A Hybrid Method for Characterizing Complex Unit Cell Designs Used in Domain-Decomposition-Based Finite Reconfigurable Reflectarray Analyses

Paper in proceeding, 2026

This paper presents a hybrid method for the characterization and analysis of complex unit cell designs used in domain-decomposition-based reconfigurable reflectarray analyses. Building on a previously proposed domain-decomposition (DDM) framework based on a generalized aperture-admittance formulation, the reflectarray is split into exterior and interior regions that share a common aperture. The exterior over-the-air coupling between unit cells is modeled by a method-of-moments formulation. The interior problem of each unique unit cell is characterized once for a normal incidence plane wave using a commercial full-wave solver (CST), where the tangential electric and magnetic aperture fields define the interior admittance of the unit cell. This hybrid approach is demonstrated for four waveguide unit cells with different dielectric and reactive loading. The reflection responses of two of these unit cells are subsequently used to synthesize two 1 × 8 reflectarrays designed to steer the main beam to ?=30° under broadside incidence. For all unit cells and array configurations, the peak-normalized mean absolute error in the far-field pattern between the proposed hybrid DDM and CST integral-equation solver remains below 1%. The method is further assessed for an oblique incidence of ?=-20°, with results in very good agreement with CST integral-equation, time-domain, and frequency-domain solvers.