Multi-Band Multi-Functional Metasurface-Based Reflective Polarization Converter for Linear and Circular Polarizations

Rahul Dutta,Jeet Ghosh,Zhengbao Yang,Xingqi Zhang

doi:10.1109/access.2021.3128190

Abstract

In this paper, we present a simple metasurface based multiband reflective polarization converter for both linear and circular polarizations. We show that, on one hand, the proposed structure can convert the polarization of linearly polarized waves to the orthogonal direction at four frequency bands — 4.3 GHz, 7.2 GHz, 12.3 GHz, and 15.15 GHz. On the other hand, this metasurface can achieve linear to circular or circular to linear polarization conversion at 4 GHz, 4.75–5.95 GHz, 8.35–8.8 GHz and 14.35–14.6 GHz frequency bands. Such multiband operation originates from multiple resonances occurring in the structure based on meandered square ring and diagonal split strip resonator. Moreover, the polarization transforming capability is stable for oblique incident angle up to 15°, for both transverse electric (TE) and transverse-magnetic (TM) polarizations. Furthermore, the proposed structure acts as a meta-reflector that maintains the handedness of the circular polarization upon reflection. Finally, a prototype of the proposed meta-structure is fabricated and measured for both normal and oblique incidence of electromagnetic waves. All the results present excellent resonant stability with respect to the different polarization and incident angles. In addition, we have also performed the tolerance analysis of different material parameters to understand the robustness of the structure. Due to the ability of the structure to perform three functionalities through a single layout, the proposed design can pave its way in different microwave applications such as satellite, radar, and 5G communications.

Highlights

Metasurfaces, known as two-dimensional metamaterials, are sub-wavelength artificial structures that are used to modulate the propagation of electromagnetic (EM) waves
The above mentioned polarization converters are based on singular functionality and due to the the advancement in technologies, there is a great demand for structures serving more than one function
It can be concluded that the proposed reflective polarization converter structure is capable of performing linear-to-circular polarization conversion at these four frequency bands

Summary

INTRODUCTION

Metasurfaces, known as two-dimensional metamaterials, are sub-wavelength artificial structures that are used to modulate the propagation of electromagnetic (EM) waves. Such approaches are bulky in nature and required a long propagation distance to obtain the phase accumulation, limiting their practical applications [13]. The above mentioned polarization converters are based on singular functionality and due to the the advancement in technologies, there is a great demand for structures serving more than one function With this motivation, few researches on multiple conversion, such as LP to LP, LP to CP, of EM waves with the help of a single metasurface have been reported. We theoretically and experimentally determine a compact, ultrathin reflective polarization converter that can achieve different polarization conversions at multiple frequency bands.

DESIGN METHODOLOGY

RESULTS AND DISCUSSION

Findings

CONCLUSION