设计了一种用于高功率径向线螺旋阵列天线的极化转换天线罩。利用三层介质层包夹双层金属折线，形成密封的埋入式折线栅结构。在实现圆极化与线极化相互转换的同时，又避免金属与空气接触，可以提高功率容量。分析了埋入式折线栅单元各参数的影响，并优化单元参数，以此构建埋入式折线栅极化转换天线罩并加载至X波段高功率径向线螺旋阵列天线，分析了天线的基本性能以及功率容量。仿真结果显示：天线匹配良好，增益和波束宽度变化很小，中心频率轴比由1.16 dB变为40 dB，圆极化波转换为线极化波效果良好；经初步分析，极化转换天线罩的功率容量为121 MW，实现了极化转换天线罩的高功率应用。

A radome with polarization conversion for high power radial spiral array antenna is designed. Three-layer dielectric substrate are used to sandwich double-layer metal meander line to form sealed and embedded structure. The power capacity can be improved by avoiding the contact between the metal and the air while the conversion between the circular polarization and the linear polarization is realized. The influence of each parameter of the embedded meander-line grid unit is analyzed, and the unit parameters are optimized. An embedded meander-line radome with polarization conversion is made and loaded into an X-band high power helical array antenna. The basic performance and power capacity of the antenna are analyzed. The simulation results show that the matching performance of the antenna is good, the axial ratio of the center frequency is changed from 1.16 dB to 40 dB, and the circular polarization is converted to linear polarization. Through preliminary analysis, the power capacity of the embedded radome with polarization conversion is 121 MW, and the high power application of the radome with polarization conversion is realized.