Research On RCS Reduction Of Microstrip Antenna And Antenna Array

The stealth performance of objects is becoming more and more important in modern electric wars, which is the key factor to enhance penetration capability and safety. As a special scatterer, antenna is one of the main sources of scattering for its carrier for its high gain. So how to reduce the scattering of the antenna system is crucial for enhancing the stealth performance of the entire platform. Meanwhile, to ensure the antenna works normally, the radiation characteristics of the antenna should not be weakened when the RCS of the antenna is reduced. Therefore, the conventional stealth measures, such as coating absorbing material can not be applied to the antenna. This paper focuses on the research about RCS reduction techniques of microstrip antenna and antenna array. Two effective methods are proposed to reduce the RCS of microstrip antenna and array antenna, and low RCSs microstrip antenna and antenna array are designed with applications of these methods. Researches show that with the application of these methods not only the RCSs of the microstrip antennas and microstrip array antenna are effectively reduced, but also the radiation performances of the antenna and array antenna are well kept.The main work of this paper can be summarized as the following three points:1. The basic structure and principle of a rectangular microstrip antenna are studied. According to the cavity mode theory of microstrip antenna, the slotting and loading shorting pin techniques are both used to propose a lower RCS microstrip antenna structure. This method can effectively reduce the out-band RCS by bringing down the higher order modes of microstrip antenna.2. The characteristics of UC-EBG are researched. Utilizing its characteristics of band-stop and in-phase reflection, UC-EBG structure is applied to reduce the RCS of microstrip antenna. A low scattering microstrip antenna is designed by loading the UC-EBG structure around the radiation patch of the antenna. The impact of the UC-EBG structure to the monostatic RCS and the bistatic RCS of microstrip antenna under incident plane wave with different polarization is analyzed. The simulation results show that the in-band backscatter of microstrip antenna can decline13dBsm, while the radiation performances are kept. It indicates that this method is an effective method to reduce the RCS of the microstrip antenna. 3. According to the research results of the UC-EBG structure in microstrip antenna RCS reduction, two kinds of4elements antenna array are designed with UC-EBG loaded aiming at in-band and out-band RCS reduction respectively. The results show that the in-band or out-band RCS of the antenna array can be reduced by adjusting the dimension of UC-EBG structure, while the radiation performance is not weakening.