A Study On RCS Reduction Of Vivaldi Antenna

In today’s high-tech information warfare,as an important part of the stealth design,the stealth design has an important and far-reaching influence on the survivability and operational effectiveness of future weapons. As the most effective remote electronic detection equipment, the radar can determine the presence of radar targets and determine the location of the target by the scattered energy of the target to the radar. For the primarily purpose of reducing the radar cross section, the stealth technology asks one’s own equipment to maintain low observability under the detecting of the enemy radars. For airborne stealth platform, as a kind of planar structure, the Vivaldi antenna becomes the preferred solution in today’s stealth aircraft phased array radar antenna unit. Although Vivaldi antenna already has a low radar cross section, it still can not meet the design needs of low visibility platform.Based on the research of the radiation and scattering characteristics of Vivaldi antenna, this article proposes different kind of methods to reduce the RCS while maintaining the radiation performance of the antenna unchanged. The works of this article is as follows:1. The article has discussed the operating principle and design steps of the traditional Vivaldi antenna and designed a bilateral Vivaldi antenna. Compared with the traditional Vivaldi antenna, the bilateral Vivaldi antenna can improve the performance of the gain at higher frequency while maintaining the frequency bandwidth. Meanwhile, the radiation and scattering characteristics of the antenna have been researched and summarized when the incident wave with different polarization and angles.2. Based on the research of the radiation and scattering mechanism of the Vivaldi antenna, this article proposed a novel method of etching the CSRR structure on the metal patches of the antenna to reduce the RCS in part of the operating frequency band. However, this structure of antenna is rather complex and can just work when the incident wave is θ polarized and the incident angle ranges from 10°to 75°. In response to these deficiencies, under the condition that the distribution of the current keeps almost unchanged, a low RCS Vivaldi antenna is proposed with the shape of the metal patches modified. Compared with traditional Vivaldi antenna, this novel antenna can achieve RCS reduction in wider frequency band.3. In order to achieve the RCS reduction over the whole operating frequency band, the article proposed a method of applying the PBG structure to the substrate of antenna and modifying the shape of patches to reduce the RCS of Vivaldi antenna over the whole operating frequency band. Thus, it can solve the contradiction between the antenna radiation performance with low RCS good between certain extent.