Research On Low Frequency Stealth Technology Of Aircraft Based On Active Cancellation

With the increasingly complex battlefield environment in modern war,the traditional passive stealth methods can no longer meet the needs of stealth weapons.Active countercounterfeiting stealth technology has been gradually paid attention because of its unique characteristics of flexibility and controllability,and does not affect the structure of the target body itself.In recent years,the research on active cancellation has mostly focused on the waveform,time delay and signal processing algorithm in the time domain,and little discussion has been made on the overall practical application.The research in this thesis mainly focuses on the specific antenna and wing carrier model.On the premise of knowing the information of each field,by adjusting the excitation conditions at the antenna feed end,the cancellation effect has been studied and effective stealth has been achieved,It has certain value for future practical application.After a systematic understanding of the principle of active cancellation stealth,this thesis proposes an active cancellation stealth scheme based on conformal antennas.First,the feasibility of the scheme was verified by using a simple antenna and low scattering carrier model,and then a conformal phased array antenna was designed based on this.Considering factors such as miniaturization,low profile,and easy conformal behavior,a broadband dual polarization conformal phased array antenna suitable for aircraft wings was designed using strong coupling,dielectric loading,and other methods,achieving a bandwidth of 7 times the frequency,a standing wave in the band of<3,and an azimuth of± 45 ° scanning.After the antenna is installed and combined with a low scattering carrier,the radiation and scattering performance of the integrated model is analyzed,which proves the superiority of the antenna as a cancellation source.Based on the designed antenna and low scattering carrier,the effectiveness of active stealth is verified.Using the characteristics of phased array antennas that can perform beam scanning,it is proposed to use beam scanning to point the beam in the corresponding radar incoming direction,thereby achieving stealth while flying.Based on this idea,the cancellation effects were also studied for scanning angles of 0 °,10 °,and30 ° during cancellation.The results showed that various degrees of stealth were achieved,with a maximum RCS reduction of 36 d B,and excellent stealth effects.Secondly,as for the error problem in active cancellation,taking the antenna wing combination in the article as an example,the influence of different errors on the cancellation effect is analyzed from three aspects: amplitude,phase,and polarization.Then,the conformal ability of the antenna was analyzed from a time domain perspective,and a physical object was processed for testing,providing a certain reference for engineering applications.