Optimum design of travelling rectangular waveguide edge slot array with non-uniform spacing

Slot arrays on the narrow wall of rectangular waveguides are designed for the realisation of arbitrarily specified radiation patterns. The derivation of design equations is similar to the procedure introduced by Elliott for the broad wall slots. An error function is constructed having four terms: impedance matching, array pattern synthesis, slot design equations and radiation efficiency. The minimisation of the error function is performed by the combination of genetic algorithm and conjugate gradient method, which determines the geometrical dimensions of slots, such as their slant angles, lengths and spacings. The performance of designs by the proposed method of least squares is verified using full-wave simulation software.