Analysis of electrical large radiation problem with precorrected multilevel fast multipole algorithm

In order to accelerate the solution procedure of radiation problems using multilevel fast multipole algorithm, a novel precorrected method is presented in this letter. A rather small impedance matrix in the local region near the feed point is generated to evaluate the local surface current, which could approximately describe the characteristic near the feed point. Because the difference between unknown and the local currents is closer to the zero vectors than the unknown currents themselves, it does need fewer iteration steps using the difference as the unknown vector to get the solution. As is shown, this method could decrease the number of iterations and greatly reduce the time of solution.