Abstract : Microstrip reflectarrays combine advantages of both conventional reflectors (feed efficiency, low cost) and planar microstrip arrays (low profile, possibility to shape or tilt the radiation pattern). The radiation pattern of the reflectarrays is controlled by the array elements phase law. For many years, investigations are led on reflectarrays in order to get broadband, low losses and low cost antennas. This study focusing on passive dual-polarized microstrip reflectarrays for satellite telecommunication applications in the Ku band. The behavior of a microstrip patch loaded by slots is analysed. The cell is defined by many geometrical parameters offering numerous solutions to achieve a given phase. Thus, this cell diversity leads to a large number of distinctive generable layouts. In this work, a synthesis process taking advantage of the cell diversity is proposed. It is based on the use of cell selection strategies. The objective is to obtain one layout that respects specifications in term of coverage, losses and bandwidth. In this thesis, four cell selection strategies are presented and compared by the measurement of the four 22 lambda x 22 lambda reflectarrays at 14.25 GHz. The proposed synthesis process can be validated and the conception rules obtained are then applied to a realistic size of reflectarray. Its simulated performance seem to be very promising.