Comparison of Floquet Port-Based Unit Cell Design and Characteristic Mode Analysis for Anomalous Reflecting Metasurfaces

A comparison of Floquet port-based design and Characteristic Mode Analysis (CMA) for anomalous reflecting metasurfaces is presented. Floquet port simulations of a unit cell are performed to realize the desired induced phase gradient over the surface. While this method is well established and implemented in commercial software, it offers little insight into the electromagnetics of the structure. Therefore, a CMA utilizing the Floquet theorem is linked to the structure analysis to give further insight into the current distribution of the unit cell. An example setup as well as computational results are provided to compare both methods. It is shown that the CMA method provides advanced analysis of the physical behavior of the reflecting metasurface, which helps to improve the design process.