Numerical homogenization and synthesis of wave polarizers through the Material-by-Design paradigm
A Material-by-Design (MbD) strategy is introduced for the design of multi-layer wave polarizers based on metasurfaces with arbitrarily-shaped unit cells. Following the MbD paradigm, the design is carried by integrating a solution-space exploration block, an electromagnetic simulation block (exploiting a full-wave Method-of-Moments with periodic boundary conditions), a homogenization block, and a cost function evaluation block. Numerical example showing the effectiveness of the proposed strategy is presented.
Generalized QCTO for Metamaterial-Lens-Coated Conformal Arrays
The use of inhomogeneous metamaterial lenses is proposed to enable suitable radiation properties for arbitrary-shape antenna arrays. Towards this end, the Quasi-Conformal Transformation Optics (QCTO) methodology is generalized to allow an arbitrary physical arrangement coated with a suitable lens to exhibit the same radiating features of an arbitrary reference virtual array in free space. A representative numerical example, concerned with a two-dimensional layout, is presented to assess the effectiveness of the proposed method as well as the enhanced features of the resulting metamaterial-coated arrays with respect to standard conformal arrangements.
Normed units in abelian group rings
We compute explicitly the isomorphic structure of the normalized unit group of an abelian group ring under some minimal natural restrictions on the group basis and the coefficient ring. This enlarges affirmations due to Chatzidakis-Pappas (J. London Math. Soc., 1991) and Mollov (Publ. Math. Debrecen, 1971).