星载可展开天线研究

海洋二号卫星微波校正辐射计天线(HY-2 CRA)是高增益、低副瓣、高波束效率、低损耗的天线子系统.其高主波束效率、低损耗等要求对天线展开精度、形面精度、测试等提出了极大挑战.由于卫星发射整流罩结构限制,天线采用可展开机构形式,并用正交模耦合器实现频率复用.天线频率分别达到18.7 GHz,23.8 GHz和37 GHz.为了减小天线形面变形,保证天线波束指向,天线反射面(包括反射面支架、馈源支架)采用碳纤维复合材料,确保天线在宇宙空间变形尽可能小.本文就HY-2 CRA的设计、加工、测试等进行了论述.

Research on Space-borne Deployable Antenna

Due to the limited space of the fairing, HaiYang-2 satellite microwave Calibration Radiometer Antenna (HY-2 CRA) used deployable structure and two hinges to perform the stretching action. Many efforts had been also exerted to meet the demand of high gain, low noise, high beam efficiency, low loss etc. The offset paraboloid made of carbon fiber together with conical corrugated horns was selected for this antenna to reduce the total mass. The working frequencies were selected to be 18.7 GHz, 23.8 GHz and 37 GHz respectively with 600MHz bandwidth. The new compact two septums Orthomode Transducers (OMT) were proposed and analyzed by full wave method, and these OMT were employed to meet the demand of the dual polarizations for all three frequencies. Finally the whole antenna was tested in the far field testing system. The technical renovation about working mode, key knowledge, design procedure, and measurement were analyzed in this paper.