Abstract: A windowed function of data signal processing is introduced and applied to t he addition theor em, whichsucceeds in solving the difficult problem: it has a bad result when the r ecursive T-matrix is applied to calculate thewave scattering of electrically large objects and multipole objects in the excitation of TE wave. Another mode of thetotal T matrix is der ived from the integral equation. Finally, the calculation result of two dielectric cylinders pr ovest he effect iveness of the windowed function and the corr ectness of the expression of the total T-matrix.

Key words: windowed function, addition theorem, total T matrix, weight, MoM