Journal ArticleDOI
The effects of subreflector diffraction on the aperture efficiency of a conventional Cassegrain antenna--An analytical approach
TLDR
In this article, an asymptotic theory is presented with which the reduction in aperture efficiency caused by diffraction from a subreflector edge can be calculated for any dual-reflector system.Abstract:
An asymptotic theory is presented with which the reduction in aperture efficiency caused by diffraction from a subreflector edge can be calculated for any dual-reflector system. The theory is applied to conventional Cassegrain antennas, for which approximate analytical effieiency formulas are derived. These formulas show that subreflector diffraction may represent a significant efficiency loss even for subreflector diameters as large as 20 wavelengths. The formulas are used to obtain an optimum subreflector size which represents the best trade-off between losses due to subreflector diffraction and geometrical shadowing.read more
Citations
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Journal ArticleDOI
The Allen Telescope Array: The First Widefield, Panchromatic, Snapshot Radio Camera for Radio Astronomy and SETI
Jack Welch,Donald C. Backer,Leo Blitz,Douglas C.-J. Bock,Geoffrey C. Bower,Carina Cheng,Steve Croft,Matthew R. Dexter,G. Engargiola,Ed Fields,James R. Forster,Colby Gutierrez-Kraybill,Carl Heiles,T. T. Helfer,Susanne Jorgensen,Garrett K. Keating,John Lugten,Dave MacMahon,Oren Milgrome,D. D. Thornton,L. Urry,J. van Leeuwen,Dan Werthimer,Peter H. Williams,M. C. H. Wright,Jill Tarter,Robert Ackermann,Shannon Atkinson,Peter Backus,William C. Barott,Tucker Bradford,M. M. Davis,Dave DeBoer,John Dreher,G. R. Harp,Jane Jordan,Tom Kilsdonk,Tom Pierson,Karen Randall,John Ross,Seth Shostak,Matt Fleming,Chris Cork,Artyom Vitouchkine,Niklas Wadefalk,Sander Weinreb +45 more
TL;DR: The first 42 elements of the Allen Telescope Array (ATA-42) are beginning to deliver data at the Hat Creek Radio Observatory in northern California as mentioned in this paper, and the fundamental scientific program of this new telescope is varied and exciting; some of the first astronomical results are discussed.
Journal ArticleDOI
Factorization of the feed efficiency of paraboloids and Cassegrain antennas
TL;DR: The first approximation to the aperture efficiency of a paraboloidal reflector antenna is called the feed efficiency as mentioned in this paper, which is derived by factorizing the antenna's feed efficiency into subefficiencies which account for losses due to spillover, cross polarization, nonuniform aperture illumination, and phase errors.
Journal ArticleDOI
The Allen Telescope Array: The First Widefield, Panchromatic, Snapshot Radio Camera for Radio Astronomy and SETI
Jack Welch,Don Backer,Leo Blitz,Douglas C.-J. Bock,Geoffrey C. Bower,Calvin Cheng,Steve Croft,Matt Dexter,Greg Engargiola,Ed Fields,James R. Forster,Colby Gutierrez-Kraybill,Carl Heiles,Tamara T. Helfer,Susanne Jorgensen,Garrett K. Keating,J. B. Lugten,Dave MacMahon,Oren Milgrome,Douglas Thornton,Lynn Urry,Joeri van Leeuwen,Dan Werthimer,Peter H. Williams,Melvin Wright Jill Tarter,Robert Ackermann,Shannon Atkinson,Peter Backus,William C. Barott,Tucker Bradford,M. M. Davis,Dave DeBoer,John Dreher,G. R. Harp,Jane Jordan,Tom Kilsdonk,Tom Pierson,Karen Randall,John Ross,Seth Shostak Matt Fleming,Chris Cork,Artyom Vitouchkine Niklas Wadefalk,Sander Weinreb +42 more
TL;DR: The design elements of the ATA, the cost savings made possible by the use of commercial off-the-shelf components, and the cost/performance tradeoffs that eventually enabled this first snapshot radio camera are summarized.
Journal ArticleDOI
The Atacama Compact Array (ACA)
Satoru Iguchi,Koh-Ichiro Morita,Masahiro Sugimoto,Baltasar Vila Vilaro,Masao Saito,Tetsuo Hasegawa,Ryohei Kawabe,Ken'ichi Tatematsu,Seiichi Sakamoto,Hitoshi Kiuchi,Sachiko K. Okumura,George Kosugi,Junji Inatani,Shigehisa Takakuwa,Daisuke Iono,Takeshi Kamazaki,Ryusuke Ogasawara,Masato Ishiguro +17 more
TL;DR: The Atacama Compact Array (ACA) as discussed by the authors is an array composed of four 12 m dishes [TP (Total Power) Array] and twelve 7 m dishes (7 m Array).
National Radio Astronomy Observatory
TL;DR: In this paper, the state-of-the-art radio telescope arrays such as the Very Large Array and Very Long Baseline Array (VLBS) have been used for the design of high performance, frequency flexible antennas, reliable low noise receivers and highly phase stable local oscillator systems.
References
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Journal ArticleDOI
A uniform geometrical theory of diffraction for an edge in a perfectly conducting surface
R.G. Kouyoumjian,P.H. Pathak +1 more
TL;DR: In this article, a compact dyadic diffraction coefficient for electromagnetic waves obliquely incident on a curved edse formed by perfectly conducting curved plane surfaces is obtained, which is based on Keller's method of the canonical problem, which in this case is the perfectly conducting wedge illuminated by cylindrical, conical, and spherical waves.
Journal ArticleDOI
Offset-parabolic-reflector antennas: A review
A.W. Rudge,N.A. Adatia +1 more
TL;DR: In this paper, the state of the art of the offset-parabolic reflector antenna's performance and design is discussed. But the authors do not discuss the performance of the single-and double-reflector antennas.
Journal ArticleDOI
Design of dual-reflector antennas with arbitrary phase and amplitude distributions
TL;DR: In this paper, a generalization of the optical design is presented which allows the synthesis of reflector shapes for arbitrary phase and amplitude distributions in the aperture of the larger reflector with an arbitrary primary feed.
Journal ArticleDOI
Microwave antennas derived from the cassegrain telescope
TL;DR: In this paper, the fundamental performance of a Cassegrain double-reflector system was analyzed by means of the equivalent-parabola single reflector concept, and a set of polarization-operative surfaces was developed for these twisting antennas.
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