Abstract—This letter proposes an optimal patch based on the Haar function series and a genetic algorithm to design waveguide-fed traveling-wave arrays. A supercell is designed that provides better pattern characteristics. The conductance and susceptance equations are obtained in terms of offset and resonance length from simulation results. Using Elliot's design equations of the proposed structure, a waveguide slot-fed traveling-wave path antenna array, is designed and fabricated for broadside radiation at 9.5 GHz frequency. The gain of the proposed array is 17.6dB, and 17.7dB, and the side lobe level is -22.5dB, and -21dB in H-plane and E-plane , respectively. Near broadside, radiation is achieved
