The Research Of Terahertz Demultiplexer Based On Metamaterial

Terahertz communication technology is a promising broadband communication technology for 6G mobile communication applications.The wide frequency band and multiple windows of the terahertz band make WDM technology possible to be applied to terahertz communication systems.THz wave division multiplexing devices are essential components in terahertz communication systems.It is vital to research terahertz demultiplexers since their theoretical research value and potential practical significance.Firstly,this thesis analyzes the research status of terahertz wave demultiplexers at home and abroad in more detail and analyzes the electromagnetic response,equivalent medium theory,equivalent circuit theory,and spring resonance model of the metamaterials involved in the terahertz wave demultiplexers,and so on.Secondly,based on metamaterial's resonance response and impedance matching characteristics,designing four metamaterial terahertz wave demultiplexers.Then,electromagnetic simulation analysis of its structure is carried out to study its working mechanism and discuss the influence of structural parameter changes on its operating performance.Among them,the working frequency of the first cutting line type terahertz demultiplexer is 0.225 THz and 0.3THz,the isolation of the two ports is 28 d B,42 d B,and the insertion loss is 0.36 d B,0.08 d B;the working frequency of the second asymmetrical linear terahertz demultiplexer is 0.225 THz and 0.3THz,the isolation of the two ports is 31 d B,32 d B,and the insertion loss is 0.23 d B,0.06 d B;the working frequency of the third two-line terahertz demultiplexer is 0.225 THz and 0.35 THz,the isolation of the two ports is 48 d B,36 d B,and the insertion loss is 0.12 d B,0.15 d B;the working frequency of the fourth dual U-shaped terahertz demultiplexer is0.225 THz and 0.41 THz,the isolation of the two ports is 41 d B,43 d B,and the insertion loss is 0.1d B,0.09 d B,respectively.Compared with the cutting line type and asymmetric line type terahertz demultiplexer,the double line type and the double U type terahertz demultiplexer have more significant advantages in structure and performance.Therefore,the latter two devices are selected for processing and testing.The simulation results and experimental test results are analyzed,and the reasons for the errors are analyzed.In summary,the metamaterial-based terahertz demultiplexer designed in this thesis has the advantages of large isolation,small insertion loss,and stable group delay.The designed terahertz device is expected to promote the development and progress in the field of terahertz communication in the future.