Lommel expansions in electromagnetics

Lommel expansions and the important role they play in electromagnetic theory are reviewed in this chapter. These expansions are shown to be useful in developing an exact integration procedure for evaluating electromagnetic field quantities associated with current-carrying wire antennas such as cylindrical dipoles and circular loops. Several exact series representations are introduced in this chapter which are valid not only in the far-field of the source, but also in its near-field region. These series expansions are general and can be shown to contain all of the well-known classical approximations as special limiting cases. Some applications of these recently found exact series expansions are discussed, including their use in the development of efficient yet accurate algorithms for computational modeling of moderately thick cylindrical wire antennas.