Comment on “Polarization-insensitive and thin stereometamaterial with broadband angular absorption for the oblique incidence”

Abstract

In a recently published report, a polarization-insensitive and thin stereometamaterial (PITS) is proposed by Li et al. (2015) and they indicated that it can realize a broadband absorption by the orthogonal double-split-ring structure for the oblique incidence. However, the high cross-polarization reflection component is ignored by the original authors for the proposed PITS. When the incident angle is 45° for TE-polarization, it is found that there are only a few absorption peaks occurred at 6.79 GHz, 11.79 GHz, 12.54 GHz and 14.53 GHz with the corresponding absorptions of 36.08%, 56.24%, 58.70% and 60.54%, respectively. For TM-polarization, there are only three absorption peaks at 6.81 GHz, 11.83 GHz, 13.28 GHz with the corresponding absorptions are 67.85%, 52.16% and 62.14%. Obviously, the designed absorber reported by Li et al. cannot qualify the mission of absorbing electromagnetic wave. Keywords: Metamaterial, Polarization conversion, Absorber