Dynamic Blazed Metasurface Grating Mechanism for Terahertz Beam Steering

Next-generation wireless sensing and communication will require efficient terahertz beam steering to enhance spatial coverage and establish non-line-of-sight links. Beam steering can be achieved using tunable metasurfaces, but this can be difficult to achieve in practice, particularly if low loss and continuous tunability is required. In this article, we present a novel terahertz metasurface designed as a grating that leverages diffraction for beam selection. Our device operates at 145 GHz and uses an air-gap tuning mechanism to keep losses low. Importantly, we show for the first time that this device constitutes a terahertz blazed grating, whose blaze angle is dynamically tuned by adjusting the air gap within the metasurface. This enables a low-loss selection of the fractions of power radiated into the zeroth and first diffraction orders, thus demonstrating continuous and simultaneous control over the beam intensities.