Technology Study And Design Of The Opto-mechanical Reflective Microwave Metasurface

Metasurface is an artificial plane structure with subwavelength scale.By designing metasurface units with different sizes,rotation directions,and shapes,the characteristic parameters of incident waves can be controlled.Metasurfaces are widely used in new generation wireless communication,new system radar technology and other fields.However,there are some problems in the current metasurface technology,especially the reconfigurable metasurface,such as complex preparation process and difficult integration.The opto-mechanical metasurface can realize the manipulation of electromagnetic properties only by changing the power of the external excitation,which has the advantages of simple manipulation and fast control response.Therefore,it is widely concerned.The realization mechanism of the opto-mechanical reflective microwave metasurface are studied.Two basic structures are designed.This thesis carries out the corresponding simulation and analysis of the electromagnetic properties,optomechanical coupling properties and mechanical properties of the opto-mechanical reflective microwave metasurface.Moreover,we explored the corresponding preparation process and testing methods.The controllable function of beam direction is experimentally studied and verified.The main research contents and innovative contributions of this thesis are as follows:1.The array arrangement theory of reflective metasurfaces based on generalized Snell's law and the nonlinear opto-mechanical coupling theory of opto-mechanical metasurfaces are analyzed.We analyze the realization mechanism and design method of opto-mechanical reflection microwave metasurface.The metasurface element is optimized and simulated from three aspects: the structural design of electromagnetic resonance,the structural design of mechanical cantilever,and the collaborative optimization of mechanical and electromagnetic characteristics.Finally,two kinds of opto-mechanical reflective metasurface elements and sub arrays in millimeter wave band are designed.2.Based on the theory of structural mechanics and electrodynamics,we model and simulate two kinds of the opto-mechanical metasurface units by using HFSS,COMSOL,PYCHARM,and MATLAB software.The electromagnetic characteristics,optomechanical coupling characteristics,mechanical properties of the metasurface element were obtained.In the end,we simulate three kinds of metasurface excited by plane waves,which achieve beam deflection from 0 ° to-29.5 °,from 34 ° to 0 °,and from 0 ° to 25 °.In addition,we obtained the corresponding xoz plane electric field path diagram,Ey farfield radiation direction diagram,etc.At the same time,the simulation obtains different electromagnetic characteristics of arrays of different sizes under the excitation of horn antennas of different heights.3.The test results show that the central operating frequency of metasurface is 28 GHz,the relative operating bandwidth is 2.1%,and the abnormal deflection angle is 35°.When the EIRP value of the applied power varies from 41 dbm to 47 dbm at 3dbm intervals,the reconfigurability of the abnormally deflected beam is obviously observed.The experimental results are basically consistent with the simulation results.Finally,the function of controllable beam direction is realized.In this thesis,the research and design of opto-mechanical reflective microwave metasurface provide a new idea for intelligent reflective metasurface.It can be used in military and civil fields such as wireless communication network and UAV communication system.