Comment on Polarization-Adjustable Dual-Band Absorption in GHz-Band Metamaterial, Based on the No-Smoking Symbol

Abstract

Recently, a polarization-adjustable dual-band metamaterial absorber based on a modified no-smoking symbol was reported by Yoo et al. [J. Korean. phys. Soc. 67, 1651 (2015)]. When the angle (φ) between the y-axis and the incident electric field E is 0°, the proposed absorber based on a modified no-smoking symbol has two resonance absorption peaks, one at 4.59 GHz and the other at 6.75 GHz with absorption of 99% and 84%, respectively, and the high-frequency peak can be controlled by changing φ. In addition, the original author indicated that the absorption effect could be expressed in a split-ring structure and the real no-smoking symbol. In this paper, we express doubt that the design of Yoo et al. is not an absorber. When the missing cross-polarization reflection component is taken into the calculation of the absorption, we confirmed that the absorption peaks were 4.05 GHz and 6.03 GHz with real absorption rates of 36.31% and 34.88%, respectively. Obviously, the proposed absorber cannot act as an absorber.