Comment on “Broadband ultrathin low-profile metamaterial microwave absorber”

Abstract

In a recently published report, Sood et al. (Appl Phys A 122.4:1–7, 2016) proposed a single-layer broadband ultrathin low-profile metamaterial absorber (ULMA) to realize the broadband absorption with the wide angle of incidence. The proposed ULMA has three absorption peaks at 8.25 GHz, 11.72 GHz and 14.37 GHz with the absorption of 99.72%, 99.64% and 99.26%, respectively. However, we found that the cross-polarization reflection component is ignored by Sood et al. [1]. It is found that there are only two absorption peaks at 7.904 GHz and 14.768 GHz with real absorption rates of 2.56% and 7.90%, respectively. Obviously, the authors mistakenly regard a polarization converter as an absorber.