The Spatial Distributions of Radiation Emitted from a Sinusoidal Current Filament and a Dipole Antenna

Authors

  • Edmund K. Miller Los Alamos National Laboratory (Retired)

DOI:

https://doi.org/10.13052/2022.ACES.J.370403

Keywords:

Charge reflection Dipole radiation;, Differentiated Poynting Vector, Distributed radiation resistance;, Farfield analysis of radiation sources;, IEMF method, NEC, Poynting Vector;, Sinusoidal current filament;, TWTD

Abstract

While the analytical and numerical tools for determining the basic properties of a variety of antenna types have been long-established, there remains some continuing curiosity about how electromagnetic radiation is launched by such a simple antenna as a dipole. The following article discusses this problem in both the frequency domain and time domain. The sinusoidal current filament (SCF) is investigated first as a prototype of a wire dipole. The length-wise distribution of radiated power for the SCF is obtained from the distributed radiation resistance of Schelkunoff and Feldman, the induced electromotive force (IEMF) method, and the far-field analysis of radiation sources (FARS) developed by the author.

The FARS approach is next used to analyze a frequency-domain numerical model of a dipole antenna, producing results similar to those for the SCF for a dipole of near-zero radius. Differentiating the decaying on-surface Poynting vector (PV) produces results comparable to those from FARS to explicitly demonstrate the power loss caused by radiation of the propagating current and charge. The lobed distributed radiated power is shown to be closely correlated with the square of the dipole current, confirming the cause of the radiation to be due to a partially reflected charge as the current and charge form standing waves on the dipole. Application of a time-domain version of FARS yields a smoothed length-wise distribution of radiated energy as opposed to the lobed variation of the frequency domain.

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Author Biography

Edmund K. Miller, Los Alamos National Laboratory (Retired)

Edmund K. Miller received the Ph.D. degree in electrical engineering from the University of Michigan in 1965 with an emphasis on computational electromagnetics (CEM), a rapidly developing field at the time.

His working career has been quite varied including employment at four universities (Michigan Technological University, University of Michigan, Kansas University, and Ohio University), three companies (MBAssociates, Rockwell International Science Center, and General Research Corporation, all in California), and two national laboratories (Lawrence Livermore and Los Alamos from which he retired in 1993). He has served two terms on the IEEE Antennas and Propagation Society (AP-S) Administrative Committee and has twice been an APS Distinguished Lecturer.

Dr. Miller was elected as IEEE Fellow in 1984 and received the IEEE Third Millennium Medal in 2000. He was the recipient (with others) of the 1988 Best Paper Award from the IEEE Education Society. Between 1985 and 2002, he served on the editorial board of IEEE Potentials Magazine as Editor or Associate Editor for which he wrote a regular column “On The Job.” He also wrote a column for the AP-S Magazine “PCs for AP and Other EM Reflections” from 1984 to 2000. He was an organizer, served as its first president, and is a Fellow of the Applied Computational Electromagnetics Society (ACES) for which he served two terms on its Board of Directors. His research interests include CEM, applied signal processing, visual electromagnetics, and promoting the incorporation of accuracy statements in published CEM numerical results. He has published numerous articles dealing with his major interest, the physics of electromagnetic radiation, and recently completed a draft book on the topic with the title “Charge Acceleration and the Spatial Distribution of Radiation Emitted by Antennas and Scatterers.”

References

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Published

2022-04-01

How to Cite

[1]
E. K. . Miller, “The Spatial Distributions of Radiation Emitted from a Sinusoidal Current Filament and a Dipole Antenna”, ACES Journal, vol. 37, no. 04, pp. 388–395, Apr. 2022.

Issue

2022: Vol 37 Iss 4

Section

Articles