Performance Evaluation of Wide-Angle Ultrathin Microwave Metamaterial Absorber with Polarization Independence

Abstract

A novel dual-band wide-angle ultra-thin absorber composed of dual closed-concentric ten-point stars with polarization independence is presented in this article. The ten-point stars formed resonators are engraved on low cost FR4 substrate. The EM absorber performance is studied in terms of electrical and physical parameters. The polarization independence is practically demonstrated using waveguide measurement method. The measured results are in good agreement with simulated results. The absorbance values of 99.37% and 97.18% are achieved at 2.13 GHz and 2.52 GHz, respectively. The presented absorber design is wide-angle RF absorber with high absorbance values of about 80% up to 60° under TE mode and 87% up to 75° of oblique incidence angle for TM mode excitations. The experimental results demonstrate the absorption effectiveness of the proposed design to be utilized in RF energy harvester modules for capturing ambient UMTS band signals and in RF absorber applications for S band radar systems. The presented absorber unit cell is ultrathin and compact with the thickness and size less than λ/56 mm and λ/5 mm, respectively, at lowest absorption frequency.

Analysis of Conformal Quad Band Metamaterial Absorber Design on Planar and Cylindrical Surface

“…The thickness of the presented QCMA h = 0.5 mm, which is λ/146 miniaturized at the lowest frequency. The effect of substrate thickness on the multiband structure was reported in [22].…”

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

“…A widely used FR‐4 dielectric substrate is replaced with neoprene rubber. Different studies show that higher the dielectric loss tangent value, higher the RF losses, wider is the absorption bandwidth, which deteriorates absorption level . Primarily, for enhancing the degraded absorption additional neoprene rubber layer is added in the proposed MMA structure.…”

Analysis of Electrically Low Profile Wideband Microwave Absorber for C Band Applications

“…Since MMA is a frequency-dependent device, a band of frequency shall be decided by CMMA in which it cannot reflect incident wave, thus its absorptivity increases, and CMMA can absorb the incident wave. The bandwidth of CMMA can be increased by including more substrate materials [12,21]. So radar crosssection (RCS) of respective CMMA is reduced by impedance matching at operating frequency band for the stealth application.…”

“…Wideband and thin substrate material is used for stealth application. Till now, so many designs of metamaterial absorbers have been analyzed, such as single band [2,32], double band [9][10][11][12][13], triple band [14][15][16][17], quad-band [18,19], wideband [20][21][22][23][24][25], polarizationindependent [12,26,27,[33][34][35][36], oblique angle independent [28,29], reconfigurable frequency selective absorber [30,31].…”