Frequency-tunable metamaterials using broadside-coupled split ring resonators

TL;DR

This paper demonstrates frequency-tunable terahertz metamaterials using broadside-coupled split ring resonators, where in-plane displacements enable significant resonance frequency shifts, with differences observed between electrical and magnetic excitations.

Contribution

Introduces a novel method for tuning metamaterial resonances at THz frequencies via layer displacements in BC-SRR arrays, highlighting differences between electrical and magnetic excitation tuning.

Findings

Vertical displacement shifts resonance by 663 GHz (51%)

Horizontal displacement shifts resonance by 270 GHz (20%)

Tuning behavior differs between electrical and magnetic excitations

Abstract

We present frequency tunable metamaterial designs at terahertz (THz) frequencies using broadside-coupled split ring resonator (BC-SRR) arrays. Frequency tuning, arising from changes in near field coupling, is obtained by in-plane horizontal or vertical displacements of the two SRR layers. For electrical excitation, the resonance frequency continuously redshifts as a function of displacement. The maximum frequency shift occurs for displacement of half a unit cell, with vertical displacement resulting in a shift of 663 GHz (51% of f0) and horizontal displacement yielding a shift of 270 GHz (20% of f0). We also discuss the significant differences in tuning that arise for electrical excitation in comparison to magnetic excitation of BC-SRRs.