This letter provides correction comments to an article published in 2015, by Ghosh et al. in which the authors have proposed a circular-split-rings-based ultrawideband ultrathin metamaterial absorber and claimed 90% absorption between 7.85 to 12.25 GHz. It is found that the authors have misinterpreted a cross polarizer as a broadband absorber by neglecting its cross-polarized reflection. It is found that by incorporating the cross-polarized coefficient of the reflected wave, the absorption of the proposed structure gets below 20% over the complete claimed operating band. Additionally, the polarization conversion ratio is above 90%, which proves that the proposed structure is predominantly a cross polarizer rather than an efficient absorber.

中文翻译：

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评“一种基于圆形裂环的超宽带超薄超材料吸收体”

这封信为 Ghosh 等人于 2015 年发表的一篇文章提供了更正评论。其中作者提出了一种基于圆形裂环的超宽带超薄超材料吸收器，并声称在 7.85 至 12.25 GHz 之间有 90% 的吸收。发现作者通过忽略交叉偏振反射将交叉偏振器误解为宽带吸收器。发现通过结合反射波的交叉极化系数，所提出的结构的吸收在整个声称的工作频带内低于 20%。此外，偏振转换率高于 90%，这证明所提出的结构主要是交叉偏振器而不是有效的吸收器。