Abstract: An algorithm is presented for solving electromagnetic problems in special domains with many branches. According to the geometric shape of domains the large matrix is divided into several small ones. The convergence rate of iterative solution is geometrical. The method is applied to the reflecting parameter and phase analysis of the slotting slow wave guide. Then we find the main factors of affecting the above parameter and phase, finally give them the relation curves.

Key words: projective method, orthogonal design, slow wave guide, maximum difference