A Novel Multitrace Boundary Integral Equation Formulation for Electromagnetic Cavity Scattering Problems

We present a new multitrace boundary integral equation (BIE) formulation for the solutions of the time-harmonic electromagnetic (EM) scattering from large and deep cavities. Comparing to previously integral equation formulations, the new formulation has two major benefits: 1) it leads to a well-conditioned system equation after multiplicative Schwarz preconditioning and 2) the localized impedance matrices arising from decomposed boundary value problems are immune from cavity resonance effects. We outline the key technical aspects of the new multitrace formulation, give the details of the numerical analysis and report numerical experiments verifying the analysis, and display the capabilities of the proposed methods.