Design and optimization of a graphene-enhanced tunable wire-grid-like polarizer operating in the 0.5–0.75 THz band

Abstract

Wireless networks are experiencing a surge in demand for data bandwidth, necessitating higher performance and faster data rates. However, conventional signal processing techniques are inadequate for potential future developments that require the use of higher carrier frequencies. The terahertz region of the spectrum has become an increasingly prominent area of research for wireless communication applications. However, components commonly utilized for lower frequency ranges exhibit inefficiencies and significant losses when operating at terahertz frequencies. Furthermore, the miniaturization of antenna sizes to the micrometer scale has made the concept of perfect electric conductor ineffective in the terahertz range. Therefore, it is imperative to establish a reference system of electromagnetic devices. Due to the essential role of polarization in wireless communication and the convenient and widely used properties of wire-grid polarizers, this article establishes a reference for the polarization effect of wire grid polarizers and obtains their optimal parameters. The optimal parameters are 61.58 μm distance, 20 μm thickness and 20 μm width within the frequency band from 0.5 THz to 0.75 THz. We proposed a three-layer structure consisting of copper wire-grids, monolayer graphene, and silicon dioxide substrate to combine the remarkable electromagnetic properties of graphene with wire-grids polarizer. The resulting graphene-enhanced polarizer achieved excellent polarization improvement, with a strongly reduced S21 transmission magnitude up to −55 dB compared to the case without graphene, representing an approximately 20 dB decrease.