Wideband Nonuniform Tapered Antipodal Vivaldi Antenna With Improved Radiation Pattern

In this paper, a novel antipodal Vivaldi antenna (AVA) is designed and fabricated using nonuniform taper inner and outer flares. The inner and outer flares Fourier series coefficients are optimized with particle swarm optimization (PSO) algorithm to reduce side lobe level (SLL) on both E- and H-planes. The lower frequency of the proposed AVA is reduced from 9.78 to 5.22 GHz compared with the conventional one. The proposed low-profile antenna has significantly lower SLL versus frequency on both E- and H-planes, and high gain rather than the conventional one. These valuable specifications prove the high performance of the proposed AVA compared with the conventional AVAs.