Research On Metasurface For Terahertz Communication

The terahertz electromagnetic wave,located between the mi-crowave band and the visible light band,has the dual characteristics of photonics and electronics,which makes it have incomparable ad-vantages in other bands in terms of target detection,ultra-wideband high-speed wireless communication and imaging.But it has the dual characteristics of light waves and electromagnetic waves,so it is not completely suitable for the study of a single theory.Traditional te-rahertz research is often based on terahertz devices,which have the disadvantages of complex configuration,large size,low work effi-ciency,and are not conducive to integration and systemization,which limit the application of terahertz waves in integrated circuits and communications.The metasurface with a two-dimensional pla-nar structure can effectively control the incident electromagnetic wave in the sub-wavelength structure,and has many characteristics such as excellent control ability,low loss and easy integration.It is considered to be an indispensable technology for future communica-tion development.Therefore,this article focuses on the design of metasurface in the terahertz band,studies the regulation of metasur-face on different dimensions of terahertz waves,and combines the needs of terahertz communication to design and realize terahertz de-vices with different functions.The communication based on Terahertz wave will face serious propagation loss and penetration loss because of its special frequen-cy.Therefore,the communication distance and coverage of the Te-rahertz communication system will be greatly reduced under certain transmission and transmission power.To solve this problem,we de-signed an orthogonal polarized multibeam metasurface,which can independently control the different polarized waves of the incoming electromagnetic wave.Without additional aperture increase,it gen-erates a high gain multibeam reflective wave,and different beams can carry useful information for propagation,thus improving the communication distance and coverage of the terahertz communica-tion system.On the other hand,the prototype validation system of Terahertz system implemented by domestic and foreign research teams at this stage has a high transmission rate and bandwidth,but considering the large number of wireless communication devices and scarce spectral resources in today's society,the communication capacity of Terahertz communication system still needs to be further improved.To solve this problem,we designed a dual polarized OAM multibeam metasurface,which enables each generated multibeam to carry a different number of modes of OAM and orthogonal to each other independently.Similarly,different beams can carry useful in-formation for communication propagation,which can effectively improve the communication capacity of terahertz communication system.The two kinds of metasurface designed in this topic are not on-ly suitable for communication in the terahertz frequency band,but also have certain applicability for other applications of terahertz technology,such as wavefront shaping and holography.Simulation and experimental results show that the performance of the four su-per-surfaces designed is in line with expectations.