A Low Noise 100 GHz Sideband-Separating Receiver

Chin, Chee Kok; Derdall, D.; Sebesta, Jerry; Jiang, Frank; Dindo, P.; Rodrigues, G.; Bond, D. J.; Pan, S. K.; Kerr, A. R.; Lauria, E. F.; Pospieszalski, M.W.; Zhang, J.; Cecil, T.; Lichtenberger, A. W.

doi:10.1023/b:ijim.0000020748.79086.e9

Cited by 12 publications

(7 citation statements)

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“…The design is based on a narrower bandwidth split block version, developed for the ALMA project by Claude and Cunningham et al 29 . 30 Design and optimization of the wideband quadrature hybrid coupler were carried out in HFSS.…”

Section: Quadrature Waveguide Coupler With Large Fractional Rf-bandwidthmentioning

confidence: 99%

Heterodyne Instrumentation Upgrade at the Caltech Submillimeter Observatory

Kooi

Kovács

Bumble

et al. 2003

Millimeter and Submillimeter Detectors for Astronomy

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Balanced receivers are under development at the Caltech Submillimeter Observatory (CSO) for the 230/460 GHz and 345/660 GHz atmospheric windows. The mixers are tunerless, implemented in a balanced configuration, have a 4-8 GHz IF, and can be used in dual frequency observation mode. As shall be seen, the balanced arrangement provides a high level of amplitude noise immunity and allows all of the available LO power to be used. In turn, this permits complete automation of the receivers by means of synthesized LO source(s). A disadvantage of balanced mixers is, perhaps, that the sidebands at the IF remain convolved (DSB), unlike sideband separating (2SB) receivers. The latter, however are unbalanced and do not have the noise and LO injection advantages of balanced mixers. For the CSO, balanced mixers covering the range 180-720 GHz were judged most promising to facilitate many of the astrophysical science goals in the years to come.In parallel, a dual polarization 280-420 GHz continuous comparison (correlation) receiver is in an advanced state of development. The instrument has two beams on the sky; a reference and a signal beam. Using only cooled reflecting optics, two polarizing grids, and a quadrature hybrid coupler, the sky beams are coupled to four tunerless SIS mixers (both polarizations). The 4-12 GHz mixer IF outputs are, after amplification, correlated against each other. In principle, this technique results in flat baselines with very low RMS noise, and is especially well suited for high redshift Galaxy work.Not only do these changes greatly enhance the spectroscopic capabilities of the CSO, they will also enable the observatory to be integrated into the Harvard-Smithsonian Submillimeter Array (SMA), as an additional telescope.Keywords: Balanced mixer theory, continuous comparison receiver, radial probe, full-height waveguide to thinfilm microstrip transition, split-block, high current density superconducting-insulating-superconducting (SIS) tunnel junction, broad bandwidth quadrature waveguide hybrid, DC-break, IF match, Wilkinson in phase power combiner, Low noise amplfier (LNA), 4-8 GHz intermediate frequency (IF).

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Section: Quadrature Waveguide Coupler With Large Fractional Rf-bandwidthmentioning

confidence: 99%

Heterodyne Instrumentation Upgrade at the Caltech Submillimeter Observatory

Kooi

Kovács

Bumble

et al. 2003

Millimeter and Submillimeter Detectors for Astronomy

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“…Systems of this type are referred to as dual sideband (2SB) and are used for bands 3-8. To minimize losses, compact designs have been developed in which the RF hybrid and a local oscillator (LO) power divider are in the form of waveguide circuits in a single split metal block, within which all the elements of the 2SB mixer are mounted, see, e.g., [21], [22] or [23]. As the wavelength becomes shorter, it is increasingly difficult to produce such compact designs and above 600 GHz, for the top two bands, double sideband (DSB) mixers without sideband separation are used, see, e.g., [24].…”

Section: The Alma Receiving Systemmentioning

confidence: 99%

Atacama Large Millimeter/Submillimeter Array

2015

Encyclopedia of Astrobiology

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Abstract-The Atacama Large Millimeter/submillimeter Array (ALMA) is an international radio telescope under construction in the Atacama Desert of northern Chile. ALMA is situated on a dry site at 5000 m elevation, allowing excellent atmospheric transmission over the instrument wavelength range of 0.3 to 10 mm. ALMA will consist of two arrays of high-precision antennas. One, of up to 64 12-m diameter antennas, is reconfigurable in multiple patterns ranging in size from 150 meters up to ∼15 km. A second array is comprised of a set of four 12-m and twelve 7-m antennas operating in one of two closely packed configurations ∼50 m in diameter. The instrument will provide both interferometric and total-power astronomical information on atomic, molecular and ionized gas and dust in the solar system, our Galaxy, and the nearby to high-redshift universe. In this paper we outline the scientific drivers, technical challenges and planned progress of ALMA.

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“…Development goals include wide RF bandwidth with fixed-tuned operation, wide IF bandwidth, dual polarization, balanced mixers, sideband separation, and beam-lead contacts [19], [192]- [194], [208], [209], [241]- [251]. The ALMA memo series [252] is a particularly valuable source of technical information for this area, describing the latest progress being made by the numerous institutions involved in ALMA development.…”

Section: F New Directionsmentioning

confidence: 99%