This paper presents a new approach for the synthesis and optimization of linear and planar microstrip antennas array. The proposed approach is based on the Minimax method which permits to determinate the optimal combination between the amplitude and phase feed law and spatial repartition of radiant elements so that the synthesized diagram is closed as possible as an optimal desired diagram, defined by a function or a pattern shape. Simulation results show a significant reduction of side lobes level and the close-up of the radiant diagram to the imposed functions either the Gaussian or the pattern shape.