Switchable near-zero-index magnetic metamaterial for dynamic beam-scanning lens

A design for a switchable metamaterial is presented that allows for digital control over its bulk properties, from near-zero-index to near-free-space at the targeted operational frequency. A distributed shift register is formed over the slab of metamaterial for individual control of varactor diodes within each unit cell, which tune the resonant frequencies of modified split-ring resonators within selected regions of a hexagonal array. The metamaterial was designed using off-the-shelf components for integration into a cylindrical transformation electromagnetics metamaterial beam-scanning lens for dynamic single-feed antenna beamforming.