Slot coupling control for a novel edge slot array fed by a rectangular single-ridged waveguide

A novel edge slot array using a rectangular single-ridged waveguide is proposed [3]. A thin single ridge is situated at a center of the narrow and the slots are arrayed on the same narrow wall straddling the ridge. In order to avoid producing grating lobes and to excite the slots in-phase, the staggered slots are arranged at an interval of a half guided wavelength. However, slot coupling control by the slot offset is not available since the current distribution on the narrow wall is constant to the transversal direction. In order to solve this problem, another slot is adjoined transversely to the original slot on the narrow wall straddling the ridge [3]. Because two slots are excited out-ofphase, the total radiation from the combined slot is controlled by a combination of lengths of the two slots. Furthermore, the combined slot can be a resonant slot by setting two slots to inductive and capacitive, respectively. This edge slot array radiates vertical polarization. This paper presents slot coupling control of two separated slots for a edge slot array fed by a single-ridged waveguide. Figure 1 presents a configuration of the edge slot array consisting of the two separated slots. The slot pair is arrayed on the ridged narrow wall at a spacing of approximately a half guided wavelength. Radiation power as well as a resonant condition of the slot pair are obtained by using Ansoft HFSS for design of the array. It is exhibited that the slot pair can realize a wide control range of the radiation power and good return loss characteristics.