Effects of a low pressure plasma on a negative-permeability metamaterial

Abstract

This article is focused on understanding of the effect of a low-pressure argon plasma on split ring resonator (SRR) metamaterial resonance. After an experimental characterization of SRR arrays that denies reaching critical density at 2.45 GHz, we present an alternative SRR, called sparse SRR, tunable in resonance frequency, that admits higher plasma density in its structure. This innovative structure is characterized with plasma to search for left-handed material signature. Several plasma effects such as gradients and sheaths are quantified. It is shown that plasma shifts the SRR resonance to higher frequencies. The amplitude of the resonance shift can not be estimated without taking into account the sheath thickness. Moreover, the plasma gradient causes the appearance of several distinguishable dips of resonances. These different effects are studied with simulations, highlighting the difficulty to create a left-handed material based on plasma-metamaterial.