Optically Transparent Microwave Absorbing Structures Research Based On ITO Material

With the rapid development of science and technology modernization,wireless communication technology has been developed rapidly.With the popular application of wireless intelligent terminals under multi-system,multi-mode and multi-purpose,electromagnetic interference between devices has become an urgent problem to be solved.In the military,with the rapid development of advanced anti-stealth technology,enhancing the stealth effect of targets has also become a research hotspot,of which radar cross section reduction technology has become one of the key technologies.Based on the above,microwave absorbers developed for microwave absorption,electromagnetic shielding and other applications have been proposed one after another,but the current microwave absorbers are generally unable to simultaneously have thin thickness,broadband,high absorption,good flexibility and other characteristics,making them extremely limited in practical applications.Currently,metamaterials have tunable electrical parameters,making them one of the key ways to solve the above problems.In this dissertation,microwave absorbers can achieve high performance microwave absorption and optical transparency will be designed by using ITO(Indium Tin Oxide)metamaterial as core component.The main research work of the dissertation is as follows:(1)Petal-shaped broadband microwave absorber based on metamaterials.In this dissertation,the design of the structural unit is optimized by using optically transparent and flexible absorbers,and its electromagnetic properties are simulated.The simulation results illustrate its excellent absorption capability of achieving over 90%absorption in the frequency band of 33.0-54.5 GHz and its radar cross section reduction capability in the range of 34.2-52.4 GHz.(2)ITO checkerboard pattern absorber.In this dissertation,an ITO checkerboard pattern absorber is designed using a tessellated pattern coding sequence.The absorber not only has a radar cross section reduction of more than 10 dB in the frequency band of 5.03-8.2 GHz,but also has an overall absorption efficiency of more than 90%in the frequency band of 4.08-8.17GHz and its relative bandwidth of 66.8%.(3)Optically transparent coding absorber.Based on the above,an optically transparent coding absorber with a five-layer structure is proposed in this dissertation,and the relevant electromagnetic properties are analyzed in terms of structural unit design,absorption efficiency and radar cross section reduction,and its excellent absorption performance is verified by experimental tests.The absorber achieves more than 90%absorption in the 5.06-9.01 GHz range,and the reflection coefficient can reach -45.21 dB with a total thickness of 6.2 mm,and its thickness at the lowest cutoff frequency of 0.104λ_L.The research work in this dissertation is based on the study of optically transparent absorbing structures of ITO material.By optimizing the structure of ITO conductive film,the designed related absorbing structures are optically transparent and flexible,and all of them achieve better broadband microwave absorption capability and radar cross section reduction characteristics in a certain frequency range.