Design and optimization of waveguide-fed non-uniform transverse slot arrays

Design and optimization of non-uniform transverse slot arrays, cut on the broad wall of rectangular waveguides, is presented by the Method Of Least Squares (MLS). Parallel to the approach used by Elliott for the design of longitudinal slot arrays, two design equations are developed for the waveguide-fed transverse slot array, taking into account the non-uniform spacing of the slots. As a common approach in MLS an error function is formulated consisting of three terms (namely those for the input impedance matching, design equations and pattern synthesis). It is then minimized with respect to the slot parameters (namely lengths, offsets, spacings and excitations). Having obtained the slot array parameters, one can design an array of slots which accounts for the desired input impedance matching and array pattern. This approach has the advantage of speed enhancement relative to conventional methods. The MLS design results and those obtained by the HFSS simulation software are in agreement and verify the accuracy of the proposed method.