Coupling losses of rectangular waveguide resonators are discussed in this p
aper in terms of fourier analysis theorem. Compared to the traditional time
-consuming method, the scheme presented in this paper will decrease the sim
ulation time considerably. Under the conditions given in the paper, the EH1
1-mode coupling coefficient is calculated numerically. The conclusions can
be applied to higher-order mode. (C) 2001 Optical Society of America.