Angle- and polarization-insensitive metamaterial absorber based on vertical and horizontal symmetric slotted sectors

Abstract

This novel vertically and horizontally symmetric slotted-sector design aims to realize an angle-and polarization-insensitive metamaterial absorber. The unit-cell symmetries achieve polarization insensitivity, while an optimized slotted-sector inner angle enables angle insensitivity. Because the absorptivity of a metamaterial absorber depends on the incident angle and polarization, many researchers have studied angle-and polarization-insensitive unit cells. In this work, a novel vertically and horizontally symmetric slotted sector is proposed in order to realize an angle-and polarization-insensitive metamaterial absorber. The absorber performance is demonstrated with full-wave simulation and measurements. Angular sensitivity is studied for different slotted-sector inner angles. For an 85 degrees inner angle, the simulated absorptivity exceeds 90% and the frequency variation is less than 1.2% up to 70 degrees incidence. The measured absorptivity at 10.34 GHz is close to 98.5% for all polarization angles at normal incidence. As the incidence angle varies from 0 degrees to 70 degrees, the measured absorptivity at 10.34 GHz remains above 90% in the transverse electric mode. (C) 2016 Optical Society of America