimental and simulated results indicate that the proposed circular fractal MMA is a promising candidate for absorbing elements in scientific and military applications.

Ultra‐thin metamaterial perfect absorbers for single‐/dual‐/multi‐band microwave applications

“…The concept of perfect metamaterial absorber (MMA) came into existence with the significant experimental work of Landy et al in 2008 [8]. Since then, numerous MMA based structures, including T-shape [7,9], split-ring structures [10], ring-shape [6,11,12], circular fractal [13], H-shape [14] and Jerusalem cross (JC) resonator [15][16][17] were proposed as a perfect multi-and broadband absorber in a wide EM-spectral regime. Several efforts have also been carried out for the advancement of multi-and broad-band MMAs by introducing coplanar or stacked multi-layer configurations employing different metallic resonant structures [5,[18][19][20].…”

Ultrathin dual-layer triple-band flexible microwave metamaterial absorber for energy harvesting applications

“…First MTM‐based absorber has been experimentally verified by Landy in 2008. Since then many multiband, wideband, polarization insensitivity, wide angle, compact‐ultrathin absorbers have been proposed with their practical verification. MTM absorbers can be conveniently designed to absorb freely available electromagnetic energy in the form of propagating electromagnetic radiation in the specific operation bands to be used for RF energy harvesting purposes.…”

Broadband aperture‐coupling patch antenna with improved radiation and scattering performance based on metamaterial absorber

“…Compared with phase cancellation, metamaterial absorber (MA) can achieve nearly 100% absorption rate, which remarkably decreases the reflected energy in the scattering field [9]. Several MA are designed to broaden absorption bandwidth, such as fractal structures [10,11], multilayer structures [12,13], and loading lumped elements [14][15][16][17].…”