Research On Antenna RCS Reduction Technique Based On EBG Structure

With the rapid development of the airborne communication system,the communication environment becomes more and more complex,and a variety of stricter requirements are put forward for the components of the system.As an indispensable front end device,the antenna's stealth performance is being paid more and more attention.The stealth of the antenna is to achieve low visibility and enhance the stealth ability of the incoming electromagnetic wave,so the antenna stealth technology is also the radar cross section reduction technology.Based on a large number of literature research on antenna stealth technology,this paper mainly studies the stealth EBG structure applied to the microstrip antenna and the stealth characteristics of the structure on the broadband microstrip antenna.The research contents are expanded from the following aspects:1.The basic theory of antenna,the radiation principle of microstrip antenna and the broadband band technology are introduced.At the same time,the theory of antenna scattering,including radar cross section,scattering of structure term and pattern term scattering,is analyzed in detail.2.A high impedance electromagnetic band gap periodic structure is designed and applied to the microstrip patch antenna.Under different incidence angles and different polarization conditions,the zero reflection phase wave is used to cancel the scattering of the antenna itself,so that the radar cross section RCS is reduced in a wide range.Compared with the reference antenna,the single station RCS of the microstrip antenna loaded with EBG structure is reduced by more than 3d B in the whole S band,and RCS is reduced by 20 d B in the 1.5GHz to 4.5GHz band.At the same time,the radiation performance of the microstrip antenna is good.The simulation results show that the EBG periodic structure has obvious absorption effect.3.With the broadband technology,while the EBG structure is remained the same,the original microstrip patch antenna is treated with U slot with EBG periodic structure.By doing this,the original bandwidth is expanded to 38%.The single station RCS of the microstrip antenna stealth structure is reduced by more than 3d B in the working frequency band,and the RCS is reduced by 22 d B in the 1.5GHz to4.5GHz frequency band.Moreover,the RCS reduction effect is good under different polarization and multi angle incidence conditions.