A hybrid ADI-RPIM scheme for efficient meshless modeling

This paper describes a novel hybrid technique, by combining the original radial point interpolation meshless method (RPIM) and the unconditionally stable leapfrog alternating-direction implicit (ADI-) RPIM scheme, to analyze electromagnetic radiation and scattering problems of multi-scale resolutions. The leapfrog ADI-RPIM is applied to computational regions with dense nodal distributions, while the original RPIM is applied to regions with coarse nodal distributions. In such a way, usage of memory and CPU time with the meshless is optimized without need of temporal interpolation to synchronize different time steps of different regions. Two numerical examples, including a lightning striking on a PEC structure and a substrate integrated waveguide (SIW), are presented to verify the effectiveness and efficiency of the hybrid technique. Numerical examples show that the proposed scheme does not suffer from late time instability or reflection from region interfaces.