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Modeling curved metasurface structures represents a computing challenge due to the complexity of considered designs. This creates a need for specialized efficient analysis methods. An approach that combines the spectral-domain field representation and surface sheet impedance concept is proposed. The considered cascaded cylindrical metasurface structures can span across only a part of a canonical surface and unit cell elements can vary along the metasurface, giving a spatially-varying sheet impedance. The analysis method is experimentally verified against a cylindrical metasurface for shaping the feed antenna beam. The problem of manufacturing curved metasurfaces is also discussed in the paper. KeywordsMetasurfaces, curved metasurfaces, spectral domain approach, sheet impedance, metasurface production technology, high-frequency conductive materials      J E J J J    (15) Here, the presence of a supporting dielectric structure is taken into account through the EJ G  Green's function for

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Among different approaches to designing metasurfaces, surface sheet impedance is proving to be a straightforward path for many applications. Recent publications have proposed several methods for optimizing this design approach, enabling rapid metasurface development. Upon finding the requirements using the sheet impedance approach, design continues with the selection of unit cell geometry. This choice is usually based on approximate expressions that have been published throughout the years. We review the approximate expressions for metasurface unit cell design, with consideration of their applicability to certain applications, namely polarization-dependent beam-shaping metasurfaces. We evaluate the accuracy of the approximate expressions against simulation results from a full-wave electromagnetic solver, and propose an optimization approach to correct the proposed design for the observed error. The applicability of different unit cell types is discussed, especially considering the limitations of technological processes typically used in metasurface production. A prototype was developed to verify the validity of this design approach.

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