Gradient index lens antennas find their application in modern wireless communication including radar systems, satellite communication, etc. They can ensure highly directional beamforming, support multibeam operations and beam steering capabilities within a wide angle of view. The development of 3D printing technologies enables the implementation of complex gradient refractive index distribution with high accuracy as well as obtaining a significant reduction in the production time and cost. This paper presents the state of the art in gradient refractive index lens antenna design using different types of additive manufacturing processes. It shows the applicability of 3D printing to a wide range of operational frequency bands from microwave to sub-THz and THz.INDEX TERMS Additive manufacturing, antennas, 3D printing, radio frequency applications, dielectric lens, gradient refractive index lens, lens antennas.