Abstract: A lens antenna including at least one diffractive dielectric component capable of shaping a microwave frequency wave front having a wavelength comprised in a range from 1 millimeter to 50 centimeters, said diffractive dielectric component including a plurality of main microstructures formed in a substrate material with a substrate refractive index so as to form an artificial material of an effective refractive index, each main microstructure having a size of less than a target wavelength taken from said range of wavelengths, said main microstructures being laid out per zones, so as to make a surface filling level vary, the effective refractive index being a function of said surface filling level, the layout being such that the effective refractive index varies inside said one zone of said diffractive dielectric component quasi monotonously between a minimum value and a maximum value less than or equal to the substrate refractive index.