射电天文研究室知识库

圆极化器是射电望远镜天线馈线系统的重要器件,其作用是把反射面天线接收的圆极化波变成2个垂直的线极化波。超宽带圆极化器由正交模耦合器和移相器组成。通过网络级联的方法和有限元数值分析相结合的方法对正交模移相器进行了研究。对方波导高次模精确分析,选择合适的方波导口径。利用HFSS电磁仿真软件,对波纹波导正交模移相器各个参数对圆极化器的影响进行分析。仿真结果表明,在30~50 GHz频率范围内,相移特性达到90°±6.7°,交叉极化和正交隔离度优于-65 dB。

Circular polarizer is an important device of a radio telescope antenna feeder system, its role is to convert the circular polarized wave received by the reflector into two mutually perpendicular linear polarized waves. The ultra wideband circular polarizer is composed of orthogonal mode transducer and phase shifter. The article studies the orthogonal mode phase shifter through the network cascade method and finite element numerical analysis method. The high modes of the square waveguide are analyzed accurately and the appropriate square waveguide caliber is selected. Using HFSS electromagnetic simulation software, the effects of parameters of the corrugated waveguide orthogonal mode phase shifter on the circular polarizer are analyzed. The simulation results show that phase shift characteristics is better than 90°±6.7°,and the orthogonal isolation is better than -65 dB within the bandwidth of 30 GHz to 50 GHz.