Research Of Independent Control Of Different Electromagnetic Waves By Metasurface

Metasurface is a two-dimensional planar structure which is arranged by the sub wavelength electromagnetic cell.The reflection and refraction of the electromagnetic wave can be adjusted by the design of the structure and arrangement of the unit.Because of the characteristics of different polarized electromagnetic waves can be controlled independently by using anisotropic metasurface.This paper designs a polarization splitter working in terahertz waveband and proposes a double feed anisotropic metasurface design which realizes the real-time adjustable outgoing wave polarization.The main research contents are as follows:(1)An anisotropic metasurface is used to split terahertz polarization beam.Calculating the reflection phase distribution of electromagnetic wave required by the generalized Snell's law,using the different electromagnetic wave polarization independent response of anisotropic element structure to find the corresponding reflection phase distribution of cell size.A terahertz polarization beam splitter based on anisotropic metasurface is designed and tested.The test results are in good agreement with the simulation results.(2)By adjusting the phase difference of the two feeds,the polarization mode of a single beam is controlled by an anisotropic metasurface.Using phase compensation theory to calculate the reflection phase distribution of a single point of view for a single feed.In this paper,a dual feed single beam anisotropic metasurface is designed in the Ku band.The relation between the polarization state of the outgoing wave and the phase difference between the two feeds is analyzed when the beam is in the same direction.(3)By adjusting the phase difference of the two feeds,the metasurface is used to control the polarization of multiple beams simultaneously.Calculation of the reflection phase distribution of multi beam generated by a single feed by using the superposition of the surface field.In this paper,a dual feed dual beam anisotropic metasurface is designed in the Ku band.The relationship between the polarization state of each outgoing wave and the phase difference of the feed is analyzed when the two orthogonal feed sources produce the same multi beam.