Low-profile, wideband RCS-reduction antenna array based on a metal-ink hybrid metasurface.

In this study, a highly flexible metal-ink hybrid metasurface that can be integrated with planar structures is proposed. The metasurface achieves wideband absorption performance while maintaining an efficient transmission window. Based on equivalent circuit model analysis, an aperture-coupled antenna array was integrated with the metasurface, enabling simultaneous wideband radar cross-section (RCS) reduction and high-performance radiation. The integration of the metasurface and antenna array allowed the overall structure to maintain a low profile. Simulation results show that the proposed array achieves a 10 dB RCS reduction against a metal plate of the same size over the [2.03, 8.11] GHz range, with a fractional bandwidth of 119.9% under x-polarized wave incidence. Under y-polarized wave incidence, a 10 dB RCS reduction is achieved at both [2.12, 5.1] GHz and [6.1, 8.06] GHz, with fractional bandwidths of 82.5% and 27.6%, respectively. Moreover, the array maintains a peak gain of 26.3 dBi and sidelobe levels less than -18 dB. The experimental results align well with the simulated results. The proposed low-RCS antenna array offers potential advancements in planar antenna technology, enhancing stealth capabilities.