Low-complexity DoA Estimation method based on Space-Time modulated Metasurfaces

In this contribution, we present a novel metasurface-based Direction of Arrival (DoA) estimation method. The proposed approach exploits the properties of space-time modulated reflecting metasurfaces to realize multiple beams in the scattered field, each of which propagating with a different frequency and wavenumber. In particular, the method makes use of the amplitude unbalance of the received fields at broadside at the frequencies of the two first-order harmonics generated by the interaction between the incident plane wave and the modulated metasurface. Here, we demonstrate that, breaking of the spatial symmetry of each order harmonic scattering pattern, it is possible to easily determine the DoA of a plane wave with extreme accuracy. Compared to conventional DoA estimation methods, the proposed approach simplifies the computation and hardware complexity, ensuring at the same time estimation accuracy.