A Low RCS and Array-Insensitive FSS Wideband Radome

Abstract

In order to further expand the RCS reduction model of the miniature broadband antenna, a four-notch shaped FSS radome insensitive to the number of array elements is designed based on the multi-layered medium Green’s function and the transflective coefficient of the finite radome is derived. The calculated results are in good agreement with the infinite array, showing broadband transmission performance in both C-band and X-band. The electric field distribution and far-field distribution of a finite FSS array are given and the effects of a 5 × 5 array in a V-shaped structure on the surface of a miniature broadband antenna on its gain coefficient and RCS reduction characteristics are calculated numerically. The results show that the designed radome exhibits good array element insensitivity and far-field scattering reduction characteristics and achieves significant in-band and out-of-band RCS accurate reduction under the premise of constant antenna radiation performance. At normal incidence, the single-station RCS in the passband and stopband are as low as −35 dB and −32.66 dB, respectively. The maximum reduction in the transmission band reaches 20.96 dB under oblique incidence and the projection size of the radome decreases with the increase in the bottom angle of the radome but the RSC reduction performance is basically unaffected and can be adjusted flexibly according to actual needs. The above results provide a theoretical basis and technical support for the application of FSS radome in RCS reduction in micro wideband antennas.