An inner outer iteration scheme for the spurious free solution of polynomial eigenvalue problems of electrically large structure

It is of critical importance to efficiently and accurately evaluate both the internal and external resonances of three dimensional closed and open-radiating structures. Regarding the polynomial eigenvalue problem for the case of both lossy and open radiating structures the spurious modes are being suppressed by appropriately enforcing the “divergence-free” constraint equations over the whole domain. For the spurious modes suppression, two newly presented techniques are implemented and tested for the first time in conjunction with both direct and iterative solvers exploiting Arnoldi algorithm.