Numerically efficient method-of-moments formulation valid over a wide frequency band including very low frequencies

A method of moments (MoM)-based procedure is developed for efficient treatment of scattering problems over a wide frequency band where many of the conventional algorithms often fail. The proposed method uses a type of basis function whose radiated field is expressible in a convenient closed-form. This, in turn, circumvents the need to either employ the Green´s function to formulate the problem, or having to deal with the singularities of the same. Furthermore, since the formulation deals with the electric fields generated by the basis functions directly, without involving the vector and scalar potentials typically employed in the conventional MoM formulation, it is possible to use a uniform formulation over a much wider frequency range without having to resort to special basis functions, for example, the loop-stars. Numerical results validating the accuracy and the numerical efficiency of the proposed method both in the near- and in the far-field regions are included in this study.