High-frequency scattering analysis of complex targets with biaxially electric anisotropic medium under arbitrary near-field excitation

This paper proposes a unified spectral-domain framework for high-frequency scattering analysis of complex targets coated with biaxially electric anisotropic medium (BEAM) under arbitrary near-field excitation. First, arbitrary electromagnetic sources are rigorously decomposed into spectral-domain plane-wave superpositions via Fourier analysis, enabling seamless integration with layered anisotropic boundary conditions. For BEAM-coated complex targets discretized into surface facets, the propagation matrices are explicitly derived for infinite planar interfaces under plane wave spectrum incidence, enabling single-facet modeling of electromagnetic interactions. Finally, based on the physical optics (PO) method, a Green's function modification tailored for scattering fields on illuminated facets is introduced, and saddle-point spectral-spatial asymptotic evaluation is employed to enable scattering field calculations for near-field excitation and reception scenarios. Compared with Titchener's method, the proposed method is validated, and the simulation results of representative shapes coated with the BEAM layer demonstrate the correctness and effectiveness of the algorithm.