Please wait, while we are loading the content...
| Content Provider | IEEE Xplore Digital Library |
|---|---|
| Author | Morgan, D.P. |
| Copyright Year | 2001 |
| Description | Author affiliation: Impulse Consulting, Northampton, UK (Morgan, D.P.) |
| Abstract | The DART (Distributed Acoustic Reflection Transducer) is well established as a primary technology for SAW I.F. filters, particularly for mobile phones. The transducer incorporates internal reflections, with reflection centres displaced almost ideally from transduction centres. Good directivity is obtainable, and filters based on this technology can have simultaneously low insertion loss and good multiple-transit suppression. Weighting can be applied to both transduction and reflection distributions in order to control the response, giving for example low sidelobes and sharp skirts. The Reflective Array Model (RAM) was earlier shown to be effective for analysis of uniform DART's. Here, it is shown that the RAM can also be applied when the DART has withdrawal-weighted transduction and reflection distributions. A DART such as this can be treated as a sequence of elementary units, some giving transduction and some giving reflection, and these can be cascaded to give the transducer P-matrix. The DART can also be analysed with the transduction and reflection functions taken as analogue functions, to be withdrawal-weighted later. This is convenient for design purposes because many designs can be assessed without the need for withdrawal weighting. In recent filter designs the triple-transit signal is deliberately exploited, resonant SPUDT's (R-SPUDT's) are used, and the design is carefully optimised. These factors have enabled the physical size to be reduce substantially, and important factor for mobile phone applications. |
| Sponsorship | Ultrasonics, Ferroelectr., & Frequency Control Soc |
| Starting Page | 133 |
| Ending Page | 137 |
| File Size | 279983 |
| Page Count | 5 |
| File Format | |
| ISBN | 0780371771 |
| DOI | 10.1109/ULTSYM.2001.991594 |
| Language | English |
| Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Publisher Date | 2001-10-07 |
| Publisher Place | USA |
| Access Restriction | Subscribed |
| Rights Holder | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Subject Keyword | Electrodes Filters Acoustic reflection Frequency Acoustic transducers Surface acoustic waves Mobile handsets Signal design Voltage Bars |
| 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...
|