A simple procedure for the design of two-dimensional SWA array systems with desired sidelobe level ratio (SLR) is presented. The described procedure finds the slots length, width, locations and displacements from the centerline, for each branch waveguide. For a specified number of branch waveguides, the method also finds the rotation angle of each of the coupling slots. To explain the controllable SLR, two 2D SWA array systems designed for an SLR higher than 20 dB are illustrated and compared