Electromagnetics Problem Solver


Book Description




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


Book Description

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.










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


Book Description

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).




Analysis and Design of Antennas and Algorithms for Near-Field Sensing


Book Description

This volume collects the main results of the Author’s Ph.D. course in Electromagnetics and Mathematical Models for Engineering, attended at ‘Sapienza’ University of Rome from November 2011 to February 2015, in the Electromagnetic Fields 1 Lab of the Department of Information Engineering, Electronics and Telecommunications, under the tutoring of Prof. Alessandro Galli.