The induced MMF method

The method of induced magneto-motive force in calculating the complex radiated power of planar apertures in a perfectly conducting screen is reviewed in this paper. The equivalence between the MMF method and the Fourier spectrum method is pointed out. It is shown that the basic formulas involved in the Fourier spectrum method can be derived from the existing formulas found in Green´s function method. In the case of an aperture excited by a waveguide, the MMF method yields the same results as the one obtained by the variational method using a trial function corresponding to the field distribution of the dominant mode inside the waveguide.