Analysis of Arbitrarily Oriented Thin Wire Antenna Arrays Over Imperfect Ground Planes
Analysis of Arbitrarily Oriented Thin Wire Antenna Arrays Over Imperfect Ground Planes

Author: Tapan K. Sarkar

Publisher:

Published: 1975

Total Pages: 110

ISBN-13:

DOWNLOAD EBOOK

The work considers the analysis of antenna and arrays of thin wires of arbitrary orientation above imperfectly conducting ground planes. Emphasis is placed on the development of fast and accurate techniques for computation of the characteristics of antenna systems. An important problem is the evaluation of certain semi-infinite integrals encountered in the exact Sommerfeld solution. The time required for computation of these integrals is reduced by the application of interpolatory quadrature formulas. Where applicable, a modified method of steepest descent is used to evaluate the integrals. The approximate reflection coefficient method is derived from the Sommerfeld formulation via the method of steepest descent. The accuracy of the reflection coefficient method relative to the Sommerfeld method is discussed. Finally, formulas convenient for the optimization of various performance indices are discussed. Typical indices that have been optimized, both with and without constraints, are directivity, power gain, quality factor, and main beam radiation efficiency.

Magnetic Communications: From Theory to Practice
Magnetic Communications: From Theory to Practice

Author: Fei Hu

Publisher: CRC Press

Published: 2018-07-24

Total Pages: 307

ISBN-13: 1498799787

DOWNLOAD EBOOK

This book covers comprehensively the theories and practical design of magnetic communications. It emphasizes the differences between it and RF communications. It first provides the models and signal propagation principles of magnetic communication systems. Then it describes the hardware architecture of the system, including transmitter, MODEM, inductors, coils, etc. Then, it discusses the corresponding communication software design principles and cases. Finally, it presents several types of practical implementations and applications.

Handbook of Antennas in Wireless Communications
Handbook of Antennas in Wireless Communications

Author: Lal Chand Godara

Publisher: CRC Press

Published: 2018-10-03

Total Pages: 1043

ISBN-13: 1351835920

DOWNLOAD EBOOK

The move toward worldwide wireless communications continues at a remarkable pace, and the antenna element of the technology is crucial to its success. With contributions from more than 30 international experts, the Handbook of Antennas in Wireless Communications brings together all of the latest research and results to provide engineering professionals and students with a one-stop reference on the theory, technologies, and applications for indoor, hand-held, mobile, and satellite systems. Beginning with an introduction to wireless communications systems, it offers an in-depth treatment of propagation prediction and fading channels. It then explores antenna technology with discussion of antenna design methods and the various antennas in current use or development for base stations, hand held devices, satellite communications, and shaping beams. The discussions then move to smart antennas and phased array technology, including details on array theory and beamforming techniques. Space diversity, direction-of-arrival estimation, source tracking, and blind source separation methods are addressed, as are the implementation of smart antennas and the results of field trials of systems using smart antennas implemented. Finally, the hot media topic of the safety of mobile phones receives due attention, including details of how the human body interacts with the electromagnetic fields of these devices. Its logical development and extensive range of diagrams, figures, and photographs make this handbook easy to follow and provide a clear understanding of design techniques and the performance of finished products. Its unique, comprehensive coverage written by top experts in their fields promises to make the Handbook of Antennas in Wireless Communications the standard reference for the field.

Electromagnetic Scattering Concepts Applied to the Detection of Targets Near the Ground
Electromagnetic Scattering Concepts Applied to the Detection of Targets Near the Ground

Author: David Allen Hill

Publisher:

Published: 1970

Total Pages: 150

ISBN-13:

DOWNLOAD EBOOK

Problems related to the detection of targets in the presence of clutter and ground are investigated. The two basic problems are the change in the target response due to the presence of the ground and the recognition of the target response when contaminated with clutter return. The transient fields of short dipoles in the presence of a dielectric half-space are examined and exact closed-form solutions are obtained for some particular source and observation points. The solution for the case of the source and observation points coincident is used to determine the interaction between a dipole source and the interface and the resultant dipole impedance change. The same solutions are used to compute the change in the dipole modes of scatterers due to the presence of a half-space, particularly the shift in the s-plane poles of the target. Results are presented for both dielectric and perfectly conducting half-spaces. (Author).