Flexible Intelligent Metasurface for Mitigating Beam Squint in Wideband Communications

Flexible intelligent metasurface (FIM) has emerged as a promising technology in wireless communications. FIM provides incredible flexibility to dynamically morph its surface shape in contrast to a conventional uniform planar array (UPA). In this paper, we utilize the FIM to mitigate the beam squint effect in wideband communication systems. To this end, we formulate an optimization problem aiming to minimize the total array gain loss across the whole bandwidth by morphing the surface shape of the FIM, subject to the constraint of the maximum perpendicular morphing range. An efficient gradient descent algorithm is proposed to morph the FIM's surface shape iteratively. Finally, numerical results demonstrate that replacing a rigid UPA with an FIM can effectively mitigate the beam squint effect and considerably enhance the array gain.