Controlling electromagnetic waves using tunable gradient dielectric metamaterial lens

We propose a metamaterial particle which is composed of a dielectric block with a thin metallic rod screwed inside. By adjusting the height of rod inside the dielectric block, we can control the effective medium parameters of a periodic structure composed of the particles. An experiment is presented to retrieve the effective medium parameters, which have good agreements with those from simulation results. Using the unique property of the tunable particles, gradient metamaterial lenses are easily designed to deflect and focus the incident plane waves.