Time-domain TE/TM decomposition of electromagnetic sources

Theory for the decomposition of electromagnetic sources with arbitrary time dependence into parts radiating transverse electric (TE) or transverse magnetic (TM) fields with respect to a given constant direction in space is developed. The theory is a generalization of that given earlier by the author (1988) for time-harmonic sources. Three different decomposition methods, which for a point source can be expressed in terms of point sources, line sources, and plane sources, are given. As a check it is demonstrated that for time-harmonic time dependence of the original source, the previously derived decomposition expressions are obtained as special cases