Probing Split-Ring Resonator Permeabilities with Loop-Gap Resonators

TL;DR

This paper introduces a method to experimentally measure the complex permeability of split-ring resonator arrays in metamaterials at microwave frequencies using loop-gap resonators, enabling better characterization of their electromagnetic properties.

Contribution

The paper presents a novel approach employing loop-gap resonators to determine the effective permeability of SRR arrays, including design proposals for different array configurations.

Findings

Resonance frequency and damping constants can be extracted from reflection measurements.

Method successfully demonstrated with a toroidal LGR loaded with a single SRR.

Designs enable characterization of both 1D and 3D SRR arrays.

Abstract

A method is proposed to experimentally determine the effective complex permeability of split-ring resonator (SRR) arrays used in the design of metamaterials at microwave frequencies. We analyze the microwave response of a loop-gap resonator (LGR) whose bore has been partially loaded with one or more SRRs. Our analysis reveals that the resonance frequency, magnetic plasma frequency, and damping constant of the effective permeability of the SRR array can be extracted from fits to the reflection coefficient (S11) of an inductively-coupled LGR. We propose LGR designs that would allow both a one-dimensional array of SRRs and small three-dimensional arrays of SRRs to be characterized. Finally, we demonstrate the method using a toroidal LGR loaded with a single extended SRR of length z.