A new hybrid Finite Element Method for thin material structures

The hybrid finite-element-method / boundary-element-method (FEMBEM) is a widespread tool for the computation of radiation and scattering problems in case of material structures. The method of moments (MoM) represents the exact radiation condition for the free space. The major drawback of the hybrid FEMBEM is the quadratically increasing complexity of the MoM. The material parameters demand a fine discretization because the wave length is shortened. In this case an acceleration of the MoM by applying the multilevel fast multipole algorithm (MLFMA) is not efficient because of the so-called low-frequency breakdown. We have to use a low frequency approach such as the low frequency fast inhomogeneous plane wave algorithm (LF-FIPWA).