Design of dual-band Frequency Selective Surface for antenna RCS reduction

Abstract

In this paper, the performance of a new dual-band Frequency Selective Surface (FSS) structure based on square ring and three-pole loading was presented. Two applications which were carried out to verify the feasibility of the FSS structure are using the FSS as the high impedance surface to design absorbing material and as the radome to reduce the antenna Radar Cross Section (RCS). The wave-transparent rate of the FSS is given when a plane wave is incident at some angle. Simulation results shows that the performance of the FSS is stable. In the first application, the absorbing material only designed with the FSS structure and FR4 is thinner than the traditional absorbing material, and the total thickness is low to 3.6 mm. Bandwidth of the artificial electromagnetic material (the absorptivity is more than 80%) is nearly 5.2%. Frequency Selective Radome not only can reduce the RCS, but also can resist external interference to maintain a good working environment for antenna. In the following content, we build an ideal model of antenna and radome system to discuss the influence of the Frequency Selective Radome on the conformal antenna. The results of RCS and antenna performance were compared between cylindrical conformal antenna array with radome or not. It's worth noting that the FSS radome has little effect on the performance of conformal antenna array, moreover it has a significant RCS reduction in pass band. Simulation results show that the FSS can be used to design efficient electromagnetic absorber and radome that all can be applied in RCS reduction.