Download or read book Analysis of Aperture Antennas in Inhomogeneous Media written by Dikran Damlamayan and published by . This book was released on 1968* with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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).
Download or read book Analysis of Aperture Antennas in Inhomogeneous Media written by Dikran Damiamayan and published by . This book was released on 1969-01-01 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Antennas in Inhomogeneous Media written by Janis Galejs and published by Elsevier. This book was released on 2013-10-22 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Analysis of Aperture Antennas in Inhomogenous Media written by Dikran Damlamayan and published by . This book was released on 1970 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book analysis of an aperture antenna system loaded with an inhomegenfous dielectric written by j. samuel bitler and published by . This book was released on 1967 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ANALYSIS OF AN APERTURE ANTENNA SYSTEM LOADED WITH AN INHOMOGENEOUS DIELECTRIC written by Jesse Samuel Bitler and published by . This book was released on 1967 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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).
Download or read book Fundamentals of Aperture Antennas and Arrays written by Trevor S. Bird and published by John Wiley & Sons. This book was released on 2016-01-19 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended as an advanced text for courses in antennas, with a focus on the mature but vital background field of aperture antennas. The book is aimed at final year, MSc, PhD and Post-Doctoral students, as well as readers who are moving from academia into industry, beginning careers as wireless engineers, system designers, in R&D, or for practising engineers. It assumes the reader has undertaken an earlier course of study on Maxwell's equations, fields and waves. Some of these topics are summarised in the early few chapters in order to provide continuity and background for the remaining chapters. The aperture antennas covered include the main types of horns, reflectors and arrays as well as microstrip patches, reflectarrays and lenses. To provide more than a superficial treatment of arrays, the topic of mutual coupling is covered in greater detail than most similar books in the area. Also included is an introduction to arrays on non-planar surfaces, which is of importance for applications that involve curved surfaces such as in aerodynamics or for making aperture antennas unobtrusive. A chapter is included on some modern aperture antennas to illustrate design techniques beyond the most common types of aperture antennas described in the early chapters. This is to show where advances have recently been made and where they could be improved in the future. Also included are selected topics of a practical nature for aperture antennas, namely fabrication and measurement.
Download or read book OT ITS Research Report written by Institute for Telecommunication Sciences and published by . This book was released on 1970 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aperture Antennas and Diffraction Theory written by Edward V. Jull and published by IET. This book was released on 1981 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two alternative methods of aperture antenna analysis are described in this book.
Download or read book Experimental Study of Coupled Linear Antennas in an Inhomogeneous Dissipative Medium written by Thomas Sugimoto and published by . This book was released on 1970 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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).
Download or read book Buried Vertically Polarized UHF Antennas written by Institute for Telecommunication Sciences and published by . This book was released on 1970 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Reflector Antennas written by W. V. T. Rusch and published by . This book was released on 1970 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Three dimensional cavity backed Aperture Antennas Using a Combined Finite Element Method Method of Moments Geometrical Theory of Diffraction Technique written by C. J. Reddy and published by . This book was released on 1995 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Scientific and Technical Reports written by United States. National Aeronautics and Space Administration Scientific and Technical Information Division and published by . This book was released on 1967 with total page 2300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report of the Research and Other Activities written by California Institute of Technology. Division of Engineering and Applied Science and published by . This book was released on 1969 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Aperture Antennas After Signal Propagation Through Anisotropic Ionized Media written by D. L. Knepp and published by . This book was released on 1983 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of the large ranges involved, a space based search and track radar requires a large aperture antenna to increase the energy collected and to create a narrow beam for accurate angle measurements and for resistance to localized jammers. This report gives the effects of such an antenna on measurements of received power, decorrelation time (or distance), mean time delay, time delay jitter and coherence bandwidth after propagation of the radar signal through a strongly disturbed transionospheric propagation channel. It is shown that aperture averaging can reduce observed signal power, increase observed decorrelation time and can be a significant factor in reducing the time delay jitter observed at the antenna output. As part of this analysis an analytic solution is obtained for the two-position, two-frequency mutual coherence function for spherical wave propagation in the strong scatter limit. Transmitter and receiver are located in free-space on opposite sides of a thick slab containing anisotropic electron density irregularities that are elongated in the direction parallel to the magnetic field. The orientation of the magnetic result is used to determine the effect of an antenna aperture as a function of geometry relative to the magnetic field.
