On the Efficient Scattering Analysis from Targets with Surface Discontinuities Using An Extended Half-RWG Basis Function

The surface discontinuities in the form of cylindrical protrusions or dents such as rivets, are ubiquities on modern aircraft surfaces and cause significant scattering in certain incident angles. Due to the large contrast in spatial scale between the surface discontinuity and the aircraft body, the full-wave scattering analysis for them is technically challenging in both mesh generation and numerical simulation. This paper proposes an extended Half-RWG (EH-RWG) basis function for the cylindrical-shaped surface discontinuities. The EH-RWG basis function adds a rectangular area based on the conventional Half-RWG basis function; hence the current distribution on the cylinder side surface can be modeled without additional mesh elements. Based on the integral equation discontinuous Galerkin (IEDG) method, the proposed method allows a flexible mesh generation. It improves the simulation efficiency for targets with this particular kind of surface discontinuity. Numerical experiments on low-RCS testbeds verify the accuracy and robustness of the EH-RWG basis function.