Research Of Dynamic Terahertz Beam Steering Based On Electromagnetic Metamaterials

Beam steering of terahertz using terahertz metamaterials is a major research hotspot in the field of terahertz research.In this paper,In this thesis,dynamic phase modulation based on varactor diodes and graphene terahertz metamaterials is studied.Based on this,the effect of dynamic beam steering of an array structure composed of terahertz metamaterials is studied.The main research contents of this thesis are as follows:(1)Combined with generalized Snell theorem,equivalent circuit theory and equivalent medium theory of metamaterials,the modulation of transmission phase by terahertz metamaterials is studied,and the theory of phase modulation metamaterial array to achieve dynamic terahertz beam steering is analyzed with array theory.(2)A phase-modulated terahertz metamaterial based on a varactor diode is studied.The structure of the metamaterial has a period of 800 ?m and operates at 0.1 THz.Within the variable capacitance range of 0.5-7.27 f F,a single-layer metamaterial can achieve 57 ° phase modulation.By superimposing 5 layers of metamaterials,180 ° phase modulation can be achieved,and the array structure formed by it can achieve 0-40 ° dynamic beam steering in both X and Y directions.(3)The beam steering of terahertz metamaterials based on graphene was studied.Within the modulation range of graphene Fermi level 0-1e V,a single-layer metamaterial can achieve a phase modulation of about 80 °.The superposition of 3 layers of metamaterials can achieve a maximum phase modulation of 190 °,and the formed 3 * 3 array can achieve 0-30 ° dynamic beam steering in the X direction.