A High‐Gain Broadband Dual‐Polarized Antenna Based on Phase‐Gradient Metasurfaces

A high‐gain, broadband, dual‐polarized antenna based on the top‐layer and side‐mounted phase‐gradient metasurfaces (PGMs) is proposed. The top‐layer consists of circular patch elements, the side‐mounted are formed by double circular split‐ring resonator units, resulting in a dual‐phase‐controlled metasurface configuration with both beam convergence and energy focusing capabilities. Equivalent phase gradients are generated by both PGMs, and beam focusing is achieved through non‐uniform phase shifts induced by rotating the individual units to specific angles. The axial electromagnetic waves of the dipole are converted into quasi‐plane waves by the top‐layer circular PGM, thereby the on‐axis gain is enhanced, while effective control over the radiation direction and the concentration of energy along the principal axis is achieved. The side‐mounted PGM, composed of split‐ring resonator units, is capable of applying phase shifts to the electromagnetic waves for energy focusing. Additionally, multiple resonance frequencies are induced by different phase gradients among the units, thereby antenna miniaturization is achieved. Through the coordinated manipulation of dual PGMs, the design achieves broadband and high‐gain performance, while miniaturization requirements are satisfied. The measured results indicate that the proposed antenna achieves a wide impedance bandwidth of 57.8% (2.04–3.70 GHz), with the port isolation greater than 30 dB and the stable gain of dBi. Additionally, it maintains stable radiation patterns within the entire operating frequency range.