2019 Fiscal Year Research-status Report
A Concept-proof Study of Multibeam Heterodyne Receiver Frontends for Next Generation Radio Telescopes
| Project/Area Number |
18K03708
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| Research Institution | National Astronomical Observatory of Japan |
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Principal Investigator |
SHAN Wenlei 国立天文台, 先端技術センター, 准教授 (60792570)
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| Co-Investigator(Kenkyū-buntansha) |
江崎 翔平 国立天文台, 先端技術センター, 技術員 (40794508)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | focal plane array / SIS mixer / PE-CVD / planar OMT |
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| Outline of Annual Research Achievements |
The objective of this study is to explore a new approach with using superconducting planar circuit to make essential breakthroughs in the techniques of constructing large-format and compact superconducting multibeam heterodyne receiver frontends. There are three major accomplishments in 2019FY deserving a clarification. First, we have accumulated sufficient experimental evidence to prove that the dual-polarization balanced mixer designed based on our new approach is functional as expected. A paper that concludes the measurement results got published in IEEE Trans. on THz Sci. and Tech. This is a fundamental work, on which other work stems. Second, we have made a breakthrough in fabrication of the device by introducing a compressive/tensile/compressive SiO2 trilayer technique with using PE-CVD (plasma-enhanced chemical vapor deposition). Thanks to this method the device quality and yield significantly improved. This achievement secures the devices that are necessary in the RF measurement. The evolved fabrication method has been published in J. of Low Temp. Phys. Third, we have recently demonstrated experimentally a 4-pixel dual-polarization balanced mixer frontend. The results reveal even LO distribution, high-level isolation between pixels and low cross polarization. This achievement declares that the new concept for heterodyne array receiver has been verified in the direct manner. These experimental results of the 4-pixel dual-polarization balanced mixer frontend has been presented in 31st International Symposium for Space Technology.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Our study has been completely in accord with the four steps that we set in the research plan. By the end of 2019FY, we have accomplished step 1 and 2 and partly the step 3. In 2019FY, we improved device quality and yield by introducing a PE-CVD deposition of SiO2 insulator in the fabrication process. The fabricated devices were assessed comprehensively, and the experimental results were concluded for publish. We have finished the design and manufacture of a 4-pixel frontend module. Base on this module and the devices with improved quality we have demonstrated a very compact SIS mixer 4-pixel array with dual polarization and balanced mixing scheme at 2mm wavelength. This is a first-of-its-kind demonstration and presents expected performance. As a part of work in step 3, we have finished the design of the planar integrated circuit for sideband separation mixing. Based on the design, photo mask/reticle set has been designed and manufactured.
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| Strategy for Future Research Activity |
In line with the defined research plan, in 2020FY following studies will be performed. (1) Finalize the investigation of fabrication process of thin-film resistor, which is necessary to enable sideband separation (2SB) SIS mixer configuration; (2) Applying the thin-film resistor process, fabricate single-pixel 2SB mixer integrated circuit; (3) Demonstration of single-pixel and 4-beam dual-polarization 2SB mixer.
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Research Products
(12 results)
