File:Monopole measured input resistance graph.svg
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Summary
| Description |
English: Graph of the measured input resistance of a monopole antenna fed at bottom mounted over a large wire screen ground plane as a function of length of the antenna in wavelengths for different values of the length-to-diameter ratio of the element. The horizontal axis of the graph is the electrical length of the antenna, the length divided by the wavelength of the radio frequency input multiplied by 360 degrees. For all practical purposes the vertical axis of the graph is the radiation resistance of the monopole; as the ohmic resistance of the rod was negligible. The cylindrical rod antenna was fed at bottom from under the screen by coaxial cable from a signal generator, and a slotline was used to determine the SWR and thus the input impedance. This was a large experiment in which many different lengths and diameters of rod were used determine the shape of the impedance curve. This parameter needed to be determined experimentally since, particularly near the half-wave resonance, it was difficult to calculate; the numerical algorithms used to analyze antennas have large errors near the resonance. |
| Date | |
| Source | Retrieved 23 November 2024 from Brown, George H. & Woodward, O. M.. "Experimentally determined impedance characteristics of cylindrical antennas", Proceedings of the IRE, Institute of Radio Engineers, New York, Vol. 33, No. 4, April 1945, p.259, fig.6 on https://www.worldradiohistory.com/. The downloaded PDF graph was traced in Inkscape to make an SVG version |
| Author |
Original version: George H. Brown This version: User:Chetvorno |
| Permission (Reusing this file) |
This magazine published in the US in 1945 would have the copyright renewed in 1973. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here [1]. Search of the Renewals for Periodicals for 1972, 1973 and 1974 show no renewal entries for Proceedings of the IRE. Therefore the work's copyright was not renewed and it is in the public domain. |
Licensing
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This work is in the public domain because it was published in the United States between 1929 and 1963, and although there may or may not have been a copyright notice, the copyright was not renewed. For further explanation, see Commons:Hirtle chart and the copyright renewal logs.
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 10:52, 30 November 2024 | | 671 × 793 (115 KB) | Chetvorno | Uploaded a work by George H. Brown from Retrieved 23 November 2024 from [https://www.worldradiohistory.com/Archive-IRE/40s/IRE-1945-04.pdf Brown, George H. & Woodward, O. M.. "Experimentally determined impedance characteristics of cylindrical antennas", ''Proceedings of the IRE'', Institute of Radio Engineers, New York, Vol. 33, No. 4, April 1945, p.259, fig.6] on https://www.worldradiohistory.com/ with UploadWizard |
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