Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | IEEE Xplore Digital Library |
|---|---|
| Author | Pereira, J.C.P. |
| Copyright Year | 1995 |
| Description | Author affiliation: CPqD-Telebras, Campinas, Brazil (Pereira, J.C.P.) |
| Abstract | Double reflector offset antennas with spherical main reflector have recently been considered as an interesting alternative for fixed satellite services applications subjected to the newest CCIR radiation pattern recommendation. The great appeal of this configuration is the possibility of reducing main reflector manufacturing cost, which contrary to shaped and classical double reflector offset antennas can be achieved by manufacturing spinning machines or by fitting panels of the same radius of curvature. However this configuration has a serious competitor widely employed in the range of aperture diameters above 150/spl lambda/, these are the symmetrical double reflector antennas. This configuration also has as its main advantage the facility of manufacture, since both main and subreflector are axially symmetric, and the control over antenna aperture power distribution, which can he accomplished through reflectors shaping. On the other hand this same configuration presents some significant drawbacks; these are subreflector aperture blockage and strut scattering which degrade antenna gain and result in sidelobe radiation pattern levels increasing. Regarding the double offset reflector configuration with spherical main reflector, although it is not impaired by blockage, it presents limited aperture illumination control, since the subreflector is basically designed as a phase corrector intended to yield an aperture constant phase wavefront. Recently some papers describing synthesis methods for double offset with spherical main reflector configuration, as well as parametric studies and comparisons between this and other double offset configurations have been published. In this paper the intention is to investigate the viability of employing this configuration by comparing its electrical performance with the one presented by a symmetrical double reflector antenna of similar gain. The study was carried out in a diameter range immediately superior to 150/spl lambda/ in the Ku band allocated for fixed satellite service (10.7-12.75GHz and 13.8-14.8GHz). |
| Starting Page | 905 |
| Ending Page | 908 |
| File Size | 306040 |
| Page Count | 4 |
| File Format | |
| ISBN | 0780327195 |
| DOI | 10.1109/APS.1995.530164 |
| Language | English |
| Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Publisher Date | 1995-06-18 |
| Publisher Place | USA |
| Access Restriction | Subscribed |
| Rights Holder | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Subject Keyword | Reflector antennas Manufacturing Aperture antennas Antenna radiation patterns Satellite antennas Costs Spinning machines Curve fitting Shape control Power distribution |
| Content Type | Text |
| Resource Type | Article |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|