Nonconforming discretization of the Combined-Field Integral Equation with volumetric testing

Recent attention has been devoted to the development of nonconforming method-of-moment (MoM) implementations of the Electric-Field Integral Equation (EFIE), which provide current solutions with no continuity constraints between neighboring facets. These schemes rely on the testing of the fields over small volumetric domains attached to the surface triangulation, inside the body under analysis. In the scattering analysis of closed conductors with edges and corners, improved accuracy is observed when compared with the conventional RWG-discretization of the EFIE. Similarly, in these cases, the Galerkin MoM-implementation of the Magnetic-Field Integral Equation (MFIE) with the monopolar-RWG basis functions, a low-order example of nonconforming set, shows improved accuracy with respect to the poorly accurate RWG-discretization of the MFIE. In this paper, we show RCS-results for the monopolar-RWG MoM-implementation of the Combined-Field Integral Equation (CFIE), which arises from the linear combination of the EFIE and the MFIE. As expected, it offers improved accuracy for the sharp-edged conductor tested with respect to the conventional RWG-discretization of the CFIE.