New Wine in Old Barrels: The use of the Oliner´s Method in Metasurface antenna design

This paper presents a generalization of the Oliner´s method used to investigate the guided modes supported by a Sinusoidally-Modulated Surface Reactance (SM-SR). In its original paper, Oliner applied the procedure to the case of a scalar and impenetrable impedance sheet in free space; in this work, this approach has been extended to find the guided mode configurations (both leaky and surface waves) for the more general case of Sinusoidally-Modulated Tensor Surface Reactance (SM-TSR), placed inside a generic dielectric stratification. SM-TSR can be seen as the simplest version of metasurface able to realize leaky-wave antenna with circular polarization. The results obtained have been successfully compared, in terms of complex propagation constant and polarization, with those of actual sinusoidally modulated metasurfaces constituted by small printed element over a ground dielectric substrate. These first results confirmed the possibility to use the SM-TSR as local canonical problem for the analysis of more complex metasurfaces.