SPICE‐based modeling of a polarization‐independent active frequency selective surface based tunable absorber with high angular stability

Abstract

AbstractNowadays, demand for active frequency‐selective surfaces (FSSs) is increasing due to their reconfigurable characteristics. Numerical simulations of reactive elements require a model that can replicate their physical realization. Traditionally, reactive elements are modeled as approximated lumped circuits during electromagnetic simulations. However, such lumped circuits might fail to replicate device characteristics at high frequencies, leading to approximate results. This paper presents an alternative method to model reactive elements using their simulation program with integrated circuit emphasis models (SPICE) in circuit co‐simulations. The proposed modeling method is investigated by realizing a varactor‐loaded active FSS‐based tunable absorber. Simulated results indicate that the proposed absorber provides tunability in a wide frequency range from 0.54 to 2.09 GHz under normal incidence when electrostatic bias varies from 0 to 28 V. Moreover, polarization‐independent and exhibits stable frequency response for oblique incidences up to 80° for dual‐polarizations. These characteristics make it a potential candidate for stealth applications.