  Boundary integral equation methods for analyzing electromagnetic scattering
phenomena typically suffer from several of the following problems: (i)
ill-conditioning when the frequency is low; (ii) ill-conditioning when the
discretization density is high; (iii) ill-conditioning when the structure
contains global loops (which are computationally expensive to detect); (iv)
incorrect solution at low frequencies due to current cancellations; (v)
presence of spurious resonances. In this paper, quasi-Helmholtz projectors are
leveraged to obtain a magnetic field integral equation (MFIE) formulation that
is immune to drawbacks (i)-(iv). Moreover, when this new MFIE is combined with
a regularized electric field integral equation, a new quasi-Helmholtz projector
combined field integral equation is obtained that also is immune to (v).
Numerical results corroborate the theory and show the practical impact of the
newly proposed formulations.
