基于0.22 THz高功率回旋管振荡器设计了频率步进成像雷达，采用收发分开的双卡塞格伦天线，发射信号形式为频率步进脉冲信号，回旋管频率调节通过调整回旋管电子束电压或者超导磁场强度来实现。给出了成像雷达设计方案，对雷达最大作用距离和步进频率雷达系统高分辨一维距离像进行了分析，开展了ISAR成像仿真。理论计算和仿真结果表明，该雷达对于散射面积为0.01 m²的目标探测距离可达到1.982 km，可分辨500 m处间距2 cm的点目标。该雷达可对低高度小目标进行高精度探测，比如对可携带**和危险物质的无人机进行高精度探测与目标识别。

A stepped frequency imaging radar based on 0.22 THz high-power gyrotron oscillator was designed. The dual Cassegrain antenna with separate transceiver was used for transmitting stepped frequency pulse signal. Frequency adjustment of gyrotron oscillator was achieved by adjusting gyrotron electron beam voltage or superconducting magnet strength. The design schemes for imaging radar were given， the radar detected range and high-resolution range profile of the stepped frequency radar system were analyzed， and inverse synthetic aperture radar （ISAR） imaging simulation was carried out. The results of theoretical calculation and simulation show that the radar could detect the target with scattering area of 0.01 m² by 1.982 km and distinguish the targets with a distance of 2 cm at 500 m. The radar can be used for investigations on target recognition of small objects such as UAV which can take concealed weapons and threat material.