Antenna radiation pattern control through 3D printed inhomogeneous dielectrics

Inhomogeneous dielectrics can be used as antennas or to control antenna radiation patterns. For instance, Luneburg lens antennas have the refractive index distribution of n(r)= [2 − (r/a)²]^1/2. They can achieve one focus on its surface and the other focus at infinity. Inhomogeneous dielectrics can also be used to increase the gain and narrow the beam width of a horn antenna. Moreover, inhomogeneous dielectrics can be realized by a fast and economic manufacturing method, additive manufacturing (AM), which is also called 3D printing technology. It enables 3D fabrication of arbitrary shape and structure by printing layer by layer. By changing the mixing ratio of multiple 3D printing materials, spatially varying dielectric constants can be achieved.