Development of a new wideband heterodyne receiver system for the Osaka 1.85 m mm-submm telescope: Corrugated horn and optics covering the 210-375 GHz band
Development of a new wideband heterodyne receiver system for the Osaka 1.85 m mm-submm telescope: Corrugated horn and optics covering the 210-375 GHz band
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为大阪 1.85 m mm-submm 望远镜开发新型宽带外差接收器系统：覆盖 210-375 GHz 频段的波纹喇叭和光学器件
DOI：
10.1093/pasj/psab062
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发表时间：
2021
影响因子：
2.3
通讯作者：
Gonzalez A
中科院分区：
文献类型：
--
作者：
Yamasaki Y.;Masui S.;Ogawa H.;Kondo H.;Matsumoto T.;Okawa M.;Yokoyama K.;Minami T.;Konishi R.;Kawashita S.;Konishi A.;Nakao Y.;Nishimoto S.;Yoneyama S.;Ueda S.;Hasegawa Y.;Fujita S.;Nishimura A.;Kojima T.;Kaneko K.;Sakai R.;Gonzalez A
波纹喇叭是射电望远镜中常用的高性能馈源。毫米波和亚毫米波接收器中对宽带光学器件和波纹喇叭的需求不断增长，因为它们提高了观测效率，使我们能够同时观测多个激发态的重要发射线，如CO。然而，在毫米/亚毫米波段，由于波长非常短，难以制作窄波纹，因此创建具有100%带宽的锥形波纹喇叭一直具有挑战性。在这项研究中，我们设计了一个圆锥形波纹喇叭，具有良好的回波损耗，低交叉极化，和对称的波束图案在210-375 GHz频段（56%的分数带宽），通过优化的波纹的尺寸。在大坂1.85米毫米-亚毫米望远镜上安装了波纹喇叭，并成功地对~（12）CO、~（13）CO和~（18）O（J= 2-1，3-2）进行了同步观测。我们描述了波纹喇叭的新设计，并报告包括光学性能评估结果。
The corrugated horn is a high-performance feed often used in radio telescopes. There has been a growing demand for wideband optics and corrugated horns in millimeter- and submillimeter-wave receivers as they improve observation efficiency and allow us to observe important emission lines such as CO in multiple excited states simultaneously. However, in the millimeter/submillimeter band, it has been challenging to create a conical corrugated horn with a fractional bandwidth of ∼60% because the wavelength is very short, making it difficult to make narrow corrugations. In this study we designed a conical corrugated horn with good return loss, low cross-polarization, and symmetric beam pattern in the 210–375 GHz band (56% fractional bandwidth) by optimizing the dimensions of the corrugations. The corrugated horn was installed on the Osaka 1.85 m mm–submm telescope with matched frequency-independent optics, and simultaneous observations of12CO,13CO, and C18O (J= 2–1, 3–2) were successfully made. We describe the new design of the corrugated horn and report the performance evaluation results including the optics.