毫米波赋形偏馈双反射面天线技术

The shaped millimeter-wave antenna with offset feed and dual-reflector

为了实现一种具有高口面辐射效率、斜波束出射能力的口径天线,采用几何光学方法设计了一种偏馈双反射面天线.天线主反射面采用赋形设计,副反射面的设计过程中采用Snell定理作为约束条件.通过理论公式、数值模拟仿真和实验测试研究,实现了一种出射波束口径为110 cm、天线口面场分布为抛物形分布、波束出射方向与竖直方向成20°夹角的赋形偏馈双反射面天线.在中心频率95 GHz下,实测天线增益为59.7 dB,第一副瓣电平为-19dB,天线口径效率达到78%.

A shaped scheme based on geometric optics for offset fed dual reflector antenna is presented.A ray tube emerging from a symmetric feed horn is transformed,after reflections,into a circular beam with a uniform phased and a prescribed radial power distribution on the aperture.Snell＇s law was imposed on the subreflector.Based on this design solution,theoretical analysis,numerical simulation and experimental test were carried out for a 110 cm dish baseline system with a angle of 20 degrees between X axis and the beam.The experiment shows that at 95 GHz,the antenna has a 78% aperture efficiency and the minor lobe meets a-19 dB criterion and the gain is 59.7dB.