Proceedings ArticleDOI
Full-sampling array feeds for radio telescopes
TLDR
In this article, the array design constraints imposed by complete sampling of the fields near the reflector focus are examined, and a modified form of field matching is a good starting approximation.Abstract:
Phased array feeds offer the possibility of more efficient use of large radio astronomy reflector antennas by providing more closely spaced beams over a wide field of view and higher aperture efficiency in each beam than have been realized with horn feeds. This paper examines the array design constraints imposed by complete sampling of the fields near the reflector focus. In particular, array element spacing must be less than 1 (lambda) for large F/D reflectors and less than about 0.7 (lambda) for F/D < 0.5. This rules out conventional horns as array elements and sets a limit on the array bandwidth. The receive-only case of radio astronomy permits the use of number of signal combining techniques that do not degrade system sensitivity. Because practical arrays are of finite extent, and unwanted noise from the antenna surroundings is largely coherent between the elements, neither field conjugate nor maximal-ratio diversity methods of array weight optimization can be used. A modified form of field matching is a good starting approximation, however. Correction of reflector errors is examined briefly.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.read more
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Journal ArticleDOI
Signal Processing for Phased Array Feeds in Radio Astronomical Telescopes
Brian D. Jeffs,Karl F. Warnick,Jonathan Landon,Jacob Waldron,David Jones,J. R. Fisher,Roger D. Norrod +6 more
TL;DR: A calibration and beamforming strategy for PAFs including interference mitigation with power spectral density (PSD) estimation bias correction and validated using numerical simulations and experimental data from a 19-element PAF on the Green Bank 20-m telescope is proposed.
Journal ArticleDOI
Extending the Field of View With Phased Array Techniques: Results of European SKA Research
TL;DR: Insight is provided into the status of enabling technologies and technical research on polarization, calibration, and side-lobe control that will unleash the potential of phased arrays for future growth of radio astronomy synthesis arrays.
Journal ArticleDOI
Analysis of common‐mode effects in a dual‐polarized planar connected‐array antenna
Stuart G. Hay,J.D. O'Sullivan +1 more
TL;DR: In this paper, an analysis of the efficiency of a dual-polarized planar connected-array antenna with particular reference to possible use in wideband focal-plane-array applications is presented.
Journal ArticleDOI
Decoupling Efficiency of a Wideband Vivaldi Focal Plane Array Feeding a Reflector Antenna
TL;DR: In this article, the decoupling efficiency of a Vivaldi element FPA operating between 2.3 and 7 GHz was evaluated by using measured S -parameters between all element ports.
Book
Phased Arrays for Radio Astronomy, Remote Sensing, and Satellite Communications
TL;DR: Find a modern approach to the analysis, modeling and design of high sensitivity phased arrays by combining network theory, numerical methods and computational electromagnetic simulation techniques to enable full system analysis and design optimization.
References
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Genetic algorithms in search, optimization, and machine learning
TL;DR: In this article, the authors present the computer techniques, mathematical tools, and research results that will enable both students and practitioners to apply genetic algorithms to problems in many fields, including computer programming and mathematics.
Genetic algorithms in search, optimization and machine learning
TL;DR: This book brings together the computer techniques, mathematical tools, and research results that will enable both students and practitioners to apply genetic algorithms to problems in many fields.
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Principles of Optics
TL;DR: In this paper, the authors discuss various topics about optics, such as geometrical theories, image forming instruments, and optics of metals and crystals, including interference, interferometers, and diffraction.
Principles of Optics
TL;DR: In this article, the authors discuss various topics about optics, such as geometrical theories, image forming instruments, and optics of metals and crystals, including interference, interferometers, and diffraction.