Analysis of a Rectangular Waveguide, Edge Slot Array With Finite Wall Thickness

A method to analyze a one-dimensional array comprising tilted edge slots cut in the narrow wall of a rectangular waveguide is presented. The fields in the slots are calculated from a hybrid finite element-boundary integral (FE-BI) equation method. The boundary surface integrals on both the interior and exterior surface of the slots are computed from a spectrum of two-dimensional solutions (S2DS), which allows the influence of both the interior and exterior structure of the waveguide to be included rigorously. For initial array design, the mutual coupling between slots in the exterior region is treated approximately with an infinite array assumption modeled by two slots surrounded by periodic boundary walls with an imposed linear phase progression. A short, finite slot array is designed based on the infinite array assumption and fabricated. Results from full-wave analysis of the array and measurements are presented