Comments on electromagnetic scattering from inhomogeneous impedance periodic rough surfaces by transform technique

In an recent article by Tezel (Microwave and Optical Technology Letters 51 (2009), 116-119) an electromagnetic scattering problem related to a periodic rough surface having an inhomogeneous standard impedance boundary condition is considered. The author proposes a solution method, which is based on the equivalent representation of the rough surface in terms of a planar one with higher order impedance boundary condition. We have already noticed that the mathematical formulation of the problem is completely incorrect and such a rough surface cannot be equivalently represented in terms of higher order impedance boundary condition. Therefore, the numerical results has no reliability, and they are fictitious. VC 2009 Wiley Periodicals, Inc.