Characterization and performance analysis of a chiral-metamaterial channel with Giant Optical Activity for terahertz communications

Abstract

Technology in the THz frequency band has progressed rapidly in the last few years. The THz frequency band offers greater communication bandwidth than microwaves frequencies, and is becoming a standard for nanoscale communications. Traditional channel models for lower frequencies do not take into consideration specific properties as the very high molecular absorption or the very high reflection loss. In addition, in a propagation medium exhibiting a Giant Optical Activity, it is also important to derive the characteristics of the channel affected by chirality effects. This phenomenon occurs in particular material known as chiral-metamaterials in the (4–10) THz band.The main contribution of this paper consists in the analysis of specific parameters of a chiral-metamaterial, such as the relative electrical permittivity, magnetic permeability and chirality coefficients. These parameters are considered for the channel model derivation both in Line-of-Sight and No Line-of-Sight propagation.The chiral effect affects the channel through the presence of spectral windows, due to peaks of resonance of chiral parameter. Performance analysis of the chirality-affected channel is assessed in terms of (i) channel capacity, (ii) propagation delay, (iii) coherence bandwidth, and (iv) symbol rates, for different distances and propagation modes.