Some thoughts about transient radiation by straight thin wires

Martin, R.G.; Bretones, A.R.; Garcia, S.G.

doi:10.1109/74.775245

Cited by 29 publications

(20 citation statements)

References 21 publications

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“…In such case, the antenna should not be considered as a dipole that consisted of two equivalent charges with opposite polarity, but a monopole that would generate radiation when the charge is accelerated and starts moving. Martin (1999) compared the transmission between the dipole antenna and the traveling-wave antenna, and his conclusion is that the radiation by dipole antenna at the center is different from that by accelerated-moving charge at the endpoint of the travelingwave antenna [4] . Traditionally, the relative motion between two equivalent charges with opposite polarity is regarded as the fundamental of the dipole theory of antenna, and the radiation of a dipole source can be estimated by stacking the fields from all micro charges induced by impulse.…”

Section: Introductionmentioning

confidence: 99%

A study on theory and physical mechanism of an infinitesimal current-carrying point charge

Zhou¹,

Xue²,

Chen³

2016

Proceedings of the 7th International Conference on Environment and Engineering Geophysics &Amp; Summit Forum of Chinese Academy

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Abstract-In antenna theory, the dipole hypothesis is applicable and widely used for observing the far-field radiation. However, when applied to near-field quasi-static radiation observation in geophysical surveying, the transceiver distance is often small, and thereby the source should not be treated as a dipole to avoid misfit between the observation and the modeling based on the dipole theory. To overcome such limitation, this paper first presents a new method of estimating the field generated from a dipole by dividing it into a series of infinitesimal point charge and computing both the velocity field excited by uniform-motion charge and accelerated-velocity field from accelerated charge, so that not only the far-field radiation but also the near-field quasi-static radiation can be accurately estimated. The results are well verified by the traditional methods of radiation modeling from a dipole. Then this study investigates the associated physical mechanism by developing a new equation for computing the radiated field in time-domain based on the frequency-to-time transformation, from which the relationship between a motive charge and its corresponding field is investigated. It is concluded that the field generated from dipole is in nature the same as that generated from motive charge.

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Section: Introductionmentioning

confidence: 99%

A study on theory and physical mechanism of an infinitesimal current-carrying point charge

Zhou¹,

Xue²,

Chen³

2016

Proceedings of the 7th International Conference on Environment and Engineering Geophysics &Amp; Summit Forum of Chinese Academy

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“…For example, in a half-wave linear dipole antenna, there are two ends of reflections ( ). An explanation of the transient effects of end reflections of a thin wire antenna is given in [21]. In case of implanted antennas, when the boundary between insulation and the external medium is in the proximity, reflections at the surface ( ) also contribute to the reflected wave as observed at the feed point ( ).…”

Section: A Dipoles In Dissipative Mediummentioning

confidence: 99%

Dielectric Loaded Impedance Matching for Wideband Implanted Antennas

Dissanayake

Esselle

Yuce

2009

IEEE Trans. Microwave Theory Techn.

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Abstract-In implanted biomedical devices, due to the presence of surrounding dissipative biological tissue, the antenna suffers poor impedance matching. This causes degradation in the performance of a wideband or ultra-wideband (UWB) implanted device. Moreover, the electrical properties of tissue change from organ to organ, and possibly from time to time. In this paper, it is shown that loading of antennas with suitable insulators can deliver broadband matching across a range of dissipative medium properties. An impedance-matched UWB antenna designed to operate inside a lossy medium, which has varying electromagnetic properties within the range expected in biological tissues, is presented. The operating bandwidth of the proposed design is 3.5-4.5 GHz, which is an interference-free subset of the unlicensed UWB band in the US. It is demonstrated that once the dielectric loading is applied, the conventional procedure for antenna design in free space can be followed. The proposed implantable small capsule-shaped slot antenna has been characterized using numerical simulations. Details of a proof-of-concept experiment are presented.Index Terms-Biomedical electronic, biomedical engineering, implanted device, ultra-wideband (UWB) antenna.

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“…The phenomenon is relevant, in particular, in applications involving very large bandwidths, where the distortion of the signal waveform causes problems. Some recent papers, e.g., [5][6][7], deal with this subject, although from the point of view of the time-domain response of finite length wire structures in the radiation zone. In the present paper, however, the attention is focused on the simplest of radiators, the infinitesimal dipole, and especially the near-field it produces.…”

Section: Introductionmentioning

confidence: 99%

Aspects on the Phase Delay and Phase Velocity in the Electromagnetic Near-Field

Stén¹,

Hujanen²

2006

PIER

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Abstract-The phase of a complex field and its speed of propagation are fundamental concepts of electromagnetic wave motion. Although it seems to be well-known that faster than light propagation of the phase may occur in, e.g., waveguides and certain dispersive media, it is often ignored that a similar phenomenon, in fact a very marked one, presents itself in the near-field of an arbitrary oscillating current in vacuum. Connected herewith is the observation that the phases of the transverse field components of a dipole approach kr − π/2, and not kr, in the radiation zone. This article illustrates these phenomena by theoretical and numerical examples as well as indicates their consequences for broad-band wireless communication over short distances.

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Some thoughts about transient radiation by straight thin wires

Cited by 29 publications

References 21 publications

A study on theory and physical mechanism of an infinitesimal current-carrying point charge

A study on theory and physical mechanism of an infinitesimal current-carrying point charge

Dielectric Loaded Impedance Matching for Wideband Implanted Antennas

Aspects on the Phase Delay and Phase Velocity in the Electromagnetic Near-Field

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