Designing metamaterial four-channel terahertz demultiplexers for terahertz communication bands

Abstract In this paper, a metamaterial terahertz demultiplexer is proposed, whose structural unit consists of a vertical bar-type metal wire on the top layer and three open metal square rings on the bottom layer. The demultiplexer shown in this paper has higher isolation and lower insertion loss than the photonic crystals and silicon on insulators used today. The terahertz demultiplexer is designed to operate in the dual bands 0.275–0.296 THz and 0.356–0.450 THz within the terahertz communications spectrum. The device achieves effective separation of four different terahertz beams centered at 0.17 Terahertz, 0.28 Terahertz, 0.36 Terahertz, and 0.47 Terahertz, with isolation levels of 36.2 dB, 32.2 dB, 31.0 dB, and 31.6 dB, respectively, and with insertion losses of around 0.9 dB. The demultiplexer’s structure is also evaluated by parametric analysis, which reveals the trend of the performance as the parameters change. The results show that the designed terahertz demultiplexer is characterized by small insertion loss and large isolation, and the performance index is less affected by the parameter variations, which has a better application prospect in terahertz communication system.