Design of Single-Layer Dense Metasurfaces on Irregular Grids Using Discrete Dipole Approximation

A design technique for single-layer metasurfaces of planar and conformal profiles utilizing nonperiodic, irregular grids for meta-atom placement is presented. Meta-atoms are placed at the node positions in planar and conformal surface grids created by an unstructured mesher. They are represented by point dipoles using the discrete dipole approximation (DDA), and mutual coupling effects from neighboring resonators are accurately evaluated. Each meta-atom is individualized for representing a desired average current density over the corresponding cell area. Examples of fully reflecting metasurfaces using DDA-based individualized meta-atoms exhibit closer-to-ideal performance than identical meta-atoms on the same grid.