Antennas in Inhomogeneous Media
Antennas in Inhomogeneous Media

Author: Janis Galejs

Publisher: Elsevier

Published: 2013-10-22

Total Pages: 312

ISBN-13: 1483186377

DOWNLOAD EBOOK

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.

Experimental Study of Coupled Linear Antennas in an Inhomogeneous Dissipative Medium
Experimental Study of Coupled Linear Antennas in an Inhomogeneous Dissipative Medium

Author: Thomas Sugimoto

Publisher:

Published: 1970

Total Pages: 54

ISBN-13:

DOWNLOAD EBOOK

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).

Fundamentals of Aperture Antennas and Arrays
Fundamentals of Aperture Antennas and Arrays

Author: Trevor S. Bird

Publisher: John Wiley & Sons

Published: 2016-01-19

Total Pages: 452

ISBN-13: 1118923561

DOWNLOAD EBOOK

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.

Antennas and Wave Propagation
Antennas and Wave Propagation

Author: A. R. Harish

Publisher: Oxford Higher Education

Published: 2007

Total Pages: 424

ISBN-13:

DOWNLOAD EBOOK

Aimed at a single-semester course on antennas at the undergraduate level, Antennas and Wave Propagation provides a lucid explanation of the fundamentals of antennas and propagation. This student-friendly text also includes simple design procedures along with a large number of examples and exercises.

Microwave Imaging Methods and Applications
Microwave Imaging Methods and Applications

Author: Matteo Pastorino

Publisher: Artech House

Published: 2018-06-30

Total Pages: 295

ISBN-13: 1630815268

DOWNLOAD EBOOK

Microwave Imaging Methods and Applications provides practitioners and researchers with a complete overview of the latest and most important noninvasive and nondestructive techniques for inspecting structures and bodies by using microwaves. Placing emphasis on applications, the book considers many areas, from medical imaging and security… to industrial engineering and subsurface prospection. For each application, readers are presented with the objectives of the inspection and related challenges. Moreover, this groundbreaking resource details computational methods that can be used to solve inverse problems related to specific applications. Including clear examples or the most significant practical results, this forward-looking reference focuses on systems that have been recently developed. Professionals gain the knowledge needed to compare imaging methods used in different applications and develop new uses of imaging apparatuses and systems.

The Paraboloidal Reflector Antenna in Radio Astronomy and Communication
The Paraboloidal Reflector Antenna in Radio Astronomy and Communication

Author: Jacob W. M. Baars

Publisher: Springer Science & Business Media

Published: 2007-08-06

Total Pages: 270

ISBN-13: 0387697349

DOWNLOAD EBOOK

Radio astronomers have developed techniques of calibration of large reflector antennas with radio astronomical methods, but these have not been comprehensively described. This text aims to fill this gap, taking a practical approach to the characterisation of antennas. All calculations and results in the form of tables and figures have been made with Mathematica by Wolfram Research. The reader can use the procedures for the implementation of his own input data.