Radiation and scattering from structures involving finite-size dielectric regions

A full-wave approach to calculating the scattered fields produced by structures that involve finite-size dielectric regions is presented. The dielectric is approximated by a thin-wall structure, and the electric field boundary conditions are applied through the use of appropriate surface impedances. Rooftop basis functions are employed in the moment method approach. The matrix elements are calculated, depending upon the distance between the source and field locations, through a scheme that employs Taylor series expansions and point source approximations. The technique is applied to scattering from dielectric cubes and composite dielectric-conductor structures, and to radiation from microstrip structures. Numerical convergence and agreement with the literature are demonstrated.<>