A comparative study of different Calderón preconditioned PMCHWT formulations

The PMCHWT formulation is widely used to analyze the scattering properties of dielectric objects because it is known to be accurate and free of interior resonance corruption. However, the poor spectrum property owing to the electric field integral equation (EFIE) operator involved in the PMCHWT formulation results in a very slow convergence rate in an iterative solution. To improve the spectrum property of the EFIE operator, a Calderon preconditioner is introduced based on the Calderon relation and Calderon identities. In this paper, different Calderon preconditioners are used to accelerate the convergence rate of the PMCHWT solution. The performances of these preconditioners are studied and compared through several numerical examples.