A method of moments (MOM) technique is described for analyzing the radiation from two parallels, perfectly conducting circular cylindrical waveguides whose apertures may be noncoplanar. By means of an equivalence principle and the appropriate boundary conditions, a set of integral equations is obtained with surface currents as the unknowns. These integral equations are solved by the MOM to yield the surface currents, from which the radiation patterns for the two waveguides are calculated. Numerical results are presented for two uniform waveguides and for two stepped waveguides. To validate the analysis, these results are compared with corresponding results obtained from other numerical methods and also with practical measurements. ¿ 2000 American Geophysical Union