A combined FEM/MOM technique of coupling and radiating apertures in rectangular waveguide

Waveguide coupling and radiation by means of apertures is modelled using a hybrid technique which combines the finite element method with the moment method. Unlike the conventional pulse expansion and point matching technique, it ensures the convergence of the resultant admittance matrix elements without introducing any assumptions about the field distribution on the apertures. Coupling and radiation problems formed by a conventional transverse slot in rectangular waveguide and a complex T-shaped slot in a bifurcated waveguide are examined respectively, and excellent agreement has been obtained for both cases when compared both with alternative theoretical predictions and with measurements