| Project/Area Number |
13554005
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Astronomy
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| Research Institution | National Astronomical Observatory |
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Principal Investigator |
CHIKADA Yoshihiro National Astronomical Observatory, Div. Radio Astronomy, Professor, 電波天文学研究系, 教授 (30126122)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAHIRA Katsuko Waseda Univ., Fac.Edu., Research Associate, 教育学部, 助手 (80339621)
KASUGA Takashi Hosei Univ., Fac.Eng., Professor, 工学部, 教授 (70126027)
KAWAGUCHI Noriyuki National Astronomical Observatory, Div. Earth Rotation, Professor, 地球回転研究系, 教授 (90214618)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 2002: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2001: ¥3,600,000 (Direct Cost: ¥3,600,000)
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| Keywords | Radio Astronomy / Radio Telescope / Antenna / Lens / Satellite Antenna / 衛星搭載アンテナ |
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| Research Abstract |
Aperture area of a radio telescope is approaching its limit. It is caused by the fact that, for a telescope whose diameter exceeds 10^4 of observing wavelength, it is difficult to maintain its surface error less than 1/10 of the wavelength, under actual conditions of gravity, winds, non uniformity of temperature distributions, etc. Considering the sensitivity of the receiver front-ends are now approaching its theoretical limits, it appears for the radio astronomy of the 21^<st> century to meet the dead-ends without realizing much larger collecting area.
A room mirror of a car swings as the car roll, and the scenery through it will suffer blur. On the other hand, eye glasses may jump on your nose without serious blur. That is, compared to reflective mirrors, the transparent lenses may easily be held maintaining their line of sight. In the latter case, only the line between the focus and the center of the lens should be kept towards the celestial object, and the tilt of the lens is allowed to a certain amount. In other words, from the view point of the symmetry, the lens could be folded or be in arbitrary shape if the "thickness" be kept. This is the advantage of lenses.
We had succeeded in receiving the radio wave from the Sun at 22 GHz with a one meter square lens antenna consisting of two layers of distributed phase shifters on films. The efficiency turned out to be very high, around 40 %. With further experiments and measurements of lens elements, we made firm steps toward a multi-frequency lens.
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