| 研究課題/領域番号 |
23K20871
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| 補助金の研究課題番号 |
21H01134 (2021-2023)
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| 研究種目 |
基盤研究(B)
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| 配分区分 | 基金 (2024)
補助金 (2021-2023) |
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| 応募区分 | 一般 |
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| 審査区分 |
小区分16010:天文学関連
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| 研究機関 | 国立天文台 |
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研究代表者 |
SHAN Wenlei 国立天文台, 先端技術センター, 准教授 (60792570)
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| 研究分担者 |
江崎 翔平 国立天文台, 先端技術センター, 研究技師 (40794508)
田村 友範 国立天文台, 先端技術センター, 技師 (90897828)
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| 研究期間 (年度) |
2021-04-01 – 2026-03-31
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| 研究課題ステータス |
交付 (2024年度)
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| 配分額 *注記 |
17,030千円 (直接経費: 13,100千円、間接経費: 3,930千円)
2025年度: 3,770千円 (直接経費: 2,900千円、間接経費: 870千円)
2024年度: 2,730千円 (直接経費: 2,100千円、間接経費: 630千円)
2023年度: 4,030千円 (直接経費: 3,100千円、間接経費: 930千円)
2022年度: 3,510千円 (直接経費: 2,700千円、間接経費: 810千円)
2021年度: 2,990千円 (直接経費: 2,300千円、間接経費: 690千円)
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| キーワード | Focal plane array / SIS mixer / Radio astronomy / planar OMT / Focal Plane Array / Heterodyne / SIS Mixer / Radio Astronomy |
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| 研究開始時の研究の概要 |
This research is relevant to a new technological approach to constructing sub-mm heterodyne focal plane arrays for radioastronomical observation. This approach is characterized by the adoption of superconducting monolithic microwave integrated circuits (MMICs) and hybrid planar integration (HPI) schemes.
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| 研究実績の概要 |
Three significant achievements have been made in the development of MMIC SIS mixers. Firstly, a microfabrication method for on-chip resistors was established, allowing for the successful fabrication of NbTiN thin-film resistors with a wide range of resistivity. The method were published in the international journal "Thin Solid Films" and are crucial for the development of MMIC SIS mixers. Secondly, we conducted an experiment to investigate the performance of silicon membrane waveguide transitions, a key component in MMIC mixers. The results, which agreed well with theoretical predictions, were accepted for publication. Lastly, we identified the primary cause of crosstalk in MMIC mixer chips and developed a fabrication process for through-substrate via-holes in the chips. The results showed that conductive via-holes can be fabricated using a non-Bosch silicon etching process and will be published in IEEE Trans. On Applied Superconductivity. These achievements are significant in advancing the understanding of reactive plasma processes and will allow for the continued development of MMIC SIS mixers.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
The achievements of the research plan for the 2022 fiscal year are as follows:
Task 1: "Establish a fabrication process for through-substrate via holes (TSV)." We have developed a TSV fabrication process using non-Bosch and DC magnetron sputtering processes and observed a superconducting transition of the Nb films of TSVs at 7.8 K. Task 2: "Revisit the quantum mixing theory and identify the reason for unexpected excess receiver noise measured in the devices fabricated in 2022." We conducted an in-depth study on two important aspects of the noise of SIS mixers, namely RF input noise and IF noise. We are now able to confidently separate the noise components of a SIS mixer and pinpoint the excess receiver noise in some of our devices. Task 3: "Establish an Au-plating process for silicon micro-machined components." We have developed a compact electroplating system. The hardware is now ready, and experiments are underway. Task 4: "Publish the experimental results of thin-film resistor fabrication, which was done in 2022." The thin-film resistor process has been concluded, and the results have been published.
Additionally, we have initiated an on-chip measurement method to assess the transmission loss of superconducting transmission lines at millimeter wavelengths. This method is important because our MMIC mixer experiment results imply unexpected loss of superconducting transmission lines in the signal path before the mixers. Based on the results, we will try to reduce the loss by improving our fabrication process.
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| 今後の研究の推進方策 |
The following studies will be performed in the 2023 fiscal year:(1) Continue to investigate the transmission loss of planar superconducting transmission lines that conduct signals in MMICs. We will further improve the fabrication process to reduce the transmission loss.(2) Carry out studies on the fabrication process of MMICs to improve the fabrication yield and the quality of SIS junctions in terms of the nonlinearity of the IV characteristics. (3) Investigate an alternative method to TSVs to solve the crosstalk problem. In the alternative method, we will try to avoid stimulating the substrate oscillation modes by weakening the coupling.(4) Finally, complete the demonstration of sideband separation configuration with silicon-based MMICs at ALMA Band 4.
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