A dual-wideband bi-layered chiral metamaterial to develop cross polarization conversion and asymmetric transmission functionalities for the linearly polarized electromagnetic waves

摘要

A novel modified bi-layered chiral metamaterial (CMM) with dual-wideband cross-polarization conversion and asymmetric transmission (AT) operations is introduced for the transmission of the linearly polarized electromagnetic (EM) waves. To this end, any unit cell of the presented CMM includes a pair of twisted meander-shaped metallic layers arranged on two opposite sides of a thin dielectric slab. The proposed CMM can cover two frequency bands from 8 GHz to 12 GHz and 14 GHz to 15 GHz, which makes it appropriate to be used in X-band and Ku-band applications. The simulated and measured results with acceptable coincidence indicate that the suggested CMM has a significant potential to transform an incident linearly x- (y-) polarized wave into the orthogonal polarization by transmission across the sample along -z (+z) propagation. Parametric studies of the applied structural modifications are investigated to achieve desirable asymmetric transmission. The realized polarization conversion ratio (PCR) has values above 86% at both operating frequency bands. Also, the obtained polarization rotation azimuth angle theta confirms that the plane of the polarization for the transmitted linearly polarized wave rotates relative to the incident one. Furthermore, the procedures of the cross-polarization conversions are investigated by the surface current distributions at two resonant frequencies. (C) 2019 Elsevier GmbH. All rights reserved.