Slot arrays on single-hard-wall waveguides: A study of slot mutual coupling using the aperture integral equation

Corrugated surfaces have been commonly used to design antennas with low cross polarization or chokes to reduce coupling. Recently, soft and hard surfaces have found novel applications due to its ability to control propagation in a desired way. One of these applications is an oversized waveguide with one single hard wall; from now on Single-Hard-Wall Waveguide (SHWW). This waveguide was first presented for quasi-TEM propagation. Later, it was proposed as a promising guiding structure to feed a slot array. The reason for that stands on the unique property of SHWWs: the simultaneous propagation of a plurality of local independent quasi-TEM modes within the same waveguide.