Development and installing High-effective circular polarized receiver for 100-500GHz VLBI observation

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540234
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: Osaka Prefecture University
• Principal Investigator: OGAWA Hideo 大阪府立大学, 理学(系)研究科(研究院), 教授 (20022717)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 電波天文学 / 導波管 / セプタム型 / 円偏波 / ポーラライザー / VLBI観測 / 広帯域化 / 高周波化

Outline of Final Research Achievements

Waveguide-Septum type Circular Polarizer , which is needed on VLBI Observation - the way to achieve the highest angular resolution - , has some defects ; narrowness of usable frequency band-width , and the degradation of its frequency characteristics at over 80 GHz Band.
In our study , we have addressed to improve , resolve those defects , and the results are ; 1. Broaden 10% to 24 % of fractional bandwidth ( bandwidth / center freq. ) at CX and Ka Band ( 6-9 GHz , 22-32 GHz ), 2. Invent the solution to suppress causing degradation , and stabilize its frequency characteristics at 80 and 230 GHz band, 3. Put 230GHz band deliverables into practical use on radio-observation.
We expect that these results are led to improve and expand VLBI observation on each band , especially not possible until now .

Free Research Field

電波天文観測機器開発