Noninterleaved Bidirectional Metasurface for Spatial Energy Allocation

This article presents a high-efficiency noninterleaved bidirectional metasurface operating at the same frequency and polarization. The bidirectional metasurface can independently control reflection, transmission, and energy allocation ratio in the full space. The noninterleaved design offers high aperture efficiency and a steady energy allocation ratio in broadband. Furthermore, transmit-reflect-array antennas (TRAs) based on the presented metasurface are proposed. These TRAs can radiate asymmetric bidirectional beams with near-continuous adjustable energy allocation ratios. To validate the design, TRAs with gain differences of 0 and 6 dB are fabricated and measured. Results indicate that the peak aperture efficiencies are 41.1% and 41.6%, respectively. Besides, the 2-dB gain bandwidths of all beams exceed 25.6%. Overall, this study paves the way for designing high-efficiency spatial energy allocation devices.