Research On Ultra-Broadband Cross-Architecture Absorber Based On Imidazole Ionic Liquids

Imidazole ionic liquids are becoming a kind of new flexible microwave absorbing materials with strong development because of their excellent dielectric properties,flexibility and easy processing.They show unique advantages in the process of constructing microwave absorbing devices.In order to meet the requirements of improving the effective absorption bandwidth and materialization of the absorber,imidazole ionic liquid is selected as the absorbing material in this thesis.In this thesis,a ultra-broadband cross-architecture absorber based on imidazole ionic liquids is proposed and manufactured.The absorber uses the cross-architecture.Under the condition that the effective absorption bandwidth of two single unit structure is roughly complementary,the composite unit structure can be designed through the cross-architecture,It is possible that its effective absorption band can be wider than that of any single unit structure.The comparison between simulation and experiment shows that the Ultra-broadband cross-architecture absorber has an absorption rate of more than 90% and a relative absorption bandwidth of 153% in the frequency range of 7.5 GHz-57 GHz.Due to the use of symmetric origin structure design,the absorber can work effectively at any polarization angle from 0 ° to 90 °.In addition,the distribution of electromagnetic field vector,current density vector and energy density at the resonant peak is analyzed and summarized in order to improve the interpretation of the absorption mechanism of the cross-architecture absorber.In order to further explore the impact of class cross-architecture on microwave absorbing devices,a positive and negative cross-architecture absorber model with ionic liquid as absorbing material and graphene as regulating material is proposed and constructed.The model uses the positive and negative cross-architecture to arrange the graphene surface.At the same time,the concept of impedance ranking method is proposed based on the special mathematical logic relationship of the positive and negative cross-architecture and the impedance value of graphene.With the help of the impedance ranking method,this thesis finds the corresponding relationship between the graphene impedance value and the resonant peak frequency value of the absorber model,so that the resonant peak frequency value can be any value in the adjustable spectrum range according to the existing data.The adjustable spectrum bandwidth of the absorber is widened to 5 GHz（5.9 GHz-10.9 GHz）.At the same time,the reflection loss of the absorption resonance peak exceeds-15 d B,that is,the absorption rate is 96.8%.Through the research and analysis of the surface current layout at the absorbing resonance peak,this thesis completes the explanation of the absorbing loss source of the positive and negative cross-architecture absorber.In conclusion,due to the excellent microwave absorbing characteristics of imidazole ionic liquids,this thesis combines them with cross-architecture and positive and negative cross-architecture respectively to realize the manufacturing of ultra-broadband microwave absorbing devices and the construction of electrically adjustable micro band absorber model,which provides a new idea for the design and implementation of ultra-broadband and resonant peak tunable absorbers.