An Accelerated GSTC-Based Integral Equation Method Using Characteristic Basis Functions for Metasurface-Based Radar Absorbing Material

This letter proposes an accelerated integral equation method using the characteristic basis function (CBF) for metasurface-based radar absorbing material. The metasurfaces are converted into zero-thickness sheets having specific surface susceptibilities, which satisfy the generalized sheet transition conditions in our formulation. To address general problems, we consider the geometry of composite structures in which the perfectly electric conductor (PEC) surface and metasurface are combined to each other. The CBFs are used to reduce the number of unknowns to analyze problems including electrically large metasurfaces. We provide various numerical simulation results to validate the accuracy of the proposed method by comparing the results from commercial finite-element method-based full-wave simulation. Also, we conduct the evaluation and optimization for enhancing the performance of our method.