Wide-Angular Scanning Performance Enhancement Phased Aarray Using Phase Gradient Metasurface

This work proposes a novel concept for improving beam scanning performance in a phased array. Theoretical analysis demonstrates that a 1D linear array integrated with a phase gradient metasurface ground can introduce additional phase delays to the corresponding image elements, enhancing array scanning performance, especially for gain improvement across the entire scanning range as well as sidelobe reduction at large scanning angles. To validate this concept, a printed 1D linear dipole array with a rectangular-shaped digital coding metasurface was designed and fabricated. The proposed phased array achieves accurate angle scanning and low sidelobe levels by adjusting the phase distribution of the metasurface ground. The proposed structure achieves a maximum gain enhancement of 2.7 dBi compared to the conventional phased array with a PEC ground, and the maximum sidelobe level is −9.6 dB when scanning at elevation angle of 60 degree.