An Experimental Study of Simulated Plasma-covered Slots

An Experimental Study of Simulated Plasma-covered Slots PDF Author: N. V. Karas
Publisher:
ISBN:
Category : Antenna radiation patterns
Languages : en
Pages : 36

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The effect of a lossless isotropic plasma on the admittance of a waveguide slot terminating in a ground plane has been studied by means of a plasma simulation technique. The relative dielectric constant between the plasma and freespace was maintained by using two contiguous real dielectric materials. Freespace was simulated by an alumina powder of high dielectric constant, and the plasma by a material of lower dielectric constant. The admittance of the slot radiator was measured by (a) a direct method, (b) Deschamps' method, (c) a tuner method. All three gave similar results. Experimental values were determined for the normalized aperture admittance of a slot covered by a simulated plasma of thickness varying from asymptotically equal to 0.1 in. to infinity. The results showed good agreement with theory. (Author).

An Experimental Study of Simulated Plasma-covered Slots

An Experimental Study of Simulated Plasma-covered Slots PDF Author: N. V. Karas
Publisher:
ISBN:
Category : Antenna radiation patterns
Languages : en
Pages : 36

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Book Description
The effect of a lossless isotropic plasma on the admittance of a waveguide slot terminating in a ground plane has been studied by means of a plasma simulation technique. The relative dielectric constant between the plasma and freespace was maintained by using two contiguous real dielectric materials. Freespace was simulated by an alumina powder of high dielectric constant, and the plasma by a material of lower dielectric constant. The admittance of the slot radiator was measured by (a) a direct method, (b) Deschamps' method, (c) a tuner method. All three gave similar results. Experimental values were determined for the normalized aperture admittance of a slot covered by a simulated plasma of thickness varying from asymptotically equal to 0.1 in. to infinity. The results showed good agreement with theory. (Author).

An Experimental Study of Plasma-covered Slots on Cylinders and Cones

An Experimental Study of Plasma-covered Slots on Cylinders and Cones PDF Author: Nicholas V. Karas
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ISBN:
Category : Antenna radiation patterns
Languages : en
Pages : 36

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Book Description
The effect of a plasma on the radiation characteristics of slot and gap apertures located on structures such as cylinders and cones has been studied by means of a plasma simulation technique. The relative index of refraction of less than unity between plasma and free space was maintained for the model by an analog tank that represented free space by a high dielectric constant liquid and the plasma by a lower dielectric material. This technique differs from a previous simulation method in that the models can be immersed into the tank, rather than being kept external. This modification allows the study of nonplanar geometries of complex shapes. Antenna patterns of axial slots on cylinders of various radii and thicknesses of plasma covering were observed to have good agreement with theory for radiation in the equatorial plane, as did the antenna patterns for a plasma-covered center-fed cylindrical antenna. Experimental patterns of a slot on a cylinder partially covered by a plasma are presented. Various effects of the plasma on the radiation characteristics of the slot were observed by varying the location of the plasma on the cylinder in relation to the slot and by varying the amount of surface area covered by the plasma. Experimental patterns of slots on cones covered by a plasma are also presented. (Author).

Application of Plasma Simulation to Slot and Gap Antennas

Application of Plasma Simulation to Slot and Gap Antennas PDF Author: Nicholas V. Karas
Publisher:
ISBN:
Category : Antennas
Languages : en
Pages : 40

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Book Description
A plasma simulation technique has been applied to determine the effects of a plasma on the aperture admittance of radiators located on structures that are of a nonplanar shape. Specifically the normalized aperture admittance, with and without plasma, has been determined for a slot on cylinders of different radii, and for a cylindrical gap antenna. In addition, the plasma effects on the mutual coupling of two rectangular slots has also been found experimentally and compared to theory. All experimental results show good agreement with theory. (Author).

U.S. Government Research and Development Reports

U.S. Government Research and Development Reports PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 616

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Proceedings of the Third Symposium on the Plasma Sheath-Plasma Electromagnetics of Hypersonic Flight

Proceedings of the Third Symposium on the Plasma Sheath-Plasma Electromagnetics of Hypersonic Flight PDF Author:
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 370

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Book Description
This volume is a collection of the unclassified papers presented at the Third Symposium on the Plasma Sheath-Plasma Electromagnetics of Hypersonic Flight. This symposium consisted of the review of progress in reentry communication studies during the three year period since the prior meeting. The program of this symposium on plasma electromagnetics of hypersonic flight involves a wide range of scientific disciplines, including electromagnetics, aerodynamics, aero-thermochemistry, plasma dynamics, electronics, and high- temperature phenomena. The papers were selected to explore as many of these facets of research, including the results of laboratory, flight, and system tests, as time permitted.

U. S. Government Research and Development Reports

U. S. Government Research and Development Reports PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1174

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OAR Cumulative Index of Research Results

OAR Cumulative Index of Research Results PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1264

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Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 994

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Report on Research at AFCRL

Report on Research at AFCRL PDF Author: Air Force Cambridge Research Laboratories (U.S.)
Publisher:
ISBN:
Category : Geophysics
Languages : en
Pages : 400

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Government Reports Announcements

Government Reports Announcements PDF Author:
Publisher:
ISBN:
Category : Research
Languages : en
Pages : 1002

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