Combined Field Integral Equation Using a Constraint-Based Helmholtz Decomposition

A new version of the combined field integral equation (CFIE) is introduced for the formulation of time-harmonic electromagnetic wave interactions with perfect electric conductors (PECs). The new CFIE-hd formulation is obtained by imposing a Helmholtz decomposition of the current via appropriate surface integral equation constraints. Discretization is performed using a locally corrected Nyström method, and the performance of the resulting numerical scheme is examined for several PEC objects. It is observed that the proposed strategy is frequency stable, provides accurate solutions for the electric and magnetic fields from low to moderate frequencies, and eliminates false interior resonances.