为了提升高功率微波辐射天线的带宽，提出并设计了一种X波段高功率圆极化反射阵列天线，该天线采用喇叭天线作为馈源，阵列天线单元由可旋转金属双螺旋线构成，通过旋转螺旋线可以实现360°的相位补偿，同时反射损耗极小。设计了15×15矩形栅格螺旋反射阵列天线，全波仿真结果表明：该口径为315 mm的阵列天线在中心频点9.3 GHz下，增益为28 dB，轴比为0.53 dB，口径效率为52.6%；在8.5~10.9 GHz的频带范围内增益大于26.8 dB，轴比小于1.14 dB，1 dB增益带宽和40%以上口径效率带宽均大于21%；在真空中所能承受的最大功率约为207 MW。

In order to broaden the bandwidth of high power microwave radiation antenna, an X-band high power circularly polarized reflectarray antenna constructed by mechanically rotational helical elements is proposed and investigated. The array antenna is fed by an X-band left-handed circularly polarization circular horn. The variable rotation of helical element enables full 360° phase adjustment with low reflection loss. The rectangular reflectarray antenna of 225-element is put forward and simulated. Full-wave simulation result shows that at 9.3 GHz, the antenna gain is 28 dB, the antenna axial ratio is 0.53 dB and the aperture efficiency is 52.6%. In the range of 8.5 to 10.9 GHz, the gain is over 26.8 dB, the axial ratio is below 1.14 dB, and both the 1-dB gain bandwidth and the 40% aperture efficiency bandwidth are over 21%. The power handling capacity of the reflectarray antenna is found to be 207 MW in vacuum.