Varactor-loaded metagratings for the dynamic manipulation of the diffracted waves

The ability of metagratings to perform extreme wavefront manipulation allowed them to cover a wide range of functionalities in different frequency ranges, from microwave to optics. However, in nowadays applications, reconfigurable devices are often required. In this contribution we present a metagrating enabling the dynamic control of the total diffraction pattern, both in reflection and transmission, using arrays of varactor-loaded strips. First, we analyze the static case of capacitively loaded strips and show how it is possible to control the power carried by each diffraction order by properly tuning the load capacitances. Second, we employ varactor diodes to achieve reconfigurability using a resistive bias network. The developed design procedure is validated through numerical simulations and the effect of losses is also discussed.