Accurate Characterization of Bent Waveguide Short Circuit in Waveguide Slot Arrays

In a waveguide slot array it is sometimes required to introduce bent short-circuit terminations. This affects significantly the behaviour of the coupling slots with a reduction in the coupling coefficient up to 90%. A procedure to evaluate accurately the effect of such bends is presented. It is based on the Method of Moments using the MFIE, but expressed in terms of the vector potential which appears to be the most efficient way for waveguide problems. The development is aimed at a very effective implementation, which allows to include it in design tools for waveguide slot arrays without increasing the total computational load.