Linear and Elliptical Antenna Array Synthesis Using Frilled Lizard Optimization for Maximum Sidelobe Level Reduction

This study investigates the use of Frilled Lizard Optimization (FLO) for the synthesis of linear antenna arrays (LAAs) and elliptical antenna arrays (EAAs) in 5G-oriented communication applications. The excitation amplitudes were optimized to minimize the maximum sidelobe level (MSL), whereas the excitation phases, element locations, and geometrical parameters were kept fixed for each array configuration. Fixed first-null beamwidth (FNBW) conditions were considered during the synthesis process. The proposed approach was evaluated using five array configurations: 10- and 16-element LAAs and 8-, 12-, and 20-element EAAs. FLO was executed over 20 independent runs for each case. The best MSL values were compared with those reported for selected metaheuristic methods under the same fixed FNBW conditions. Mean MSL and standard deviation values were also considered for the EAA cases. The results showed that FLO achieved the lowest best MSL values among the compared methods in all evaluated configurations. In LAA cases, lower sidelobe levels were achieved while maintaining comparable main-beam characteristics. For the EAA cases, FLO also produced the lowest best and mean MSL values, together with low standard deviation values across the independent runs. These results indicate that FLO is a competitive optimization approach for sidelobe reduction in LAA and EAA synthesis under fixed FNBW conditions.