Time-Domain Far-Field Analysis of Radiation Sources

A procedure called FARS (Far-field Analysis of Radiation Sources) was previously described by the author as a means of determining the quantitative contribution per unit length or per unit area to the power radiated from a perfect electric conductor in the frequency domain. It is based on a source-integral expression for the fields of an object of interest. Extension of frequency-domain FARS (FDFARS) to the time domain (TDFARS) is presented here, together with some representative results. Just as frequency-domain and time-domain solutions provide complementary perspectives of general electromagnetic phenomena, so do FDFARS and TDFARS for their particular applications. For example, while a frequency-domain result explicitly demonstrates the effects of standing waves, a time-domain result has the advantage of separating various contributions to the far field due to their different time delays. The motivation for both FDFARS and TDFARS is to provide information about radiation from a perfect electric conductor. A brief description of TDFARS is given here, and demonstrated for some simple wire geometries.