A hybrid method of FMM and multi-region mode

In this work, a fast algorithm is proposed to evaluate the radiation properties of antennas near to or attached on a large-scale three-dimensional (3D) PEC object with arbitrary shape using the fast multipole method (FMM) and MRM. Similar to the conventional MRM, the PEC object under consideration is first divided into multiple regions depending on the position of the antenna in the new model. Then FMM is employed to evaluate the current distribution in the rigorous region. Therefore, the rigorous region is referred as the FMM region in the new model. Furthermore, the mutual coupling among multiple regions has also been considered efficiently using FMM. Numerical results are given to show the validity and efficiency of the proposed algorithm.