ABSTRACT
One of the most powerful tools for the analysis of electromagnetics problems is the integral solution to Maxwell's equations formulated by Stratton and Chu. Many antennas may be analyzed in terms of electric currents and charges radiating in unbounded space. Since antennas are used to transmit information over great distances, the fields far from the sources are often of most interest. Assume that the sources are contained within a sphere of radius rs centered at the origin. The authors show that the radiation function contains all of the angular dependence of the field and thus describes the pattern of the dipole. They derive the formula for a bounded, source-free region of space by specializing the general Stratton–Chu formulas. When the authors use the equivalent sources to form the equivalent problem, they know that they produce a null field within the excluded region.
