Simulation and Analysis of a Stacked Intelligent Metasurface (SIM) Architecture in a Real-World Scenario for 2D DFT Implementation

This paper presents a performance analysis of a non-ideal implementation of a Stacked Intelligent Metasurface (SIM) designed to realize a two-dimensional discrete Fourier transform (2D-DFT) transfer function. The study employs a multi-port network model based on the impedance (Z-) matrix representation, which accounts for mutual coupling between the layers of the SIM. The Z-matrix used in the optimization process is derived from numerical simulations of stacked layers composed of metallic strip dipoles over a finite ground plane. A comparison is presented and discussed between the resulting 2D-DFT responses in the realistic model, which includes couplings between non-adjacent layers, and the ideal model, which does not include such couplings.