The Decoupled Potential Integral Equation for Time-Harmonic Electromagnetic Scattering

We present a new formulation for the problem of electromagnetic scattering from perfect electric conductors. While our representation for the electric and magnetic fields is based on the standard vector and scalar potentials A, phi in the Lorenz gauge, we establish boundary conditions on the potentials themselves rather than on the field quantities. This permits the development of a wellconditioned second-kind Fredholm integral equation that has no spurious resonances, avoids low-frequency breakdown, and is insensitive to the genus of the scatterer. The equations for the vector and scalar potentials are decoupled. That is, the unknown scalar potential defining the scattered field, phi(scat), is determined entirely by the incident scalar potential phi(inc). Likewise, the unknown vector potential defining the scattered field, A scat, is determined entirely by the incident vector potential A(inc). This decoupled formulation is valid not only in the static limit but for arbitrary omega >= 0. (C) 2016 Wiley Periodicals, Inc.