Researche and optimization of characteristics of lens antennas based on a homogenous dielectric sphere, taking into account the aberration effects, reflections, dielectric losses, radiator directional diagrams, matching layers and technological tolerance are carried out; the relation of antenna characteristics to its geometrical dimensions and dielectric parameters is derived; the maximum possible antenna characteristics are determined; the characteristics of antennas based on a homogenous sphere and Luneberg lens are compared; the estimation of hydrometeor (water, ice) effect on antenna characteristics is given.