Power balance in MoM/SIE and FEM solved by Galerkin method

The power balance is analyzed in MoM/SIE for metallic and metallic-dielectric structures and in FEM. The Galerkin method, when applied to the analyzed MoM and FEM formulations of radiating problems, under certain conditions leads to exact satisfaction of the power balance, regardless of the accuracy of the approximate solution. This property can be used for accurate determination of some global parameters of a radiating structure, such as antenna gain. In cases in which the power balance is not satisfied exactly, its error can be used for estimation of the solution error, thus enabling a self error estimation of the applied numerical method.