This paper deals with the design of scalar metasurface antennas able to radiate a well-polarized beam in the far field or near field zones. The equivalent electric current over the metasurface is used to derive design equations to generate the desired field pattern based on the scalar impedance condition. In particular, it is shown that scalar metasurfaces can be used to generate linear and circular polarizations for a fixed pointing direction in the far field by properly changing locally the scalar impedance boundary condition. In addition, they can also be used to generate normal polarized Bessel beams in the near field region. Several solutions are presented at 20 GHz, with different polarizations and feeders developed in the framework of a two-year research project financed by the French space agency (Centre National d'Etudes Spatiales, CNES). Measurements and full-wave results validate the proposed approach.