A SINGULARITY FREE MOM-TYPE OF FORMULATION USING THE DIPOLE-MOMENT-BASED APPROACH (Invited Paper)

In this work we present a new physics-based approach for formulating MoM problems based on the use of dipole moments (DMs) — as opposed to the conventional Green's functions. The proposed technique is valid over the entire frequency range without any need for special treatments and is also free of singularities associated with the Green's function. The DM approach can be used equally well to both PEC and Dielectric objects. We also introduce certain refinements to the DM method to improve its computational efficiency like the use of higher-order basis functions, combining the DM with the Characteristic Basis Function Method (CBFM), the use of closed-form expressions for the calculation of interaction matrix elements and employing Fast Matrix Generation (FMG) for electrically large problems. We also demonstrate ways to incorporate lumped loads, capture sharp resonances even at low frequencies, calculate the input impedance of small antennas, calculate fields from irregular geometries; from faceted surfaces; from geometries with slot and slit; and also demonstrate the capability to model microstrip line type of geometries with fine features.