Comments on “An Ultrawideband Ultrathin Metamaterial Absorber Based on Circular Split Rings”
Fahad Ahmed, Tayyab Hassan, Nosherwan Shoaib
Abstract
This letter provides correction comments to an article published in 2015, by Ghosh <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al.</i> 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.