Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | IEEE Xplore Digital Library |
|---|---|
| Author | Wu, Jiangfeng Sarabandi, Kamal |
| Copyright Year | 2015 |
| Description | Author affiliation: Radiation Laboratory, the University of Michigan, Ann Arbor, 48105, USA (Wu, Jiangfeng; Sarabandi, Kamal) |
| Abstract | Circularly polarized (CP) antennas are commonly needed for satellite communication, WLAN, RFID, Radar and many other systems. Circularly polarized waves can avoid the negative effects of polarization rotation in propagation channels, such as ionosphere. It can also reduce the effect of multipath fading for co-polarized transceiver systems as the odd bounce reflections change the handedness of the wave polarization. For many communication and radar problems with omni-directional antenna elements are needed. For the communication the reason is obvious as the direction of arrival or the orientation of the antenna is arbitrary. For the radar, distributed imaging network of transmitters and receivers are envisioned to create all direction imaging from a number of moving receivers. To reduce the direct signal between the transmitter and receivers CP antennas with orthogonal polarization can be used. Existing omni-directional CP antennas have complex 3D structures and are large in size. In this paper, a planar CP antenna having omni-directional pattern within a ring area is designed. The CP polarization is synthesized by combining two linearly polarized and omni-directional antennas and feeding them with signals having the same amplitude but 90 degree phase difference. The first antenna is a slot antenna on a finite and small ground plane which is made to have an omni-directional pattern on its E-plane. To achieve that, the radiation null on the E-plane that exists on conventional slot antennas is removed by constructing a parallel plate waveguide delay line between the two sides of the antenna and forming an antiparallel field distribution on the aperture of each side. As a result, the far field radiation from both apertures adds up in phase and becomes uniform. The other antenna consists of two PIFA elements which radiate omni-directionally on their H-plane. The feeding network splits the input power equally to excite both antennas and introduces an extra 90 degree phase delay for one of the antennas. The feeding network is realized by microstrip lines and is optimized to have an axial ratio lower than 2 within a bandwidth of 2–3%. The simulation results demonstrate that the antenna has a figure-eight pattern in elevation with a beamwidth of about 100 degree. The gain of this small antenna is 2dB with small fluctuation as a function of angle in the horizontal plane. |
| Starting Page | 175 |
| Ending Page | 175 |
| File Size | 66563 |
| Page Count | 1 |
| File Format | |
| ISBN | 9781479978175 |
| DOI | 10.1109/USNC-URSI.2015.7303459 |
| Language | English |
| Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Publisher Date | 2015-07-19 |
| Publisher Place | Canada |
| Access Restriction | Subscribed |
| Rights Holder | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| 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...
|