Affiliated with the
Communication & Space
Sciences Laboratory

Computational EM Modeling Techniques

MoM Analysis of Thick Wire Antennas

..: References :..

1-) A Method of Moments Approach for the Efficient and Accurate Modeling of Moderately Thick Cylindrical Wire Antennas
by Douglas H. Werner

ABSTRACT: This paper introduces a moment-method formulation, which is capable of accurately modeling moderately thick cylindrical wire antennas. New algorithms are presented for the efficient computation of the cylindrical wire kernel and related impedance matrix integrals. These algorithms make use of exact series representations as well as efficient numerical procedures and lead to a significant reduction in overall computation time for thicker wires. Another major advantage of this moment method technique is that it is no longer restricted by the segment length-to-radius ratio limitations inherent in past formulations, thereby making it possible to achieve solution convergence for a much wider class of wire antenna structures. Several examples illustrating the superior convergence properties of this new moment-method formulation are presented and discussed.

2-) On a New Cylindrical Harmonic Representation for Spherical Waves
by Douglas H. Werner and Thomas W. Colegrove

ABSTRACT: An exact series representation is presented for integrals whose integrands are products of cosine and spherical wave functions, where the argument of the cosine term can be any integral multiple n of the azimuth angle Φ. This series expansion will be shown to have the following form:

It is demonstrated that in the special cases n = 0 and n = 1, this series representation corresponds to existing expressions for the cylindrical wire kernel and the uniform current circular loop vector potential, respectively. A new series representation for spherical waves in terms of cylindrical harmonics is then derived using this general series representation. Finally, a closed form far-field approximation is developed and is shown to reduce to existing expressions for the cylindrical wire kernel and the uniform current loop vector potential as special cases.

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