Variational nature of Galerkin and non-Galerkin moment method solutions

There is renewed interest in the use of variational methods in conjunction with numerical solutions of electromagnetic radiation and scattering problems. The variational aspects of secondary calculations based on a method of moments (MoM) solution are investigated. These calculations exhibit a type of second-order accuracy, regardless of whether or not the operator being discretized is self-adjoint, and regardless of whether or not testing functions are identical to the basis functions (Galerkin's method). Numerical results support these conclusions and suggest that the advantage of Galerkin's method in actual calculations is grossly overstated.