Angle- and Polarization-Insensitive Metamaterial Absorber using Via Array

Abstract

In this paper, we propose an angle- and polarization-insensitive metamaterial absorber. We design a metamaterial unit cell that is based on a split ring cross resonator (SRCR). We observe that the absorption frequency and absorption ratio are insensitive to incident angles when a via array surrounds the SRR. We demonstrate the effect of the via array using full-wave simulations by comparing the absorptivity of the SRCR with and without the via array. Because of the symmetric geometry, we also realize polarization insensitivity. We build the proposed absorber on a printed-circuit-board with 30 × 30 unit cells, and we demonstrate its performance experimentally in free space. Under normal incidence, the fabricated absorber shows 99.6% absorptivity at 11.3 GHz for all polarization angles, while for oblique incidence, the fabricated absorber maintains an absorptivity higher than 90% for incident angles up to 70° and 60° for transverse magnetic (TM) and transverse electric (TE) modes, respectively.

Recent progress in angle-insensitive narrowband and broadband metamaterial absorbers

“…In addition to the circular sector-based geometry, other techniques can be used to realize angle-insensitive MM absorbers. Lim et al have presented a via-array-based structure that exhibits an improved angular response compared to its counterpart [39]. The proposed design consists of a split ring cross-resonator arranged periodically on a grounded dielectric substrate.…”

“…Simulated absorptivities of the proposed structure under TE polarization: (a) without via array and (b) with via array[39].…”

Genetic Algorithm Optimized X-Band Absorber Using Metamaterials

“…They have myriad applications [2][3][4], and one of them is the design of Xband absorbers or radar absorbing material [5,6]. Several X-band absorbers have been proposed in the literature [7][8][9][10][11][12][13][14][15][16] that can be broadly classified into two categories: polarization dependent absorbers [7,8] and polarization independent absorbers [9][10][11][12][13][14][15][16]. The polarization independent absorbers are generally symmetrical structures and are insensitive to polarization states with a narrow absorption bandwidth [13].…”

“…A wide-band absorber using RLC screen that absorbs TEM polarized fields was presented in [8]. Similarly, via array absorber was proposed in [9] which exhibited polarization insensitivity, but is difficult to design due to the presence of vias. Several multiband absorbers were proposed in [11][12][13], but had a low peak absorption and narrow absorption bandwidth.…”

A Bilayer Plasmonic Metasurface for Polarization‐Insensitive Bidirectional Perfect Absorption

“…Metasurfaces‐based perfect absorbers with narrow band, dual band, multiband, and broadband optical responses have been proposed for different applications. Polarization‐insensitive and wide‐angle perfect absorption of optical waves have been further demonstrated in metasurfaces, which offers helpful insight and great potential for the commercialization of metasurfaces‐based perfect absorbers . However, these designs composed of metal–insulator–metal structures can only absorb optical waves in one direction while reflect optical waves in the other direction .…”