A frequency expansion technique based on iterative solver and lump matrices

With the finite element method, the electromagnetic equations, including frequency dependent material properties, can be written as a power series of frequency. This paper describes a frequency domain expansion method, which combines the preconditioned conjugate gradient method with the Lanczos algorithm. A lump matrix method is also used to accelerate the frequency expansion. A numerical example is included in the paper to illustrate the effectiveness of the proposed methods.