Bifunctional Luneburg-Eaton Lens Fabricated of 3-D-Printed Anisotropic Medium

Luneburg lens (LL) and Eaton lens (EL) are well known as optical and microwave components. This letter proposes a bifunctional Luneburg-Eaton lens (LEL) fabricated by three-dimensional (3-D)-printed anisotropic medium. The spherical LEL is designed as a LL for incident vertical polarization and as an EL for incident horizontal polarization through the use of anisotropic dielectric. In order to realize a good continuous refractive index, the proposed lens structure is divided into many cells, and the equivalent permittivity of each unit is calculated by using the equivalent media theory. The prototype of LEL is designed and excited by X-band waveguide WR-90, and the ideal results are achieved. The gain of the antenna is from 15.7 to 16.4 dBi in X-band with the LEL functioning as a LL, and the waveguide can have a beam deflection of set angle with the LEL functioning as an EL.