Download or read book Deployable Reflector Antenna Performance Optimization Using Automated Surface Correction and Array feed Compensation written by Lyle C. Schroeder and published by . This book was released on 1992 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deployable Reflector Antenna Performance Optimization Using Automated Surface Correction and Array Feed Compensation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods for increasing the electromagnetic (EM) performance of reflectors with rough surfaces were tested and evaluated. First, one quadrant of the 15-meter hoop-column antenna was retrofitted with computer-driven and controlled motors to allow automated adjustment of the reflector surface. The surface errors, measured with metric photogrammetry, were used in a previously verified computer code to calculate control motor adjustments. With this system, a rough antenna surface (rms of approximately 0.180 inch) was corrected in two iterations to approximately the structural surface smoothness limit of 0.060 inch rms. The antenna pattern and gain improved significantly as a result of these surface adjustments. The EM performance was evaluated with a computer program for distorted reflector antennas which had been previously verified with experimental data. Next, the effects of the surface distortions were compensated for in computer simulations by superimposing excitation from an array feed to maximize antenna performance relative to an undistorted reflector. Results showed that a 61-element array could produce EM performance improvements equal to surface adjustments. When both mechanical surface adjustment and feed compensation techniques were applied, the equivalent operating frequency increased from approximately 6 to 18 GHz. Schroeder, Lyle C. and Bailey, M. C. and Mitchell, John L. Langley Research Center...
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1993 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1993 with total page 1158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1993-08 with total page 956 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1993 with total page 1450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1993-03 with total page 1452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Aeronautical Journal written by and published by . This book was released on 1993 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Reflector Antennas and Feed Systems Volume I Theory and Design of Reflectors written by Satish K. Sharma and published by Artech House. This book was released on 2013-07-01 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first truly comprehensive and most up-to-date handbook available on modern reflector antennas and feed sources for diversified space and ground applications. There has never been such an all-encompassing reflector handbook in print, and no currently available title offers coverage of such recent research developments. The Handbook consists of three volumes. Volume I provides a unique combination of theoretical underpinnings with design considerations and techniques. The need for knowledge in reflector antennas has grown steadily over the last two decades due to increased use in space and ground applications, as well as their high gain and wide bandwidth capabilities at relatively low cost. This volume brings you to the leading edge of developments in the field related to numerical techniques, classical reflector geometries, adaptive reflector antennas, shaped reflectors, bifocal and bicollimated dual reflectors, advanced reflectors, and reflect arrays. A must-have reference for both practicing engineers as well as academic researchers.
Download or read book Compensation of Relector Antenna Surface Distortion Using an Array Feed written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-30 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dimensional stability of the surface of a large reflector antenna is important when high gain or low sidelobe performance is desired. If the surface is distorted due to thermal or structural reasons, antenna performance can be improved through the use of an array feed. The design of the array feed and its relation to the surface distortion are examined. The sensitivity of antenna performance to changing surface parameters for fixed feed array geometries is also studied. This allows determination of the limits of usefulness for feed array compensation. Cherrette, A. R. and Acosta, R. J. and Lam, P. T. and Lee, S. W. Glenn Research Center NAG3-419; RTOP 650-60-20...
Download or read book Handbook of Reflector Antennas and Feed Systems Volume III Applications of Reflectors written by Sudhakar Rao and published by Artech House. This book was released on 2013-06-01 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first truly comprehensive and most up-to-date handbook available on modern reflector antennas and feed sources for diversified space and ground applications. There has never been such an all-encompassing reflector handbook in print, and no currently available title offers coverage of such recent research developments. The Handbook consists of three volumes. Volume III focuses on the range of reflector antenna applications, including space, terrestrial, and radar. The intent of this book volume is to provide practical applications and design information on reflector antennas used for several communications systems. This book covers recent developments of reflector antennas used for satellite communications, terrestrial communications, and remote sensing applications. New subjects are introduced for the first time, including satellite antennas, Terahertz antennas, PIM, multipaction, corona, deployable mesh reflector antennas, and mechanical aspects of reflector antennas. In addition, this book contains a separate topic on integrated feed assembly for reflector antennas covering analysis, design, fabrication, and test.
Download or read book Handbook of Reflector Antennas and Feed Systems Volume II Feed Systems written by Lotfollah Shafai and published by Artech House. This book was released on 2013-07-01 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first truly comprehensive and most up-to-date handbook available on modern reflector antennas and feed sources for diversified space and ground applications. There has never been such an all-encompassing reflector handbook in print, and no currently available title offers coverage of such recent research developments. The Handbook consists of three volumes. Volume II focuses on feed sources. Reflector antennas are extraordinary devices that combine high gain with geometrical simplicity, and can operate in broad frequency bands. Their performance, however, depends on the electrical characteristics of the feed system with which they operate. This comprehensive volume provides you with a solid understanding of feed system theory, design, and analysis. Featuring chapters authored by experts in each aspect of feed systems, this book takes you from fundamental mathematical techniques, electrically small and large dual reflectors, feed geometry and telemetry, tracking and command antennas, and more. Throughout the book numerous examples are provided to guide you in the practical aspects of feed design.
Download or read book Feasibility Study of a Synthesis Procedure for Array Feeds to Improve Radiation Performance of Large Distorted Reflector Antennas written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-24 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface errors on parabolic reflector antennas degrade the overall performance of the antenna. Space antenna structures are difficult to build, deploy and control. They must maintain a nearly perfect parabolic shape in a harsh environment and must be lightweight. Electromagnetic compensation for surface errors in large space reflector antennas can be used to supplement mechanical compensation. Electromagnetic compensation for surface errors in large space reflector antennas has been the topic of several research studies. Most of these studies try to correct the focal plane fields of the reflector near the focal point and, hence, compensate for the distortions over the whole radiation pattern. An alternative approach to electromagnetic compensation is presented. The proposed technique uses pattern synthesis to compensate for the surface errors. The pattern synthesis approach uses a localized algorithm in which pattern corrections are directed specifically towards portions of the pattern requiring improvement. The pattern synthesis technique does not require knowledge of the reflector surface. It uses radiation pattern data to perform the compensation. Stutzman, W. L. and Smith, W. T. Unspecified Center NASA-CR-186641, NAS 1.26:186641, EE-SATCOM-90-2 NAG1-859...
Download or read book System Overview on Electromagnetic Compensation for Reflector Antenna Surface Distortion written by R. J. Acosta and published by . This book was released on 1993 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compensation of Relector Antenna Surface Distortion Using an Array Feed written by and published by . This book was released on 1988 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technology for Large Space Systems written by and published by . This book was released on 1989 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technology for Large Space Systems A Bibliography with Indexes supplement 20 written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Division and published by . This book was released on 1989 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
