Parametric study of the coupling aperture in CPW-fed microstrip antennas

Coplanar-fed microstrip patch antennas with inductive and capacitive coupling are extensively studied with the help of a numerical model. The distribution of magnetic current in the apertures is used to explain the coupling mechanism between the aperture and the patch. The inductive coupling is shown to be dependent on the aperture length and the aperture width, while the capacitive coupling is very sensitive to the feeding line dimensions. The influence of a patch shift over the aperture is also investigated