Mechanism Research And Verification Of Opto-mechanical Microwave Metamaterials

Electromagnetic metamaterials are a new type of synthetic electromagnetic materials with singular electromagnetic properties.The"wave-matter"interaction in the metamaterial structure enables the efficient coupling of electromagnetic wave energy and structural mechanical energy.Based on this,a special artificial structure of optomechanical metamaterials has been developed.Optomechanical metamaterials have unique advantages in structural design,electromagnetic wave performance control,and multi-physics coupling characteristics.At this stage,the structure of optomechanical metamaterials is limited to nanometer size,which is difficult to process.At the same time,there are few researches on optomechanical metamaterials in the microwave frequency range.In this thesis,an opto-mechanical microwave metamaterial based on flexible medium(FPC)is designed;the synthesis and design methods of opto-mechanical microwave metamaterials are analyzed;the nonlinear coupling mechanism,electromagnetic characteristics,mechanical displacement characteristics and multi-physics coupling phenomena of opto-mechanical microwave metamaterials are deeply studied.Finally,experiments verified the electromagnetic resonance characteristics of this type of opto-mechanical microwave metamaterials and its nonlinear frequency shift characteristics under different incident electromagnetic wave power conditions.The main research content and innovative contributions of this thesis are as follows:1.Analyze the realization mechanism and design method of opto-mechanical microwave metamaterials based on flexible medium(FPC);Construct the optical-mechanical theoretical relationship model in the opto-mechanical microwave metamaterials structure.According to the equivalent circuit analysis method,the theoretically deduced the equivalent capacitance,inductance,resistance and other key performance parameters of an inductance-capacitance opto-mechanical microwave metamaterials based on a flexible medium.The intensity change law of electromagnetic induction current and induced ampere's force generated by the structure.2.Based on the HFSS and COMSOL Multiphysics simulation platform,the induced current distribution characteristics,resonance characteristics,nonlinear characteristics,mechanical displacement characteristics,flexible medium deformation characteristics and multi-physics coupling laws of opto-mechanical microwave metamaterials are studied.The law of physical coupling.The simulation results show that the electromagnetic resonance frequency of the 4/2/1 unit structure of opto-mechanical microwave metamaterials are in the X(8GHz-12GHz)band of about 10GHz;Under the coupling of electromagnetic waves,magnetic fields,solid mechanics,and thermoviscous acoustics,the flexible medium of this type of metamaterial structure deforms up and down as a unified whole.When the incident power density of electromagnetic waves is0.04W/mm~2,the deformation displacement of the flexible medium can reach up to 6um.3.Based on the optical-mechanical coupling model,combined with magnetostatic theory,electrodynamics theory,structural mechanics,and nonlinear coupling theory,the nonlinear coupling mechanism and multiplicity of the elastic force and electromagnetic induction ampere force of opto-mechanical microwave metamaterials are studied.Steady-state nonlinear phenomenon.The three stable states of this kind of opto-mechanical microwave metamaterials with the strength and frequency of the EM wave as the influencing factors are analyzed.By means of electromagnetic simulation and experimental verification of the opto-mechanical microwave metamaterials,the electromagnetic resonance frequency shift characteristics of the X-band opto-mechanical microwave metamaterials under the incidence of electromagnetic waves of different powers are analyzed.The experimental results show that when the power of the incident electromagnetic wave increases from 15dBm to 40dBm,the electromagnetic resonance frequency offset of the opto-mechanical microwave metamaterial is 40MHz.The opto-mechanical microwave metamaterials researched and designed in this thesis can be used in many fields such as sensing,microwave circuits and devices,electromagnetic stealth,and so on.The application prospect is wide.