3-D Printing Implementation of an X-band Eaton Lens for Beam Deflection

In this letter, a 3-D Eaton lens with gradient refractive index (GRIN) distribution for beam deflection at X-band is designed, fabricated, and measured. The ideal 90° beam bending of Eaton lens is verified by the numerical simulation with the commercial software COMSOL Multiphysics. The practical refractive index of the lens is realized by controlling the mixing ratio of a polymer to air void. The dimensions of unit cell are designed with effective medium theory and verified by the full-wave simulation software ANSYS HFSS. A polymer jetting 3-D printing method is applied to implement the Eaton lens. The radiation pattern and near-field distribution of the lens are measured using an X-band waveguide as the feed, and the experimental results agree well with the simulated results.