Please wait, while we are loading the content...
Please wait, while we are loading the content...
Content Provider | IEEE Xplore Digital Library |
---|---|
Author | Newell, A.C. Gregson, S.F. |
Copyright Year | 2013 |
Description | Author affiliation: Nearfield Systrems Inc., Torrance, CA, USA (Newell, A.C.; Gregson, S.F.) |
Abstract | A previous study (1) by the authors reported on a computer simulation using Open Ended Waveguide probe data and actual test antenna data to quantify the effect of using higher order probes with the spherical processing that assumes the probe has only μ = ±1 modes. That study was based on the observation that since the higher order probe's azimuthal modes are directly related to the probe's properties for rotation about its axis, the near-field data that should be most sensitive to these modes is a near-field polarization measurement. Such a measurement would be taken with the probe at a fixed (θ,φ,z) position and the probe is then rotated about its axis by the angle χ over 360 degrees. The amplitude and phase received by the probe would be measured as a function of the χ rotation angle. A direct measurement using different probes would be desirable, but since the effect of the higher order modes is very small, other measurement errors would likely obscure the desired information. A computer simulation rather than a measurement was therefore used where the plane-wave transmission equation was used to calculate the received signal for an AUT/probe combination where the probe is at any specified position in the near-field. The plane wave spectra for both the AUT and the probe were derived from measured planar data for the AUT and spherical near-field data for the probe. The plane wave spectrum for the AUT was the same for all calculations with the main beam along the Z-axis and the AUT at the origin. The receiving spectrum for the probe at each (θ,φ,χ) orientation was determined from the far-field pattern of the probe after it had been rotated by χ. The far-field pattern of the probe as derived from spherical near-field measurements can be filtered to include or exclude the higher order spherical modes, and the near-field polarization data can therefore be calculated to show the sensitivity to these higher order modes. This approach focuses on the effect of the higher order spherical modes and completely excludes the effect of measurement errors. The study indicated that the effect of the higher order probes on the measured near-field data was on the order of 50 dB below the peak of the near-field data and would likely be below the effect of other errors such as scattering, alignment, and total system random errors. Two test antennas were used in the previous study, and a limited number of probe positions were used in the simulation. The results described in this paper extends the initial study to include additional simulation results that are more representative of a spherical near-field measurement. For the current simulations, the AUT pattern is first rotated about the Y-axis to simulate off-axis θ angles on the measurement sphere and the probe z position is varied to simulate different measurement radii. |
Sponsorship | IEEE Antennas Propagation Soc. |
Starting Page | 3874 |
Ending Page | 3878 |
File Size | 365127 |
Page Count | 5 |
File Format | |
ISBN | 9781467321877 |
e-ISBN | 9788890701832 |
e-ISBN | 9788890701818 |
Language | English |
Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
Publisher Date | 2013-04-08 |
Publisher Place | Sweden |
Access Restriction | Subscribed |
Rights Holder | EurAAP |
Subject Keyword | Antenna measurements uncertainty analysis spherical OEWG probes near-field Equations spherical modes Measurement uncertainty Mathematical model Probes Antennas high order probes measurements |
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...
|