Analysis of Aperture Antennas in Inhomogeneous Media

Analysis of Aperture Antennas in Inhomogeneous Media PDF Author: Dikran Damlamayan
Publisher:
ISBN:
Category : Antennas (Electronics)
Languages : en
Pages : 86

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Book Description
The object of this report is to calculate the admittance and the radiation pattern of aperture antennas fed by waveguides of arbitrary cross-section and radiating into dielectric slabs, whose constitutive parameters may be functions of position along the direction normal to the slab faces. For a given aperture field distribution the antenna aperture admittance and the radiation field are expressed here, for the first time, in terms of two auxiliary quantities directly related to the plane wave reflection and transmission coefficients of the dielectric slab. These quantities are the input admittance of the dielectric slab and the ratio of the total electric field amplitude transmitted at one end of the slab to the transverse field at the other, both calculated for plane waves as a function of incident propagation direction. This approach introduces a great simplification in the solution of the problem, particularly in the case of an antenna radiating into an inhomogeneous dielectric slab. A simple and powerful method has been devised for the computation of the input admittance of an inhomogeneous dielectric slab as well as for electric field ratio. In this case the impracticability of obtaining analytical results has necessitated the use of numerical techniques. Applications of theory are discussed. (Author).

Analysis of Aperture Antennas in Inhomogeneous Media

Analysis of Aperture Antennas in Inhomogeneous Media PDF Author: Dikran Damlamayan
Publisher:
ISBN:
Category : Antennas (Electronics)
Languages : en
Pages : 86

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Book Description
The object of this report is to calculate the admittance and the radiation pattern of aperture antennas fed by waveguides of arbitrary cross-section and radiating into dielectric slabs, whose constitutive parameters may be functions of position along the direction normal to the slab faces. For a given aperture field distribution the antenna aperture admittance and the radiation field are expressed here, for the first time, in terms of two auxiliary quantities directly related to the plane wave reflection and transmission coefficients of the dielectric slab. These quantities are the input admittance of the dielectric slab and the ratio of the total electric field amplitude transmitted at one end of the slab to the transverse field at the other, both calculated for plane waves as a function of incident propagation direction. This approach introduces a great simplification in the solution of the problem, particularly in the case of an antenna radiating into an inhomogeneous dielectric slab. A simple and powerful method has been devised for the computation of the input admittance of an inhomogeneous dielectric slab as well as for electric field ratio. In this case the impracticability of obtaining analytical results has necessitated the use of numerical techniques. Applications of theory are discussed. (Author).

Analysis of Aperture Antennas in Inhomogeneous Media

Analysis of Aperture Antennas in Inhomogeneous Media PDF Author: Dikran Damiamayan
Publisher:
ISBN: 9780403044931
Category :
Languages : en
Pages : 93

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Antennas in Inhomogeneous Media

Antennas in Inhomogeneous Media PDF 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.

Analysis of Aperture Antennas in Inhomogenous Media

Analysis of Aperture Antennas in Inhomogenous Media PDF Author: Dikran Damlamayan
Publisher:
ISBN:
Category :
Languages : en
Pages : 178

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ANALYSIS OF AN APERTURE ANTENNA SYSTEM LOADED WITH AN INHOMOGENEOUS DIELECTRIC

ANALYSIS OF AN APERTURE ANTENNA SYSTEM LOADED WITH AN INHOMOGENEOUS DIELECTRIC PDF Author: Jesse Samuel Bitler
Publisher:
ISBN:
Category : Aperture antennas
Languages : en
Pages : 129

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Book Description
An analysis is made of an aperture system loaded with an inhomogeneous dielectric. The system consists of two parts. The first part is a section of rectangular waveguide extending from negative infinity along the z-axis to a distance z0 back from an infinite, perfectly conducting ground plane, whose normal is also in the z direction. This section of waveguide is filled with a homogeneous dielectric. The second part is a section of rectangular waveguide of the same dimensions extending from z0 to an aperture in the ground plane. This section of waveguide is filled with an inhomogeneous dielectric. The dielectric is characterized by a permeability and permittivity that varies exponentially with distance from the aperture. At first the waveguide containing the inhomogeneous dielectric was considered to extend to negative infinity. A set of modes was found to satisfy Maxwell's equations and the required aperture symmetries when the field incident at the aperture was a conventional TE10 mode. The fields on the free-space side of the aperture were written in integral form using the free-space Green's Function as a kernel and the aperture electric field as its source. (Author).

analysis of an aperture antenna system loaded with an inhomegenfous dielectric

analysis of an aperture antenna system loaded with an inhomegenfous dielectric PDF Author: j. samuel bitler
Publisher:
ISBN:
Category :
Languages : en
Pages : 134

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Experimental Study of Coupled Linear Antennas in an Inhomogeneous Dissipative Medium

Experimental Study of Coupled Linear Antennas in an Inhomogeneous Dissipative Medium PDF 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).

Buried Vertically Polarized UHF Antennas

Buried Vertically Polarized UHF Antennas PDF Author: Institute for Telecommunication Sciences
Publisher:
ISBN:
Category : Radio
Languages : en
Pages : 128

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Book Description
As a result of a 10-month study funded by the Air Force Space and Missile Systems Organization and carries out by ESSA's Institute for Telecommunication Sciences, four UHF antennas were designed and their gains versus elevation angle up to 45° and horizontal plane patterns for a 5°elevation angle were measured with each antenna buried beneath 1 m of refractory concrete. Techniques were developed and used to measure loss tangent and dielectric constant of plane ground and large samples of refractory concrete versus drying time and temperature. Theoretical studies of buried annular slots, buried antenna patterns, encapsulant geometry, and dielectric-coated linear antennas paralleled the measurement effort.

Aperture Antennas and Diffraction Theory

Aperture Antennas and Diffraction Theory PDF Author: Edward V. Jull
Publisher: IET
ISBN: 9780906048528
Category : Science
Languages : en
Pages : 194

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Book Description
Two alternative methods of aperture antenna analysis are described in this book.

OT/ITS Research Report

OT/ITS Research Report PDF Author: Institute for Telecommunication Sciences
Publisher:
ISBN:
Category :
Languages : en
Pages : 128

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Book Description