A fast and accurate O(1) solution to the low-frequency breakdown problem of fullwave solvers

In this work, a fast full-wave finite-element based solution is developed to eliminate the low frequency breakdown problem in a reduced system of order one. It is applicable to general 3-D problems involving ideal as well as nonideal conductors immersed in inhomogeneous, lossless, lossy, and dispersive materials. The accuracy of the proposed method is theoretically guaranteed. Instead of introducing additional computational cost to fix the low-frequency breakdown problem of fullwave solvers, the proposed method significantly speeds up the low-frequency computation with its O(1) solution.