S/X双频共用同轴馈源

Coaxial Dual-Band Feed Operating in S/X Band

提出了一种用于射电望远镜50m天线、S/X双频共用且对S、X双频段具有不同照射角的同轴馈源设计方法,S、X两个频段的相对工作频带宽度均为20%,S频段为同轴馈源,内导体为圆波导馈源工作在X频段。采用电磁仿真和实验的方法研究了同轴馈源辐射方向图-10dB点波束宽度的调整方法和减小同轴馈源电压驻波比和轴比的技术途径。对同轴馈源方向图、电压驻波比和轴比进行了测试,测试结果与电磁仿真结果比较吻合。

This paper presents a design method of coaxial feed that is common in S/X band, has different illumination angle of - 10 dB in S and X band and can be used to illuminate a radio telescope antenna with a diameter of 50 m. The relative operation bandwidth of S and X bands is 20% .The feed is a coaxial form in S-band and a circular waveguide form in X-hand .The technique is studied by making use of EM simulation and experimentation for adjusting the beamwidth of - 10 dB and reducing the VSWR and axial ratio for circular polarization. Comparing the EM simulation and experiment results showes a good agreement in directivity pattern, VSWR and axial ratio of circular polarization.