Author: Thomas Tameo Sugimoto
Publisher:
ISBN:
Category : Antennas (Electronics)
Languages : en
Pages : 446

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Book Description

Author: Thomas Sugimoto
Publisher:
ISBN:
Category : Antennas (Electronics)
Languages : en
Pages : 54

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Book Description
An experimental investigation of a pair of coupled linear antennas in an inhomogeneous dissipative medium was made. The medium was obtained by diffusing a water solution of NaCl into a large block of agar agar gel contained in a wooden tank. The relative dielectric constant was approximately 78 while the loss tangent could be varied from 0.13 to 3.0 at 114 MHz, the frequency used throughout the investigation. Driving point admittances and current distributions were measured with the medium inhomogeneity oriented parallel to the axes of the antennas. Self and mutual input admittances were measured as a function of the antenna length (beta h = 0.3 to 2 pi in steps of 0.1). Symmetric and antisymmetric current distributions were measured for four different antenna lengths (h/lambda = 0.25, 0.50, 0.75, and 1.0). Each measurement was repeated for three antenna separations (beta/lambda = 0.125, 0.25, and 0.50). Self and mutual driving-point admittances were measured as a function of base separation (b/lambda = 0.25 to 1.5 in steps of 0.125) for four antenna lengths (h/lambda = 0.25, 0.50, 0.75, and 1.0) with the medium inhomogeneity direction perpendicular to the antenna axes. Also studies were the effects of a medium discontinuity at the input, nonidentical elements, and input aperture size on the measured input admittance. (Author).

Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 772

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Author:
Publisher:
ISBN:
Category : Bibliography
Languages : en
Pages : 170

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Author: Janis Galejs
Publisher: Elsevier
ISBN: 1483186377
Category : Technology & Engineering
Languages : en
Pages : 312

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Book Description
Antennas in Inhomogeneous Media details the methods of analyzing antennas in such inhomogeneous media. The title covers the complex geometrical configurations along with its variational formulations. The coverage of the text includes various conditions the antennas are subjected to, such as antennas in the interface between two media; antennas in compressible isotropic plasma; and linear antennas in a magnetoionic medium. The selection also covers insulated loops in lossy media; slot antennas with a stratified dielectric or isotropic plasma layers; and cavity-backed slot antennas. The book will be of great use to electrical, communications, and radio engineers.

Author: Bob M. Duff
Publisher:
ISBN:
Category :
Languages : en
Pages : 96

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Book Description
The results of an experimental study of two identical, parallel, nonstaggered thick antennas are presented in this report. The term 'thick antenna' means a cylindrical dipole whose radius is significant compared to the free space wavelength of the exciting signal. Three thicknesses of antenna were used in the experiment: ka = 0.318, 0.639, and 0.877. Measurements were made of the apparent input admittance for both symmetric and antisymmetric drive, from which apparent self- and mutual admittances were computed. Both axial and transverse components of the current on the surface of the antennas were measured as functions of the cylindrical coordinates phi and z associated with the antenna. A complete description is given of the experimental system including the design of the antenna system, the arrangement for driving the antennas, a description of the measuring system, and a discussion of some of the problems encountered in carrying out the measurements. The variations of self- and mutual admittance as a function of spacing between antennas is shown with comparison to the behavior of thin antennas. Available theoretical results for the current distribution on coupled thick antennas are compared with the measured current distributions. (Author).

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 32

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Book Description
Research studies on electromagnetic radiation and antennas are summarized for the period beginning November 1, 1967 and ending October 31, 1972. Brief reviews are given of work on antenna arrays, electrically thick antennas, modified dipole antennas, the end correction for monopole antennas, antennas in different media, and scattering from finite cylinders and imperfectly conducting spheres. (Author).

Author: Harvard University. Division of Engineering and Applied Physics
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 100

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Author: Roy Carl Fosberg
Publisher:
ISBN:
Category :
Languages : en
Pages : 68

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Author: Larry D. Scott
Publisher:
ISBN:
Category :
Languages : en
Pages : 30

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Book Description
Two representations previously introduced for the distribution of current in an isolated antenna in a general, infinite, homogeneous, isotropic medium have been used to solve the simulataneous integral equations for the currents in coupled dipole antennas. These are a polynomial and a trigonometric form, each with an exponential multiplier. A description of the apparatus for measuring the properties of coupled antennas is also presented together with tables of measured admittance, current and charge distributions. A comparison of the theoretical and experimental results shows fairly good agreement. (Author).