Design considerations for spatially reconfigurable metamaterials

Spatial tuning of a volumetric metamaterial introduces many new design considerations that strongly affect the performance and practicality of a resulting system implementation. This paper discusses the design rules and procedures for spatially reconfigurable metamaterial systems using a tunable near-zero-index slab with adjustable shape as a representative design example. We propose a split-ring resonator-based metamaterial, where each resonator is tuned in and out of resonance using a varactor diode to change the effective material response. The periodic, hexagonal tiles may be combined and connected in a planar spiral to form a cylindrical metamaterial panel whose radius may be arbitrarily large. Multiple panels are then stacked, with appropriate cropping, to form a volumetric metamaterial slab.