Comment on ‘Wide‐angle broadband microwave metamaterial absorber with octave bandwidth’

Abstract

This comment demonstrates that in a recent study by Bhattacharyya et al., a linear reflective polarisation converter is erroneously interpreted as broadband absorber. It is clearly shown that the incident electromagnetic wave is reflected with its orthogonal polarisation state due to which co‐polarised reflection is reduced. Total absorption, when both the co‐ and cross‐polarised reflected components are considered, is less than 20% in the operating band claimed by the authors.

A wideband wide‐angle ultrathin low profile metamaterial microwave absorber

“…However, in these papers authors ignored crosspolarization effect and interpreted phenomenon as absorption. This fact is addressed by the comments, respectively, and article …”

Comment on "A Wideband Wide-Angle Ultra-Thin Metamaterial Microwave Absorber"

“…However, on further investigations, it was found that the broadband absorption resulted from ignorance of cross-polarized reflections from the structures. This fact is addressed by the articles respectively [7][8][9][10][11]. In subsequent section, study and investigations are carried out on the structure proposed in [12], and it is shown that already reported structure is not a metamaterial absorber.…”

Square Patch-Based Dielectric Microwave Absorber

“…In this context, Metamaterial Absorbers (MAs) offer novel features such as low thickness, nearly perfect absorption and flexibility for tuning of resonant frequency [6]. However, the MAs have disadvantages such as narrow bandwidth owing to the formation of resonating structure, and polarization conversion due to the absence of resistive components [6,7].…”