Research On Theory And Application Technology Of The Metamaterial Radome

With the development of science and technology,radar stealth performance of aircraft has become the main index to measure combat effictiveness.The difficulty lies in the radar stealth stealth of antenna system.Metamaterial with its unique electromagnetic properties is playing an important role in RCS reduction of antenna system.The complex scattering properties of the antenna itself give limitation to shaping stealth technology.Reasearch on theory,design and application of absorbing materials with bilateral absorbing bands resistance film is with great value.Taking metamaterial as the research object,the RCS reduction of antenna system as the research goal,no significant reduce of the performance of the antenna as the premise,design,analysis and application of radome structure with bilateral properties was studied.The main works are summarized as follows:1.The proposed design method of radome unit structure with bilateral absorptive bands based on second resonant characteristics of resistive film unit was proposed.The absorbing principles were analyzed using its equivalent circuit model and the design process of absorber layer were studied.The unit design requirements and objectives of resistance layer and FSS metal layer were also analyzed.On this basis,three 5mm-thick radome structures was developed with different polarization characteristics.Their performance was compared.This work provides a theoretical basis and method guidance for the design of bilateral absorber radome.2.Combining the lumped resistance absorbing unit and resistance film absorbing unit,a model of absorber was proposed based on the connection of resistance film unit and copper line.Its absorption principles were analyzed detaliedly through the equivalent circuit model.Also,the influence of main parameters was given.With the typical square ring slot frequency selective surface unit,absortive radome unit was designed,verifying its ability of bilateral absorptivities.Considering the feasibility of engineering application,the unit structure was optimized.The resistance of resistance film elements and copper lines were set on both sides of dielectric substrate separately being connected by the cooper hole.At the same time,new absorptive radome unit was introduced by removing the thick dielectric substrate absorbing unit structure,widening the radome bandwidth and absorption band bandwidth.This new structure expands the scope of application of the radome,and lay a foundation of microstrip antenna array system design with low RCS.3.Taking the bandpass FSS reflector of absorptive radome as the application,a thin double-layer FSS with a flat ransmission characteristics and steep cut-off characteristics was designed.The frequency response characteristics are analyzed through its equivalent circuit model.The impact on response of various parts of the response of main parameters and contribution to the overall requency of transmission characteristics of each subunit was studied.On this basis,combined with absorbing unit,new absorptive radome with the characteristics of good frequency selection was builded.Electromagnetic waves out of band were reflected and absorbed.The radome unit shows better stealth capability by the combination of shaping stealth technology4.Researching on the application of metamaterial radome,analyzing the wave absorbing principle and characteristics of the antenna itself,integrated design of microstrip array antenna and radom was proposed.The radome was made of metamaterial with only absorbing layer.A microstrip array antenna system with low RCS and little effect on antenna radiation was developed.The radome is thin,easy to engineering application.At the same time,for the application of passive seeker,taking the dipole antenna array as an example,the antenna array with cover system was integrated.the influence on the performance of the antenna array angle of radome was emphatically analyzed.