Study On Electromagnetic Shielding Effectiveness Of Graphene Surface Microstructures

The electromagnetic shielding effectiveness of graphene with different geometric topological structure is studied,which provides a new perspective for the application of graphene.Graphene has high infrared transmittance and high electrical conductivity.Applying graphene to optical windows can alleviate the inherent contradiction between high electromagnetic shielding effectiveness and high infrared transmittance,and provide conditions for the development of more accurate optical detection devices.The electromagnetic shielding effectiveness of graphene was discussed based on high-frequency simulation structure software(HFSS).The electromagnetic shielding effectiveness of graphene with different geometric topologies was studied when the infrared transmittance was constant.The influence of line width,period and thickness on the electromagnetic shielding effectiveness of graphene in the same geometric topology was compared.Different geometric topologies were designed,and the infrared transmittance formula was given according to structures.According to the formulas of different geometric topologies,the electromagnetic shielding effectiveness was compared to 1GHz to 18 GHz when the infrared transmittance of each geometric topology are constant.An electromagnetic shielding effectiveness testing scheme in the range of 0.3GHz to18 GHz was designed after the principle of network analyzer and waveguide testing was analyzed.Finally,the graphene was etched by photolithography.The electromagnetic shielding effectiveness test is carried out according to the designed scheme.The test results of different test fixtures(rectangular waveguide and micro-coaxial)were compared and analyzed.The selection of the rules of the waveguide and flange coaxial in the specific band were given.The simulation analysis of graphene with the same geometric structure shows that when the infrared transmittance is constant,the thicker the graphene thickness,the higher the electromagnetic shielding effectiveness,and the wider the line width,and the higher the electromagnetic shielding effectiveness.When other conditions are the same,the electromagnetic shielding effectiveness of "regular triangle" with different parameters were compared.The electromagnetic shielding effectiveness of "cross" geometric topology is highest from 1GHz to 18 GHz at the same frequency point.Comparing the testing results of the rectangular waveguide and the micro coaxial fixture,it is found that the electromagnetic shielding effectiveness of the graphene measured by the rectangular waveguide is higher than the flange coaxial at the same frequency point.