An Inverse-based Multifrontal Block ILU preconditioner for the 3D finite-element eigenvalue analysis of lossy SWSs

In this paper, a novel inverse-based multi/rantal block ILU preconditioner is praposed, which is derived from the complete multi/rantal method and the inverse-based dropping strategy. The new preconditioner is used to solve the large-scale complex unsymmetric linear systems arising from the 3D finite element eigenvalue analysis of lossy slow-wave structures of traveling-wave tubes. In the simulations of many slow-wave structures, the 3D finite element eigenvalue analysis of lossy slow-wave structures based on this pre conditioner has shown the high-efficiency computational performance and the low memory requirement. It is shown that this novel preconditioner is very useful to design the lossy slow-wave structures for high-efficiency traveling-wave tubes.