Low-Profile Dual-Band Shared-Aperture Metantenna Array With a Reusable Periodic Radiator

To realize a compact shared-aperture array with maximized aperture reuse and consistent dual-band performance, this letter presents a dual-band metantenna that uses a common multilayer periodic radiator for both bands. Dual-band operation is realized by selectively exciting different sub-array groupings (4×4 and 2×2 units) within the same metasurface via optimized slot-coupled feeds. Auxiliary coupling patches are employed to enhance radiation efficiency, while series filtering stubs are integrated into the feedlines to suppress inter-band interference. The two bands feature a 1:2 center-frequency ratio with 26.3% and 29.3% relative bandwidths, a compact 0.11λ₀ profile, an aperture reuse ratio approaching 100%, over 20 dB inter-band isolation, and consistent polarization. Moreover, both bands support low-sidelobe beam scanning over ±50°. These results demonstrate the suitability of the proposed design for compact multi-band communication and sensing systems.