Characterizing Scalar Metasurfaces Using Time-Domain Reflectometry

Two efficient methodologies for the determination of electromagnetic (EM) constitutive properties of scalar metasurfaces are introduced and discussed. In contrast to the available methods, and in line with the recent increasing interest in time-domain (TD) analyses of metasurfaces, we show that the material parameters of a scalar metasurface can be readily achieved directly in the TD merely from the EM reflected pulse shape. The two methodologies are based on an analytical TD reflectometry (TDR) approach and a modern stochastic optimization technique. A number of illustrative numerical examples demonstrating the validity and properties of the proposed techniques are presented.