On the variational aspects of the moment method [electromagnetics]

The variational properties of the moment method as applied via the electric field integral equation (EFIE) to perfectly conducting radiators and scatterers with time-harmonic excitation are discussed. It is shown that the admittance, impedance, gain and radar cross-section can be expressed in terms of the self-reaction or the mutual reaction of the electric current distribution induced on the body. Subject to the above restrictions and assuming the usual reciprocity theorems are applicable, it is shown that the reaction is stationary with Galerkin´s method, but it is not when the non-Galerkin moment method is applied in the customary manner. Numerical results are included to compare the performance of the variational and nonvariational moment method