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ALMA MEMO #481

Preliminary Tests of Waveguide Type Sideband-Separating SIS Mixer for Astronomical Observation


Shin'ichiro Asayama (Osaka Prefecture University/Nobeyama Radio Observatory), Kimihiro Kimura (Osaka Prefecture University), Hiroyuki Iwashita(Nobeyama Radio Observatory), Naohisa Sato (National Astronomical Observatory of Japan), Toshikazu Takahashi (Nobeyama Radio Observatory), Masao Saito (National Astronomical Observatory of Japan), Bungo Ikenoue (National Astronomical Observatory of Japan), Hideharu Ishizaki (National Astronomical Observatory of Japan), Nobuharu Ukita (National Astronomical Observatory of Japan)

2003/11/24

Keywords: Sideband-Separating mixer, SIS mixer, ¹²CO(J = 1 - 0)spectrum

We have developed an integrated sideband-separating SIS mixer at 100 GHz based on waveguide split block with 4.0-8.0GHz IF. The measured receiver noise temperatures with 4.0-8.0GHz IF are less than 60K in the LO frequency range of 90-110GHz, and minimum value of around 45K is achieved at 100GHz. The image rejection ratios are more than 10dB in the LO frequency range of 90-110GHz in the laboratory measurements. We have installed the sideband-separating SIS mixer into the cartridge-type receiver cryostat for Japanese prototype antenna and successfully observed a spectrum of ¹²CO(J = 1 - 0) from Orion KL and confirmed the image rejection ratio as large as 13 dB in the astronomical measurements. This result is the first astronomical observation with a waveguide type Sideband-Separating SIS mixer.


View a pdf version of ALMA Memo #481.






Last modified: 2004-01-05

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