Directivity maximization and optimal far-field pattern of time modulated linear antenna arrays using evolutionary algorithms

In this paper evolutionary algorithm based design of time modulated 16-element linear antenna array with improved directivity and side lobe level (SLL) with low radiated power at sideband harmonics has been dealt with. In time modulated linear antenna array time is used as fourth dimensional parameter. The comparative study has been made with all the possible combinations of control parameters like constant excitation amplitude, inter-element spacing, and “time” as the fourth dimension. The same array radiates at various harmonic frequencies. In this paper the authors have considered only two harmonic frequencies; first sideband frequency and second side band frequency. Various simulation results are presented showing better side lobe performance, better side band performance and improved directivity with respect to the uniform case. The statistical analysis and t-test have been done to prove the superior performance of differential evolution with wavelet mutation (DEWM) better than real coded genetic algorithm (RGA), particle swarm optimization (PSO), and differential evolution (DE).