  This paper presents an extension of the recently introduced planewave density
interpolation (PWDI) method to the electric field integral equation (EFIE)
formulation of problems of scattering and radiation by perfect electric
conducting (PEC) objects. Relying on Kirchhoff integral formula and local
interpolation of surface current densities that regularize the kernel
singularities, the PWDI method enables off- and on-surface EFIE operators to be
re-expressed in terms of integrands that are globally bounded (or even more
regular) over the whole domain of integration, regardless of the magnitude of
the distance between target and source points. Surface integrals resulting from
the application of the method-of-moments (MoM) using Rao-Wilton-Glisson (RWG)
basis functions, can then be directly and easily evaluated by means of
elementary quadrature rules irrespective of the singularity location. The
proposed technique can be applied to simple and composite surfaces comprising
two or more simply-connected overlapping components. The use of composite
surfaces can significantly simplify the geometric treatment of complex
structures, as the PWDI method enables the use of separate non-conformal meshes
for the discretization of each of the surface components that make up the
composite surface. A variety of examples, including multi-scale and intricate
structures, demonstrate the effectiveness of the proposed methodology.
