Radiation resistance of an electric dipole in a magnetoionic medium

Weil, Herschel; Walsh, D.

doi:10.1109/tap.1964.1138203

Cited by 27 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our work differs from that of other workers who have considered similar or identical problems [Bun- kin, 1957;Kogelnik, 1960a, b;Kuehl, 1962;Mittra and Deschamps, 1963;Arbel and Felsen, 1963;Balmain, 1964;Ament et al, 1964;Staras, 1964;Weil and Walsh, 1964;Blair, 1964;$eshadri, 1965; 167 WANG AND BELL Gale]s, 1966a, b] in that we have started from a full-wave treatment of the problem and have derived approximate closed form expressions for the radiation resistance which are valid for a wide range of antenna lengths. Using these expressions, we are able to define for the first time the range of antenna length for which a quasi-static analysis, such as that employed by Balmain [1964] and Blair [1964], accurately predicts the radiation resistance of the antenna.…”

Section: Introductioncontrasting

confidence: 54%

Radiation Resistance of a Short Dipole Immersed in a Cold Magnetoionic Medium

Wang¹,

Bell²

1969

Radio Science

View full text Add to dashboard Cite

Electromagnetic radiation from sources immersed in a cold magnetoplasma is analyzed by the use of 'principal-polarized' wave coordinates; and the wave fields, the mean complex radiated power, and the Poynting vector are systematically expressed in terms of 'polarized' wave modes. For each polarized wave mode, the medium is effectively isotropic, since the Fourier-transformed wave equation for each principal mode is decoupled and is similar to the one obtained from the usual scalar Helmholtz operator. In application of the theory, consideration is made of the radiation resistance of a linear electric antenna of moderate length oriented both parallel and perpendicular to the static magnetic field. Approximate closed form expressions for the radiation resistance are obtained for the VLF frequency range by using a plasma model appropriate to the magnetosphere. These approximate closedform expressions are compared with the results obtained previously by other workers using a quasi-static approximation, and it is shown that excellent agreement exists between the two methods of analysis. It is concluded that the quasi-static approximation can accurately predict the radiation resistance of a linear antenna in the magnetosphere, given certain moderate restrictions on the antenna length.

show abstract

Section: Introductioncontrasting

confidence: 54%

Radiation Resistance of a Short Dipole Immersed in a Cold Magnetoionic Medium

Wang¹,

Bell²

1969

Radio Science

View full text Add to dashboard Cite

show abstract

“…10. This figure agrees with the results of H. Weil and D. Walsh [12]. When the wave normal surfaces are plotted for each region shown in Fig.…”

Section: Clemmow-mually-allis (Cma) Diagramsupporting

confidence: 91%

Wave Propagation and Dispersion Characteristics for a Nonreciprocal Electrically Gyrotropic Medium

Eroğlu¹,

Lee²

2006

PIER

View full text Add to dashboard Cite

Abstract-The general dispersion relation for a nonreciprocal electrically gyrotropic or a gyroelectric medium is derived in two distinct forms by using three different methods. One of them is a new method which can be used when the stratification of the layers is in the z-direction. The wave numbers corresponding to each dispersion relation are obtained in closed form. It is shown that there exist two types of waves, type I and type II, in a gyroelectric medium. The wave propagation is investigated and the polarization of the waves, resonances and cut off conditions are obtained for the principle waves. The general wave propagation regions are identified using resonances and cut off conditions. These regions are then used to construct the Clemmow-Mually-Allis (CMA) diagram. The conditions showing the frequency bands for which wave can propagate in each region are tabulated for the first time. The results presented in this paper can be used in the development of nonreciprocal devices and in ionospheric problems including radiation and scattering applications.

show abstract

“…It can be shown that, for very slight losses (i.e., Z • 0), this increase in the real part of the impedance corresponds to true radiation as opposed to being an intrinsic loss in the medium, i.e., it appears in the far field. Therefore, although a small circular loop is an extremely inefficient transmitting antenna in free space [Weeks, 1968], the enhancement of its radiating characteristics [Weil and Walsh, 1964] due to the magneto-. plasma suggest that it may well be used as a transmitting antenna on board extraterrestrial vehicles.…”

Section: The Plasma Dependence Of the Second Term Of (42) Is Not Of Tmentioning

confidence: 99%

Loop Impedance in Magnetoplasma: Theory and Experiment

Duff¹,

Mittra²

1970

Radio Science

View full text Add to dashboard Cite

The impedance of a small loop in magnetoplasma is derived for the cases of magnetic field normal to and parallel to the plane of the loop. The quasi‐static and uniaxial approximation methods are used, and an argument is given to justify the uniaxial approximation as the more desirable method. The results of the theory are given in analytic form and are evaluated numerically and presented graphically. The loop impedance is seen to be much less plasma‐dependent than the impedance of a short electric dipole. It is shown that the small loop can be an efficient radiator under certain plasma conditions. The results of laboratory measurement of loop impedance in magnetoplasma are also given for the cases of normal and parallel orientation of the magnetic field with respect to the plane of the loop. The laboratory plasma is generated by using a brush‐electrode configuration. The measured impedance is compared with the theoretical predictions, and good agreement is shown for the perpendicular orientation. Quantitative agreement with the theory is not as good for the case of parallel orientation, but much of the gross impedance behavior is verified for this orientation, particularly the fact that the impedance is relatively plasma‐dependent.

show abstract

Radiation resistance of an electric dipole in a magnetoionic medium

Cited by 27 publications

References 4 publications

Radiation Resistance of a Short Dipole Immersed in a Cold Magnetoionic Medium

Radiation Resistance of a Short Dipole Immersed in a Cold Magnetoionic Medium

Wave Propagation and Dispersion Characteristics for a Nonreciprocal Electrically Gyrotropic Medium

Loop Impedance in Magnetoplasma: Theory and Experiment

Contact Info

Product

Resources

About