Demonstration of Metamaterial-Enabled Overlapped Subarray for a Linear Array

Known overlapped subarray antennas combine array elements in a complex corporate or space-fed beamforming network, resulting in reduced scan loss and grating lobes. In this paper we demonstrate an overlapped subarray antenna enabled simply by a low index metamaterial lens (metalens) over a 5 horn line array. The metalens was designed to spread the field from the horn element with an aperture field distribution that generates an element pattern with flat top and low sidelobes. The paper presents the analytical technique used in the lens design, shows predicted and measured patterns, and discusses challenges and opportunities for achieving wide bandwidth and full scan from a 2-dimensional aperture array with a metalens.