Fast Scattering Analysis of Large Open-Cavity Based Reflectarrays Using a Hybrid Method of Moment and Physical Optics Approach

Journal article, 2025

This paper introduces a hybrid modeling approach for the fast analysis of large reflectarrays. The scattering from a 3-D all-metal reflectarray is modeled by a Perfect Electric Conductor (PEC) sheet with impressed aperture magnetic current sources. These currents are obtained by analyzing the aperture fields of isolated unit cells through the method of moments. The induced electric current on the large PEC sheet is then computed through the Physical Optics (PO) approach, thereby reducing the computational complexity from ON3 for classical MoM to O(N) for PO. The results show, compared to CST, that the total scattered field yields an error of max. 0.32 dB in the main lobe direction for a 5 × 5 reflectarray with peak gain of 21.8 dB. Furthermore, the relative error related to the PO approach is less than 0.13 dBi, which confirms the validity of the hybrid modeling approach.