Fig. 3
From: Extremely wideband ridge gap waveguide-based 3-dB coupler using supershaped coupling apertures
Central cross-section of the coupler and even and odd modes. The step dimensions on the ridges are defined by a width ws = 1.54 mm and a height hs = 1.07 mm, while the coupling region between the waveguides spans a width of 5 mm.
