“…However, when k is large, these techniques are limited in terms of stability because the mathematical structure and physics of the underlying operator, that is the Maxwell operators, are lost during the purely algebraic operations. To overcome this problem, recent promising directions [11][12][13]10,9,22,23,2,19,42,21,41] have emerged by producing new preconditioning techniques based on (pseudo differential) operators calculus and integral equations that are then discretized to get a matrix representation. One crucial point in these approaches is to build approximate and accurate representations of the operators linking the magnetic (M) and the electric (J) surface currents through the so-called Magnetic-to-Electric (MtE) map [51]: MtE(M, J) = 0 on Γ , where Γ is the scattering surface.…”