低旁瓣微波辐射计天线设计和应用

New design technique and application of microwave radiometry with low sidelobe and high sensitivity

提出一种高灵敏度微波辐射计设计方法,它采用辐射计天线的低旁瓣和高主波束效率设计,通过降低辐射计的系统噪声温度(尤其是外部变化的天线噪声温度),实现系统的高灵敏度。给出了微波辐射计天线方向图的理论仿真和实验结果及系统灵敏度的测量结果。辐射计天线实测结果表明:二个波段的天线副瓣电平均低达-30dB,天线主波束效率均高于95%。微波辐射计系统的实测结果表明:新方法使辐射计实际测量达到0.05K的高灵敏度。该系统也可在大气遥感测量、人工影响天气、土壤水分测量等领域应用,为防洪抗旱提供实时的降雨特性资料,在雷达和卫星通讯等领域,应用于电波的中性大气折射订正。

New design technique of high-stability microwave water vapor radiometry with low sidelobe is presented. Performance of the radiometer is evaluated. The radiometry antenna was designed to meet the specifications of a very low cross-polarization level,high main beam efficiency,good pattern symmetry,and low VSWR at two separated frequency bands. The data from the computer can be processed to provide real-time results. Gain instabilities were separated from variations of the effective input noise temperature of...