Graphene-based THz tunable ultra-wideband polarization converter

• Published in: Physics letters. A Vol. 384; no. 23; p. 126567
• Main Authors: Sajjad, Muhammad, Kong, Xiangkun, Liu, Shaobin, Ahmed, Afzal, Ur Rahman, Saeed, Wang, Qi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 17.08.2020
• Subjects: Graphene; Polarization converter; Terahertz; Tunable; Tunable; Terahertz; Polarization converter; Graphene
• ISSN: 0375-9601; 1873-2429
• DOI: 10.1016/j.physleta.2020.126567

•The designed polarization converter has a very simple structure.•Two types multifunction terahertz cross polarization converter based on graphene is designed.•A high conversion ratio (>0.98) over a tri-band is achieved.•The designed converter keep high conversion ratio over an incident angle of 0∘ to 60∘.•An ultra-wideband (3.75 to 11.35 THz) with a conversion ratio of 0.85 is achieved. This paper presents the design and simulation of two distinct reflection-mode graphene cross-polarization converters (CPCs), which operate in the THz region. The first is a tri-band converter capable of converting linear and circular to cross-polarized waves at 6.0, 9.0, and 13.3 THz, with a polarization converter ratio (PCR) greater than 0.98. Also it converts linear to circular-polarized waves at 5.0 and 11.0 THz. The designed converter is stable over incidence angles from 0∘ to 60∘, with a slight degradation in bandwidth near 60∘. The second is an ultra-wideband (3.75 to 11.35 THz) linear to cross- and circular to cross-polarization converter with a PCR ratio of 0.85. The bandwidth of the second converter has been enhanced by using the same structure as the first, but with dual-layered graphene. Furthermore, the proposed structures can be dynamically tuned by varying the chemical energy of the graphene, without needing to modify the physical geometry.