Research On Radar Absorbing Material Design And RCS Control Technology

As one important way of radar cross section reduation,radar absorbing materials and its application own great background.In addition,microwave absorbing materials also have be widly used in antenna design.In this thesis,the design of ultra wideband absorbing materials based on lossy frequency selective surface is researched.Frequency selective surface radome with microwave absorption characteristics is studied and the application of the absorbing materials in the design of antenna and is studied.The research work is done as follows:First,based on the investigation of the design principle of Salisbury screen and Jaumann absorber,the pure resistance film of the Salisbury absorbing screen and the Jaumann absorber screen is replaced by a lossy frequency selective surface made up of the resistance film.The frequency selective surface cell can introduce complex reactance components,which partly counteract the reactance component cuased by the grounding dielectric plate.As a result,the bandwidth of the absorbing material is greatly improved.Based on this,a broadband absorbing material based on Lossy frequency selective surface can be formed by combining support medium structure.Based on the principle of Salisbury absorbing screen,Jauamnn absorbing body and circuit analog absorbing material,the thesis analyses the equivalent circuit of absorbing material based on the lossy frequency selection surface,and designs the ultra wideband,low thickness and low cost absorbing materials which can cover 2-18 GHz by designing and optimizing the multilayer composite structure.Next,based on the proposed microwave absorbing materials,the frequency selective surface radome with microwave absorption characteristics and its application in RCS reduction of an antenna are studied.Finally,the ultra wideband absorbing materialis are used as the absorbing material in the cavity-backed ultra wideband planar spiral antenna and four arm sinuous antennas.Combined with optimizations of the feeding structure,the overall profile of the antenna is reduced from 30 mm to 15 mm.Furthermore,by using the resistance loading and structure optimization,the lightweight and miniaturization design of the antenna is realized.The simulation and experimental results verify the excellent performance of the antenna.Furthermore,the RCS control technology of electromagnetic bait is studied.The contents of this paper can be extended to differen application in RCS control and antenna design,which make it has good reference value and application potential.