Modeling Cascaded Cylindrical Metasurfaces with Spatially-Varying Impedance Distribution

Abstract

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

Designing Metasurfaces with Canonical Unit Cells

“…When developing an MTS of this kind, certain caveats have to be kept in mind due to the restrictions posed by the development technology. Recently, research on curved metasurfaces had covered the manufacturing process to some extent [19]. The production of planar and simply-curved MTS layers has been suggested by exploiting the common printed circuit board (PCB) manufacturing techniques.…”

“…In our recent research, we presented several methods for obtaining an MTS sheet impedance profile from a functional requirement [19][20][21][22]. Focus was placed on beam-steering metasurfaces, notably curved structures.…”

“…Focus was placed on beam-steering metasurfaces, notably curved structures. While the prime focus of these papers was to present an analysis method for obtaining the required sheet impedance profile, here we discuss the design methodology and its application on the development of the MTS structure proposed in [19].…”

“…The cell period is taken as 7.854 mm to produce a semi-cylinder of the given radius. The sheet impedance profile of such a metasurface achieving the desired function was found by utilizing one of the methods presented in earlier works [19][20][21][22]. We then examine Figure 11a and determine the appropriate type of each unit cell.…”

Analysis and Synthesis of Cascaded Cylindrical Metasurfaces Using a Wave Matrix Approach

“…Since fields along a cylindrical geometry can be decomposed into elementary cylindrical waves with different azimuthal orders, arbitrary field transformation is not possible with merely azimuthallyinvariant structures. In order to address this issue, we combine the concepts of multimodal matrix analysis [20] as well as the mode matching technique [21]. By considering multiple azimuthal modes simultaneously, the proposed theory can be generalized, and azimuthal mode converters successfully designed [22].…”