Amorphous Metamaterial With Negative Permeability

This letter investigates a metamaterial composed of ring resonators that are randomly distributed in space both in their positions and their orientation. Such metamaterial behaves as an amorphous material with isotropic response. The main problem of the fabrication of this material is the spread of resonant frequencies of particular planar ring resonators. This spread is caused by tolerances of the fabrication process of planar resonators. Simulation shows that there is a limit of the dispersion of resonant frequencies allowing the metamaterial to behave as metamaterial with negative effective permeability. The amorphous metamaterial with negative permeability was fabricated, and measurement verified the simulation.