Ka波段被动成像天线系统设计与研究

Design and research of Ka band passive imaging antenna system

针对Ka波段被动毫米波成像应用,设计了一种由介质透镜与缝隙天线馈源组成的天线系统.将高斯波束理论与光学透镜中的等光程原理相结合,设计了一种大口径介质透镜,该透镜具有良好的聚焦性能;提出了一种新型的共轭直线渐变缝隙天线作为透镜的馈源,该天线呈现出截面小、增益高的优良性能,可以在焦平面上形成密集的馈源阵列.将所设计的介质透镜与馈源天线进行联合仿真,研究结果表明,该系统在距透镜2.81 m处聚焦焦斑为50 mm,并且在±5°偏焦时聚焦焦斑都小于60 mm.所设计的天线系统具备很好的聚焦性能且具有较大的偏焦工作角度,可以适用于被动毫米波近场成像应用.

For the Ka-band passive millimeter-wave(PMMW)imaging application,the antenna system design consisting of a dielectric lens and a feed antenna is completed.Combining Gaussian beam theory with the equal optical path principle in optical lens,a large aperture dielectric lens is designed,which has excellent focusing performance.A novel antipodal linear tapered slot antenna is proposed as the feed of the lens.The antenna exhibits excellent cross-section and high gain,and can form a dense feed array on the focal plane.The designed dielectric lens and the feed antenna are joint simulation.The results show that the antenna system has a focal spot of 50 mm at a distance of 2.81 m from the lens and a focal spot of less than 60 mm at±5°off axis.The designed antenna system has good focusing performance and a large offset working angle,which can be applied to passive millimeter wave near-field imaging applications.