Compound coupling slots for arbitrary excitation of waveguide-fed planar slot arrays

A resonant coupling slot cut in the common broad wall of two crossed rectangular waveguides is analyzed. The slot is offset from the center line and tilted with respect to the longitudinal axis of the main waveguide, whereas it is centered-tiled in the branch waveguide. It is shown that the slot offset and tilt control the branch waveguide excitation amplitude with a phase variability of 360 degrees . Pertinent integral equations are developed, taking into account finite wall thickness. The integral equations are solved for the slot aperture electric field using the method of moments. Dominant mode scattering by the slot in both waveguides is obtained. >