Research On Cancellation Effect Of Targets In Active Stealh Technology

As the traditional passive stealth technology has been difficult to adapt to the requirements of informatization.People are attaching greater importance to the active stealing and stealth technology because of its wide applicability,high flexibility and non-interference to target's own structure and performance.Based on the previous research,this paper analyzes the scattering field distribution and cancellation effect in the target body by using the method of coherent cancellation of electromagnetic waves,adopting the moment method and multi-layer fast multipole algorithm,and using electromagnetic simulation software to simulate scattering between radar waves and cancellation signals in various typical targets.Eventually,the appropriate cancellation signal source parameters are obtained,and the total scattering field of the target body in the direction of the radar incidence is reduced,and an ideal result is obtained.At first,the basic principles of wave interference theory and radar cross section are introduced in this paper.The amplitude and phase conditions of wave elimination are described,and the effects of amplitude error and phase error to cancellation are analyzed.Besides,the scattering properties of typical ideal objects such as cylinders and elliptic cylinders are deduced.Several commonly used electromagnetic scattering calculation methods are also introduced.The Method of Moment and Multi Level Fast Multipole Method are adopted in the electromagnetic scattering calculation methods in this study.They are introduced in detail and verified with examples and data.In the end,we uses electromagnetic simulation software to establish a variety of typical target models.The plane wave source is used to simulate the radar incident signal,and the ideal line current source is used as the cancellation signal source,and the cancellation effect of the parameters of the cancellation source on the target has been studied.As a result,a relatively ideal cancellation stealth is obtained on the targets.The results indicate that scattering electric field amplitude,which towards the direction of radar incoming on the cylinder model,reduced from 1.42 V to 0.1447 V.That means cancellation ratio of the scattering field amplitude is 0.8981,and scattering electric field amplitude,especially 10.25 ° angular domain near the radar,reduced in different degrees.In this way,The results are obtained on the elliptical cylinder model: the cancellation ratio is 0.9857 and the cancellation domain is 8.96.So it is with the spheroid model,the cancellation ratio is 0.9712 and the cancellation domain is 8.67,and its cancellation effect was satisfying.Some practical rules and methods are summarized: In order to realize the targets cancellation effectively,we should adjust the position and angle of the signal source firstly,make the minimum value of the total scattering field of the cancellation signal and the radar signal aim at the radar incident direction.Then adjust the parameter of the cancellation signal intensity,the scattering echo on the radar direction will get further reduced.