Frequency Selective Structure Of Printed Graphene Nanoflakes

Graphene is a promising material with high conductivity,which can be used for manufacturing frequency selective structure(FSS)with flexible structure,low cost and good performance.The thesis studies printed graphene conductive composite material and flexible FSS based on it.The main work and results of this paper are as follows.The introduction part summarizes the research trends of printable conductive composites and flexible frequency selective structures.In chapter 2,the preparation,printing technology and conductivity testing technology of graphene conductive composites are studied.By comparing the preparation methods of several graphene conductive composites,it can be seen that the liquid phase exfoliation(LPE)method is the most suitable method to obtain the composites needed for graphene printing process.Based on this type of material,graphene conductive films can be realized by screen printing process,and then improved by post-treatment methods such as drying and rolling.In chapter 3,a FSS with dual stopband and a FSS with circular polarization selectivity are designed.The equivalent circuit method is used to analyze dual stopband FSS.Silver and graphene conductive composites are used as conductor respectively in the design and simulation of FSS.As for circular polarization selective FSS,the principle of polarization selection of incident circular polarization is illuminated.A flexible circular polarization selective FSS is designed.Aiming at the deficiency of three-dimension element structure,a double-layer flexible circular polarization selective FSS is designed.Finally,the preparation and measure of dual stopband FSS based on the printed graphene nanoflakes are implemented.The results show that the designed structure performs well in dual stopband,which proves the feasibility of the printed graphene in microwave and RF domain.