Side lobe level (SLL) reduction has a great importance in recent communication systems. It is considered as one of the most important applications of digital beamforming since it reduces the effect of interference arriving outside the main lobe. This interference reduction increases the capacity of the communication systems. In this paper, our home made synthesis scheme that is based on the Method of Moments and the Genetic Algorithm to synthesize linear antenna arrays is utilized. The algorithm accepts a desired radiation pattern and provides the excitation coefficients that realize the required pattern. If this pattern is applied to the synthesis scheme, it results in the optimum element spacing and the excitation coefficients that lead to maximum SLL reduction with a minimum number of array elements. The MoM/GA scheme provides SLL reduction with exactly the same half power beamwidth (HPBW) as the original array pattern.