Design of Planar and Conformal, Passive, Lossless Metasurfaces That Beamform

A general technique for synthesizing both planar and conformal beamforming metasurfaces is presented that utilizes full-wave modeling techniques rapid optimization methods. The synthesized consist of a patterned metallic cladding supported by finite-size grounded dielectric substrate. are modeled using integral equations which accurately account mutual coupling the metasurface's finite dimensions. synthesis consists three phases: direct solve phase to obtain an initial metasurface design with complex-valued impedances satisfying desired far-field beam specifications, subsequent converts purely reactive ones, final patterning realize as cladding. introduces surface waves facilitate passivity. optimized gradient descent semi-analytic obtained adjoint variable method. Three examples presented: low-profile directly-fed antenna near perfect aperture efficiency, scanned-beam reflectarray controlled sidelobes, reflectarray. near-field performance verified bandwidth loss tolerance investigated.