Fast Frequency Scanning of Dielectric Targets Utilizing MLFMM-Maehly Approximation

A rapid approach utilizing the PMCHWT framework with Maehly approximation is suggested for the estimation of monostatic radar cross section (RCS) of the dielectric targets. Firstly, the Chebyshev nodes within a specific wideband are obtained through coordinate transformation. Subsequently, the Method of Moments (MoM) is applied to address the electric field integral equation, enabling the determination of the surface current at the Chebyshev nodes. This process facilitates the computation of the Chebyshev polynomial representing the induced surface current across a broad frequency range, thereby allowing for the calculation of the necessary coefficients. Meanwhile, the Chebyshev polynomial undergoes a conversion process into a rational function through the Maehly approximation technique. Finally, the current is computed at various frequency points falling within the designated frequency spectrum, and the Radar Cross Section (RCS) of the dielectric target is ascertained. Additionally, the utilization of the multilevel fast multipole method (MLFMM) is employed to diminish the computational time required for predictions.