Prolate spheroidal antennas in isotropic plasma media

Lytle, R.J.; Schultz, F. V.

doi:10.1109/tap.1969.1139469

Cited by 14 publications

(9 citation statements)

References 29 publications

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“…The earlier studies of the radiation field of spheroidal antennas [1][2][3][4], both without a shell and surrounded by a dielectric or plasma shell, insufficiently covered the question of influence of the shape variation of a spheroidal source on the field in free space. The answer to this question can be found for spheroidal antennas of small electrical sizes (ka 0 1, where k is the wave nunmber in free space and a 0 is the major semiaxis of a spheroidal antenna), for which the solution can be found in analytical form.…”

Section: Radiation Frommentioning

confidence: 99%

“…spheroids [1,3], such a formulation of the problem of the radiation field of a spheroidal antenna with plasma shell bounded by two inserted spheroids permits, for a continuously varied shape of the spheroids, a limiting transition to the case of a spherical antenna surrounded by a spherical plasma shell.…”

Section: Radiation Frommentioning

confidence: 99%

“…In Eq. (2), we used the following designations: S 1n (d ε3 , η) is an angular spheroidal function of the first kind, the function he (1) 1n (d ε3 , ξ) is related to the radial spheroidal functions je 1n (d ε3 , ξ) and ne 1n (d ε3 , ξ) of the first and second kinds, respectively, by the formula…”

Section: Radiation Frommentioning

confidence: 99%

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Radiation from a small spheroidal antenna with plasma shell

Bichutskaya

Makarov

2006

Radiophys Quantum Electron

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We construct and study an analytical solution of the boundary-value problem for the radiation field of a small spheroidal antenna located in free space and surrounded by a thin shell of cold homogeneous isotropic plasma. Conditions for a resonant increase in the field in free space as a function of the plasma-shell thickness with the variation in the spheroidal-antenna shape are studied. It is shown that the plasma shell has the largest effect on the radiation field of a strongly prolate spheroidal antenna.The earlier studies of the radiation field of spheroidal antennas [1-4], both without a shell and surrounded by a dielectric or plasma shell, insufficiently covered the question of influence of the shape variation of a spheroidal source on the field in free space. The answer to this question can be found for spheroidal antennas of small electrical sizes (ka 0 1, where k is the wave nunmber in free space and a 0 is the major semiaxis of a spheroidal antenna), for which the solution can be found in analytical form. In this paper, we construct an analytical solution for the radiation field of small spheroidal antennas, both prolate and oblate, covered by a thin plasma shell of spheroidal shape with k |ε|a 1, where ε is the dielectric permittivity of the plasma and a is the major semiaxis of a spheroidal plasma shell, and study the field characteristics in the far zone of the source as functions of the variable shape of a spheroidal antenna and the relative thickness of the plasma shell.The influence of the small plasma shell of a point source (electric dipole) studied earlier [5-8] using the models of a plasma shell in the form of a circular or elliptical cylinder, as well as a plasma sphere or spheroid, showed that because of the frequency dispersion of the plasma, there exist such resonant frequencies at which the radiation-field amplitude in free space turns out to be one or two orders of magnitude higher than at the neighboring frequencies for the same current at the source input. The resonant frequency and amplitude of the resonant field considerably depend on the shape of the plasma shell, so that for the oblate shape of a spheroid or the elliptical cross section of a cylinder, the amplitude of the resonant field is maximum. We will call a resonant increase in the field of a point source with fixed current and small plasma shell the current resonance as distinct from the voltage resonance considered in the present paper for a plasma-coated spheroidal antenna with fixed voltage in the gap.Consider a metal antenna located in an unbounded medium with dielectric permittivity ε 3 and having the form of a spheroid with interfocal distance 2d 0 , major and minor semiaxes a 0 and b 0 , respectively, and a plasma shell bounded by the surface of a spheroid with interfocal distance 2d and semiaxes a and b. We assume that the eccentricities e of the external and internal spheroids having a common origin of coordinates (see Fig. 1) are identical. In the further analysis, the shape of the spheroids will vary from strongly...

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Section: Radiation Frommentioning

confidence: 99%

Section: Radiation Frommentioning

confidence: 99%

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Radiation from a small spheroidal antenna with plasma shell

Bichutskaya

Makarov

2006

Radiophys Quantum Electron

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“…Numerous investigations have been based upon the hydrodynamic model of a cold (incompressible) or a warm (compressible) isotropic plasma. Three approaches have been commonly used to determine antenna characteristics in plasma: assuming the current distribution [Balmain, 1965], a boundary value problem formulation [ Wait and Spies, 1966;Miller, 1968;Lytle and Schultz, 1969], and an integral equation approach [Lin and Mei, 1968;Wunsch, 1968;Monroe, 1968;Preis, 1972a].…”

Section: Introductionmentioning

confidence: 99%

“…Spherical antennas have been investigated, and input impedance results have been obtained for sphere radii up to many acoustic wavelengths [ Wait and Spies, 1966]. Numerical results for prolate spheroidal antennas [Lytle and Schultz, 1969] have been limited to antenna lengths of five acoustic wavelengths or less Copyright ¸ 1975 by the American Geophysical Union.…”

Section: Introductionmentioning

confidence: 99%

A Toeplitz matrix application: A dipole in a warm plasma

Lytle¹,

Lager²

1975

Radio Science

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A linear dipole antenna has an impedance matrix of Toeplitz form. The problem of an acoustically long cylindrical antenna in a warm plasma thus becomes numerically tractable. Both the electromagnetic and acoustic wavelengths are evident in the current distribution for acoustically long antennas. Relative accuracies of 10−11 were obtained for inversion of a 5000×5000 complex impedance matrix, including both electromagnetic and acoustic contributions. Antennas up to 500 acoustic wavelengths long are considered in numerical examples.

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VIII Evaluation, Design and Extrapolation Methods for Optical Signals, Based on Use of the Prolate Functions

Frieden

1971

Progress in Optics

144

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Prolate spheroidal antennas in isotropic plasma media

Cited by 14 publications

References 29 publications

Radiation from a small spheroidal antenna with plasma shell

Radiation from a small spheroidal antenna with plasma shell

A Toeplitz matrix application: A dipole in a warm plasma

VIII Evaluation, Design and Extrapolation Methods for Optical Signals, Based on Use of the Prolate Functions

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