Ultrabroadband Design for Linear Polarization Conversion and Asymmetric Transmission Crossing X- and K- Band.

Linbo Zhang,Peiheng Zhou,Jianliang Xie,Haipeng Lu,Longjiang Deng,Li Zhang,Haiyan Chen,En Li,Haiyan Xie

doi:10.1038/srep33826

Abstract

In this work, a high-efficiency and broadband reflective converter using ultrathin planar metamaterial (MM) composed of single-layered SRR is firstly realized. Numerical and experimental results demonstrate that the cross-polarization conversion reflectance above 0.84 is achieved from 8.6 to 18.6 GHz for linearly polarized (LP) incident waves under normal incidence. Subsequently, a multi-layered MM based on SRR enables a dramatic improvement of the recently demonstrated asymmetric transmission (AT) effect. Theoretical and measured results present that strong one-way transmission of two orthogonally polarized waves crossing C- and K- band has been observed. These two separated AT pass-bands have a function of selective polarization filter, which can be switched on/off by changing the polarization state of incident waves. The physical mechanisms are elucidated by taking advantage of electric fields and current distributions. Considering the broad bandwidth and the dual band, we believe that these two structures will be beneficial for designing polarization-controlled and selective transmission converter.

Highlights

Metamaterial (MM) – artificial EM structure with unconventional elements – has opened new routes towards the efficient manipulation of EM propagation due to its unusual properties[19,20,21,22]
A multi-layered MM based on split-ring resonator (SRR) enables a dramatic improvement of the asymmetric transmission (AT) effect
Theoretical results show that the multi-layered MM can achieve cross-polarization with broad bandwidth and high efficiency for two orthogonal linearly polarized (LP) EM waves in two separated frequency regions, where LP waves can be mostly converted to its cross-polarization and transmitted

Summary

Introduction

Metamaterial (MM) – artificial EM structure with unconventional elements – has opened new routes towards the efficient manipulation of EM propagation due to its unusual properties[19,20,21,22]. The physical mechanisms of the polarization conversion and AT effect can be explicated by Lorentz-theory approach and Fabry-Perot like resonance model[3,47,48,51,52] These intriguing features make it possible to give us some new idea to design high magnitude and broadband converter. We firstly present a high-efficiency and broadband reflective converter using ultrathin planar MM, which are capable of converting a LP wave into its orthogonal polarization. This device exhibits wideband property numerically as well as experimentally. The phenomenon can be functionalized as a dual-band polarization-selective filter by changing the polarization state of incident waves

Methods

Results

Conclusion