Extremely Sub-wavelength Planar Magnetic Metamaterials

TL;DR

This paper introduces highly miniaturized planar magnetic metamaterials operating at radio frequencies, achieving unit cell sizes thousands of times smaller than the wavelength, enabling practical low-frequency RF applications.

Contribution

The paper presents a novel dual-layer planar spiral design with via connections that significantly reduces unit cell size relative to the wavelength, advancing magnetic metamaterials for RF use.

Findings

Unit cell size is approximately 700 times smaller than the wavelength.

Using vias, the unit cell size is further reduced to about 2000 times smaller.

Experimental results agree well with numerical simulations.

Abstract

We present highly sub-wavelength magnetic metamaterials designed for operation at radio frequencies (RFs). A dual layer design consisting of independent planar spiral elements enables experimental demonstration of a unit cell size (a) that is ~ 700 times smaller than the resonant wavelength ({\lambda}0). Simulations indicate that utilization of a conductive via to connect spiral layers permits further optimization and we achieve a unit cell that is {\lambda}0/a ~ 2000. Magnetic metamaterials are characterized by a novel time domain method which permits determination of the complex magnetic response. Numerical simulations are performed to support experimental data and we find excellent agreement. These new designs make metamaterial low frequency experimental investigations practical and suggest their use for study of magneto-inductive waves, levitation, and further enable potential RF applications.