Patterned Unit Cell Design in Aperiodic Metasurfaces

A technique is presented for the design of printed-circuit unit cells in aperiodic metasurface environments. The method begins with a matrix equation governing electromagnetic scattering from a homogenized metasurface design. The matrix equation is used to find the local electric field exciting the printed-circuit unit cell geometry and to compute the electric field scattered by the printed-circuit unit cell onto its neighbors. A printed circuit geometry is found which scatters the same fields as the homogenized unit cell when excited with the local electric field computed from the matrix equation. A finite-sized, wide-angle reflecting metasurface is designed and realized with printed-circuit unit cells using the new approach. It is shown that the local periodicity approximation cannot be used to accurately design the printed circuit unit cells of the finite, wide angle reflecting metasurface.