| The metamaterial absorber is a hot topic of concern in recent years,to explore the absorption of electromagnetic waves for structural response,will greatly promote the stealth materials,solar photovoltaic devices such as microwave absorption and has a very important significance of research and development in the field of exploration.In order to overcome the special drawback of the narrow-band absorber of metamaterial absorber,two different broadband metamaterial absorbers are designed,which can realize wide band and strong wave absorption characteristics of electromagnetic wave.The main research work includes the following aspects:Firstly,the paper presents a multi-layer square structure of ultra wide band design for wave absorbing material,the composite structure superposition between multiple absorption peaks in the electromagnetic field,in the range of 7.76GHz~17.24 GHz resonant frequency,the electromagnetic wave absorption rate reached more than 90%,the absorption of broadband electromagnetic wave band,the overall the thickness of the absorber is only 5.625 mm,establishing the multi-layer type super absorbing material equivalent circuit model of filter structure,explain its broadband absorbing mechanism of extraction of equivalent electromagnetic parameters inversion method by using the S parameter,analyze the absorption characteristics of the surface current distribution unit structure and energy loss distribution,and the changes of cell structure geometry the parameters of metamaterial absorber absorbing properties.Then,the design of a broadband metamaterial absorber based on lumped lumped elements(pure resistor combination)is proposed.In the traditional metamaterial absorber structure loaded with lumped elements,can match the characteristics of electromagnetic impedance loss characteristics and effectively improve the structure,enhance the suction filter loss of electromagnetic wave energy,thus expanding the absorption band.The equivalent electromagnetic parameters and the surface current distribution of the unit structure are extracted by the inversion method to explain the absorption mechanism,and the absorption characteristics of the energy loss distribution of the unit structure are analyzed.The absorber of the working frequency in the range of 7.8GHz~17.2GHz,the frequency band metamaterial absorber absorption rate reached more than 90%,the absorption bandwidth reaches 9.4GHz,the ultra broadband wave absorbing material for the absorption of electromagnetic wave;in addition,also study the effects of changes in the size of the resistance value super absorbing materials for absorption.The etching technology of PCB printed circuit board,fabricated resistor loaded broadband metamaterial absorber structure,using microwave darkroom and vector network analyzer N5244 A system,the absorbing properties of the absorber were tested,test results show that in the frequency range of 6.8GHz-17 GHz,the absorption rate is below-7dB,further verify the effectiveness of the wave absorbing structure design. |
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