摘要
相控阵馈源(Phased Array Feed, PAF)是将阵列天线放置于射电望远镜焦面场处,用于实现更高增益及更灵活波束调控的接收机技术。与阵列天线一样,相控阵馈源是由多个天线单元以一定方式组合排列而成,工作时阵元之间难免产生电磁耦合。选用螺旋天线作为阵列天线单元,工作频率为1.25 GHz,对独立天线进行仿真优化后,该天线-10 dB阻抗带宽仅为70 MHz。依托该天线单元建立5×5矩形排布的螺旋天线阵列模型,分别选取阵元间距为1,0.5,0.25和0.125倍波长(1.25 GHz@0.24 m),验证不同阵元间距下的互耦效应对整个阵列带宽的影响。最终通过对各阵元输入阻抗进行匹配,仿真得到在0.25倍波长间距下,阵列中心阵子的-10 dB阻抗带宽可扩展至550 MHz,而阵列天线的带宽也基本表征了将其用作相控阵馈源的工作带宽。上述工作加深了对阵列天线带宽特性的理解,也为实际应用于射电望远镜系统的相控阵馈源实现更宽的工作带宽提供了可能。
Phased Array Feed is a receiver technology that places the array antenna at the focal plane field of radio telescope to achieve higher gain and more flexible beam regulation. As same as the array antenna, it is composed of multiple antenna elements in a certain way, so electromagnetic coupling between the array elements during operation is inevitable. In this paper, the helical antenna is selected as the array antenna unit, and the working frequency is 1.25 GHz. The independent antenna is simulated and optimized, and the-10 dB impedance bandwidth is only 70 MHz. Relying on the antenna unit for the model of rectangular arrangement 5 × 5 helical antenna array, the array element spacing of 1, 0.5, 0.25 and 0.125 times of wavelength are selected respectively(1.25 GHz@0.24 m), in order to verify the influence of mutual coupling effect under different array element spacing on the bandwidth of the whole array. Finally, by matching the input impedance of each array element, the simulation shows that under 0.25 times the wavelength spacing, the-10 dB impedance bandwidth of the central element of the array is expanded to 550 MHz, and the bandwidth of the array antenna basically represents the working bandwidth used as the phased array feed. The above work not only deepens the understanding of the bandwidth characteristics of the array antenna, but also makes it possible for the phased array feed applied to the radio telescope system to achieve a wider working bandwidth.
作者
段雪峰
王凯
李健
闫浩
宁云炜
曹亮
马军
Duan Xuefeng;Wang Kai;Li Jian;Yan Hao;Ning Yunwei;Cao Liang;Ma Jun(Xinjiang Astronomical Observatory,Chinese Academy of Sciences,Urumqi 830011,China;Xinjiang Key Laboratory of Microwave Technology,Urumqi 830011,China)
出处
《天文研究与技术》
CSCD
2022年第6期606-612,共7页
Astronomical Research & Technology
基金
国家自然科学基金(11973078)
新疆维吾尔自治区重点实验室开放课题(2020D04014)
中国科学院“西部之光”人才培养引进计划(2020-XBQNXZ-018)
上海合作组织科技伙伴计划及国际科技合作计划研究项目(2020E01041)
中国科学院天文台站设备更新及重大仪器设备运行专项经费资助。
关键词
阵列天线
相控阵馈源
阻抗
耦合性
带宽
array antenna
Phased Array Feed(PAF)
impedance
coupling
bandwidth
