A broadband MLFMA using pseudospherical harmonics

The Multilevel Fast Multipole Algorithm (MLFMA) is widely used for the acceleration of matrix-vector products in the iterative solution of scattering problems. The MLFMA, however, suffers from a low-frequency (LF) breakdown. This breakdown is usually avoided by hybridizing the MLFMA with a method that does not fail at LF. For example, the Green function can be decomposed using the spectral representation or multipoles. Recently, a novel decomposition was presented, which uses so-called pseudospherical harmonics in the translation operator. In this contribution, the coupling of this method and the MLFMA will be investigated in detail.