Analysis The Electromagnetic Characteristics Of The High Efficiency Microwave Devices Based On Metamaterials

Metamaterial is an artificial structure composed of subwavelength metal and dielectric elements arranged periodically.The amplitude and phase of electromagnetic wave can be adjusted by reasonably designing the unit structure.Thus,it can realize wave absorbing stealth and electromagnetic wave polarization control.Based on the special electromagnetic properties of metamaterials,this paper designs high-performance absorbers and polarizers for microwave band applications and investigates their electromagnetic properties respectively.The main works are listed as follows:(1)Based on transparent indium oxide(ITO)resistive film,two transparent perfect absorbers are designed.The first one is ultra-wideband rigid transparent perfect absorber.The resonant structure is composed of Jerusalem and cross shaped ITO resistive film.The absorber uses transparent organic glass(PMMA)as the dielectric layer,which can be used in Windows stealth and other scenes.The simulation results show that the composite structure produces electromagnetic resonance at different frequency points,which makes the absorber achieve an absorption efficiency of more than 96% in the range of 3.6-8.6 GHz(relative bandwidth 82%).The structure has wide incidence angle and wide polarization angle absorption characteristics.The second one is a flexible transparent perfect absorber.The resonance structure at the top of the absorber is improved from Jerusalem structure,which effectively optimizes the impedance matching between the absorber and the free space.The second absorber is a flexible transparent perfect absorber.The resonance structure at the top of the absorber is improved from Jerusalem structure,which effectively optimizes the impedance matching between the absorber and the free space.The absorber achieves more than 96% absorption efficiency in the bandwidth range of 3.3-6.7 GHz.The absorber uses flexible and transparent polydimethylsiloxane(PDMS)as the dielectric layer to solve the conformal stealth problem of irregular objects.The absorption mechanism.is analyzed by impedance matching theory and field distribution theory to explain(2)A high-performance polarization converter with multilayer open-ended resonant rings is proposed.The simulation results show that the incident y-polarization wave is converted to its perpendicular x-polarization wave in the range of 2.7-4.6 GHz,and the polarization conversion rate is more than 99%,and the polarization conversion mechanism is analyzed through the property of the electromagnetic resonance.Finally,the polarizer sample is tested by experiment,and the test results are consistent with the simulation results.It has broadband polarization characteristics,which verifies the feasibility of the structural design of the high-performance polarizer.