Beam Scanning for Dual-Polarized Antenna With Active Reflection Metasurface

In this letter, a dual-polarized antenna with steerable beam is presented. The antenna consists of an active reflection metasurface and a cross dipole antenna. The beam scanning of the antenna is obtained by tuning the capacitance of the varactor diodes mounted on the active reflection metasurface cell. A reflection phase covering 300 degrees can be obtained by tuning the capacitance value. The air layer in the middle of the reflection unit makes the reflection phase curve flat and achieve a stable phase difference over a wide band. Moreover, the cross-shaped structure of the reflection unit can manipulate the reflection phase of the electromagnetic waves with two polarizations. Therefore, the dual-polarized antenna can maintain good radiation performance and port isolation while the beam is deflected. The simulated radiation efficiency is higher than 88%. The measured results demonstrate that the beam-steering range is +/- 20 degrees, short for voltage standing wave ratio (VSWR) is less than 1.7 and the port isolation is greater than 20 dB in the frequency range of 3.3-3.6 GHz.