Analysis And Research Of Integrated Low-scattering Platform Antenna Based On Shaping Technology

Platform antenna stealth technology is committed to solving the problem of military carrier stealth.In addition to requiring the platform antenna to normally radiate electromagnetic waves of a certain power and frequency,it also requires that it does not generate a large radar cross section under electromagnetic wave irradiation.In the conventional RCS reduction method,loading the absorbing material has a great influence on the radiation performance of the antenna,and the metamaterial technology is not very adaptable to the change of the incident angle,while the microstrip antenna is easy to obtain different scattering characteristics and radiation characteristics from the shape design due to its simple structure,which provides the feasibility of solving the antenna scattering problem from the source.This thesis studies the stealth requirements of platform-antenna integration,and designs several antenna scattering reduction schemes based on shaping technology.Different shaping methods are used to reduce the structure mode scatter of the antenna for normal incidence and grazing incidence,and the scattering characteristics of the integrated model of the platform antenna are analyzed.Firstly,the reasons for the strong in-band scattering of the cross-polarization of antenna under the normal incidence of plane waves are analyzed,and the 2×2 hybrid passive cancellation array is designed by using the method of slotting to control the reflection phase to realize the in-band RCS reduction under this polarization.Secondly,a dual-passband FSS ground is designed for the antenna for the out-band ground specular scattering.The FSS ground can achieve broadband RCS reduction without reducing the antenna gain.In addition,a fractal low-RCS antenna is designed based on fractal technology.The fractal slotting technology is applied to the design of the antenna ground,and the broadband scattering reduction characteristics are obtained under the condition of ensuring the antenna gain.In view of the traveling wave scattering effect of the ground under grazing incidence of the antenna,a sawtooth slotted ground is designed,and the antenna is loaded on the ground to eliminate the influence of the ground traveling wave scattering effect on the antenna scattering.In order to suppress the strong structural mode scatter of the antenna in the case of grazing incidence,the traditional microstrip square patch is first subjected to slot shaping treatment,which avoids the generation of high-order resonance and reduces highfrequency scattering.The integrated structure with the stealth platform was analyzed for scattering,and good scattering reduction characteristics were obtained on the elevation plane.Then,in view of the poor adaptability of slotted shaping to azimuth angle changes,an antenna unit and array with slotting and filling technology were designed.While ensuring the antenna area,the antenna is formed into a streamlined structure,and the sharp part of the tail is cut to improve the high-frequency scattering reduction effect,and low scattering characteristics are achieved in the X-band and Ku-band.Through analysis,the low-scattering characteristics of the integrated structure in the wide-bandwidth and wide angular domain are realized.