Generation and Curvature Control of Airy Beam in RF Field Based on Fourier Transform and Anisotropic Metasurface

The radio-frequency Airy beam (RFAB) with self-bending and non-diffraction characteristics will play an important role in microwave wireless power transfer (WPT). This letter presents the mechanism to generate x -polarized 2-D RFAB based on the combination of the Fourier transform and holographic principle, and all information of the Fourier transform, the curvature modulation can be recorded on an anisotropic metasurface designed based on the holographic principle. Under this mechanism, two methods of controlling the RFAB trajectory curvature are achieved to improve the beam coverage and bypass obstacles in the WPT of the RF field, which is different from the existing method for only changing the launch angle of the RFAB. The anisotropic holographic metasurface is designed by integrating the feed and tensor units, which eliminates the Fourier lens and ensures the accuracy and flexibility of high-performance RFAB trajectory control by manipulating both the amplitude, phase, and polarization of the electromagnetic (EM) wave. The anisotropic metasurface works at 10 GHz, and the simulation and experimental results prove the correctness of the design.