A Review of the Modal Decomposition Matrix for Calculating the Far Field of an Infinitely Flanged Rectangular Waveguide

We determine the radiation from an infinitely flanged rectangular waveguide using the modal decomposition matrix (MDM) method. The MDM method computes the electromagnetic field components at the aperture in the Fourier domain by representing the radiated field in terms of a sampling of the free-space transverse wave number. The results of the MDM approach show good agreement with numerical approaches using commercial electromagnetic modeling software.