Comments on ‘Broadband metamaterial absorber on a single-layer ultrathin substrate’

Abstract

Sen G, Kumar M, Islam SN, et al. [Broadband metamaterial absorber on a single-layer ultrathin substrate. Waves Random Complex Media. 2019;29(1):153–161.] published a research paper in 2019 in which a broadband metamaterial-based absorber is said to be designed and fabricated using a single-layered ultrathin substrate providing an absorption range 8.86–15.5 GHz. However, the present work shows that the proposed structure has been misinterpreted as a broadband metamaterial absorber as the cross-polarization effect has been neglected. After incorporating the cross-polarization effect, the absorptivity obtained is <12% throughout the intended frequency band. Moreover, the Polarization Conversion Ratio (PCR) is observed to be >85% for the entire frequency band which proves that the proposed structure is effectively a polarization converter rather than an absorber over the said frequency range.