蒙皮天线的浅介质腔体散射特性分析

Scattering Characteristics Analysis of Dielectric Cavity of Skin Antenna

随着隐身技术的不断发展,天线雷达散射截面(RCS)的缩减成为实现低散射平台电磁隐身特性的关键。蒙皮天线是天线RCS缩减的重要技术方向,而腔体散射又是蒙皮天线难以避开的问题,因此,介质浅腔的RCS缩减是实现低RCS天线的重要保障。通过仿真软件FEKO对浅腔、介质及介质浅腔的散射特性进行研究,得到了介质浅腔散射随介质浅腔深度呈现单调变化的条件,给出了一种具有低RCS值的菱形介质浅腔设计方法。该方法利用天线电性能及介质浅腔隐身性能对介质板厚度呈现单调变化的特性,在满足天线驻波比要求的基础上,通过尽量减薄介质基板的厚度实现介质浅腔RCS的缩减。实测结果表明,通过上述方法设计的介质浅腔的RCS得到了接近10 d B的缩减效果。

With the development of stealth technology,the radar cross section reduction（RCSR） of antennais the key to realize the low scattering platform. The skin antenna is an important technique of antenna RCSR,and the cavity scattering is a problem which is hard to be avoided,the RCSR of dielectric cavity is animportant guarantee for the realization of low RCS antenna. Through studing the scattering properties ofcavity,dielectric and dielectric cavity by simulation software FEKO,this paper obtaines the variation law ofdielectric cavity scattering with depth and presents the design method of a dielectric cavity with low RCSvalue. The method utilizes the characteristics that the antenna＇s voltage standing wave ratio （ VSWR）bandwidth and RCS of the dielectric cavity monotonously change with the height of the dielectirc,and according to VSWR bandwidth requirements of the antenna,realizes the RCSR by minimizing the dielectricsubstrate thickness. The experimental result proves that by using the proposed method,the RCSR of the dielectric cavity is close to 10 dB.