A Transparent MMW Liquid Fresnel Lens Antenna for 5G Communication

In this paper, a reconfigurable transparent millimeter wave liquid Fresnel lens with dynamic beamscanning capability is proposed. The liquid Fresnel lens consists of a series of rectangular containers fabricated by 3D printing technology. When the ethyl acetate is pumped into the container, the lens unit will provide a 180° phase shift. By pumping in and pumping out of ethyl acetate liquid, a 180° phase compensation strategy can be realized, which is used to focus the incident spherical wave at a desired direction. To verify the proposed approach, the liquid Fresnel lens designed at 24 GHz was fabricated and measured. The experimental results show that the proposed liquid Fresnel lens can not only achieve 0-40° dynamic beam-scanning, but also enhance the gain in the beamscanning direction. With the advantages of simple structure and low cost, the proposed lens will have a wide range of applications in 5G millimeter wave communications.