“…Practically important analytical solutions describing waves generated by a linear combination of exponentially decaying current pulses propagating in lossy media are constructed in (Utkin, 2008). Although the present discussion is constrained to the line sources, its extension to the more complicated source configurations is straightforward: for instance, the multipole expansion and introduction of the Debye potential result, in the spherical coordinate system, to the Euler-Poisson-Darboux equation of known Riemann function with respect to the transient spherical-harmonic expansion coefficients of the desired wavefunction (Borisov et al, 1996). Less complex solutions were obtained by Borisov and Simonenko for sources located on moving and expanding circles (Borisov & Simonenko, 1994, 1997, 2000.…”