Impedance calculation of complex surfaces-wire structures with multilevel fast multipole algorithm and variational formulation

The multilevel fast multipole algorithm (MLFMA) has a great advantage in analysing the radiation and scattering of complex surfaces with wire attachment. It has a computational complexity of O(NlogN) for a matrix-vector product, which is much lower than the complexity of the traditional full-matrix method in the method of moments (MOM). The low complexity of the MLFMA is especially favorable for fast impedance calculation over a sweep of frequencies for large complex structures. This paper discusses the MLFMA for analyzing surface-wire interconnects. A variational formulation for calculating the input impedance is presented. Measured data and numerical simulation are used to validate the algorithm and the formulation.