Metasurface Embedded Microwave Absorbing Composites on Curved Surfaces for Radar Cross Section Reduction

In this paper, a radar cross section (RCS) reduction strategy, in which a metasurface is embedded in a microwave absorbing composite on a curved surface, is presented to achieve low-RCS aircraft wing structures. A genetic algorithm is employed to design the pixelated metasurface for broadband absorption. The pixelated metasurface is screen-printed on a flexible polyimide film and integrated into foam core sandwich layers and composite layers for obtaining a flat, robust, and lightweight absorber sample. The measured microwave absorption of the sample is 90%, with a fractional bandwidth of 102% in the C- and X-bands. The designed metasurface embedded microwave absorbing composite is applied to investigate the effect of the curvature radius on the RCS considering the performance and manufacturing cost. The proposed design on a curved surface with a 200 mm curvature radius achieves an average RCS reduction up to 96% relative to that of the copper counterpart from full-wave simulation, which is validated via RCS measurements. The metasurface embedded microwave absorbing composite on curved surfaces can be used to increase stealth performance.