面向新疆奇台110 m射电望远镜宽带双极化Vivaldi馈源设计

Broadband Dual-polarization Vivaldi Feed Design for QTT 110 m Radio Telescope

射电望远镜一般要在宽频段内进行连续观测,但传统相控阵天线设计方法难以兼顾宽频带和大角度扫描特性.紧耦合天线的设计方法为宽带大角度扫描天线提供了新的设计思路,基于此设计了一款宽带双极化Vivaldi相控阵馈源.首先结合Wheeler提出的连续电流片概念及等效电路对紧耦合原理进行理论分析,然后针对Vivaldi天线分析了阵元间的强耦合能够有效拓展天线的工作带宽.在此基础上设计了一款宽带Vivaldi相控阵馈源.馈源阵列由8×9 Vivaldi天线阵元组成,该阵列的工作带宽为2-8GHz,并且能够在E面和H面均实现±45∘的扫描特性.最后对该馈源阵列进行了样机加工和测试,测试结果与仿真结果具有较好的一致性.

Radio telescopes usually conduct continuous observation across a wide frequency range,but traditional phased array antenna designs struggle to meet the requirements of both wide band and large scanning volume.The development of tightly coupled antennas offers a novel approach for addressing these challenges.Accordingly,a wideband dual-polarized Vivaldi phased array feed has been designed.Firstly,a theoretical analysis of the tightly coupled principle is conducted,incorporating Wheeler's concept of continuous current and equivalent circuit.It reveals that the strong coupling between the antenna elements effectively expands the operational bandwidth of the Vivaldi phased array.Based on this,a wideband Vivaldi phased array feed composed of 8×9 Vivaldi antenna elements with a operational frequency ranging from 2 to 8 GHz is designed.Furthermore,the phased array enables 45∘scanning characteristics in both E-plane and H-plane.Finally,a prototype of the phased array is fabricated and measured.The measurement results are in good agreement with the simulated ones.